Wikipedia:Reference desk archive/Science/May 2006 part 2

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< Wikipedia:Reference desk archive | Science

See Wikipedia:Reference desk archive/Science/May 2006 for the archives of May 1 to May 20 2006.

1 May 21
2 May 22
3 May 23
4 May 24
5 May 25
6 May 26
7 May 27
8 May 28
9 May 29
10 May 30
11 May 31

[edit] May 21

[edit] Server Park

what is the definition of a computer "server park"?—The preceding unsigned comment was added by 12.164.252.227 (talk • contribs) .

Isn't a server park the same as a Server_farm? --Swift 00:57, 21 May 2006 (UTC)

It sounds like the place the servers in a server farm would go on their day off. However, while Google has 1.7 million hits on "server farm" it also has 28 thousand for "server park". This page appears to use both interchangeably [1]. Coming soon: "server sweatshop". Notinasnaid 11:27, 22 May 2006 (UTC)

[edit] Eat my hair

Since hair is protein, can you eat it, and would it be nutritious? Also, what is the best way of cooking it? Im serious! 8-)--Light current 00:44, 21 May 2006 (UTC)

I remember hearing a story about a girl who would eat her hair, and accumulated a large hairball in her stomach. It's called trichophagia. Seems like you shouldn't do it. Dysprosia 02:10, 21 May 2006 (UTC)

And the resultant product is a "hairball", or if you're not a cat, a "trichobezoar". Keratin is basically insoluble, so there's no way for you to digest it. - Nunh-huh 07:29, 21 May 2006 (UTC)

So you would need to convert it into something soluble- then you could eat it?--Light current 12:17, 21 May 2006 (UTC)

That 'fur' enough! 8-)) Perhaps it needs preparing in a proper manner.--Light current 03:23, 21 May 2006 (UTC)

I propose you the following scheme: cut your hair off, burn it, then use the ash to fertilize cucumbers. ellol 06:11, 21 May 2006 (UTC)

You can eat hair, but your body won't digest it. However, blood can be eaten and digested.Patchouli 11:33, 21 May 2006 (UTC)

Even though you can't digest it as is, Cannibalism#Modern cannibalism claims that there are edible products made from human hair. – b_jonas 19:16, 21 May 2006 (UTC)

I have trichotillomania! Kilo-Lima|^(talk) 19:44, 21 May 2006 (UTC)

OK. Well I guess Id better clear the larder of all those hanks!--Light current 19:47, 21 May 2006 (UTC)

Papain digests keratin - hair and nails. Eventually you'll have a soft soggy mess. Whether the result is edible I know not, nor do I wish to, I think. --Seejyb 23:20, 21 May 2006 (UTC)

[edit] Cortical Arousal

Can you explain cortical arousal? Especially as it pertains to hypnosis?

Cortical arousal is controlled in large part by the reticular activating system (RAS), a network of centers in the brainstem that regulate how effectively cortical neurons respond to stimuli. During arousal, two centers in the RAS, the locus coeruleus and raphe nuclei, bathe the brain in norepinephrine and serotonin, respectively, increasing the effectiveness with which neurons of the cortex respond to stimuli. I'm not sure how hypnosis fits into that picture, but I suspect it has to do with habituation to a persistent stimulus. --David Iberri (talk) 03:31, 21 May 2006 (UTC)

[edit] Acetic Acid

I'm doing highschool chemistry and I need to know what the chemical formula for acetic acid is to balance an equation. The wikipedia article says it's CH₃COOH. I don't think that's what I'm looking for. Can someone help me out here? Thanks.

That indeed is acetic acid's chemical formula. What makes you think it's not what you're looking for? --David Iberri (talk) 03:20, 21 May 2006 (UTC)

Well there's more than one of each C,H, and O. Shouldn't it be something like C₂H₄O₂? Or something like that?

That's the molecular formula. CH₃COOH is a "condensed structural formula" which also gives you some idea how the atoms are connected. —Keenan Pepper 04:26, 21 May 2006 (UTC)\

(After edit conflict)

You're right that there are more than one atom each of C, H, and O in acetic acid, but the molecular formula C₂H₄O₂ isn't the only way to represent that. The formula CH₃COOH conveys the exact same information: in CH₃COOH, you count two Cs, four Hs, and two Os, making it equivalent to CH₃COOH. The benefit of the latter formula is that it gives you clues about the structure of the molecule represented. In particular, COOH is the common representation for a carboxylic acid functional group, while CH₃ is the common representation for a methyl group. So from glancing at CH₃COOH, one can reasonably guess the structure of the molecule. The C₂H₄O₂ formula provides no such structural clues (aside from what can be gathered by calculating degrees of unsaturation) and is therefore ambiguous: does C₂H₄O₂ refer to acetic acid or to its isomer ethen-1,2-diol? --David Iberri (talk) 04:48, 21 May 2006 (UTC)

I...have no idea, actually. I'm in highschool chemistry and am currently doing titration. So C₂H₄O₂ actually does work? I really just need it to balance an equation. Thank you for the feedback BTW

Yes, C₂H₄O₂ is fine. — TheKMan^talk 05:01, 21 May 2006 (UTC)

It's fine for stoichiometric purposes (balancing an reaction). But since it's ambiguous with respect to what the compound *is* (as David says) it's not a very useful way of writing the reaction, because you don't know what the reaction is - which is usually the main point of writing the thing up to begin with. --BluePlatypus 06:59, 21 May 2006 (UTC)

Whether you condense it further from CH3COOH is up to you and really depends on the application you're talking about. If you use CH3COOH it's clearly an acid, but if you say C2H4O2 there's ambiguity, as BluePlatypus said. --M1ss1ontomars2k4 | T | C | @ 23:45, 21 May 2006 (UTC)

[edit] Charge of an electron

This IS a homework question, but i am a bit at loss at the answer. 'Given that the charge on an electron is 1.6 * 10^-19 C. which of the following amounts of charge are possible?'

a)6.4 * 10^-19 C

b)5.6 * 10^-19 C

c)6.0 * 10^-6 C

My answer was a, (1.6*4 =6.4). The book says that c is also possible- im not sure how this can be. Please help me (Thanks in advance)

Well, just to make sure we're all on the same page, have you looked closely at the exponents? Melchoir 07:51, 21 May 2006 (UTC)

Sorry, Melchoir, I'll proceed with your thought. If c) is actually 6.0 * 10^-6, you should note that this value is 10^13 times greater than the charge of an electron. To make sure that the value c) is a multiple of 1.6 * 10^-19, you would need at least 13 digits. But you have only two digits, and it means, that the value may actually be in the range from 5.95*10^-6 to 6.044*10^-6. This range covers a great many multiples of charge of the electron. So, of course, c) is possible. ellol 08:31, 21 May 2006 (UTC)

Let me guess, you're an engineer? ;P --

Mac Davis] ⌇☢ ญƛ. 08:42, 21 May 2006 (UTC)

I'm a student who hopes to become a physicist, so you are mistaken here :).

There are no exact numbers in physics(contrary to mathematics) and each value has some error. A physicist must "feel" the values, may be, as well as an engineer. If you wanna become a physicist you'll (besides other things) need to know by heart constants, such as Planck's_constant or charge of the electron, etc, -- in order to be able to make quick estimations. ellol 09:28, 21 May 2006 (UTC)

Ooh, I'm all over that. 1 and −1. Do I get a prize? Melchoir 09:40, 21 May 2006 (UTC)

Theoretical physicists are not considered :-) Yeah, I meant only experimenters. ellol 10:08, 21 May 2006 (UTC)

Electron charge should not be measured in degrees Celsius. --

Mac Davis] ⌇☢ ญƛ. 08:40, 21 May 2006 (UTC)

But it could be measured in coulombs... G N Frykman 09:22, 21 May 2006 (UTC)

Ok thanks all for your help, i understand now.

Electron charge should not be measured in centimeters. — Knowledge Seeker দ 09:24, 21 May 2006 (UTC)

But it may be measured in speeds of light. Howard Train 13:25, 22 May 2006 (UTC)

You have the choice between C and Java. --DLL 17:31, 21 May 2006 (UTC)

[edit] Static electricity

When you get a shock of static electricity, the reason is presumably that your body has acquired a surplus or deficit of electrons compared to the environment. How would one go about to estimate the number of electrons that is transferred in such a shock? Does somebody have an idea of the approximate number? When walking on synthetic carpets etc., do we usually acquire a positive or negative charge? --Vibo56 12:24, 21 May 2006 (UTC)

No ,when you get a shock, its because charge has passed through your body causing the muscles to contract. THe amount of current passing depends upon the voltage, the resistance of the static generator, and the body's internal reistance (which is about 700R).

As to charge build up, I would try the Faradays ice pail experiment with the victim standing in the pail. The pail needs to be insulated from earth. THe victim would not actually get a shock because current would not pass thro the body (hopefully). Then by knowing the capacitance of the pail and its final voltage after charge transfer, one can calcualte the amount of charge passed.8-)--Light current 12:36, 21 May 2006 (UTC)

There are some calculations done by Mr Static here. The answer in his case was a positive charge of about 3 x 10^-8 coulombs, which is about 2 x 10¹¹ electrons. --Heron 13:39, 21 May 2006 (UTC)

Thanks a lot, Heron, that was exactly what I was looking for. The value of 3 x 10^-8 coulombs appears to be per step, the graph might suggest a charge buildup about 20 times larger. --Vibo56 13:58, 21 May 2006 (UTC)

[edit] Construction of Houses and Apartments

Currently in Iran, homes in cities and towns are built using steel, metal rods, and cement. In the United States, only skyscrapers are built using cement.

Why is it that homes in even major American cities such as Los Angeles are built using wood? Is there an advantage with respect to cost or something else? Can't cement better withstand earthquakes?Patchouli 13:31, 21 May 2006 (UTC)

Properly engineered, a wood construction is very resistant to earthquake damage, and it's much cheaper to build an earthquake-safe construction from timber frame than from masonry. Timber constructions flex enough to avoid damaging themselves, and generally fail gradually; masonry constructions don't flex, and so fail dramatically. Plus timber framed constructions are much lighter, so there's less moving mass that the structure has to absorb. In California houses are (hopefully) bolted to their foundations (to stop the house falling off the slab), walls and roofs are secured together (particularly to prevent the roof falling off, which would squish one side of the house) and walls (particularly in the basement) are braced with sheets of hardboard to prevent a shearing of walls. To properly reinforce a masonry construction to earthquake safe standards requires great amounts of metal and bolting, and often the attention of a structural engineer. The efficacy of this approach is shown by the fatality levels in comparable earthquakes - the 6.9 Loma Prieta earthquake shook the entire San Francisco Bay Area, with most of the regions 8 million^{[citation needed]} people within 70 miles of the epicenter. Yet only 63 people died, and two thirds of them died in when the Cypress Street Viaduct collapsed - so no more than 21 people died in other places. Compare that with the 2003 earthquake in Bam, which at 6.6 was considerably less powerful and struck an area with only a few hundred thousand people - yet 26,271 people died. In San Francisco there are some older masonry buildings which were constructed before current building code was introduced. By law these have large signs outside which read "This is an unreinforced masonry construction: such structures are known to be unsafe during earthquakes". Similarly, during the last quake in Napa, I believe only one person was killed - when the brick fireplace/chimney in his (otherwise timber) house failed, and fell on him. Timber and shingle is a very good material with which to build homes in a quake zone. -- Finlay McWalter | Talk 13:53, 21 May 2006 (UTC)

First, I conclude that skyscrapers need tremendous attention from structural engineers. Next, I am led to think that in a non-quake zone, it is better to build homes with steel and cement because then they are less prone to catch fire. Regardless of this fact, perhaps timber frames are used in those zones to save money.Patchouli 14:25, 21 May 2006 (UTC)

There's a number of other reasons, although saving money is a good reason to use wood - why would you want to spend more money?

Home renovation is popular in the United States, and it's much more difficult to modify a concrete structure than a wooden one. Concrete would have to be chipped out, and the rebar cut using steel cutting tools. Designing reinforcement is more difficult than framing carpentry, and creating it again requires the use of welding and steel cutting equipment. It's even more difficult to hang a picture on a concrete structure -- I know because I live in an apartment with outside and between-suite walls of concrete, but internal wooden walls. And guess where my pictures are?
Formwork is needed for a poured concrete structure; constructing this is specialized, skilled work and requires a lot of -- you guessed it -- wood. So a concrete structure first gets a temporary wooden structure, which is then replaced with concrete. You can see how this is wasteful.
In the United States, fire fighting and fire prevention is of sufficient quality that flammability simply isn't an important consideration. According to our article on houses, 67% of Americans live in a house, which, given 122 million housing units is roughly 82 million houses. This fascinating report on fire losses in the US says there were 300 thousand house fires in 2004. This sounds like a lot, but it's only 0.37% of the houses. In other words, on average, a house in the US can be expected to have a fire once every 272 years. Furthermore, the average damage is only $16,400 where the median value of a house is $119,600. Assuming the contents of a house are worth 10% of the total value, and assuming a house sustains only very minor damage in a house fire (say $2,000) or is totally destroyed, only 1 out of 9 houses would be totally destroyed.
Concrete structures can have issues in wet and in particular cold climates. The freeze-thaw cycle can damage concrete, reinforcement can rust, and freezing inhibits the concrete curing process, which means that houses could only be constructed in the summer. Iran obviously has a much warmer temperature than much of the United States.
Finally, concrete is heavy, and a house built of it usually needs more involved structural engineering than a house made out of wood. Concrete is really not a very good building material -- it's about as strong as uncooked spaghetti. But it's cheap, and we can use a lot of it, and reinforce it with steel to make reinforced concrete, which has some merits. --ByeByeBaby 16:57, 21 May 2006 (UTC)

These are very good explanations.Patchouli 18:01, 21 May 2006 (UTC)

Also, while uncommon, concrete houses are not unknown in the U.S. Various energy-efficiency designs use concrete construction - thermal mass, earth-sheltered, etc. Some areas with hurricane and tornado risks also have some concrete houses - Habitat for Humanity favors this type of construction. Using interlocking styrofoam forms, which may also preposition the rebar makes this construction much simpler and avoids the issues of building removable wooden forms. This is said to be a fast-growing market in the U.S.[2]. Rmhermen 18:51, 21 May 2006 (UTC)

On the topic that a wooden house is more resistant to earthquakes than a brick house, see also [3]. (By the way, here in Budapest where earthquakes are very rare, there are almost no wooden houses.) – b_jonas 19:10, 21 May 2006 (UTC)

Building wooden houses in Iran would presumably be very expensive, they do not have forests to chop down for timber. All countries outside of the tropics and the world's northern forest zone would have the same problem. The logical building materials would be stone, bricks, and mortar. Only the rich would use reinforced concrete for building a private house, but when governments are involved in housing projects, with architects and engineers all involved, it's use seems logical - low maintainance requirements, durability and fire resistance would be factors favouring concrete over wood. The concrete high-rise structures I have seen being built don't have concrete walls; there is a reinforced concrete "skeleton", floors often made of prestressed beams overlain with a screed; exterior walls of brickwork and interior walls of composite board. What do the European countries make houses of - e.g. Scandinavia vs Spain? In practice, how many storeys high can an all-wood house be? --Seejyb 22:00, 21 May 2006 (UTC)

Well, as you guessed - Spain traditionally uses stone/bricks/adobe, whereas Scandinavia traditionally builds fully-timbered (log-houses) or wooden houses. Once you get down to Denmark and Germany there are less forests and to conserve wood, people built Half-timbered houses. And south of the Alps it's pretty much all non-wood. Modern wooden houses can be pretty high, the highest one (a recent construction) is claimed to be a 5-story building in Trondheim. I've personally seen modern 3-story apartment buildings in Scandinavia which were wood. (You wouldn't think it looking from the outside though). But those are an exception, not the rule. In general modern buildings are of course built in modern materials even in Scandinavia just as everywhere else. --BluePlatypus 23:50, 21 May 2006 (UTC)

[edit] Paralysis causes loss of feeling?

Does paralysis cause loss of sense of feeling in the affected limbs? Can a person feel pain, heat, pressure where he is paralysed?

"Doctor, Doctor, I can't feel my legs!" "That's because we've chopped your arms off." Often, but not always; it would depend how the paralysis is caused. Spinal cord trauma will typically interrupt both motor and sensory fibres to the affected areas, but a stroke in the motor cortex might leave sensation undamaged. -- EdC 15:56, 21 May 2006 (UTC)

In other words, paralysis doesn't cause anything. It's the underlying cause of the paralysis that determines whether sensation is affected. One example of paralysis with some sensory sparing is anterior cord syndrome (ack, redlink -- try this), in which only the anterior (front, ventral) portion of the spinal cord is damaged. An oversimplified explanation is that the fibers carrying motor information are located in the anterior region of the spinal cord, while the sensory fibers are carried in the posterior region and are therefore preserved in anterior cord syndrome. Also, since different types of sensory information are carried in different parts of the spinal cord, the type of sensory information affected by an injury depends upon the injury itself. For example, in anterior cord syndrome, typically only fine touch and conscious body sense is preserved, while pain and temperature information is lost. (See dorsal column-medial lemniscus pathway and anterolateral system if you're interested in the details.) Hope that helps, David Iberri (talk) 16:46, 21 May 2006 (UTC)

Perfect, exactly what I was looking for. Thanks for the help! --82.146.104.90 17:29, 21 May 2006 (UTC)

[edit] working model related to astronomy

how to make a simple low cost working model of anyhing related to astronomy??

hmmm... Sounds like homework... Philc _T^E_C^I 17:09, 21 May 2006 (UTC)

A disc with a big blob in the middle, and a smaller blob on the outside? Star and planet?--Light current 17:51, 21 May 2006 (UTC)

It shouldn't be that difficult to upgrade that to a basic orrery, depending on the level of education the project is set for. GeeJo ^(t)⁄_(c) • 20:46, 21 May 2006 (UTC)

Quite! But you cant get much simpler than that!--Light current 20:58, 21 May 2006 (UTC)

Yeah. Piece of dark paper and punch some holes in it. Hold it up to the sun and you have a cheap-ass planetarium. freshgavin ΓΛĿЌ 15:37, 22 May 2006 (UTC)

Thats not really a model tho is it? Imean mine can be made to rotate by sticking a pencil thro the centre 8-)--Light current 15:56, 22 May 2006 (UTC)

[edit] about svchost.exe

There is a process called svchost.exc in my computer that downloads data when the Internet connection is on even though I am not downloading any file or any website. Is it a virus that has installed in svchost.exe or is it something like - the system itself is downloading essential software from Microsoft? What is that? Is there any thing wrong or is there anything to worry here?

I'm assuming the ".exc" is a typo. Svchost.exe is an integral part of microsoft windows, and there is usually serveral instances running. I believe it can by hijacked by viruses, though. You might check this by turning off automatic Windows updates. If svchost.exe still wants to contact the internet, there might be a problem. --Vibo56 18:12, 21 May 2006 (UTC)

There are web sites that explain various standard Windows processes. The easy way to find those sites is to google for "svchost.exe", here is one: [4].

Whenever I see a process in my task list that I'm not familiar with, I google the filename and the word 'virus', which has so far always given me the information I need. Despite the fact that most of the programs have turned out to be harmless, I find using the word 'virus' in the search is useful because it returns results where other people have asked about the safety of the process. Furthermore, I find that most antivirus sites maintain listings of native operations that might seem suspicious to users. Also, while a great many sites describing standard OS programs are quite detailed (so much so that it's sometimes difficult to figure out whether or not they're safe), I find the antivirus sites' descriptions seem to be quite succinct and easy-to-understand.--Anchoress 07:11, 22 May 2006 (UTC)

In addition, consider that there are viruses and worms which disguise themselves as apparently harmless processes (e.g., "svchosts.exe"). If the name "svchost.exc" is not a typo, chances are you indeed fell on a virus. Cthulhu.mythos 09:37, 22 May 2006 (UTC)

Microsoft's page "explaining" svchost.exe is here. It also mentions a command that can be run to show specifically which services are associated with an instance of svchost.exe. I am currently on a Windows 2000 box, so I can not test this. Also, the page refers specifically to XP Pro, so the command might not exist in XP Home, however the description of the program is still valid.

In any event, you should be sure to (download if necessary and) run some malware detection programs, such as AdAware and Spybot, to check your system. --LarryMac 13:49, 22 May 2006 (UTC)

[edit] plasma containment

What is the cheapest way to confine magnetically a cool, by fusion standards, plasma with a temeperature of 100 000 K? This is not for fusion, but needs to be confined magnetically. Thanks. 24.137.78.34 18:44, 21 May 2006 (UTC)

It depends on the scale. Any significantly large quantity of plasma would require the same sort of equipment (a tokamak or stellarator) regardless of the use you're putting the plasma to. I thought I'd recalled reading about an undergrad producing a small-scale reactor for a project and on searching, found this story. I'm not sure about teh temperatures that the plasma reached in the apparatus though. GeeJo ^(t)⁄_(c) • 20:39, 21 May 2006 (UTC)

Thanks alot.24.137.78.34 11:21, 22 May 2006 (UTC)

[edit] Cashews

After eating (about 24 hours) nearly two pounds of Cashews in about the same amount of time my lips began to crack and peel in fairly large sections of skin. Is this due to the resin or oil from the Cashew shell still clinging to the meat of the nut or from the salt the Cashews are covered with? -- PCE 18:44, 21 May 2006 (UTC)

IMHO it's the salt--you need to drink some water. But after eating anything that's two pounds' worth you should be drinking water anyway. --M1ss1ontomars2k4 | T | C | @ 23:42, 21 May 2006 (UTC)

Yeah, the salt. --Mac Davis 00:16, 22 May 2006 (UTC)

You should nt eat so many in 24 hrs!--Light current 00:20, 22 May 2006 (UTC)

Your lips and mouth have had an unusual duration of exposure to cashew nuts, so you may be experiencing toxic effects which are not normally seen. Salt may be the culprit, but would you get the same (with extensive skin peeling) from eating peanuts? I think not. So: local allergy? local toxicity? An unprocessed whole cashew nut is pretty toxic, with skin blisters being a major symptom of contact. Peeling or dehusking a cashew is downright dangerous. I have not looked further into this, but the the possible culprits could be: anacardic acid, cardol, urushiol (as you say, the resin or oil). Or something else? The reaction you had it sometimes seen with drugs such as anti-inflammatories - one of the chemicals in the cashew has an effect on similar enzymes. Could inadequate cleaning leave active toxin behind, in small enough amounts not to cause symptoms with normal consumption? All speculation, but to simply write off your experience as salt may not be scientific - though it would suit cashew nut producers to blame the salt. --Seejyb 03:33, 22 May 2006 (UTC)

Really, I don't think it's an allergic or toxic reaction. Cracking and peeling is the normal and usual reaction to dry lips, and salt can do that, as can cold/dry air. It can happen quite fast. --BluePlatypus 04:46, 22 May 2006 (UTC)

The Urushiol that Seeyjb mentions is also found in my old nemesis Poison ivy, so I wouldn't completely discount a slight allergic reaction. --LarryMac 13:36, 22 May 2006 (UTC)

Thanks everyone for your comments. Although I had some hot coffee during the same period my tongue has also become extra sensitive just like that following a mouth full of hot coffee. Furthermore I had a lot of gas and what look to be similar "sheet’s of skin as opposed to mucus as the stool and I'm sure the salt alone could not have been responsible for that. I've had no dizziness or other symptoms associated with poison versus an organic acid or some type of caustic. Thanks again. -- PCE 06:40, 22 May 2006 (UTC)

By the way, if you are thinking about health, you might like to consider that 2 pounds of cashew nuts contains around 5200 calories, probably twice what you need in a day. I derived this from information on the site [The World's Healthiest Foods]. Notinasnaid 10:23, 22 May 2006 (UTC)

World's Oldest Joke: Doctor, Doctor, it hurts when I do this. Doctor: Well, don't do it! --Zeizmic 19:56, 22 May 2006 (UTC)

No response... I think he's dead. - R_Lee_E (talk, contribs) 19:55, 22 May 2006 (UTC)

Not dead - just delayed in my return from the store to purchase the ingredients for my next consumer risk experiment... Macadamia nuts. ---- PCE 23:29, 22 May 2006 (UTC)

You should try one of your experiments with fruit instead. 8*) No avocados though. - R_Lee_E (talk, contribs) 01:37, 23 May 2006 (UTC)

What's wrong with avocados? -- PCE 18:41, 23 May 2006 (UTC)

[edit] crosse' s acari how is it possible?

hai i just read about anderw crosse who was a scientist and accidentaly discovered an organism which lives on no substance , imean it consumes no food for its survival and this thing really doesnt use any growth culture and any life supporting media for itself and its birth also is misterious

well thats all i know about this organism and i also have an copy of "sem" scan please help me i really wanna know my mail id: <email removed> (Kilo-Lima|^(talk) 19:48, 21 May 2006 (UTC))

Well, there're always breatharians. GeeJo ^(t)⁄_(c) • 20:21, 21 May 2006 (UTC)

No it is not possible (it'd violate the 2nd law of thermodynamics), Crosse was mistaken. --BluePlatypus 22:44, 21 May 2006 (UTC)

To be fair, Crosse never thought that that was the explanation, instead believing that it was an experimental error (as our article on him points out.) So he wasn't really mistaken, just careless.GeeJo ^(t)⁄_(c) • 03:12, 22 May 2006 (UTC)

It is theoretically possible that given a source of energy (e.g. light) and the ability to dissipate waste heat, that an organism could sustain itself without taking in any additional food (though it would be unable to grow). Some plants and mosses can approximate this for moderate time scales (i.e. weeks), and some bacteria can shut themselves down for millenia, but I'm not sure there are any known organisms that can truly live in a sealed environment indefinitely. As to the experiment in question, I would suggest reading Andrew Crosse as a good place to start. Dragons flight 22:56, 21 May 2006 (UTC)

The illustration at rexresearch.com is a drawing of what the eminent scientists in London saw under their microscope. It is a mite. Nothing new, and no great mystery. How they got there could possibly be explained if someone was patient enough to reconstruct the experimental scenario. They could have been inside the "stone" or "cloth" he used in his experiment, or quite possibly fell off his head or clothes as he was examining his contraption. They are hardy little fellows, and feed, inter alia, on dust and bits of old skin. Apparently Mary Shelley was in the audience when Crosse gave his presentation, so that the electrically animated mites may have given us a more entertaining story than Crosse's --Seejyb 23:54, 21 May 2006 (UTC)

[edit] Odontodes

Just created a page odontodes, left a message on my talk page asking for someone to 'check' it and got directed here (see User talk:HappyVR). As I mentioned there I'm not a biologist and hence not entirely confident in my abilities to write such a page - I've done it anyway. I've also got three references that might be useful for citation (they're on my user page User:HappyVR). I doubt this is the sort of thing that gets looked at very often so I thought I should get it checked to prevent someone being misinformed if I've made a mistake... Thanks.HappyVR 22:08, 21 May 2006 (UTC)

Thanks for being bold and creating this stub! I touched on it a little, adding two of your refs, and will do more when I have time. I changd the name to odontode because article titles should generally be singular. I also tagged it with {{biology-stub}}. It would fit developmental biology, evolutionary biology, or anatomy, but I decided to go general. --Ginkgo100 22:59, 21 May 2006 (UTC)

[edit] 1/3 meter

The following was moved from Talk:Main Page. - dcljr (talk)

Is there anything that is 1/3 of a meter, which would be the equivalent of a foot?

No. Such things don't exist. Broken Segue 22:12, 21 May 2006 (UTC)

The whole point of the metric system is that everything is in powers of ten. Having "1/3 of a meter" would defeat the purpose of the meric system. —Cuivi é nen^T|C, Sunday, 21 May 2006 @ 23:15 UTC

Actually, 1/3 of a metre is about 13 inches, and that's more than and not equivalent of a foot. --199.71.174.100 04:42, 22 May 2006 (UTC)

The question seemed to be whether SI has a unit roughly that size. The closest would be the decimeter, which is about 4 inches. But SI wasn't designed to have "equivalents" to other measurement systems. --Dhartung | Talk 04:51, 22 May 2006 (UTC)

For mental calculations from feet to metres, and vice versa, I use 1 ft = 0.3m = 30cm. It should be 30.48cm, but it works ok for everyday (shortish) measures. A common ruler, with 0 to 12 inch imperial markings, also goes from 0 to 30cm, if it has a metric side. Maybe the .3m is confused with 1/3m ? --Seejyb 21:16, 23 May 2006 (UTC)

Actually yes, 1/3 of a meter can be expressed as 33.33333333333333333333333333... centimeters (sorry, I don't know how to get that line on top of the first .3 to show that it repeats forever). However this is certainly not equivalent to a foot. I believe you're mixing apples and oranges (the metric system with the imperial system). 1/3 of a yard is a foot. Not 1/3 of a meter (which although relatively comparable, is certainly not the same unit of meausrement as a yard). Loomis51 20:43, 24 May 2006 (UTC)

[edit] May 22

[edit] How long it takes to photosynthesise

I would like to know the answer to the question "How long does it take for a plant to photosynthesise six molecules of carbon dioxide and six molecules of water into one molecule of glucose and six molecules of oxygen (a balanced photosynthesis equation), provided all factors are at their peaks?" I have asked everywhere and cannot get an answer, is it even possible to answer the question? Thank you. --Daniel 21:14, 22 May 2006 (UTC)

That would depend on the proximity the molecules have to each other, but I can tell you right away, it's a ridiculously short time. It would be more useful to think in moles instead of loose molecules. - Mgm|^(talk) 20:56, 23 May 2006 (UTC)

[edit] How to remove a fluorine based organic grease from aluminum

I am interested in looking for a solvent or another approach to remove a fluorine based organic grease (Christo-lube MCG 101) from aluminum walls. The approach cannot damage the aluminum walls as they serve a purpose of a vacuum chamber.

Suggest a fluorine based solvent - a perfluoroalkane or perfluoroether. - this method shouldn't damage the walls at all.HappyVR 06:29, 22 May 2006 (UTC)

Would dry ice (CO2) pellet blasting work? Most solvents are pretty toxic and difficult to dispose of safely. --Seejyb 19:32, 22 May 2006 (UTC)

re organofluoro compound removal - the right solvent should just dissolve the grease (might need warming/swirling for some time though) - then it can be distilled off the grease easily - and reused - you even should get the grease back - needs a rotary evaporator or similar though.

Don't know - have you heard of super-critical carbon dioxide extraction - requires high pressures - but as you have a vacuum chamber maybe it will be ok for high pressure as well (probably not I'm clutching at straws here) - Is any damage acceptible eg minor abrasion etc, what about heating the chamber whilst under vac to attempt to volatalise the crease (catching it in a cold trap?). Sorry I can't help more.HappyVR 17:59, 23 May 2006 (UTC)

Just checked your compound (it's a perfluoropolyether I wasn't familar with the trade name) - I can't give an answer about dry ice (CO2) pellet blasting work? - actually this is totally new to me - does a compressed gas blow the pellets at the aluminium? I've never tried anything like this - my guess is that it might not work well but you never know - if you try it out I'd be interested to find out how well it worked (use my talk page if you have time)- as a last resort hot water (a lot) will remove it just as hot water will remove conventional petroleum greases. Good luck with it.HappyVR 18:10, 23 May 2006 (UTC)

[edit] Definition File

What is the meaning of definition file?

Technical term: it's a data file used by some particular program to check other data against. For example, anti-virus programs compile extensive virus definitions (markers, characteristics) to which they compare what they find while scanning files on your computer. --Halcatalyst 02:34, 23 May 2006 (UTC)

[edit] Plotting graphs for excel through visual basic

Hi. Is there a way to plot graphs through visual basic? The data and everything is already in excel, and it's all read into arrays in visual basic. It's Excel 2003 and Visual Basic 6. Thanks. - 150.203.2.85 07:26, 22 May 2006 (UTC)

Yes. You don't say where you want the graphs to appear. If you want them within Excel then you can call excel commands from VB. If you want graphs on your own form then there are a lot of different components you can put on your form that can produce graphs. You could try the OWC chartspace. If Excel 2003 is anything like 2000 the documentation is really bad but with a bit of work this can be used to produce better graphs than excel (multiple charts in one chartspace etc). JMiall 22:19, 22 May 2006 (UTC)

[edit] Evolution?

This article Wast Performs Roach was brought up a few questions ago and I'm still scratching my head about it. When I was a kid I couldn't explain how eyes came about through evolution, but eventually I learned a little more about how sensory organs worked and it started to make sense to me. I am completely baffled by this wasp and roach relationship though. I can imagine a wasp suddenly gaining the ability to burrow into a roach to eat it, or to lay its eggs, but I can't fathom how this could transgress into a mind-control waza if the wasp hadn't been conciously thinking about what it was doing. Since it obviously did evolve such skills, how does one explain it? freshgavin ΓΛĿЌ 09:38, 22 May 2006 (UTC)

What other sources do you have other than the article? Is the wasp even real? I don't see how it could do so. Also, I think a cockroach has only a cluster of neurons for a brain, and it is more of a network neural system like cnidarians have. I forget what its called. This site may help [5] title inspires the utmost intrigue. If all the facts are straight: It is like a mud-dauber wasp making a nest for this type of wasp. The only thing peculiar is the forcing of the roach to walk. Of course it is probably significantly limited control, and the wasp may only actually be steering the roach, while it is trying to run away. --

Mac Davis] ⌇☢ ญƛ. 10:00, 22 May 2006 (UTC)

Here's a much more comprehensive article (an essay actually) about the wasp by the same author: The Wisdom of Parasites. Actually, I thought it was more curious that the wasp steered the roach at all. How would the wasp know how to get to the roach's nest? It could be using the roach as a security pass or something but I still think the whole mind control thing is strange. Never mind that thought, it goes to the wasp's nest. The roach doesn't seem to be running away, though. Apparently it stops obediently when it reaches the layer, and doesn't resist when the wasp inserts her eggs. That's understandable because the second sting from the wasp takes out its ability to resist. It seems to have a reasonable level of control over the roach. freshgavin ΓΛĿЌ 10:08, 22 May 2006 (UTC)

Ironically when a human being realizes he is being controlled like that we offer him a phenothiazine. If it works, he is no longer "controlled"-- or at least doesnt feel like he is. So is a phenothiazine an anti-parasite drug or does it just alter perception of similar parasites? A new horror movie anyone? alteripse 10:54, 22 May 2006 (UTC)

I have a meeting shortly, so I cannot Google this, but it is very similar... There is a parasite that has evolved into a complex system. From memory: The parasite eggs are eaten by an ant. They move through the ant's system and to its brain. This causes the ant to lose control of normal actions and, instead, hang off the top of long blades of grass. Rabbits come by and eat the grass (and ants). The eggs hatch in the rabbit's intestines and come out when it poops. A certain snail loves to eat the rabbit poop, so it stops by. The parasite wiggles into the snail's shell. This irritates the snail, so it puts a mucus ball around the parasite and ejects it. As the parasite dies in the mucus shell, it lays more eggs. The ants love to munch on the mucus balls, which starts the whole process again. --Kainaw ^(talk) 12:31, 22 May 2006 (UTC)

Sigh. That's about enough to make me believe in God. God with a really strange sense of humor. freshgavin ΓΛĿЌ 12:36, 22 May 2006 (UTC)

This reminds me of another parasite that makes use of both birds and snails. This particular parasite (or perhaps its eggs, I forget) can survive within bird droppings. Once the droppings are dropped, the parasite can make its way into the soil, where it is picked up by snails.

Once inside the snails, a remarkable thing happens. The parasite travels up the snail's nervous system, and somehow compels the snail to climb plants or grass as high as it can. A side effect of this is that the eyestalks of the snail pulse rapidly--an amazing sight--and they also change colors. Birds are attracted to the exposed snail (or maybe slug, again I forget) and eat it, beginning the cycle anew. --Tachikoma 14:35, 22 May 2006 (UTC)

I should note that while these are condidered far too complex for dumb evolution, it isn't as complex as it appears. In the example I gave, the evolution of the parasite took advantage of existing systems. The rabbit was already esting the grass. The snail was already climbing around on the rabbit poop. The ants were already eating the snail mucus. So, a snail parasite would occasionaly get into the snail mucus and eaten by the ant. No big deal. Eventually, one of those parasites causes a weird behaviour in the ant - it climbs up a stalk of grass. This single action greatly increases that parasites genes' chance of survival to the next generation. Instead of being left inside an ant that eventually dies somewhere, the parasite goes into a rabbit and is deposited where the snails crawl around. So, there was only one evolutionary step - ant control. The rest already existed (due to previous eveolutionary steps, of course). --Kainaw ^(talk) 14:47, 22 May 2006 (UTC)

Ah yes, I didn't clarify myself that the behaviors could be explained by the reproductive success of whatever organism happened to do something a bit different. But it's still fascinating. --Tachikoma 14:53, 22 May 2006 (UTC)

Even if all those intermediate steps had already existed, the fact remains that one fateful day, a ginormous coincidence occurred that began the cycle for the first time, and it never stopped. freshgavin ΓΛĿЌ 15:30, 22 May 2006 (UTC)

I need to look up the math guy who said, "A coincidence is not surprising. They happen all the time. Absense of a coincidence is what is truly amazing." I'd like to get the quote correct and attribute it to him. --Kainaw ^(talk) 16:09, 22 May 2006 (UTC)

Nobody beats Douglas Adams on coincidences:

Now it is such a bizarrely improbable coincidence that anything so mind-bogglingly useful could have evolved purely by chance that some thinkers have chosen to see it as the final and clinching proof of the non-existence of God.

The argument goes something like this: "I refuse to prove that I exist," says God, "for proof denies faith, and without faith I am nothing."

"But," says Man, "The Babel fish is a dead giveaway, isn't it? It could not have evolved by chance. It proves you exist, and so therefore, by your own arguments, you don't. QED."

"Oh dear," says God, "I hadn't thought of that," and promptly vanished in a puff of logic.

"Oh, that was easy," says Man, and for an encore goes on to prove that black is white and gets himself killed on the next zebra crossing. freshgavin ΓΛĿЌ 16:48, 22 May 2006 (UTC)

A possible way for the wasp's behavior to evolve: Presumably the wasp already had a stinger, like all hymenopterans, and was stinging its prey to feed its young. Stinging the prey in a certain spot would create a tremendous survival advantage if it meant the prey didn't die right away. (Dead prey tends to rot, meaning it won't be available for the wasp larva for long.) Of all the millions of wasp-stings to cockroaches, it only takes one to sting in the right place. (This presupposes that placement of the sting is a purely instinctual, not learned, behavior, and therefore the behavior can be passed along in the genes.) Leading the roach to a safe place surely came later. --Ginkgo100 19:30, 22 May 2006 (UTC)

[edit] Home Made Carbon Dioxide (CO2)

How would I efficiently and cheaply create a quick source of CO2 for trapping mosquitoes? (Only things that I can make at home please). Thanks, --DanielBC 10:38, 22 May 2006 (UTC)

How about baking soda and vinegar? [6] - Mgm|^(talk) 10:47, 22 May 2006 (UTC)

How about farting? Of course, the problem here is to get a good aim at them... Cthulhu.mythos 10:50, 22 May 2006 (UTC)

How much CO2 is ther in the average fart?--Light current 12:36, 22 May 2006 (UTC)

About 9% of a fart is CO2 [7]. The average male farts 15-17 times a day, for a total volume of 0.6 liters (there is variation from 0.2 liters up to 2 liters; source: The Ultimate Book of Farting). So an average human male farts 50 milliliters of CO2 a day (women half that because they do it less). Exhalation produces a hundred times more CO2 per day, more if you engage in some physical activity. And how bored do I have to be to research this? Weregerbil 14:03, 22 May 2006 (UTC)

IAL. I read somwhere that women do it the same amount (or is it more?)-- they just disguise it better! Actually, that info could be added to the farting artcle- it wasnt there when I looked. 9-) --Light current 14:07, 22 May 2006 (UTC)

I don't have the info in front of me, but I have seen in several places that women actually do fart less; anecdotally, I wonder if the reason may be differing hormone levels and constituents between men and women? It is common for a woman to expel varying quantities of gas at different times of her menstrual cycle, perhaps it's related to progesterone?--Anchoress 23:51, 22 May 2006 (UTC)

No its becuase they dont swallow as much air as men! I cant think of a reason why this would be tho! 9-)--Light current 00:53, 23 May 2006 (UTC)

Just breathe. Or burn something. – b_jonas 11:13, 22 May 2006 (UTC)

Breathing is what attracts the mosquitos to your body in the first place. Burning things]] works too, especially those special "antimosquito" citronella candles. The baking sonda and vinegar idea above is not a bad idea, nut the reaction won't last too long. Another alternative is to get a big block of dry ice. It's pure CO2, so when the mosquitos "smell" it, they will try to land on it and instantly freeze to death. --Chris 14:49, 22 May 2006 (UTC)

Per b_jonas, burning something is definitely a quick and easy way to produce CO2. Please do it outside, and well away from combustible materials that you don't want to be a part of your experiment. (Many commercially sold mosquito traps employ this strategy. They burn propane to produce CO2, which attracts mosquitos; the mosquitos are then captured and/or killed in various ways.)

You can also buy dry ice – solid, frozen carbon dioxide – fairly readily. It will set you back a couple of bucks or less per kilogram. Handle carefully; it's cold! One kilogram of dry ice, warmed to room temperature, is about five hundred liters of gas. TenOfAllTrades(talk) 14:52, 22 May 2006 (UTC)

Look up mosquito and 'mosquito attractant' on Google. You will find that CO2 just gets them interested, and other things are needed. From a Canadian who's been to Mosquito Hell, and back, you will also find that those various 'squito suckers' are a big waste of money. You are draining the ocean with a thimble! --Zeizmic 22:28, 22 May 2006 (UTC)

Thankyou all, yes unfortunatly I don't want to go out into the mosquitoe ridden world and fart. Maybe that's just me. Zeizmic, yeah we are in a similar situation with mosquitoes. I know the various things we need to make a trap, but we need to attract them to the trap and I was hopeing that somebody could help for a way of getting CO2 for a while (to attract them to a trap). How feasible is dry ice Chris? How expensive is it? I wouldn't think that could be maintained as a longer term solution. --DanielBC 06:21, 23 May 2006 (UTC)

We used to promote plant growth in the aquarium by yeast-n-sugar fermentation (leading to a steady supply of alcoholic waste material) but that would probably be too slow for your purpose, and a hassle to maintain. A slow drip of conc citric acid into a tall container of CaCO3 (e.g. eggshells) in a citric acid solution yields a steady supply, controllable by the drip rate. If the vessel had tall sides the CO2 would collect inside it, or you could tube it to your trap (as we eventually did for the aquarium). The only reason I mention citric acid is because we found that easy to work with for our purpose, being stored as crystals. Dry ice inside an open vacuumflask, with a funnellike cardboard hood around the top, did work to catch mozzies that have slipped thru the door and windows netting - they suffocate before they freeze, I think, because many weren't inside the flask at all. A supply is a problem, we got ours from the local canteen for free. --Seejyb 22:09, 23 May 2006 (UTC)

[edit] Siren

What is a siren and how does it work?

Awesome question! Siren. Please note that this is an encyclopedia with EVERYTHING in it, just type in "siren" in the search. --

Mac Davis] ⌇☢ ญƛ. 11:48, 22 May 2006 (UTC)

Oh, we have everything now? I guess there's nothing left to do, then.... E WS23 | (Leave me a message!) 20:00, 22 May 2006 (UTC)

Of course we have Everything. And Anything and Nothing too. --Halcatalyst 02:13, 23 May 2006 (UTC)

You forgot something... I can't tell you what though. —

The Mac Davis] ⌇☢ ญƛ. 05:08, 23 May 2006 (UTC)

Looks like we don't have everyone yet. But uncyclopedia does... transwiki? freshgavin ΓΛĿЌ 05:16, 23 May 2006 (UTC)

[edit] How to hydrolise Cellulose, CMC and other

I want to know how to do: 1. the chemical hydrolise(acid hydrolyse) of cellulose, Carboxymethyl cellulose (CMC), hydroxyethyl cellulose HEC)and CMC&HEC based Hydrogel. I have to do a complete (100%) hydrolise of them. 2. I want to know, too, which is the best method to analyse and control the % of hydrolyse and to measure from quantitative point of view the reaction products (glucose, carboxymethyl glucose etc)? I have tried the hydrolise of CMC, HEC and CMC& HEC Hydrogel with sulfuric acide 97% having first a swelling phase at 37 °C for 1 hour and then diluting 10 times with water and incubation at 90-100°C for 3 other hours. The results are not good: I arrived till 25 % of Hydrolyse. Mesuring with HPLC and spectrophotometer at 540 nm.Please help me. 22 May 2006 Xh.D (Ph.D Student, Italy)

[edit] how is a football made

what type of plastic material is used to make a football and how?

See Football (ball), if it's not in there just let us know. :) Henning 18:25, 22 May 2006 (UTC)

[edit] Reason for 25°C "Standard Temperature"

Working through a calculation of electrical conductance of tap water, I noted that most tables are for a temperature of 25°C. Where and when would 25°C have been a standard ambient temperature? --Seejyb 18:26, 22 May 2006 (UTC)

It's about the temperature of an air-conditioned room. —Keenan Pepper 18:46, 22 May 2006 (UTC)

My dad's chemistry textbooks used 20°C, which is a little too cool for most people's comfort; more contemporary ones seem to use 25°, which is a little too warm. I think in both cases they're just chosen to be nice round numbers; someone thought 22° would be too hard to remember or seem too specific or something. --Trovatore 19:40, 22 May 2006 (UTC)

I was taught that STP (standard temp and pressure) was 20 Celsius and 1 Atm. Thats in UK!--Light current 22:31, 22 May 2006 (UTC)

There are a bunch of different so-called standard conditions for temperature and pressure. (They're tabulated in that linked article.) The reasons for the different standards are based in historical baggage, tradition, and convenience.

0 °C makes a good standard temperature because you can easily maintain it with a water/ice bath. 20 and 25 °C have the appeal of being close to a comfortable room temperature. 15 °C...well, someone else will have to explain that one, but it probably had a good reason, too. I'd be tempted to suggest the adoption of 26.85 °C just because it works out to a round 300 kelvin.

101.325 kPa is used as standard pressure because it's equal to the old standard atmosphere—760 mmHg (torr). 100.000 kPa is used because it's a nice round number. TenOfAllTrades(talk) 23:54, 22 May 2006 (UTC)

The original question was about tap water. As far as I know, no public water system heats or cools tap water. Wouldn't the temperature then depend mostly on the temperature of the water supply? (And the standard then on an average?) --Halcatalyst 01:04, 23 May 2006 (UTC)

Er, the question was about the tables that Seejyb was consulting. He happened to be doing a measurement on tap water, but that's moot. Besides, once you get the water sample back to the lab for testing, it's going to be up to room temperature anyway. TenOfAllTrades(talk) 05:23, 23 May 2006 (UTC)

[edit] posterior cervix

i need information on how a very posterior facing cervix may complicate child birth

I recommend you contact an obstetrician or nurse-midwife. --Ginkgo100 19:33, 22 May 2006 (UTC)

[edit] Footballs

after having looked at the new official world cup footballs, for the up and coming 2006 FIFA World Cup this summer at [8] and [9], I was wondering, how does the shapes that a ball is constructed from affect the roundness of a ball, how is this ball rounder, what have they done to prove their claims that it is rounder, and seeing as it has an underlying structure of very large pentagonal shapes, how is it rounder, when surely the larger shapes decrease the roundness of a ball. Finally surely the difference in play of this ball and previous constructions is minimal as the ground will never be perfectly flat, so the path of the ball still cannot be relied on. Philc _T^E_C^I 19:04, 22 May 2006 (UTC)

I think the point of it is to travel through the air well, rather than on the ground. The difference from previous balls can't be minimal, since that would mean Adidas are just trying to cash in. Henry ^Flower 22:17, 22 May 2006 (UTC)

The larger tiles will only make the ball less round if they are as flat as the smaller (traditional) ones. I don't know how they are made, but if they are molded around a sphere before being cut, the fewer seams will help it hold its shape. --Swift 00:10, 23 May 2006 (UTC)

[edit] Weird language problem

What's that disease or brain damage thing called where people have sentences that go like "I will monkey crayon sinople travel kitten walk the dog." Where they have a string of random words in the middle of the sentence or whatever? I think they said it in Muse mgazine, but I don't knwo where mine is. 64.198.112.210 19:45, 22 May 2006 (UTC)

You may be talking about word salad, which occurs with some types of aphasia. —Zero Gravitas 19:55, 22 May 2006 (UTC)

More specifically, you may be thinking of Wernicke's aphasia, or a phrase like "receptive aphasia" or "fluent aphasia". "Word salad" is a psychiatric symptom; the others are neurological diseases. - Nunh-huh 22:34, 22 May 2006 (UTC)

Hence the old psych joke that using the wrong words is simply getting your Wernicke's in a twist. Grutness...wha? 03:34, 23 May 2006 (UTC)

Then what's it called when nobody can understand what you're saying even when you have no brain damage? freshgavin ΓΛĿЌ 05:10, 23 May 2006 (UTC)

It's called vandalism. For example, an anon user has recently inserted random words to a reference desk question to create a completely nonsensical question. – b_jonas 09:25, 23 May 2006 (UTC)

[edit] Genetic Engineering

Can you alter the genetic order of the egg cell or the sperm cell before copulation, if you have the knowledge about the history or the lineage of the family, to avoid the future disease will infect the offspring?

Genetic engineering, genetic modification (GM), and the now-deprecated gene splicing are terms for the process of manipulating genes, usually outside the organism's normal reproductive process.

It involves the isolation, manipulation and reintroduction of DNA into cells or model organisms, usually to express a protein. The aim is to introduce new characteristics or attributes physiologically or physically, such as making a crop resistant to a herbicide, introducing a novel trait, or producing a new protein or enzyme. Examples can include the production of human insulin through the use of modified bacteria, the production of erythropoietin in Chinese Hamster Ovary cells, and the production of new types of experimental mice such as the OncoMouse (cancer mouse) for research, through genetic redesign.

Since a protein is specified by a segment of DNA called a gene, future versions of that protein can be modified by changing the gene's underlying DNA. One way to do this is to isolate the piece of DNA containing the gene, precisely cut the gene out, and then reintroduce (splice) the gene into a different DNA segment. Daniel Nathans and Hamilton Smith received the 1978 Nobel Prize in physiology or medicine for their isolation of restriction endonucleases, which are able to cut DNA at specific sites. Together with ligase, which can join fragments of DNA together, restriction enzymes formed the initial basis of recombinant DNA technology.

Is this possible?

Not anytime soon. alteripse 20:10, 22 May 2006 (UTC)

UK law allows parents to test embryos for genetic diseases and abort the embryo if the condition is found. The law was recently changed to allow this to be done even if the likelihood of the genetic defect causing the syndrome is below 100%. The rationale is that if e.g. the disease is a caused by a single recessive gene, then only 1 out of 4 pregnancies will be affected, so the next pregnancy will likely be OK. EdC 22:23, 22 May 2006 (UTC)

I thought the rational was "Oh noes! Imperfect babies! Costing money and upsetting their parents!", but maybe that's just me.... Skittle 23:39, 22 May 2006 (UTC)

I think that's unfair. The regulations were relaxed to allow screening out embryos which would have a 90% chance of developing eye cancer. If one is selecting which embryo to implant, it makes rather good sense to select the one that will grow up with two eyes. - Nunh-huh 23:51, 22 May 2006 (UTC)

But also note that selective elimination of a defective embryo is not what the inquirer asked about. The answer to his question is a simple "not for the foreseeable future" or a much more detailed listing of all the scientific, practical, ethical, and political barriers to be overcome before his scenario could be a reality. alteripse 02:27, 23 May 2006 (UTC)

Yes, you answered the actual question perfectly. I was just responding to a response. - Nunh-huh 03:02, 23 May 2006 (UTC)

Indeed. If one is selecting which embryo to implant. (deleted a little rant I was going to put) And of course, you aren't 'selecting the one that will grow up with two eyes', you are choosing to implant the ones that do not have a currently detectable high genetic risk of developing eye cancer. There is a difference, and I fear an often overlooked one. Skittle 16:49, 23 May 2006 (UTC)

If one is in the position of performing a genetic test, then one is in the position of selecting which embryo to implant, as they are not created one-at-a-time. Yes, you are selecting the one that has a (roughly) 100% chance of having two eyes, vs. the one that has a (roughly) 10% chance of surviving to adulthood with two eyes, a situation which is very inadequately and only offensively described as "Imperfect babies! Costing money and upsetting their parents". - Nunh-huh 10:11, 26 May 2006 (UTC)

1) Surely the actual reason for selecting embryos is avoiding imperfect babies. That you can try again is not a reason to terminate the current choice, by itself. 2) Not all genetic tests are performed when selecting embryos, some are made during pregnancy. But my actual point was that selection for less than ideal genes does make sense if one is selecting embryos, and hence is internally consistent with current law and reasoning. Many people who are ok with the current law are not okay with selecting for tendencies. I was trying to express this. 3) Having a 90% likelihood of developing eye cancer at some point in your life is in no way equivalent to having a 10% chance of reaching adulthood with two eyes, particularly if you factor in advances in cancer treatment as the subject ages. And our current knowledge level is insufficient to claim that a baby without that particular gene, born to a family with a history of eye cancer, has a close to 100% chance of completely avoiding eye problems. 4) If I had eye cancer, I would be far more offended by the implication that someone else should have been born instead of me than by the suggestion that the motive for genetic selection is to avoid 'imperfect babies', for the benefit of the parents and the government. Not the baby. Skittle 10:28, 26 May 2006 (UTC)

You're simply mistaken about a few things: the case in which the genetic testing was recently permitted was selection of embryos before implantion, not testing during pregnancy. And in the case of retinoblastoma, which is the condition that changed the law: it's not a 10% chance of developing retinoblastoma as any random point in a 70 year life: retinoblastoma generally develops before the age of 2. And yes, people with diseases get attached to them, and get their self-worth bound up in having them. That doesn't make disease a good idea. (And we haven't figured in the cases of bilateral retinoblastoma either). The idea that 100% is somehow "morally" different than 90% is silly and unnuanced. - Nunh-huh 11:37, 26 May 2006 (UTC)

[edit] Water protecting against bullets

How much water does one need to stop a bullet? From 5.56 up to 12.7, travelling normal bullet speeds. Would 1 meter be enough to stop most, you think? If not stop the bullet completely, at least a percentage reduction in velocity. Henning 20:40, 22 May 2006 (UTC)

I remember this being tested in Mythbusters, even a .50 was stopped within a meter if I recall correctly. - Dammit 20:48, 22 May 2006 (UTC)

The MythBusters episode in question found that slower rounds maintained underwater lethality longer than faster ones (I think as a result of sustaining less damage upon initial impact with the water). — Lomn Talk 21:04, 22 May 2006 (UTC)

Ah, these are nice answers. Thanks for swift clearance. :) Henning 21:42, 22 May 2006 (UTC)

Are slower rounds usually heavier? If so is it a case of momentum v kinetic energy?--Light current 21:55, 22 May 2006 (UTC)

According to the Mythbusters article, it's because the faster rounds shattered/deformed on impact with the water, where the slow ones sustained little damage and just slowed down. I'd like to remind the original questioner that the disclaimer about Wikipedia Help Desk not being reliable for legal, medical or dental advice also applies on not relying on our data to stop bullets, either. --ByeByeBaby 00:18, 23 May 2006 (UTC)

Why? You must be talking ballistics! 8-)--Light current 00:48, 23 May 2006 (UTC)

It depends a lot on the the size of the bullet and it's velocity and the mass. A more massive bullet will tend to retain momentum longer and go farther. A bullet with a large cross sectional area will tend to lose momentum faster. This means a long skinny bullet will tend to go farther, and a short fat one will not. A streamlined shape will go farther than one not so streamlined (I think there are bullets called wadcutters that are not streamlines at all. A faster bullet will tend to go farther, but is is not a linear progression, a bullet twice as fast will lose velocity 4 times faster. Of course one that deforms easier will slow down faster than one that does not, so durability is an issue too.

Ballshot? --Halcatalyst 00:57, 23 May 2006 (UTC)

I see you talk my language! 8-))--Light current 01:03, 23 May 2006 (UTC)

There are guns that can fire underwater, but they have to be specially designed to shoot long, heavy pieces of metal. —Keenan Pepper 03:10, 23 May 2006 (UTC)

[edit] My dream.

I am unsure if I can post this here, but anyway. The other night there I had a dream I was in a bed, which was supposed to be in my aunts house. Now the room WASNT my aunt's house, but in my dream it was. Now, at the start of the dream I woke up and found myself attached to a drip, which seemed to be supplying me with blood and some kind of intravenous medicine, which was a yellowy orange opaque liquid. I think it was supposed to be an antibiotic.

Now, where was i? I woke up and noticed this drip. SoI got out of the bed and switched off at the socket the machine which was giving me the blood/medicine, but at that, at the tube which went into my vein (in my upper arm rather than my elbow joint), I appaered to get some kind of hypodermic haematoma. like from where the tube was, a red mark, blood, spread outwards under the skin. I then removed the tube and the haemorraging disappeared.

Does anyone know what this might mean? I woke up shortly after that.

Thank you.

It means you should stop mainlining the stuff!--Light current 21:25, 22 May 2006 (UTC)

I think only you can say what this means to you, since it is your brain and your life. Someone who knows you very well might be able to guess, but you have to wonder if you want to share something so potentially personal with them until you know what it means. To start you off, try thinking about how you felt during this dream, what certain things made you think of, why you did what you did. It could even just be that you're worried about something to do with hospitals or medicine, but without knowing you and your life, how can anyone guess? Skittle 21:29, 22 May 2006 (UTC)

thank you for your quick replies. I thought there were "stock answers" for certain dreanms. I dont think it is to do with paranoia regarding medicine etc as I am interested in a career in medicine and am not afraid of hospitals etc. Thank you again anyway.

There can't really be any stock answers because there isn't any agreement that dreams have meaning in the first place, let alone what that meaning might be. But one school of interpretation would use the occasion of the dream to ask you the following questions about your life: What is there about your aunt, or the aunt-like portion of yourself, that gives you nutrition and succor? What is there about Sol, or the Sol-like portion of yourself, that cuts off that support? What was the emotional tone of the dream? Was it upsetting, or matter-of-fact? Were you upset to be connected to the IV, or upset to be disconnected, or unconcerned either way? Was Sol's action a deprivation or a rescue? - Nunh-huh 22:30, 22 May 2006 (UTC)

No its not Sol!!! Its 'So I' 8-)--Light current 22:33, 22 May 2006 (UTC)

So substitute "you" for Sol <g>. - Nunh-huh 22:48, 22 May 2006 (UTC)

Yeah thats right!--Light current 22:50, 22 May 2006 (UTC)

Just so you're clear, when Nunh-huh said, "there isn't any agreement that dreams have meaning," he meant it. You can take a look at Dream interpretation if you want. There isn't much there, though. As best I can tell from the dreams I remember, they aren't any more "windows into my soul" than my waking thoughts are. I suppose they would be if I was seriously repressed, like most of Freud's patients. Anyway, I'd recommend basic self-awareness long before I'd support something like dream interpretation. Unless you think you're psychic, though; that's the other (rather more ancient) school of thought, that our dreams predict the future. Black Carrot 01:37, 23 May 2006 (UTC)

A really easy way I find for attaching logic to dreams is just considering how it could possibly relate to the events of the day before. Sometimes the connections are really vague, but they're almost always there, if you give the brain some room for interpretation. For example, a dream about going to the zoo with your long dead aunt and the zookeeper is your teacher and he makes you write down the statistics of every animal you see. Most likely in the past day, you saw a TV show about animals, you learned how to say the word "aunt" in Hangul, and your teacher told you to smarten up and do your homework. There are studies that show that the brain sometimes creates strange stories (or our mind fills in the blanks to make sense of sequences of information) in order to promote original thought. If you think of dreams that way, you see that there's no real meaning to dreams, although you can extract reason from them. freshgavin ΓΛĿЌ 04:58, 23 May 2006 (UTC)

Dreams, flat out, don't have any meaning. Your subconscious is not trying to tell you anything! I know from lucid dreaming experience: nearly all my dreams are lucid dreams and I consciously have full control. If I'm dreaming, and my conscious has full control, how can my subconscious continue to conjure up things that "mean" something? If your conscious was trying to tell you something, it would be easier to figure out— it would not put you in a conundrum. When your subconscious tells you something it damn well does! Ever got burned before! You didn't have to think about if you should leave your hand there or take it out! —

The Mac Davis] ⌇☢ ญƛ. 05:06, 23 May 2006 (UTC)

Sure dreams have 'meaning', just not necessarily very useful meaning. I know that when my Mum dreams about being chased by elephants she's been worrying about weight-loss again, when I dream about my teeth falling out I'm worrying about money, when I dream about rushing ahead of natural disasters to rescue my brothers it's time to visit home again. These things you probably already know, so they're not that useful unless you don't have time to think about how you're feeling. I consider disaster dreams as a reminder that I haven't been to see my family for too long; if I thought about it at the time, I would probably already know that. And they aren't hard to figure out unless you deliberately try not to; you made them, you decypher them. Lucid dreaming is slightly different, although it's the same you making the decisions and you're not always as lucid as you might think. Skittle 16:40, 23 May 2006 (UTC)

People who insist they have lucid dreams always amaze me... what about a dream was EVER outside your control? People just have dreams about being in control... Although it does raise an interesting question, if you could somehow force your dreams to be about purely conscious thoughts and repress any subconscious emergence, would you be forced to dream in your dream to ever get to the bottom of your mind?

Say what? Black Carrot 01:48, 24 May 2006 (UTC)

No I fully understand that there is a lot of research in the area of lucid dreaming, and it is intriguing, but what i don't see is anyone looking to figure out how its so different than every other kind of dream. After all, you are ALWAYS in control of your dream, it's kind of hard to argue that something happening PURELY in your head is conscious or unconscious. In my opinion, people are just getting better at seeding their minds with material for dreams, and then when the time comes they recollect that the dream was purely deliberate. Kind of like saying you control gravity by making it pull stuff toward the earth... dreaming is ALWAYS in your head it's just come under different interpretation when studied like this.

Whether you can believe in lucid dreaming depends on whether you believe in monism or dualism, or variations of those. freshofftheufo ΓΛĿЌ 04:00, 24 May 2006 (UTC)

[edit] Sharp pain in the chest

Hi, I'm 19 years old. I know that Wikipedia isn't a source for medical advice and I don't want to be hypochondriac but it's more of curiosity than of preoccupation. I sometimes feel a short strike of sharp pain in the center of the chest, sometimes it driffs a bit to the right and sometimes in the other direction. If I'm nervous it seems to become a little more common and other young people have told me to experience something similar so... what does causes that? thanks very much.

Sounds like wind to me, but please go see a doctor!(just to make sure)--Light current 22:22, 22 May 2006 (UTC)

It's a good thing to write all these things down for the next visit to the doctor. --Zeizmic 22:30, 22 May 2006 (UTC)

I had something similar around that ages, it turned out that the muscles on my chest were slightly too short (due to fast growth I guess). Remember ofcourse that the answers here are not by experts and if you think it could be something more serious you should consult your doctor. - Dammit 22:46, 22 May 2006 (UTC)

I forth the motion... With toe pain there are relatively few possibilities but with chest pain whatever it is is most likely not something to keep from the person who can actually save your life. ---- PCE 22:55, 22 May 2006 (UTC)

An occasional brief twinge of pain, especially if it is occuring in the context of chest wall movement, is more likely to be musculo-skeletal (say, Tietze's Syndrome or costochondritis) than cardiac in origin, but on the other hand there are heart valve problems that can give a similar sensation, so it's a good idea to be examined to determine if you have any murmurs that may indicate other problems, especially if you are playing sports. - Nunh-huh 22:56, 22 May 2006 (UTC)

I had extremely sharp chest pains a while back. Turned out that I had really bad gas. The point - there aren't enough nerves in the abdomen to go around. So, a pain in one place tends to hurt in another. I've wondered if a heart attack can feel like bad gas. --Kainaw ^(talk) 00:04, 23 May 2006 (UTC)

Yes, it can. See also myocardial infarction#Symptoms. TenOfAllTrades(talk) 00:10, 23 May 2006 (UTC)

I've also had similar pains since I was a child, though very infrequent. Always in the chest but it felt like it was "attached" to my lungs, because there was a slight restriction in breathing. It only ever lasted for a couple minutes, and though I worried a little I soon forgot. It was also always during periods of low activity. I think I asked my (GM) doctor about it a long time ago, but as it was so infrequent and there were no present symptoms, he basically said that it wasn't something to worry about unless it started becoming frequent. I got the feeling he didn't really take me seriously, though. freshgavin ΓΛĿЌ 04:47, 23 May 2006 (UTC)

I too have had these, but for very short durations (from less than a second to two seconds). I am 17 years, and these pains have been coming on and off for some months now, with great irregularity. What frightens me is that I DO have a heart murmur, but my doctor has told me there's little to actually worry about. I should soon get another check at a different doc, I strongly advice you to do the same. I too feel like a hypocondriac, but in your situation, and mine, it should be well reasoned. Henning 11:53, 23 May 2006 (UTC)

Thank you very much to all for your responses. I also have a slight heart murmur but I have noticed that my brothers also have it, so I guess it's normal. I think my situation is similar to Henning's, both in the frequency and duration, but since I feel physically very strong and can do sport without any problem, I will just forget about this (unless symptoms become worse :) ). Thanks again to all.

Why not give your doctor a treat anyway? They like to see fit young bodies from time to time. Must make a change from all us old fogies! 8-)--Light current 13:24, 23 May 2006 (UTC)

You've noticed that your brothers have a heart murmur? You've been auscultating their hearts with your stethoscope and know enough to notice a murmur????? If you indeed have heart abnormalities in your family, that would make it more important, not less, to see a physician. - Nunh-huh 10:14, 26 May 2006 (UTC)

I think the point was that his brothers, who don't have heart murmurs, also get this sharp pain. This suggests that the sharp pain is not connected to heart murmurs. Incidentally, I also used to get these pains when I was growing up, but they seem to have stopped now I am mostly finished developing. Never did any harm that I could tell, but hurt. They felt like something was catching on the inside of my ribs. Skittle 11:07, 26 May 2006 (UTC)

Everyone's situation is unique - the fact that your brothers have it doesn't mean that it's not worth checking with the doctor. Now, my experience: When I was a teenager, I used to get sharp chest pains as well, but not in the center. Off center, and not always in the same spot each time. I would have to restrict my breathing (the movement of my chest) to avoid the pain, till it went away (up to a couple of minutes). My doctor checked it, and said it was the lungs catching on the inside of the ribs (as mentioned by Freshgavin), common in thin, fast-growing teenage boys - nothing to worry about and it would go away. And it did - it disappeared, apart from once after a strenuous uphill run when I was 22. 13 years later, I don't think I've had it again (or maybe just a tiny twinge).

Curiously, you mention heart murmurs, and I also have a minor cardiac arrhythmia - this, though, has improved through yoga, especially learning to breath out slowly in the situations that used to bring on the irregularities.--Singkong2005 13:38, 29 May 2006 (UTC)

[edit] Untitled Question

Can somebody explain to me how to write and balance the following equation in a double replacement reaction?

NaOH + C₆H₈O₇ = ?

Thanks in advance!

This is a very hard one. I think you do it by the following: Pay attention in class. Take good notes. Read the textbook. Do your own homework. --Kainaw ^(talk) 00:05, 23 May 2006 (UTC)

Look higher on this very page, since we answered the exact same question two days ago. And then tell your teacher to tell the rest of their class to stop asking homework questions on the Reference Desk. Or at least coordinate with your classmates better. --ByeByeBaby 00:15, 23 May 2006 (UTC)

[edit] May 23

[edit] Electrolysis of Baking Soda

If I electrolysize a solution of baking soda (NaHCO₃), do I get O2 and H2 or CO2 and H2 at the anodes and cathodes? Thanks. --Chris 01:35, 23 May 2006 (UTC)

O₂ and H₂. The oxidation state of carbon in carbonate, hydrogen carbonate, carbonic acid, and carbon dioxide is the same, so it's not involved in the electrochemistry. —Keenan Pepper 03:35, 23 May 2006 (UTC)

Hmm...good point. Thanks! --Chris 16:31, 23 May 2006 (UTC)

I think Baking Soda dissolved in water becomes ionized Sodium Carbonate and Carbonic Acid. The Carbonic Acid decomposes into water and CO2. It takes a bit of time for this to stabilize, but once that happens electrolysing the solution will cause some CO2 to evolve at the anode as the Sodium Carbonate breaks up into the Carbonate ion and Sodium ion. —The preceding unsigned comment was added by 12.10.127.58 (talk • contribs) .

Hmmm, close, but not quite. NaHCO₃ in water exists as Na⁺ (sodium ions) and HCO₃^- (hydrogen carbonate ions). Na⁺ could be reduced to sodium metal at the cathode, but that's never going to happen because H₂ is much more easily produced. In HCO₃^-, the oxidation state of carbon is +4 and it's not going to get any higher (because the next electron is a tightly bound core electron). The HCO₃^- will be in equlilbrium with gaseous CO₂, as it always is, but that doesn't have anything to do with the electrolysis. (Someone please correct me if I got anything wrong.) —Keenan Pepper 20:33, 23 May 2006 (UTC)

True... but... CO₂ does actually form at the anode due to the heat of resistance of the electrolysis cell, but this is nothing to do with electrolysis. It forms from the thermal decomposition of HCO₃^-, which is only found at the anode because it is -ve. --Eh-Steve

That makes perfect sense. Thanks! —Keenan Pepper 17:20, 26 May 2006 (UTC)

I see...so definately H2 at the cathode, and maybe O2 and CO2 at the anode, but not because of the electricity? All I'm really looking for is the hydrogen. Thanks. --Chris 15:25, 24 May 2006 (UTC)

Is the solution still safe to ingest after electrolysis, or will the dangerous Sodium Hydroxide (NaOH) also be produced as a by-product in the solution? If it is produced, is there any way of neutralizing it?

[edit] Global Warming- should we worry?

Does human activity on earth (burning fossil fuels etc) really make any difference to long term global temperatures? Or are the sun, volcanoes etc far more important. --Light current 01:49, 23 May 2006 (UTC)

You wouldn't, by any chance, have read State of Fear lately? You might be interested in the article on the book. -- Rick Block (talk) 02:22, 23 May 2006 (UTC)

...or, you might want to read about the opinions of competent scientists in our article on global warming. Crichton is sometimes entertaining, but any serious scientist can tell you he's just a hack. Sorry, Rick. :D TenOfAllTrades(talk) 04:18, 23 May 2006 (UTC)

If it makes me rich and famous, I won't complain about being called a hack by poor people with flakey white hair. freshgavin ΓΛĿЌ 04:41, 23 May 2006 (UTC)

I'll have you know that my hair is lush, brown, and flake-free. But I'm mostly a biochemist by trade, not a climate scientist. TenOfAllTrades(talk) 05:15, 23 May 2006 (UTC)

And you're poor! freshgavin ΓΛĿЌ 09:34, 23 May 2006 (UTC)

He is NOT a hack. Bastardization strikes again. Have you read the book, or looked at his works cited lists and appendices? Although it is a work of fiction, all the facts are right (except for the technologies the antagonists use). I recommend Light current read State of Fear. The fact is, we are not sure if humans can significantly (depends on your definition) alter the (entire) Earth's climate through increased CO2 emissions. We don't know if the sun, volcanos, or etc are far more important. We don't know. On the news I know they make everything seem like we know, but they're wrong. The debate is still going on, and still will until we get tired of talking about it publicly as much as right now. Why politicized science is bad. Scaremongering. —

The Mac Davis] ⌇☢ ญƛ. 04:48, 23 May 2006 (UTC)

Actually, it's not really a question of which is more important, humans or other natural phenomena. Rather, it is the question whether the human impact is big enough to cause significantly adverse effects on the global climate. Not everyone agrees, but the scientific consensus is pretty much that the recent steady climate change is due to human activity and that the trend will continue. As for the debate, Crichton's book can hardly be considered any more of a contribution to this debate than the Da Vinci Code is to religion. Not that they should sit, untouchable in their ivory towers, but on such complex issues, shouldn't we give more credibility to the experts. --Swift 09:13, 24 May 2006 (UTC)

I'd still urge Light current to read peer-reviewed scientific literature, rather than Harper-Collins edited science fiction. Your mileage may vary. TenOfAllTrades(talk) 05:15, 23 May 2006 (UTC)

With all due respect, TenOfAllTrades, have you actually read a peer-reviewed paper? As the only native english speaker in my research group, I read almost every paper we generate, and let me tell you - those things are mostly incomprehensible. If you don't have (at least) a bachelor's in the area, you'd be lost in 2 paragraphs, if that. So recommending he read peer reviewed papers is an EXTRAORDINARILY bad suggestion. Raul654 16:36, 23 May 2006 (UTC)

MacDavis and I have been sparring over this issue for awhile :) I'm afraid that as far as scientific credibility goes, Crichton doesn't come off very well. I have read State of Fear, and browsed through some of his references, and find that his take on the issue is very one-sided - yes, he uses some real facts, but ignores many others which would go against his conclusion. I'll admit that it makes for a good story, but it's not a fair representation of the scientific consensus. Take a look at climate change and global warming - as unpleasant as the news may be, the debate about whether humans cause climate change is essentially over, we do. This is not scaremongering, it's facing up to the facts (the many graphs in the latter article help to illustrate the point). The question remains now what to do about it, and burying our head in the sand won't make the problem go away. — QuantumEleven 08:31, 23 May 2006 (UTC)

TenOfAllTrades, you're right—scientific literature is definitely much better than any work of fiction, although it does not appeal to the masses as well. I personally read much more scientific literature than fiction book. QuantumEleven, his ignoring of other things is certainly debatable, and it has been debated on several talk pages. I believe Anthropogenic Global Warming Hypothesis (AGW) to be now somewhat based on scaremongering, and has gone politicized. It is illegal to use certain kinds of cell phones in gas stations because of the irrational fear of the radiation heating gas nearby (I was told this by a radio technician, and it is not perfectly quoted, I warn). The US government spent hundreds of millions on clearing up general radiation scares from powerlines, microwaves, and cell phones. Its electromagnetic radiation, not nuclear radiation! It seems clear to me that we are not sure if increased CO₂ emissions are currently having a global effect in the significant altering of the Earth's climate. What part do you think differently of? You think it is totally clear that CO₂ increase attributable to a global warming? I am quite well read on paleoclimetology, I'm not just some guy that read Crichton's book and is convinced by his pretty bad bias (but it might be the truth, as a "counter"). —

The Mac Davis] ⌇☢ ญƛ. 11:01, 23 May 2006 (UTC)

Uh, nuclear radiation IS electromagnetic radiation, but the frequency (and energy) is so much higher than that you get from power lines, it becomes dangerous. So it would be more accurate to say powerlines give off radio waves, not gamma waves.

No, nuclear radiation is not the same as electromagnetic radiation. Well, some of it is. Gamma radiation is indeed high-energy EM-radiation but alpha and beta aren't. --Swift 08:54, 24 May 2006 (UTC)

Mentioning mobile phone bans and radiation scares in the same breath as global warming is something of a non sequitur. Power line scares have no epidemiology to back them up; any reported symptoms are easily explainable as instances of the placebo effect or selection bias. Mobiles bans in petrol stations have some remote validity - radio waves can induce current in nearby conductors, causing sparks - except that mobiles have nowhere near enough power; ignition is more likely from exploding batteries or loose contacts (in which case ban all electronic equipment). Global warming, on the other hand, has the support of nearly the entirety of the climatological community. Personally, I can't but see the global warming "debate" from an engineer's perspective: greenhouse gasses make the world warm, so more greenhouse gasses will make the world warmer. To me, the burden of proof is on the global warming deniers to supply a theory where increased greenhouse gas levels do not affect the climate. EdC 12:47, 23 May 2006 (UTC)

No it is not a non-sequiter. It demonstrates how fearmongering is a more powerful tool than the truth. The verdict is not in on CO2 and global warming and probably will not be for a long time until the politicization of the subject is swept away.

I tend to look at it the same way as EdC. We know carbon dioxide is a greenhouse gas as much as we know anything; that's the very thing which has made Earth lovely and warm so that we could live as we do. We know that more carbon dioxide makes it hotter. We know that human activities are releasing more carbon dioxide into the atmosphere than they are locking back into trees/shells/etc. So where's the argument? And as far as the mobile phones in garages goes, I have it from someone in the industry that the bans stem from one explosion which seemed to be tracable to a man receiving a call on his phone. Nobody really knew how it could cause it, but something sparked. However, this isn't verifiable. Skittle 16:32, 23 May 2006 (UTC)

Answering Mac Davis' question on whether it is totally clear that CO2 increase attributable to a global warming: No, this is science -- nothing can be proven. The consensus, however, is that the correlation between the alleged cause and the measured effect is good enough to pass the test of science. For many the final straw was when the National Geographic had a special on global warming. Now the debate seems to be mainly on what the effect will be.

I wasn't sure if I should include the following bit on human effect, but in a crowd of vague quotes from radio technicians on cellphone legislatiure, I figured this anecdote wouldn't be the topic's weakest point. A friend of mine doing her M.Sc. in oceanography has done some research on the connection between climate data and pandemics. One of her preliminary results showed a correlation between major pandemics and some unexplaned non-negligeble fluctuations in CO2 levels. Her conclusion was that the large scale decrease in population caused a substantial enough a change in human activity to affect climate. So, yes. Even pre-industrial civilisations may have had measurable affects on the globe. --Swift 09:40, 24 May 2006 (UTC)

The science community's role is not to tell truths. It is to study and give warnings when necessary. Now the global warning has been made.

The global warming shall be a reality when other communities find it proper to their agenda. Politicians, voters, capitalists, engineers are thinking about it, e.g. in California, which is hot already (meaning hot oven). I declare the GW open! --DLL 18:37, 23 May 2006 (UTC)

I think the engineers already know it's happening. Yay for truth by concensus. Skittle 19:20, 23 May 2006 (UTC)

This is the exact kind of fear mongering that so called mainstream "scinetists" use to try and trick people into believing in other absurd things like, evolution, environmentalism, genetics, satan, dentistry, the big bang, and the moon, I'm not buying into any of this nonsense, you go Mikey C!User:Peter cotton tail20:42, 23 May 2006 (UTC)

What about the long term carbon cycle. Does that have any effect?--Light current 22:14, 23 May 2006 (UTC)

Well yes, that's the source of the problem really. The long term carbon cycle should involve large quantities of carbon being both released and locked away. The problem is that we are releasing a lot of carbon from places where it has been locked away for a long time (coal, oil, peat, gas, forests, polar ice through the warming (this being a case of positive feedback), etc), but not locking equivalent amounts back. In fact, we are destroying many of the mechanisms for doing so. Carbon can get locked away as coal by being made into trees which become peat which become coal. We are tearing up, using and burning every stage of this process, without replacement. Carbon can also be locked away in calcium carbonate shells, but obviously this requires healthy shellfish populations, growing coral, decent biodiversity in the oceans to maintain them, clean waters that aren't too acidic. Carbon dioxide is also frozen into the polar ice, but as this melts it gets released. The long term carbon cycle is a major factor in the accelerated greenhouse effect. Skittle 11:02, 26 May 2006 (UTC)

[edit] Transgenics, Genetically Engineered Organisms.

I searched "Ananda Chakrabarty" in Wikipedia, and I was shocked not to find an informational site about him. He was a microbiologist that filed for a patent on a bacterium, psuedomonas, capable of digesting the components of crude oil. He was the first to file a patent for a transgenic. Frankly, I think this was a huge discovery. In fact, he even had to go through a court battle for this genetically engineered organism.

http://www.oyez.org/oyez/resource/case/1125/

This site is excellent in explaining the court battle. (copy and pasted):

"Diamond v. Chakrabarty 447 U.S. 303 (1980) Docket Number: 79-136 Abstract

Decided:

June 16, 1980

Argued:

March 17, 1980

Subjects:

Economic Activity: Patents Facts of the Case

After genetically engineering a bacterium capable of breaking down crude oil, Ananda Chakrabarty sought to patent his creation under Title 35 U.S.C. Section 101, providing patents for people who invent or discover "any" new and useful "manufacture" or "composition of matter." On appeal from an application rejection by a patent examiner the Patent Office Board of Appeals affirmed, stating that living things are not patentable under Section 101. When this decision was reversed by the Court of Customs and Patent Appeals, Diamond appealed and the Supreme Court granted certiorari. Question Presented

Is the creation of a live, human-made organism patentable under Title 35 U.S.C. Section 101? Conclusion

Yes. In a 5-to-4 decision, the Court explained that while natural laws, physical phenomena, abstract ideas, or newly discovered minerals are not patentable, a live artificially-engineered microorganism is. The creation of a bacterium that is not found anywhere in nature, constitutes a patentable "manufacture" or "composition of matter" under Section 101. Moreover, the bacterium's man-made ability to break down crude oil makes it very useful. "

Isn't this an important bit of scientific information that should be present in Wikipedia?

This man made it possible for others to recieve patents for genetically engineered organisms.

Even MSN has an article on him: http://encarta.msn.com/media_701765369/Ananda_Chakrabarty.html even though it isn't in much detail as it should be, I think Wikipedia should create an article explaining his contributions to the world and the important court case.

We do have an article on the court case at Diamond v. Chakrabarty. We should indeed have an article on him. You could start it yourself (you'd have to get an account to be able to create the article), or add it to the appropriate section of Requested articles.-gadfium 03:05, 23 May 2006 (UTC)

If you can find the time to write up your own entry, instead of copy-pasting, you could also make a submission to WP:AFC. - Mgm|^(talk) 20:38, 23 May 2006 (UTC)

He is not well known as a person -- he is known almost entirely through the case, which we do have a (not very informative) page on, as noted. --Fastfission 19:15, 24 May 2006 (UTC)

[edit] Ester Based Drilling Fluids

Drilling fluid or drilling mud is any of a number of liquid and gaseous fluids and mixtures of fluids and solids (as solid suspensions, mixtures and emulsions of liquids, gases and solids) used in operations to drill boreholes into the earth. Synonymous with "drilling mud" in general usage, although some prefer to reserve the term "drilling fluid" for more sophisticated and well-defined "muds." Classifications of drilling fluids has been attempted in many ways, often producing more confusion than insight. One classification scheme, given here, is based only on the mud composition by singling out the component that clearly defines the function and performance of the fluid: (1) water-base, (2) non-water-base and (3) gaseous (pneumatic). Each category has a variety of subcategories that overlap each other considerably (www.slb.com)

There is a new innovation in drilling fluid which use ester as the base. What is ester based drilling fluid? What are the advantages of using ester based drilling fluid compared to the conventional drilling fluid?

--170.38.99.56

Enhanced oil recovery question

The objective of EOR process is to recover the tremendous quantity of unrecoverable oil in known deposits.

The recent discussion on EOR is to use air injection. How does the air injection works to enhance oil recovery? What are the advantages and disadvantages?

--170.38.99.56

Please refer to the instructions at the top of this page, which – in part – state that you should

Do your own homework. If you need help with a specific part or concept of your homework, feel free to ask, but please do not post entire homework questions and expect us to give you the answers.

We would be glad to provide what assistance we can, provided you work within the above guideline. TenOfAllTrades(talk) 04:21, 23 May 2006 (UTC)

[edit] Question

Duuuuhhhhhhhhhhhhhhhhhhhhhh............. IS it ok if ME askz a question for ouy guys?? THank you>,? O Mneed to eat some fish, ;;; — The Mac Twat] ⌇☢ ญƛ. 05:11, 23 May 2006 (UTC)

Mac Davis, do you know, what is 2*2=4 equal to? ellol 07:15, 23 May 2006 (UTC)

Excuse you! Its "The Mac_Davis" —

The Mac Davis] ⌇☢ ญƛ. 10:00, 23 May 2006 (UTC)

Very funny, freshgavin. I'm laughing so hard. —

The Mac Davis] ⌇☢ ญƛ. 10:47, 23 May 2006 (UTC)

[edit] The Ultimate Speed Limit

I've heard that the Special Theory of Relativity's Ultimate Speed Limit not only applies to material objects, but to influences and disturbances of any sort.I don't understand.How can it, I mean how can such a rule like that, possibly apply to anything that exists, not just matter and substances?60.241.147.187 09:57, 23 May 2006 (UTC)

The "speed of light" limit, is for objects with a mass greater than zero. The speed of light is the limit, because a photon's rest mass is zero, and it takes an infinitesimally small amount of force to move it: any force propels it to c, because it is weightless. Actions and disturbances are akin to energy—they are completely intangible. They don't actually.. exist. It is a property of the system, not a substance with an independent existence. You might as well ask "what is length made of?" or "what is momentum made of?" This is why the velocity limit only applies to masses, and it would take an infinite amount of energy to propel a mass to the speed of light. —

The Mac Davis] ⌇☢ ญƛ. 10:07, 23 May 2006 (UTC)

I think you read his question wrong, he was asking why c applies to everything, not just the speed of objects of mass. It's probably best to think of the SToR's ultimate speed (c) as just c, and not the "speed of light". Then it's easier to say that nothing can pass the speed of c, not light, not the influence of gravity, not the disturbances in space and time. It'd take someone with a little better understanding than me to explain how gravity and time are limited to c, but I think one way to imagine it easily is if someone inserted a planet right beside earth instantly. You probably wouldn't feel the gravity from the new planet for a fraction of a second, as the influence of it's mass would be travelling more or less at c. freshgavin ΓΛĿЌ 11:06, 23 May 2006 (UTC)

I think the simplest way to elaborate on this is to say space has limitations in that nothing can propagate throught it faster than light. Of course when you start talking about quantum mechanics, some of this gets pretty fuzzy.

I doubt anyone here will be able to improve on the article on faster-than-light travel and communication; suffice it to say that in general relativity anything that can go faster than light can go back in time, and time travel really messes up the maths. -- EdC 12:33, 23 May 2006 (UTC)

Shine a very powerful visible laser beam at the moon's surface and you observe the spot of light produced there. Now you quickly vibrate your laser source from side to side over a very small angle such that the beam still hits the moon. How fast can you get that spot to move? Is it limited to c? 8-)--Light current 12:42, 23 May 2006 (UTC)

You can get the spot to "move" infinitely fast, so the answer to your second question is no. You can shine a light in two different places on the moon, and it doesn't mean that anything is travelling instantly. freshgavin ΓΛĿЌ 13:44, 23 May 2006 (UTC)

Except information ?--Light current 13:50, 23 May 2006 (UTC)

What is information? It's some little changes of energy, of matter, and all this stuff can't be transmitted faster than c! ellol 14:35, 23 May 2006 (UTC)

Look it up at information --Light current 14:55, 23 May 2006 (UTC)

To address "information" and the "laser spot on the moon" -- yes, a small movement of a laser source on Earth can cause the endpoint of the beam on the moon to "move" faster than light. However, what does this accomplish? In and of itself, information is still restricted to light speed, because no outside observer can draw information until the reflection of the beam, at its various points, has reached him at light speed. — Lomn Talk 14:58, 23 May 2006 (UTC)

The one that's always gotten me is this: You've got a very long solid pole (one light-year in length, for argument's sake). You push one end. Does the other end of the pole only move one year later? --Kickstart70-T-C 16:43, 23 May 2006 (UTC)

Yes. It's a non-obvious answer, because on earth, we are used to the idea of very small poles where you push one end and the other "instantaniously" moves. A light year is a *very* long distance (3 trillion kilometers, I think). Remember, as best we know, even gravity is limited to the speed of light. So pushing one end of the poll means that the force you impart into one end of the poll will be transmitted (probably as a compression wave) to the other end of the pole, and some velocity less than the speed of light (probably substantially less too). Raul654 16:50, 23 May 2006 (UTC)

Awareness of the push propogates at the sound speed in the pole material, typically a few km per second in most solid material. Hence much slower than the speed of light. Dragons flight 17:06, 23 May 2006 (UTC)

Right. And Kickstart, you'd probably get a kick out of Bell's spaceship paradox. ---CH 09:58, 24 May 2006 (UTC)

And even when the opposite end of the pole finally moved, you wouldn't actually see it move until 1 year later. freshofftheufo ΓΛĿЌ 17:23, 23 May 2006 (UTC)

Its a good job no ones got a solid 'pole' one light year in length. The mind boggles!--Light current 23:06, 23 May 2006 (UTC)

The moon laser puzzles me; I don't understand how one can say that the light on the moon moves. The direction in which the photons from earth travel to the moon changes as the laser on earth is moved. Where they hit on the moon is determined by the direction in which they were moving on leaving the laser source, thereafter they just go straight on (gravity and refraction etc ignored). Once the get to the moon they dont't move, they just get reflected from where the landed. There seems to me nothing on the moon that is moving, except that different photons are hitting different places at different times. That is surely not a lateral movement of any single photon? --Seejyb 23:44, 23 May 2006 (UTC)

The dot itself moves faster than C, as a result of the group velocity of the photons. Or, to put it different, if you had a bunch of people stand one meter apart and each of them start doing an Audience wave at almost the same instant, the wave could move well over C, but (a) nothing of mass is moving at C or greater, and (b) the people would have to be told ahead of time when to stand (thus, information cannot move faster than C) Raul654 02:50, 24 May 2006 (UTC)

I guess you could just call it perceived motion, just like the Bionic Man was perceived moving 10x faster than the average man, though of course it was just a crappy 1970s camera trick. freshofftheufo ΓΛĿЌ 06:08, 24 May 2006 (UTC)

No, it has nothing to do with group velocity (which travels along the wave, i.e. the direction of the laser beam). As Seejyb guessed, it is just different photons hitting different parts of the Moon. Look back at the question posed by LightCurrent and you will see a smiley. I interpreted it as a tounge in cheek marker since the question is not about motion, but rather (in Freshgavin's words) about perceived motion.

Raul654's audience wave analogy is unfortunately also wrong since the wave propogates by people rising when their neighbours do -- an example of a propogation of information (the speed of which is determined by the reaction time of the audience). A more fitting analogy would be to give the audience alarm clocks with instructions to rise up when they sounded. The clocks would be timed so that the audience would create a wave, but which travelled much faster than the audience could have created by passing on the instructions to the persons beside them. In this case, no information is transmitted through the wave signal, the information has already been planted in the alarm clocks. --Swift 10:10, 24 May 2006 (UTC)

Hi there LC. What is the spot? It is not matter, you are not moving the surface that is illuminated, nor is it light, for the fotons that hit one spot are not the same that hit the next. So you don't really move anything when you do that. VdSV9•♫

For that matter, say you have a more powerful laser, you aim it to follow a planet in the end of the galaxy - say 10 light years away, after waiting the 20 years with the laser on to finally see it hit something you turn it enough to hit the moon right above you. The spot will land on the moon 10 years before "leaving" the planet, and 20 years before you see it leave the planet. VdSV9•♫

For the 1l-y pole, it would take longer that a year and its movement would be much slower in the receiver end. The pole would have a quite large spring constant. Say you have a long pipe with water in it and spheres that completely seal both ends. If you abruptly move one sphere the other one will take some time to move and the movement will also be smoother and slower. VdSV9•♫ 20:13, 30 May 2006 (UTC)

[edit] ROCKET FINS

Today in Science Class I recieved an assignment which has us create a rocket. I have already finished the rocket but I require information on how to place the fins and where. Could anybody help me? Thanx!--Devol4 10:31, 23 May 2006 (UTC)

Always put the fins on the end. (haha, get it?) —

The Mac Davis] ⌇☢ ญƛ. 10:45, 23 May 2006 (UTC)

Oh, very droll! Sum0 22:25, 23 May 2006 (UTC)

Googling for "rocket fins" and clicking on the first result brings up this page. –Mysid^(t) 11:09, 23 May 2006 (UTC)

That link doesn't tell him where to put the fins, though it does give some construction hints. Devol4, I'm assuming you're creating a rocket with a single booster on the end of it. If the wings are too far from the power source, they won't have any stablizing ability on the craft and it will spiral out of control. Some planes have wings in the middle, but that's because they're being pulled by a force instead of pushed, so it stabalizes in a different way. As long as the fins aren't going to get torched by the rocket, you should put them right at the end. freshgavin ΓΛĿЌ 11:20, 23 May 2006 (UTC)

[edit] RBC'S

RBC's are still alive and metabolizing glucose inside an SST tube prior to spinning the tube. Is this correct? (I say yes and stops after spinning, others say no because it settles at the bottom.) Please help

Please don't use ALL CAPS! It makes it look like you are yelling and can be very irritating. 222.158.163.169 12:24, 23 May 2006 (UTC)

Yes, RBC's are still alive and metabolizing glucose in inside an SST tube, both prior to centrifugation and afterwards, but at room temperature, their metabolism is a lot slower than at body temperature. Donor blood in the blood bank is centrifugated before storage, and the RBC's are still alive and metabolising after several weeks of storage at 4 degrees in the blood bank. --vibo56 12:55, 23 May 2006 (UTC)

If the blood is drawn into a fluoride tube (gray top), the metabolism is slowed, but rapid separation is optimal. alteripse 14:21, 23 May 2006 (UTC)

[edit] Sweaty drugs

I have mild hyperhidrosis (kinda-hidrosis?) and I was just reading the article on it to see how it could be treated. All of the treatments they list there are really heavy, and seem to involve long trials, have horrible side effects, and are most likely very expensive. Since my case is only very mild (I can control it by not moving too much, changing clothes a couple times a day, frequent showers) and it only effects me in the middle of summer, does anyone know of any mild treatments? Something like vitamin pills, salted drinks, or maybe cheap non-prescription drugs? (keep in mind I am not in North America and my access to very cutting-edge stuff is a little limited) 222.158.163.169 12:29, 23 May 2006 (UTC)

It affects everyone on the middle of summer! Buy a large personal fan! (and take off all your clothes) 8-)--Light current 12:49, 23 May 2006 (UTC)

Ay, that's not very nice Light current! 222.158.163.169, like the "How to ask a question" guidelines at the top of this page suggest, you might want to speak with a doctor, rather than turn to a group of anonymous Wikipedians. Good luck on this. --Swift 10:23, 24 May 2006 (UTC)

No its more effective when you're naked - believe me. There's more surface area from which the sweat can evaporate!--Light current 00:52, 26 May 2006 (UTC)

[edit] Lost My Indiglo

The electroluminescent backlight on my Oregon Scientific alarm clock/barometer only lights up around the edge. Has the electroluminscence panel reached the end of its working life? How does this happen - it isn't explained in the article. --Username132 (talk) 13:37, 23 May 2006 (UTC)

The glass on the front could have separated from the EL panel. At any rate, I think it's time to get a new...er...thingy...that you've got. --M1ss1ontom a rs2k4 ^{(T | C | @)} 03:56, 25 May 2006 (UTC)

[edit] J.Smith (talk • contribs)

Hello, i am an anonymous role account of another wikipedian, my password is swordfish. please inspect my account to confirm that i am a benign role account and am not hiding anything malicious--J.Smith 13:53, 23 May 2006 (UTC)

User_talk:J.Smith Blocked -Quasipalm 15:12, 23 May 2006 (UTC)

It's a really bad idea to post your password. I suspect that your account will now be used maliciously by those who know your password. StuRat 15:36, 23 May 2006 (UTC)

Pretty much the most malicious thing you can do to an account is post your password. I'm not sure what the purpose of that message was but he's super-banned anyways. freshofftheufo ΓΛĿЌ 16:07, 23 May 2006 (UTC)

[edit] Random Pixel Message

What is it called where you have a page of seemingly random pixels, but if you look at them out of focus you see a message that appears to float half a centimetre above the page. —The preceding unsigned comment was added by Bjwebb (talk • contribs) .

Single Image Random Dot Stereogram? Femto 14:08, 23 May 2006 (UTC)

Or Autostereogram, although the common name is Magic Eye picture -- Ferkelparade π 14:11, 23 May 2006 (UTC)

[edit] personalised google home page

In the case of my yahoo, if I subscribe to a news feed inside my yahoo, both heading and description of news feeds appear. But in the case of personalised google home page, only headlines appear. What should I do for both heading and description to appear?

I think the only way of doing this is to add your feeds to Google Reader then add the Google Reader module to your homepage. Clicking on a headline should pop the item up in a bubble; if it doesn't, click Edit and select "Items open: as bubbles". Matt Eason 14:58, 24 May 2006 (UTC)

[edit] Connecting a single solar cell to a home's power supply

Let's say I bought a single Sharp NT-S5E1U 185 Watt Solar Module solar cell. If I installed this on my roof, is there a way I could plug it into my house electricity system without any construction? What would be awesome is if there is something I could build / buy that would allow me to plug the output of one of these badboys into a regular outlet. Is this possible? I'm renting, so I can't do anything crazy with the power system. -Quasipalm 15:01, 23 May 2006 (UTC)

See distributed generation. I dont think its quite as simple as you imagine 8-|--Light current 15:11, 23 May 2006 (UTC)

After you put is all together, solar power costs about $1 per kilowatt-hour, as opposed to the usual of 4-5 cents. I'm putting a solar light on a detached cottage sauna, just because it is fun, and I don't want to dig a power cable (don't want to zap the porcupines!) --Zeizmic 17:45, 23 May 2006 (UTC)

How does solar power cost anything? Once installed the sun does not charge anything for shining, so where is the cost?

He's using the total cost of ownership i guess, because if for example, for arguments sake, the solar panel cost 1000(currency) to buy/install and in it's lifetime generated 1000kw/h of energy each would effectively cost 1(currency). It's when and only when the total energy generated is worth more than that of the solar panel that the energy really becomes free. -Benbread 18:16, 23 May 2006 (UTC)

Then there's the cost of the batteries because you can't really run your house on solar alone since the sun goes away at dusk. You need to store the energy somewhere. So that increases the cost. And, as far as I know, the batteries have to be replaced after ~20 years. But I'm not certain of that. Dismas|^(talk) 04:42, 24 May 2006 (UTC)

To answer the original question, yes you can - you just need a converter. See [Guerilla Solar]. Rmhermen 00:34, 25 May 2006 (UTC)

Thanks Rmhermen for the answer and others for the thoughtful comments. -Quasipalm 14:55, 26 May 2006 (UTC)

The installation of power-generating equipment that connectes to the utility power grid requires approval and inspection by the local government. Since this is an appartment, the local government almost certainly requires that the work be done by a licensed electrician. If a fire or electrocution occurs in the building, and the equipment to connect a solar cell to the house wiring is found, the tenant of the apartment can expect some intense questioning. Gerry Ashton 15:50, 30 May 2006 (UTC)

[edit] House cat behavior

I know house cats typically bring home "presents" i.e. little dead animals, but I'm wondering if it's typical for cats to eviscerate the animal and then arrange certain organs on the doorstep. I'm not *exactly* sure what the organs are, but it usually looks like the stomach, intestines, heart, liver, and one ear of a baby rabbit. They're all cleanly cut out and more or less undamaged. My cat (well--I suspect; I have no idea what else it could be and never entered my mind that it would be anything other than my cat) does this every other week or so, and rarely will he bring back a whole animal. I've been wondering about this for a while... Thanks for any help!

Category : cats. Category : animal behavior. Category : dissection ? --DLL 18:23, 23 May 2006 (UTC)

that cat sounds like its been infected by satan, that can happen if you let your animal watch too much tv, try and exorcismPeter cotton tail 20:54, 23 May 2006 (UTC)

I second the suggestion from Peter. It might be time to contact some able priests. But for giggle's sake... can you take a picture? Henning 21:03, 23 May 2006 (UTC)

I'm afraid that's quite normal. Each of our two has a favourite place for displaying the corpse, which by the time they've finished usually consists of the back end of a mouse and a little pile of viscera. Henry ^Flower 22:06, 23 May 2006 (UTC)

Your cat is trying to teach you to hunt and eat the prey yourself. He knows you're a slow learner, so he's taking extra care to display the samples in an enticing manner. —Ilmari Karonen (talk) 08:27, 24 May 2006 (UTC)

Is that really true? --Username132 (talk) 18:38, 24 May 2006 (UTC)

I doubt it. Unless Harvestman has a very odd relationship with his mog, he's the daddy and the cat is the baby. Baby displays his hunting prowess to get daddy's approval, but he doesn't try to teach him. Henry ^Flower 19:08, 24 May 2006 (UTC)

I'll try and take a picture next time I see it... I figured I was in for possession jokes, but oh well. It just seems a little bit more calculated then "leftovers"; but perhaps that's all it is.

Leftovers cleverly displayed so as to not look quite like leftovers - a gift for you. --hydnjo talk 18:48, 24 May 2006 (UTC)

I'm having no cats, and the original questioner no signature. DLL.

<-- I've heard two speculations, which are not mutually exclusive. One is the cat instructing the (slow learning) human kitten in what to eat and so on. And the other is the present to the social group leader (the somewhat retarded but clearly dominant human). Both speculations rely on the fact that house cats are solitary in habit, save for family life after kittens are born, so cats treatment of us is somehow fitted into that social structure (however much we don't fit the roles very well at all). How toms's behavior slots in is less than clear, and in any case feral cats do form loose social colonies. As with so much about them, there connection with the rest of the world is a mysterious and fascinating one. Anyone who's every been around a cat who suddenly picks up and races around for a couple of minutes then resumes placid life has that haunting thought that maybe they see and know things we mere two-feet aren't privileged to understand. ww 17:24, 30 May 2006 (UTC)

[edit] Generic blood pressure medicines

I've been on Lisinopril for a while, but my doctor has changed me to diovan because of side effects. He said that there were about five drugs like it. Diovan doesn't have a generic, and the simular drug cozaar doesn't have a generic either. Are there drugs similar to diovan and cozaar that have generic equivalents? Bubba73 (talk), 18:11, 23 May 2006 (UTC)

We are not drs here, ask another one. Economically speaking : maybe doctors get less incentives when prescribing generics. --DLL 18:21, 23 May 2006 (UTC)

Nope, the common incentive to prescribe generics is less paperwork. alteripse 00:39, 24 May 2006 (UTC)

Diovan is an Angiotensin II receptor antagonist. There are many options in that drug category. Not all have generic equivalents (yet). In general, the older ones are less effective, but have generic equivalents. The newer ones are more effective, without generic equivalents. Also, there is a new fad for combo-drugs. So, if you take more than one class of drugs, you might be able to get it all in one pill. --Kainaw ^(talk) 18:34, 23 May 2006 (UTC)

In general, doctors don't get incentives for prescribing any medications. Talk to your doctor or your insurance company about your concerns; if there is a drug with similar effectiveness, he may be able to substitute. However, I don't believe any of the ARBs are yet available in generic form in the United States, though perhaps I am mistaken. — Knowledge Seeker দ 19:45, 23 May 2006 (UTC)

I got the Diovan filled today. It is "preferred" by my insurance comany (along with Cozzar and Hyzaar), but I can't find a generic listed. Bubba73 (talk), 20:03, 23 May 2006 (UTC)

I don't know if doctors get incentives for prescribing particular medications. I hope not. However, even if that's the case, it doesn't mean that they are not influenced by drug companies' marketing efforts. Newer drugs may be more effective (or have data that can be interpreted to make them look more effective), but older drugs have been tried on many, many more "guinea pigs". Once in a while, we have unfortunate experiences like Baycol and Vioxx. So don't automatically assume newer is better.

[edit] Molecular weight profile of a mixture of proteins or peptides

I am interested in determining the range of molecular weights in a solution of partially hydrolyzed protein. Which technique would be more powerful for this application, SDS-PAGE or size exclusion chromatography? I realize that either would work, but I'll bet one would have some advantages. ike9898 18:49, 23 May 2006 (UTC)

I'd go with SDS-PAGE. It has several advantages. You only need a very small sample and when you get the result you can easily determine the weight (if you used a marker). If you use size exclusion chromatography, the size of the proteins in a specific fraction would depend on the flow, the eluent, pH, the conformation of the protein (not all proteins are going to be in the same state) and the gel used. To even get a proper separation would be a lot harder with the chromatography. The few times, I used it, it took ages to determine the optimum conditions. After the proteins have eluded, you still have to determine if they're pure and determine their size. Exclusion chromatography only separates, you wouldn't know the exact weight of the components after separation; only the weight relative to the other proteins. - Mgm|^(talk) 20:24, 23 May 2006 (UTC)
- Is there any sort of lower MW limit for SDS-PAGE separation? If this technique isn't good for separating really small peptides, do you have another suggestion? ike9898 20:38, 23 May 2006 (UTC)
  - You won't see many peptides under 10kDa on SDS Page, if you have small peptides it might be best just to try and sequence the breakdown products with mass spectrometry - the type of mass spec you choose would depend on the amount of sample and the machines you can get access to.--Peta 11:47, 26 May 2006 (UTC)

[edit] Physics question

Dear Wikipedians:

Why do things overwater appear blurry to swimmers underwater? And why wearing pairs of goggles make overwater things clear to the underwater swimmers again?

Thanks!

206.172.66.11 19:28, 23 May 2006 (UTC)

We've had several questions like this quite recently. Are you the same person or is it just coincidence? Anyway, the answer has to do with refractive index. —Keenan Pepper 20:14, 23 May 2006 (UTC)

[edit] wat kind of frog?

what kind of frog do you need in order to make a dinosaur cloned?Peter cotton tail 20:45, 23 May 2006 (UTC)

how do you find the amber? isn't it hard to find? do they ever find cavemen and dinosaurs burried together? could you clone both? did people ever keep dinosaurs as pets like on old TV shows? or were they too hard to domesticate?Peter cotton tail 20:45, 23 May 2006 (UTC)

Jurassic Park is fiction and it will remain that way until there are major advances in genetic engineering. —Keenan Pepper 21:07, 23 May 2006 (UTC)

You would'nt start with a frog, and the answer depends on what species of dinosaur you want to clone. For an avian dinosaur, I'd start with another avian dinosaur. And if you were to get hold of any Triceratops DNA, by definition, any bird will do, but I'd suggest an ostrich. --vibo56 21:45, 23 May 2006 (UTC)

(Non-avian) dinosaurs became extinct 65 million years ago. Homo sapiens did not evolve until a few hundred millennia ago. At the time of the dinosaurs, human ancestors resembled shrews. We therefore would not expect that humans and dinosaurs ever would be found buried together or that humans could keep dinosaurs as pets. — Knowledge Seeker দ 22:46, 23 May 2006 (UTC)

As far as frogs and dinosaurs are concerned, according to the evolutionary trees currently in use, we are more closely related to dinosaurs than frogs are, having at least descended from reptiles (amazingly, we may be more closely related to them than some reptiles such as tortoises). If you were looking for a close relation to dinosaurs to start with, try an ostrich. even then, cloning a dinosaur from an ostrich would be about as likely as cloning a squirrel from a human. Grutness...wha? 03:03, 24 May 2006 (UTC)

[edit] Linux taking advantage of Windoze device drivers

Dear Wikipedians:

What is preventing Linux from taking advantage of Windoze device drivers to access hitherto "impossible" hardware such as Winmodems and Winprinters? (And for that matter, every single hardware device that Windoze can use, which includes all the hardware devices currently on market, and new ones as they come out on the market).

After all, most Linux systems runs on x86, the exact same hardware platform that Windoze runs on. So if Windoze can drive the x86 CPU to talk to all the hardware devices to make them work, why can't Linux do the same thing?

If there is a framework created for Linux that allows it to access all the .dll, .vxd, etc. device files in the same way Windows can, wouldn't that solve the "achilles heel" problem of hardware compatibility of Linux once and for all? Wouldn't such a framework be vastly superior to having to painstakingly reverse-engineer each specific hardware device driver per se, often failing becuause hardware manufacturers refuse to release the specs.

206.172.66.11 20:46, 23 May 2006 (UTC)

There are so many things wrong with this idea I can't possibly list them all.

Though they can both run on the x86 architecture, the designs of the Linux and Windows kernels are so different it's ridiculous to ask that Windows drivers run inside the Linux kernel. To name just one of the incompatibilities, Windows kernel stacks are something like 12k or 16k while Linux kernel stacks have been 8k and there's a big push to move to 4k which would greatly simplify things (because it's one page). That's just begging for disaster.

The Linux kernel makes no promise of binary compatibility. Even native Linux kernel modules can't be run in a kernel compiled with different options, you have to recompile them to be compatible. If you don't even have the source to the driver, you're screwed.

If people become dependent on proprietary drivers, there is no incentive to develop free software drivers and hardware manufactures get the impression that it's "okay" and might even say they "support" Linux because it happens to work with this horrible klugde.

Even if proprietary Windows drivers happen to work in the Linux kernel, they can't be legally distributed together because the licenses are incompatible. This is a big problem for distributors and users alike. —Keenan Pepper 21:04, 23 May 2006 (UTC)

Although I agree with Keenan Pepper that this is not a desirable approach, it is used in certain projects, such as ndiswrapper and Captive ntfs. --vibo56 21:26, 23 May 2006 (UTC)

I agree. 2, 3 and 4 are reasons against proprietary drivers for linux available only as a binary. – b_jonas 19:48, 24 May 2006 (UTC)

[edit] SCM

SCM and trading

i don't know what that means, are you trying to convert me to satanism?Peter cotton tail 21:02, 23 May 2006 (UTC)

Get away from me! *makes cross with hand* ;) --M1ss1ontom a rs2k4 ^{(T | C | @)} 03:52, 25 May 2006 (UTC)

What are you talking about?Yanwen 21:44, 23 May 2006 (UTC)

Supply Chain Management? That would be getting the stages of production and service etc coordinated. 5 Stages: Plan - Source - Make - Deliver - Manage Returns. --Seejyb 21:48, 24 May 2006 (UTC)

Or maybe Software configuration management? --Halcatalyst 00:31, 27 May 2006 (UTC)

[edit] Is it possible to see clearly underwater by wearing spectacles instead of goggles?

Inspired by the preceding question, as well as this one and this one: The reason we do not see clearly underwater is that the refractive index of the cornea is almost equal to that of the surrounding water, so that we lose the refraction at the interface between air and cornea. Is it possible to correct this by wearing spectacles underwater, (i.e. with water between the lenses and the eyes)? It would be kinda nice, goggles tend to get foggy... And if it indeed is possible, what lens strength would you need? --vibo56 21:07, 23 May 2006 (UTC)

http://www.liquivision.ca/fluidgogglesfeatures.html —Keenan Pepper 21:12, 23 May 2006 (UTC)

Thanks, gotta get one of those... --vibo56 21:49, 23 May 2006 (UTC)

Thanks a trrrrrrrrrrrrrrrrrrrrrrrrrrrillion, that was the EXACT answer I was looking for 206.172.66.172 00:10, 24 May 2006 (UTC)

Or you could just get some defog for your SCUBA mask. There are commercial preparations, or you can use a dish soap solution, or your own saliva. They all work. And you can even get a prescription in your mask. --Ginkgo100 23:59, 24 May 2006 (UTC)

[edit] Leukocytes

In my book, basophils and macrophage come under the same heading, but esinophils come under their own - why don't they all come under the same, being granulocytes? --Username132 (talk) 23:01, 23 May 2006 (UTC)

Under what heading do basophils and macrophages fall? — Knowledge Seeker দ 23:06, 23 May 2006 (UTC)

Macrophages are not granulocytes. Strictly, they're not even leukocytes. They are derived from monocytes, which are leukocytes, but not granulocytes. Granulocytes come in three varieties, neutrophils, eosinophils and basophils. Macrophages might reasonably be grouped with mast cells, both being tissue cells. And mast cells have been thought to be derived from basophils (although I'm not sure if this still is considered to be correct). See mast cell. --vibo56 23:47, 23 May 2006 (UTC)

[edit] Ivy cuttings

Can Ivy be grown from cuttings?

Some kid pulled off a bunch of ivy from my walls and I'm trying to repair the damage - is there anything I can do short of waiting till fall and planting the berries? 71.199.123.24 23:31, 23 May 2006 (UTC)

Dont do anything. Ivy grows so quickly that before you can turn around, it'll be all over the place again! 8-)--Light current 23:52, 23 May 2006 (UTC)

This is the only way I've ever propagated ivy, I've never seen someone plant berries/seeds: Take end shoots, 4 nodes (sets of leaves) long. Strip off bottom 2 sets and lay them in potting soil, at 30 degrees to level, as you would vine cuttings. You can lay quite a lot of cuttings next to each other in a trench or long plant container. 2 sets of leaves stick out, two nodes covered. No roting pwder needed. Keep well watered (or cover with plastic), but not standing in water. Within 2-3 weeks you'll have roots forming between the buried nodes (other plant form roots at the nodes). If you have to "test", a very gentle tug reveals that they are starting to cling inside the soil = rooting) and at 4-6 weeks you can plant them out. As Light current said, if the original ivy has not been completely rooted out, it grows back in 2-3 weeks as a field of light green new shoots and leaves, and no need for making new plantings. Water the area where the remnant stems and roots are. One can use the time to clean the wall of dead tendrils, stalks and dirt, and fix unwanted holes or cracks the ivy may have exploited. --Seejyb 21:13, 24 May 2006 (UTC)

[edit] Ducklings...

What is it, specifically in the brain/psyche that that causes humans to find ducklings cute? I have never met a single person who doesn't go 'AWWWWW!' when they see/hold a duckling. There must be an evolutionary reason why seeing one triggers that response in us. Thanks.

Same thing that causes women to do the same thing when they see babies!--Light current 00:29, 24 May 2006 (UTC)

That does sound familiar now I think about it. There was an article years and years ago in something like New Scientist magazine that suggested a link between the way that people perceive human babies and the way they perceive ducklings. Apparently there is some instinct that their apperance triggers in us. Anyone have any more info? --84.68.240.254 00:49, 24 May 2006 (UTC)

Looking up "Kindchenschema" in the German WP (horrible stub, btw) yields an interwiki link to Cuteness, which has some pointers. --212.202.184.238 01:17, 24 May 2006 (UTC)

See neoteny for the features that comprise "cuteness". alteripse 02:42, 24 May 2006 (UTC)

It's because ducks resemble platypuses. And everyone loves those. :) --BluePlatypus 17:29, 24 May 2006 (UTC)

Mmmmm, platypus. Tastes like chicken! --LarryMac 17:37, 24 May 2006 (UTC)

It's called the "cute response" (refer to Biology, by Campbell, Reese, and that other guy). It's built-in so we don't eat our babies. --M1ss1ontom a rs2k4 ^{(T | C | @)} 03:51, 25 May 2006 (UTC)

[edit] "Tastes like chicken..."

Why do so many "non-standard" meats (e.g. cat, dog, rat, snake, etc.) supposedly 'taste like chicken', anyway? --84.68.240.254 23:54, 23 May 2006 (UTC)

Because they all taste foul (fowl)? 8-))--Light current 00:16, 24 May 2006 (UTC)

I doubt it's based on the actual flavor, I think it started as some sort of joke. For etymology, the Language desk is the best choice. Black Carrot 01:41, 24 May 2006 (UTC)

I agree that it's kind of a joke, possibly from the observed flavour of frogs legs, which do taste rather similar to chicken. I also remember there being some kind of reference to this in The Matrix. freshofftheufo ΓΛĿЌ 05:51, 24 May 2006 (UTC)

There's actually a (non-helpful) stub about this: Tastes like chicken. —Zero Gravitas 06:09, 24 May 2006 (UTC)

Well, it's certainly a meme today. Although my personal theory is that it's due to the fact that compared to the other meats we tend to eat (beef/mutton/pork), chicken has a relatively low-key taste. Depending on how it's prepared, the chicken flavor can at times disappear almost completely. So I always assumed that by "tastes like chicken", they meant a kind of nonintense flavor. Which figures - if something did have an intense flavor they wouldn't describe it as tasting like something else to begin with. --BluePlatypus 06:14, 24 May 2006 (UTC)

I have it on reasonably good authority that cat tastes more like rabbit than chicken. --Kurt Shaped Box 06:26, 24 May 2006 (UTC)

Ah, that's nice. I've recently eaten a very delicious rabbit meal (rabbit stuffed with stuffed dove actually). I'll have to try cats than, as they're easy to aqquire :). – b_jonas 19:43, 24 May 2006 (UTC)

Mrs. Mooney has a pie shop

Does a business, but I've noticed something weird

Lately all the neighbors' cats have disappeared

'Ave to hand it to her:

What I calls

Enterprise

Poppin' pussies into pies.

Wouldn't do in my shop

Just the thought of it's enough to make you sick

And I'm tellin' you them pussy cats is quick... - (in the words of the bard) - Nunh-huh 00:14, 26 May 2006 (UTC)

I think it was supposed to convince fussy eaters to eat something a little more adventurous. If it tastes like something they know (chicken), they're more likely to try it. Unfortunately, I can't back any of this up. - Mgm|^(talk) 08:28, 24 May 2006 (UTC)

I though thar rabbit was supposed to taste like chicken 8-) - never (knowingly) had it. --Light current 14:56, 24 May 2006 (UTC)

The rabbit I tried recently did in fact taste like chicken at first bite, but then turned out to have a much more "wild" flavor. Me gusta. --NoahElhardt 20:46, 24 May 2006 (UTC)

The frog I tried recently tasted a bit like chicken, but the fibers were skinnier, so the meat was smoother. --M1ss1ontom a rs2k4 ^{(T | C | @)} 03:50, 25 May 2006 (UTC)

On a scientific basis, its probably due to the similar myoglobin content of chicken, and whatever tastes like chicken, and the low level of collagen (compared to red meats).--Eh-Steve 16:16, 25 May 2006 (UTC)

Well, I recently tried kangaroo meat, and it tasted more like cow. Different texture, I mean, different tactile sensation, but the taste was similar to bovine meat. Cthulhu.mythos 11:08, 26 May 2006 (UTC)

If everything tastes like chicken, what does chicken taste like? TheMadBaron 19:25, 28 May 2006 (UTC)

Only cannibals know for sure. B00P 22:18, 7 August 2006 (UTC)

[edit] May 24

[edit] Atmospheric gas spectrographic image

Is there an online site where you can view a composite spectrographic image of the gases in the Earth's atmosphere? -- PCE 00:23, 24 May 2006 (UTC)

[edit] Computer processing question

I am looking for a processor / server that can process a 4 Gbps serial input stream, decommute the data by reading the headers, strip out packets, and rout the data to different IP address.

Thanks

Good luck!--Light current 00:27, 24 May 2006 (UTC)

The Cell processor. From all the hype, it can do anything! You might have to wait a while, though. --Zeizmic 01:55, 24 May 2006 (UTC)

I know far more about the cell than I care to (one of the three guys whose name appears on the patent application is an almnunus of my research group; my research group is getting one of the first ones shipped to the US). For hardcore signal processing and routing, it has good potential. For pretty much anything else - especially anything complicated to program - it's a nonstarter. Raul654 02:11, 24 May 2006 (UTC)

You may be able to find a specialized router that can do this. – b_jonas 19:38, 24 May 2006 (UTC)

It may not be quite right, but they specialize in this sort of high rate processing. Try looking into a Digital Signal Processor. Lots of software design and development probable though. Might not be worth it. You might consider throwing more than one machine at it. The really high speed processor will then only need to steer the input stream alternately. ww 20:52, 31 May 2006 (UTC)

[edit] Flower Names

Please provide me with the English names of any of the following nine flowers. I have also posted them on my user page; you can also go there and edit the page.

Flower1;dandelion (I don't think it is. It looks more like those flowers they dry and stick wire in)	Flower2;daisy	Flower3;carnation (Dianthus caryophyllus)	Flower4;snap dragon
Flower5;carnation (Dianthus caryophyllus)	Flower6; some kind of Limonium spp. (aka "Sea lavender" or "statice")	Flower7	Flower8; Alstroemeria (Peruvian lily)
Flower9;Queen Anne's Lace

Patchouli 00:38, 24 May 2006 (UTC)

How about a hint like UK, US, Canada, Europe, etc? alteripse 00:47, 24 May 2006 (UTC)

I live in southern California, United States.Patchouli 01:21, 24 May 2006 (UTC)

I'm no flower expert but my thoughts might narrow down your search for you... Flower 1 looks like a Dandelion but I can't really tell for sure from the picture. 3 & 5 appear to both be Carnations. 4 is either some sort of orchid or snap dragon. Probably an orchid though. And 9 looks like Queen Anne's Lace. Dismas|^(talk) 04:32, 24 May 2006 (UTC)

2 looks like a daisy, no? #1 could also be a daisy. (The leaf, rather than the flower, would allow us to decide dandelion vs daisy). - Nunh-huh 06:40, 24 May 2006 (UTC)

1 and 2 look like Gerber Daisies, while 4 is definitely a Snapdragon. Nrets 15:07, 24 May 2006 (UTC)

Flower 1 and flower 2 are extremely similar. Flower 1 has a series of shorter petals surrounding the stamen in addition to the larger petals whereas flower 2 doesn't.Patchouli 15:49, 24 May 2006 (UTC)

Flower 1 appears to be a yellow composite (a very large group of similar flowers). You'd need more information than just the blossom (such as leaf shape, details of the flower, possibly the root type) to narrow it down any further. --Serie 20:07, 24 May 2006 (UTC)

I agree on 3, 4(def not an orchid), & 5. I've labeled 6 and 8 - not sure on #7. Could #9 also be just a carrot flower? --NoahElhardt 20:55, 24 May 2006 (UTC)

Wikipedia has no entry for carrot flower. Maybe you mean wild carrot which is the same as Queen Anne's lace.Patchouli 21:58, 24 May 2006 (UTC)

I meant domestic carrot. Your normal everyday garden carrot. (or just plain carrot if you will) That's the flower. Maybe. But Queen Anne's lace is very closely related, and if you found it growing wild than that is probably what it is. --NoahElhardt 03:03, 25 May 2006 (UTC)

Flower 1 is an actual flower. I bought it and is now in a vase with water. It may look artificial because I used my flatbed scanner to get its picture because I don't own a digital camera.Patchouli 01:12, 26 May 2006 (UTC)

[edit] regrowing limbs

Please correct me if I'm mistaking, but I'm pretty sure the human body esentially is totally new after some months because all the cells have been replaced. Is that right? So why can't a person regrow their arm, leg, etc. after they are chopped/bitten/sliced/vaporized off? schyler 01:50, 24 May 2006 (UTC)

See Stem cells at a guess! 8-)--Light current 02:11, 24 May 2006 (UTC)

I know I kind of stuck it on the end, but I wanted to know why stem cells can't regrow entire limbs. schyler 02:39, 24 May 2006 (UTC)

Because there are certain genes that only operate at very early embryonic stages and these are especially the ones that produce limbs (see HOX genes). alteripse 02:40, 24 May 2006 (UTC)

"The liver is among the few internal human organs capable of natural regeneration of lost tissue; as little as 25% of remaining liver can regenerate into a whole liver again." from Liver. I always thought that was pretty amazing. - R_Lee_E

(talk, contribs) 02:53, 24 May 2006 (UTC)

The fact that the liver can regenerate seems to indicate that regeneration was common in the early stages of evolution and a trait that was retained due to the ever present need for its retention due to cell destruction as the result of bad stuff our ancestors ate (like Cashew husks and Avocado something) - just like some lizards have retained the ability to regenerate tails most likely due to the ever present consumption of tails by less than stealthy predators. But I speculate and know nothing absolutely for sure. -- PCE 07:18, 24 May 2006 (UTC)

I can't find the exact journal in which I was reading about the recent studies to find ways to do exactly that, but certainly scientists are working on it. A simple Google seach comes up wiith these recent stories: NYT: Missing Limb? Salamander May Have Answer, Wired News: Lost Limb? Worm May Hold Answers, Guardian: £10m to study how to regrow damaged limbs, etc etc. People are working quite hard on this. — Asbestos | Talk (RFC) 13:59, 24 May 2006 (UTC)

I believe that Schyler is indeed mistaken in saying "the human body esentially is totally new after some months because all the cells have been replaced". As I understand it, cells are replaced at different rates. We get a new stomach lining every 24 hours, but a new skeleton takes seven years. Brain cells are not replaced. IANAMD. TheMadBaron 19:38, 28 May 2006 (UTC)

[edit] Numbered lists in word

Earlier this month, I asked ( http://en.wikipedia.org/wiki/Wikipedia:Reference_desk_archive/Science/May_2006#Numbered_lists_in_Word ) about numbered lists in microsoft word and how to get them autonumbered when I want them autonumbered but otherwise left alone by word.

I think I have found a solution to this problem: Turn "Autonumber as you type" off; select the text you want numbered and use "Format | bullets and numbereing"; Selectthe newly numbered text and copy it to the clipboard; paste it into Wordpad; Copy it to the clipboard from wordpad; Paste back into Word.

This appears to give the desired numbered text where the numbers are part of the text rather than Word magic. -- SGBailey 08:06, 24 May 2006 (UTC)

Remember that good technology is undistinguishable from magic. This "word2text" method is OK, I use it to save summaries. Word allows shifting between tables and tabulated text. Maybe a macro could produce the same ? --DLL 12:07, 25 May 2006 (UTC)

A macro would definitely do it, but you can also just save the whole file as a .txt file, close it, and when the file opens, the numbers will be plain text.--Anchoress 12:20, 25 May 2006 (UTC)

[edit] Area on sphere

how do one find the area of a square drawn on a sphere?

Simple answer, you cant, a square is 2D and a sphere is 3D, so you can not draw a square on a sphere. Stefan 09:38, 24 May 2006 (UTC)

It might be better to say that a sphere is a surface (a two dimensional Riemannian manifold) with constant positive curvature, while the plane is a surface (two dimensional manifold) with constant zero curvature. ---CH 10:03, 24 May 2006 (UTC)

Well there's a way to do triangles (it's in my friends multivariable calculus book), but I dunno about squares. --M1ss1ontom a rs2k4 ^{(T | C | @)} 03:48, 25 May 2006 (UTC)

as in an object with 4 sides, and their interior angle does not add up to 360 degrees. HOw do you find the area?

See Theorema egregium. ---CH 10:03, 24 May 2006 (UTC)

If you are asking how to find the area of some shape on a sphere, then perhaps we can give you a helpful answer - but in order to do so, you have todefine the shape 'exactly'. For example we could start analysing the area of a square projected onto the surface of a sphere. This isn't a square, it has curved edges. So back to you... -- SGBailey 10:25, 24 May 2006 (UTC)

BTW, did you know that an equilateral "triangle" on a sphere touching the points lat=0,long=0; lat=0,long=90; lat=90,long=any has three 90 degree corners and has an area of 1/8 of the sphere? -- SGBailey 10:25, 24 May 2006 (UTC)

You will have to express the sides of the "square" mathmatically to determine the boundaries of the double integral that will give you the area. You will probably want to solve it in spherical coordinates. You are going to have to know some calculus for this one. --Swift 11:11, 24 May 2006 (UTC)

actually, the whole thing goes like this, i am tryin' the find the area of this...

A square with the side of 10 cm, and draw loci (10cm) on each corners (quarter of a circle in a square to give the "square")

This is NOT a homework question, i just want a head start of what to do. If you do not understand what i said, tell me and i'll create an image from Paint. many thanks!

I do not understand! OK one more 'simple' answer to your to 'simple' question, between a very very very small bit more than 100 square cm to about maybe 200 square cm.

A little bit more complicated answer, as I see it this can not be answered with the data you have given, the answer depends on the radius of the sphere. If the radius of the sphere is 'close' to infinity the area will be very close to 100 square cm, if the radius of the sphere is as small as it can be (I think sqrt(50)) before the sphere 'fall' through the square it will be around maybe 150-200 square cm. But again you do not want 'simple' answers, to get a real answer you need to give more info. I guess what you want is not a answer, but a formula f(r,s)=..... where r is the radius of the sphere and s is the side of the 'square' and the result is the area of the 'square'. But sorry I will not even try to do that math. :-) (maybe I should learn wikipedia math symbols instead ....) Stefan 14:33, 24 May 2006 (UTC)

According to Square (geometry), a hemispere would be a valid "squareon a sphere" with side length = 0.25*sphere circumference and area=0.5*sphere area. Indeed presumably a hemisphere is an instance of every regular polygon with the same area and side length = 1/N * circumference. I note that this is a "valid" (?) 2 sided polygon and even a valid (?) one sided polygon! -- SGBailey 16:12, 24 May 2006 (UTC)

I don't get this. Perhaps drawing that picture would help clear things up. --Swift 08:33, 25 May 2006 (UTC)

Is this about spherical geometry?Yanwen 20:58, 24 May 2006 (UTC)

Excuse me if I'm missing something obvious here, but M1ss1ontomars2k4 says: Well there's a way to do triangles (it's in my friends multivariable calculus book), but I dunno about squares. So, find the area of a right-angled triangle (or sphere-surfaced equivalent) with shorter sides both length 10cm, and double it. Grutness...wha? 05:46, 25 May 2006 (UTC)

Grutness, You are missing something. On a sphere triangles etc don't scale like that. -- SGBailey 11:59, 25 May 2006 (UTC)

Yes user:grutness is sort of right - but what is missing is the radius of the sphere otherwise answers will have to be expressed as a function of radius. Take the solid angle created by half the 'square' ie a spherical triangle - double it and multiply by r squared to get the surface area. Spherical trigonometry may help as will solid angle - see continued talk below Wikipedia:Reference desk/Science#(continued) Area on a sphereHappyVR 16:42, 27 May 2006 (UTC)

I have posted a follow-up in the maths section. --vibo56 14:33, 28 May 2006 (UTC)

[edit] Microsoft IRC?

Is there a IRC channel related to Microsoft? Computerjoe 's talk 15:04, 24 May 2006 (UTC)

When I was an IRCer, I remember a few channels on efnet.net along the lines of #fuckbillgates. freshofftheufo ΓΛĿЌ 05:13, 25 May 2006 (UTC)

[edit] Lifespan of safety razor: affected by length of hair/stubble shaved?

I feel like this is a silly question, but I really can't find an answer anywhere else. I shave my head, which is a great thing except that I go through a LOT of razor cartridges (I use the HeadBlade, BTW). Recently, I've been wondering if it causes more "wear" on a safety razor cartridge to cut longer hair than shorter hair... in other words, would I double the lifespan of a safety razor by shaving only every second day, or is two-day growth "twice as hard" on a razor as one-day growth?

I acknowledge that this is a bit of an odd question, but I'm genuinely stumped. There are a few factors here, like whether hair starts thin and thickens as it grows, and whether razors "slice through" or "cut along" the hair, which at a level this small I'm not sure about. --MattShepherd 15:34, 24 May 2006 (UTC)

Why not shave only once every 2 days. Then your blades would last at least twice as long! 8-)--Light current 16:37, 24 May 2006 (UTC)

That's exactly what I'm asking. Does cutting two-day growth cause exactly as much wear on the blade as cutting one-day growth? Or does the larger/thicker mass of hair negate any two-day shaving advantage?

Yes probably- maybe less because you dont have to go over it as much! But since youre only doing it every 2 days, your blades last twice as long! My theory, based on face shaving, is that, with longer hairs, they have more inertia and cant get out of the way of the blade quickly. Therfore, they are cut on the first pass. Shorter hairs whilst being stiffer, are harder to cut.--Light current 00:57, 25 May 2006 (UTC)

Dunno. You could find out the scientific way- perform a controlled experiment comparing the lifespans of your razors under different conditions. Black Carrot 20:21, 24 May 2006 (UTC)

I notice you're the same person who asked about the sheep powered lawn mower, so my suggestion, stop trying to sheer your lawnmower with a disposable razor--64.12.116.74 20:56, 24 May 2006 (UTC)

Or teach your sheep to graze on your beard. alteripse 23:26, 24 May 2006 (UTC)

[edit] Extremely thin teacher

Hello. I'm curious about a good teacher I have at university whose extreme thinness makes him look likes his starving, the most impressive part is his face where the skull shape can be seen perfectly, the same applies to the backbones: they can be seen through a woollen jersey. I'm pretty sure he's not an anorexic nor has Taenia solium. Somebody pointed out that there was an illness that didn't allow the victim to regenerate tissues... Any ideas? Thanks in advance. --GTubio 15:44, 24 May 2006 (UTC)

He may be an alcoholic -- or possibly have over active thyroid. You dont say how he moves fast or slow? 8-(--Light current 16:34, 24 May 2006 (UTC)

Also see cachexia, weight loss, and wasting. - Cybergoth 20:35, 24 May 2006 (UTC)

Or, you know, he may just be a Pod Person, happens all the time--64.12.116.74 21:00, 24 May 2006 (UTC)

Or he may simply have one of the forms of congenital or acquired lipodystrophy, conditions in which body fat is absent from parts or all of the body. alteripse 23:25, 24 May 2006 (UTC)

Thanks for the answers. The weight loss he has includes, in the same fashion starving people experience, both muscle and fat loss. His behaviour is absolutely normal and apparently healthy, so I guess the most likely possibility is that something is causing cachexia. --GTubio 15:30, 31 May 2006 (UTC)

[edit] Geometrical construction

Thinking about the "area on sphere" discussion a couple of points above here, Are there articles in wikipedia detailing how to construct various shapes using ruler and compasses? -- SGBailey 16:08, 24 May 2006 (UTC)

The oddly-named Compass and straightedge article is probably ther closest to what you're looking for, found at the Construction disambiguation. There wouldn't be a set of many methods of construction, however, as Wikipedia is not a how-to book. Perhaps someone could create one on Wikibooks? — Asbestos | Talk (RFC) 16:38, 24 May 2006 (UTC)

[edit] Etching PCBs

Is it possible to etch PCBs in a solution of copper sulphate (say) or other electrolyte by using a sort of reverse electroplating method? If so, why, apparently, is it not used?--Light current 16:24, 24 May 2006 (UTC)

There is such a thing as electrolytic etching. But I do not think it's useful for PCBs. You'll get an oxide layer on the surface, which eventually will become passivated. So it won't remove material from the suface, and probably won't break the conduction. With the opposite process, you're starting with copper sulphate in solution, and on reduction, the copper becomes solid. However, when you oxidize the copper in water, the most immediately available reductant is the water protons. So you form hydrogen gas and copper oxides, which are not soluble. --BluePlatypus 17:26, 24 May 2006 (UTC)

Does galv-etch look like that? I used to do PCBs with good ol' FeCl3 — it's been many years but I remember the smell like it was yesterday :-) Weregerbil 17:36, 24 May 2006 (UTC)

My idea is to try to avoid FeCl3 etc. Wondered if electro -etching would do it! Doesn't the copper metal just dissolve in the copper sulphate solution, and copper ions from solution get plated out onto the other electrode? I cant see the reaction to give CuO. Cany anyone write the equations?--Light current 14:06, 25 May 2006 (UTC)

I can't see electro-etching working very well. The problem i see is as you remove more copper the connections to the remaining copper will get worse and worse and the etching process will get more and more uneven. Plugwash 14:08, 25 May 2006 (UTC)

Yes I agree with that. But its a question of how thin it would go. Also, You might need multiple electrical contacts (or plating links) on the board being etched. THen it may just be a matter of a 'quick rub down' with emery to get the last bits off! What think you? Is it worth a try? 8-)--Light current 14:13, 25 May 2006 (UTC)

First half reaction: Cu(s) --> Cu²⁺ + 2e^-

Second half reaction: 2 H₂O + 2 e^- --> H₂ + 2 OH^-

Total reaction: Cu(s) + H₂O --> Cu(OH)₂(s) + H₂(g)

The copper hydroxide can then be further reduced to CuO, depending on the voltage, etc. Copper hydroxide won't normally be soluble. And the reaction does not occur in the solution, it occurs at the coper surface. Copper metal does not dissolve. --BluePlatypus 16:26, 25 May 2006 (UTC)

Since it doesn't seem you're convinced by what I've told you, maybe you should try it out and see for yourself what happens. --BluePlatypus 16:31, 25 May 2006 (UTC)

I dont know much about(electro) chemistry but I was intrigued by the 'Galv etch' page [10] which implies it can be done!

Aha! Ive found the answer! It can be done and with CuSO4.5H20 plus a spot of suphuric and a pinch of salt! [11] So it appears Weird Gerbil was correct after all! THanks WG 8-))--Light current 17:36, 29 May 2006 (UTC)

[edit] raw egg peeler

what chemical reaction will the egg and a vinegar have?

Eggshell is mostly calcium carbonate and vinegar is a solution of acetic acid. That's all you need to know. —Keenan Pepper 18:31, 24 May 2006 (UTC)

The CaCO₃ and vinegar will react to produce CO₂. --M1ss1ontom a rs2k4 ^{(T | C | @)} 03:34, 25 May 2006 (UTC)

Also calcium phosphate (similar to apatite)--Eh-Steve 15:56, 25 May 2006 (UTC)

But it won't taste very good (despite the homophone). JackofOz 09:33, 26 May 2006 (UTC)

[edit] Biologists/Catfish/Plecs/Omega eye

Hi. I'm currently in the process of creating a page for 'Omega eye' or 'Omega iris' - I haven't created it yet it's in the planning stage. It should be a short article just explaining the term plus references. I have all the info I need except:

Does the 'omega iris' structure occur in other animals than suckermouth catfish?
and
Amongst catfish is this iris structure confined to the family Loricariidae ?

Thanks.HappyVR 18:21, 24 May 2006 (UTC)

I don't kow what exactly an omega iris in catfish looks like, but goats and sheep have irises which look like thetas. ;-) --Fastfission 19:10, 24 May 2006 (UTC)

Yes, thanks - it really does give a lasting impression of a theta -(wonder if there are any other animal eye/greek letter combos that people know about) - I noticed that in one of the pictures supplied the top of the iris is flattened from a circular (human eye) shape - the situation in catfish is similar but more pronounced - the flat part becomes a loop that actually occludes the center of the eye - giving a transparent part that is banana shaped (more like one of those c shaped sausages) - I have found some examples :

http://www.scotcat.com/scotshop/amazon/bristlenose.gif From a book cover - note the black part is transparent - the 'circle' in the center is not a reflection effect.

http://maxstrandberg.com/freshwater/catfish/bristlenose_male.htm ancistrus species

http://maxstrandberg.com/freshwater/catfish/gibbiceps.htm gibbeceps species (now renamed?) the 'loop' is slightly larger in this picture than the one above - it can get a bit bigger still and block out more light.

http://maxstrandberg.com/freshwater/catfish/starlight.htm ancistrus again same structure

http://www.malawicichlidhomepage.com/other/panaque_nigrolineatus_l190.htm lots of panaque species.

If anyone has answers (of related info) please help.HappyVR 20:08, 25 May 2006 (UTC)

[edit] Another Javascript question...

So far my javascript questions have gotten very quick and prompt answers here, for which I am quite grateful. Here's one more...

I'd like to know if it is possible to use Javascript to simply read from a different webpage URL. That is, I'd like a function which could read the contents of a web page, or something along these lines, and then, say, insert it into a form element on the page which is holding the code.

I can do everything except read the page. One way I tried was to try and have the script create a new window with a URL, grab the document elements from that new window, and close the window. It didn't work -- I couldn't grab the document elements, it kept saying they had no properties.

I don't know if this is a DOM issue or a scoping issue or what -- it seems like something Javascript should be able to do via the browser, but I haven't found a way to do it yet. Googling and browsing the Javascript manual turned up no likely candidates. Is it possible, or does it require some sort of bulky applet? --Fastfission 19:06, 24 May 2006 (UTC)

For security reasons, Javascript is not allowed to read data from another site. If it is from the same site, you can open the new page in a frame or window and view the innerHtml of the document object (or the document.body object). --Kainaw ^(talk) 23:07, 24 May 2006 (UTC)

You can also use XMLHttpRequest, the technology underlying AJAX. EdC 23:37, 24 May 2006 (UTC)

OK -- innerHTML seems to do at least some of the work I want, though some tinkering will still be needed to make this work right. Thanks! --Fastfission 01:58, 25 May 2006 (UTC)

[edit] PLANTS

Hello,

I would like to know if plants release carbon dioxide at night.

Thankyou

Yes. --Ginkgo100 00:12, 25 May 2006 (UTC)

Why? —

The Mac Davis] ⌇☢ ญƛ. 05:01, 25 May 2006 (UTC)

Take a look at the image of plant cell structure. Plant cells have mitochondria, which consume O₂ and produce CO₂. They also have chloroplasts, which consume CO₂ and produce O₂. In the daytime, activity of the chloroplasts outbalances the activity of the mitochondria. At night, it's the other way around. --vibo56 10:13, 25 May 2006 (UTC)

It's been a while since I had AP Bio, but it seemed like there was a certain type of plant that was backwards. I can't remember if it was C3, C4, or CAM.--SeizureDog 06:54, 31 May 2006 (UTC)

Yeah, you are thinking of CAM plants, which are similar to C4 plants. CO₂ is taken in at night when stomata are open and "stored" for later use during the day. -postglock 07:25, 31 May 2006 (UTC)

[edit] Journal paper with a one-word abstract

Years ago I read about a research paper with a one-word abstract. I don't recall what the paper was about, but it seems to be either a math or physics paper. The title of the paper poses a question and the abstract answers it in the negative with "no."

I assume the paper was not made up, but I don't really know. Does anyone know of a paper like that?

Doesn't sound familiar, but it does remind me of the paper "Electron Band Structure in Germanium, My Ass" (Google will give many results for this). Confusing Manifestation 01:02, 25 May 2006 (UTC)

Hajdukovi´c, D., and H. Satz, 1992, "Does the one-dimensional Ising model show intermittency?," preprint CERNTH-.6674/92 and BI-TP 92/43. [12]

How about the Philosophy professor that asked "Why?" and was handed a paper that answered "Why not?". freshofftheufo ΓΛĿЌ 05:06, 25 May 2006 (UTC)

[edit] five a day

with all this stuff goign round that we need to eat heathly and that we should eat 5 fruit or veg a day but why can u only count fruiut juice once, no matter how much u drink?

I'm no expert, but I think that variety of fruit and veg is just as important as quantity. And it doesn't just affect juice - you can't eat 35 apples a week and count that as five a day either. Not only does your body need a bit of everything, but also there exist interactions between different components of nutrition - i.e. Nutrient A helps you get the most out of Nutrient B. I believe an example of this is you need Vit C to help you get the most out of iron. Also the thing with fruit juice is that for all the smoothies which are just untreated fruit, there's the Sunny D's of this world, which you wouldn't want to overdose on. --The Gold Miner 21:05, 24 May 2006 (UTC)

True enough about hte Vit C and Iron connection. But it's more than a little dnagerous in an era in which iron pots and pans (and extra strength vitamins) supply nmore iron than our ancestors used to see. Check out Hemochromatosis for the reaosn childrens' vitaimns are required to carry a warning label. Iron poisoning is sneaky, really really rotten, and only partially treatable. ww 20:59, 31 May 2006 (UTC)

It's not true that you just count fruit juice once; 8 ounces of fruit or vegetable juice = 1 serving.--Anchoress 21:08, 24 May 2006 (UTC)

That is normally correct, but sometimes liquids don't count. Studies on fruit/vegetable intake are commonly skewed by the idiocy of the participants. So, they are very particular about items that count. They try to limit liquids. Luckily, I work on hypertension studies, but I work with people who do the dietary studies. They constantly have the following scenario: "How many fruits did you have today?" "Three." "And what where they?" "A cherry coke, an orange soda, and a pack of grape gum." "How about vegetables?" "Two." "What were they?" "Ketchup and mustard." --Kainaw ^(talk) 23:04, 24 May 2006 (UTC)

Pfft. Everybody knows that ketchup is made from fruits.

Yeak well, the Reagan Administration didn't. They famously were going to classify it as a vegetable for school lunch dietetic purposes. And this despite its high sugar content. C P Snow's observation about Two Cultures is more apt than ever, yet some of the science innocent think it a virtue, they being better informed on such subjects from other sources. H L Mencken was right about it being impossibl eto underestimate... ww 21:04, 31 May 2006 (UTC)

The other problem with fruit juice is that it is often sweetened and extended with high fructose corn syrup derivatives, and you are getting the same wonderful health benefits as if you ate spoonfuls of sugar from the sugar bowl. Much "fruit juice" should simply be labeled "Sugar Water". alteripse 23:23, 24 May 2006 (UTC)

A disadvantage of fruit juice is that it contains no fiber, unlike actual fruits and vegetables. And without fiber, you would be very, very uncomfortable (and at risk for colon cancer). --Ginkgo100 00:11, 25 May 2006 (UTC)

I guess it depends on where you're from, but where I live, a beverage cannot be labelled 'fruit juice' if it contains *anything* other than fruit juice. It has to have another name, like fruit beverage or fruit cocktail. Of course, this can escape the notice of people who either don't want to give up their Tang, or don't know any better, but we're not talking about the relative stupidity of people, we're talking about what qualifies as part of RDI for fruit/veg. Also, the RDI for fruit/veg is for the phytochemicals and other nutrients, not for the fibre (lettuce and watermelon contain almost no fibre either), and while some nutritionists make a point of suggesting that a person's entire intake of fruit/veg not be juice, most places that list guidelines for RDI do not place juice on a lower rung of acceptability than other forms.--Anchoress 00:18, 25 May 2006 (UTC) Addendum I guess I should add though that if the person is diabetic or borderline, fruit juice probably *would* be discouraged because of its effect on blood sugar.--Anchoress 00:39, 25 May 2006 (UTC)

I am not sure where Anchoress is, but if you read labels closely in the US, you find that "100% fruit" drinks have a small amount of flavoring fruit and a large amount of either grape juice or apple juice. Both of these are very high in sugar and relatively low in all the things that other forms of fruits and vegetables supply. alteripse 14:02, 25 May 2006 (UTC)

Or pear juice. That's a popular natural juice sweetner with less nutritional value. — Laura Scudder ☎ 14:19, 25 May 2006 (UTC)

Maybe Anchoress is in Britain. Over here, 'Fruit Juice' will be apple juice, orange juice, tomato juice, grapefruit juice, grape juice, but no sweetener. Other things are 'Juice drinks' or 'squash' depending on the juice concentration. Interesing though; are you saying apple juice is less nutritionally useful than other juices? I tend to consume a lot of appley goodness. When I'm ill it tastes funny and makes me better, perhaps. Hmm, research for me. Skittle 22:32, 25 May 2006 (UTC)

I think apple juice is essentially sugar water. Apples themselves are good because they provide fiber, but not a lot else. I'd expect the healthiest juice, if you've got to choose one, is tomato, for its low sugar and high carotenoid content, but what you buy in the store tends to be loaded up with a lot of salt, so depending on your blood pressure and salt sensitivity that might have to be balanced into the equation. --Trovatore 22:55, 25 May 2006 (UTC)

[edit] Schwassman-Wachmann

What's the danger that the comet/asteroid pieces of Schwassman-Wachmann will hit the Earth tomorrow? Is there reason for concern or is it just another one of overblown internet stories? --Shadarian 21:43, 24 May 2006 (UTC)

Overblown internet story. --Serie 22:45, 24 May 2006 (UTC)

If you're interested in more details, an astronomer talks about the nonsense of the story here. — QuantumEleven 08:25, 25 May 2006 (UTC)

OK, we are tomorrow, but it is not 21:43 yet! --DLL 10:45, 25 May 2006 (UTC)

[edit] fusion vs. fission?

Would someone post a synopsis (or short answer) to the following: "How do emmisions from a fusion reaction compare to emmisions from a fission reaction." Thanks, *email removed*

One produces hard radiation, the other produces helium --64.12.116.74 22:12, 24 May 2006 (UTC)

Fusion = melting together of nuclei of small atoms
Fission = splitting of nuclei of large atoms.Patchouli 22:17, 24 May 2006 (UTC)

You could read fusion power and nuclear power for some information. Basically, the spent fuel from a fusion reactor is just a tiny, tiny quantity of helium. The plant itself will become radioactive; however, because you have a choice of what materials the plant is built from you can choose ones which, even if bombarded by radiation, don't remain dangerous for very long (think years or decades rather than millenia). You don't have such a choice with a fission reactor, because the fuel itself is the major component of the dangerous waste. (though there are research efforts to use thorium fuel instead of uranium; spent thorium fuel is dangerous for much less time than spent uranium fuel). --Robert Merkel 22:25, 24 May 2006 (UTC)

Surely there's a tradeoff there, though; if you bring the half-life down, for the same number of decompositions, you necessarily have a more radioactive substance (in terms of curies per gram, say). This is something I think most people don't really understand. U-238 itself, for example, has a half-life of four billion years, which is almost the same as saying that it's just not particularly radioactive. Something with a half-life measured in years or decades, on the other hand, is bound to be very high-level radioactive waste (unless the absolute quantity of radioactive substance is small, and I don't see why that should be). --Trovatore 14:06, 25 May 2006 (UTC)

The point is that we can be reasonably sure of our abilities to contain even very dangerous things for a few years or decades; it's much harder to be certain of containing things for a very long time. As far as fusion goes, the absolute quantity of waste is estimated to be a small fraction of that for fission. That said, you do have a good and very poorly understood point with regards to the fact that things with long half-lives aren't very radioactive. --Robert Merkel 03:19, 26 May 2006 (UTC)

Yeah, I've never been terribly convinced by the argument "we can't leave anything dangerous for our descendants 10,000 years from now". There are going to be dangerous spots on the planet whatever we do; these at least will be marked and labeled. It's not like we're talking about their whole ecosystem. Maybe Los Angeles in the year 12,000 will just have to find a water source that doesn't pass through Yucca Mountain or wherever it is. --Trovatore 15:06, 26 May 2006 (UTC)

Also see aneutronic fusion, a way to almost eliminate the hazardous and wasteful neutron radiation. —Keenan Pepper 23:55, 24 May 2006 (UTC)

I removed the email address. --M1ss1ontom a rs2k4 ^{(T | C | @)} 03:32, 25 May 2006 (UTC)

I think something's being missed here. Assuming heat engine extraciton of useful energy from a fusion reactor, there will be a transfer material. Water maybe, but that requires high pressure. better might be something like sodium or some such. That stuff will be very thoroughly irradiated, and there will be rather a large amount of it. And the building in which it all happens will probably be rather irradiated, unless it's sequestered away like the armored containment vessels used in pressurized water reactors today. Look at the Chernobyl site, at which an entire building (thousands of tons) is fully contaminated. Admittedly, a fusion reaction is unlikely to run away as did the reactor at Chernobyl, but the point should be stark. A long operating plant should be so designed that the building doesn't get something similar in terms of contamination. So it's not merely the small quantities of hydrogen fuel left over, or the even smaller (by mass) helium as output which will be the problem. A lot depends, as always, on the detailed nature of hte design of the fusion plant. ww 21:17, 31 May 2006 (UTC)

[edit] Crows and seagulls as food?

Does anyone know what crow or seagull meat tastes like? Are these birds regularly on the menu in any part of the world? Some of them are massive and look like they have a lot of meat on them, yet I never heard of anybody eating them.

Crows are sometimes hunted (and more rarely eaten) in the U.S. but seagull are protected species here. I have never "eaten crow" myself, except in the figurative sense. Rmhermen 00:19, 25 May 2006 (UTC)

Tastes like chicken (foul) 8-))--Light current 00:49, 25 May 2006 (UTC)

It is quite well known (though not necessarily true) that crow/raven is eaten in some Western areas of China. You can assume, though, that they are not street crows, and are probably relatively clean. Scavengers are generally leaner than fully domesticated animals, so you can imagine that the meat would be tougher than chicken. I imaging the difference between chicken and crow would be not dissimilar to the difference between cow and horse (sometimes eaten raw in Japan). freshofftheufo ΓΛĿЌ 04:59, 25 May 2006 (UTC)

We have an old nice recipe book here (in France). One starts like : "Prenez trois jeunes corbeaux, prêts à s'envoler ..." Take three young crows, ready to take flight ... : obviously, if you take them in the nest, the flesh is palatable. Either ... --DLL 10:43, 25 May 2006 (UTC)

[edit] May 25

[edit] too hot vs too cold

hi, i'm currently sharing a house with 4 others in the UK. I, having been raised by frugal parents in the north (scotland) feel more comfortable in a cold house (i.e. no central heating), however my cohabitants, raised in the tropics of the south east of england, start moaning about the cold once the temperature drops below 25c. ignoring then minor inconveniences such as the melting ice caps, is it healthier to be cold or hot or doesn't it matter? i'm obviously not talking about a choice between the sahara or the arctic, but say, 15 degrees vs 20, or 10 vs 15.. thanks! 87.194.20.253 00:05, 25 May 2006 (UTC)

I think it's a fairly complex question. On the one hand, being cold, even by a couple of degrees, over a long period of time can suppress your immune system; but on the other hand being a little bit chilly burns (a few) more calories. Moreover: the colder it is in your home compared to the outside temp the more humid it'll be, which will be better for your skin. However, humidity encourages the growth of microbes like mold. I understand that being too warmly clothed/blanketed is strongly associated with susceptibility to crib death, but I don't know if that extends to warm ambient temperatures or if it's just swaddling. I grew up in a chilly home too (18-22 during the day and 14-16 at night, furnace turned off from May to October), so I completely empathise with your POV. AFAIAC, thermostat nudging should be a misdemeanor.--Anchoress 01:51, 25 May 2006 (UTC)

Whatever happened to "toughing out" the weather anyway? freshofftheufo ΓΛĿЌ 04:55, 25 May 2006 (UTC)

At that temperature range, it doesn't matter. We're not talking about hypothermia here. —

The Mac Davis] ⌇☢ ญƛ. 05:03, 25 May 2006 (UTC)

Yesterday, they did an item about global warming and energy conservation on Blue Peter. Turning down your thermostat by just one degree already saves you tons of money and could see a lot less CO₂ released into the air. (I think it was 200 kg a month, but don't hold me on that). 15 degrees sounds quite could to me. I think you should try striking a compromis with your housemates. Don't go all the way down to 15. Have the thermostat on 18-19 when you're in; 16 when you're out (that's how we've set it right now). In the winter, you could set it to 20-21. Regardless, 25 is too much, 15 is too little. - - Mgm|^(talk) 12:30, 25 May 2006 (UTC)

I get pissed off at housemates like that aswell. I happened to wind up living for a term with this really spoiled person who left the heating constantly on full. When it got too hot - they opened a god-damned window!!! I will never get over that! Me, I say "how low can you go?" I can wear enough layers and fingerless gloves so I'm okay with anything above 10 (although I do look stupid). I can't stand living with wasteful people. I was brought up by frugal parents but something went wrong and I'm more frugal than they are. I will *never* by bread or milk from a convenience store. My bread costs 28p and I can put it in the bottom of my bag or kick it home and it will still be loaf-shaped but I don't care 'cause it's fine for beans on toast! People waste too much money on frivilous things - I'd rather save and live in my ideal (albeit cold) home. --Username132 (talk) 00:59, 31 May 2006 (UTC)

[edit] Feynman Problem

The following is from Surely You're Joking, Mr Feynman!. Does anyone care to venture the answer?

The problem is this: You have an S-shaped lawn sprinkler--an S-shaped
pipe on a pivot--and the water squirts out at right angles to the axis
and makes it spin in a certain direction. Everybody knows which way it
goes around; it backs away from the outgoing water. Now the question is
this: If you had a lake, or swimming pool--a big supply of water--and
you put the sprinkler completely under water, and sucked the water in,
instead of squirting it out, which way would it turn? Would it turn the
same way as it does when you squirt water out into the air, or would it
turn the other way?

JianLi 00:34, 25 May 2006 (UTC)

According to the Feynman sprinkler article, scientists have tried this experiment using air instead of water, and it doesn't spin at all! --Cadaeib (talk) 01:54, 25 May 2006 (UTC)

This makes sense to me [sort of]. Imagine the regular sprinkler: water that exits it is moving at a high speed, and since it's moving normal to the lever arm, it has an angular momentum. Since angular momentum is conserved, the sprinkler must pick up equal and opposite angular momentum. Now picture the Feynman sprinkler. It's sucking in water that was stationary; hence, no angular momentum to begin with. Then, as it gets sucked into the sprinkler, there's no transfer of angular momentum. Nothing happens. -- Filliam H Muffman 03:10, 25 May 2006 (UTC)

Not so much that the water was stationary to begin with but that it was stationary at the beginning and the end of the process (when only considering the angular momentum). You could just as easily imagine a water sucking machine that expells water out the end of it, which would naturally move in the direction it was sucking. The underwater sprinkler, on the other hand, catches the water it sucks in, and thus there is no overall angular momentum. freshofftheufo ΓΛĿЌ 04:50, 25 May 2006 (UTC)

So if the sprinkler were hooked up to a piston pump of some kind that sucked in and expelled fluid in a cycle, the sprinkler would...?

Doesnt the lawn sprinkler work like Hero's steam engine (by reaction forces)? Underwater the sprinkler sucking water in may turn in the opp direction if there is a resulting couple on it due to the excess water pressure at the holes.--Light current 15:36, 25 May 2006 (UTC)

I seem to recall that Feynman tried to construct a rig to perform the experiment himself, and it ended up exploding and spreading water and glass all over the lab. KWH 15:50, 25 May 2006 (UTC)

Yeah, that's what happened in the book. But before it exploded, he actually observed it turning, though he didn't say in which direction, so that seems to contradict the Feynman sprinkler article JianLi 16:28, 25 May 2006 (UTC)

Take your average portable fire pump and throw the intake into the lake. Does the suction cause the intake to move in the direction of inflow? Nope. Does this have anything to do with the topic? Who knows. The only trouble you have with large intakes is that you get a vortex developing over it. This can suck in air, or boats (as with a nuclear power plant). --Zeizmic 17:11, 25 May 2006 (UTC)

This is restating the angular momentum stuff. One way of thinking about it could be: The water gets sucked into a hole/nozzle. Where it exits from the nozzle (in this case on the inside of the pipe), it would tend to push backwards on the nozzle, i.e. cause the pipe to move towards the side where the hole is. But in this case the water jet carries on, still inside the pipe, and hits the other side of the pipe, opposite to where the nozzle/hole is, thereby tending to push that part of the pipe away in the opposite direction that it tended to when entering the pipe. Clearly all sorts of tubulence and spread of the jet occurs, but eventually the "push" on the opposite side of the pipe would be equal to the "pull" on the entry side. The water is pushing against a single object in opposite directions, with equal force, so there is no nett force to cause the pipe to be moved one way or the other. Grossly simplified, with questions like "What about the movement of water down the length of the pipe, causing the jet not to impact opposite the entry hole?", but does this "impel-expel-anation" make some sense? In a real-world set-up, I would expect some wobble, and probably some rotation due to the sprinkler not being perfectly constructed. Maybe someone else could elaborate better. --Seejyb 17:10, 25 May 2006 (UTC)

According to An elementary treatment of the reverse sprinkler, the article cited in the Feynman sprinkler article, as the water starts flowing, there is a torque that causes the sprinkler to accelerate toward the oncoming water, and there is a torque that causes the sprinkler to accelerate away from it as the water stops flowing. This would explain why Feynman initially observed the sprinkler to turn. However, as the Feynman sprinkler article said, there is no torque while the water is steadily flowing (unless, according to the link, one considers "dissipative effects such as viscosity"). JianLi 20:16, 26 May 2006 (UTC)

[edit] rocks

I have there types of rocks that I am trying to find out if they are metamorphic, sedimantary, or igneous can you please help me? The three rocks that I have are minerals and they are as followed:

1. umangite 2. goyazite 3.aragonite

Could you please tell me or help me to figure out what they are?

Thanks Eliza Marie

Well, we have stubby articles on two of these which don't spell things out but do leave clear hints. <mineral.galleries.com> spells things out a little more clearly for at least one of them, though here A search on the same site lists umangite as a natural source of copper selenide and goyazite as strontium aluminum phosphate hydroxide. That alone may give a clue... Grutness...wha? 05:58, 25 May 2006 (UTC)

The classification scheme metamorphic, sedimentary, igneous applies to rocks, but you have listed three minerals which in general could be constituents of all three classes. The University of Arizona's mineral database describes the typical occurence of these minerals:

Umangite With other selenides in hydrothermal veins, formed below 112 C.
Goyazite In granite pegmatites; from hydrothermal argillic alteration zones; in kaolinitic claystones derived from air-fall volcanic tuffs; in carbonatites; detrital.
Aragonite Converts to calcite over geologic time. A primary precipitate in warm marine waters, as oolites and carbonate mud, a principal detrital sedimentary component as the hard parts of many marine micro-organisms, shells and skeletons; also from evaporite deposits; in sinte at hot springs and dripstone in caves; characteristic of high-pressure, low-temperature (blueschist facies) metamorphism; as amygdules in basalt and andesite; a secondary component in altered ultramafic rocks.

EricR 16:30, 25 May 2006 (UTC)

[edit] antimony

We had plumber over today to do some soldering. I don't think the house was well ventilated. Does soldering with tin and antimony solder release toxic concentrations of antimony? KeeganB

You're fine. It's a myth that antimony is toxic, because there used to be a nasty compound of antimony around. I've done a lot of plumbing soldering, and there are few fumes. The nastiest thing one can do is electronics soldering, and suck in all that good rosin fume. More info: [13]--Zeizmic 12:04, 25 May 2006 (UTC)

Antimony is toxic, but I do not think it is a heavy metal poison (It does not bioaccumulate like Lead and Mercury).

Yup, for electronics soldering, I'd worry more about the resin than about the antimony, see also [14] --vibo56 22:38, 25 May 2006 (UTC)

Oh, you might get a little kookier after this episode, but if you leave the windows open I guess that's OK. And antimony is a heavy metal, so it is toxic. See here under sections 1.2 and 1.4. But since it's not very soluble in water I think you'll be just fine. If you feel any of the symptoms in section 1.4 see a doctor immediately, since Wikipedia doesn't want to be responsible if you die. ;) --M1ss1ontom a rs2k4 ^{(T | C | @)} 00:05, 26 May 2006 (UTC)

Strikes me as a little odd to call antimony a "heavy metal", when it's actually not a metal at all. Of course that depends on whom you ask; to astrophysicists it's a metal. But then so is oxygen. --Trovatore 02:15, 26 May 2006 (UTC)

[edit] convert hydrogen into BTU's

I am trying to find out how much hydrogen it takes to be equivalent to one US gallon of gasoline. I need to convert this amount of hydrogen into BTU's. Example: 1 gallon of gasoline = 124,000 BTU’s

Try higher heating value. Also see British thermal unit and gallon for information on converting from SI units to whatever collection of rods and hogsheads Americans still use. --Robert Merkel

see Heat of combustion

Just to be pendantic, it also depends what you do with the hydrogen. Are you going to burn it? Make it undergo nuclear fusion? Annihilate it with an equal amount of antimatter? The amount of energy you get out in each case is different :) — QuantumEleven 08:21, 25 May 2006 (UTC)

I wouldn't say that's pedantic at all. But since he's using it in comparison to gasoline, I'd say he's probably working in the context of cars. Therefore, we're probably talking about the combustion of hydrogen, but the question is whether the car is powered by a combustion engine or fuel cell. See hydrogen vehicle. splintax ^(talk) 10:30, 25 May 2006 (UTC)

LOL! But I think we can be pretty sure he/she/it meant combustion of hydrogen. The ΔH_f can be found in any advanced chemistry textbook. --M1ss1ontom a rs2k4 ^{(T | C | @)} 00:01, 26 May 2006 (UTC)

[edit] What is the evolutionary rationale for 'men' (masculine gender)?

What is the evolutionary rationale for ‘men’ (masculine gender)? – They don’t give birth, but they increase with their genom the genetic variation. That's be-cause when organisms reproduce sexually, some genetic "shuffling" occurs, bringing together new combinations of genes. This shuffling is important for evolution because it can introduce new combinations of genes every genera-tion. But why do men not have babies either? – Is it that hermaphrodites, dou-bling the numbers of babies, would lead to overpopulation, giving the relative high age mammals reach? Therefore ‘men’ are welcome to increase genetic variation, but not the number of babies: quality not quantity. Having reached the level of mammals the animals are already quiet robust. And in this line of questions, why is it that there are about 50% men and 50% women? - Less than 50% of men would reduce the total genetic variation exposed by men. This would result in the mating process to a reduction of genetic variation, making men an obstacle to optimal evolution.

Why do you put men in quotes? You could just as easily say why do we need women? The sperm is equally important as the egg! I expect you want a scientific answer. I like this one [15], because I thought of it myself before learning of the book. —

The Mac Davis] ⌇☢ ญƛ. 05:49, 25 May 2006 (UTC)

See Evolution of sex Raul654 05:54, 25 May 2006 (UTC)

I don't think they were questioning the importance of the sperm relative to the egg, simply why men didn't bare young as well, since that would double the number of potential babies. Skittle 09:50, 25 May 2006 (UTC)

Sorry, Mac, but your sperm is not nearly as necessary as an egg. The sperm contributes half the DNA but the egg contributes mitochondria, early nutrition, and much more. There are numerous examples of inducible or natural development of an unfertilized egg into an organism, but you can be reassured that all those millions of sperm you waste in your life didnt have the capacity to go it alone. alteripse 13:51, 25 May 2006 (UTC)

That is one way to look at it—I looked at it like if there is no sperm there is no zygote, and if there is no egg, there is no zygote. —

The Mac Davis] ⌇☢ ญƛ. 20:50, 25 May 2006 (UTC)

Instead of picturing the world as it is now, consider the time before land animals. When our ancestors were aquatic, the female spurted out one set of gametes and the male the other. When you see it this way, you realize that no one sex is really giving birth -- both are putting their gametes out in the open where they can fuse. Fast forward to land animals, and the sperm and egg still needed to meet together in an aqueous environment, and so sex evolved. Some species, such as reptiles, then laid the fertilized egg outside the body, others, like mammals, kept it inside the female during all of gestation. But as you can see, this is just the result of evolutionary chance: both sexes are creating the fertilized egg, but the female happens to store it in her body until birth. — Asbestos | Talk (RFC) 11:45, 25 May 2006 (UTC)

Why 50% males and 50% females in almost every population with separate sexes? The answer is probably in Evolution of sex but it's still one of my favorite answers about evolution. Let's say there were 90% females and only 10% males. Then males would reproduce on average nine times as often as females (if I did my math right). So there would be a huge advantage to being born male. And when there is a selection advantage for a trait, that trait increases in frequency. Thus more males are born until the ratio stabilizes around 1:1 (50% of each). This process is most clear in species such as alligators, in which an external condition (in their case, nest temperature) determines sex; if there is suddenly an advantage to being male, then there's an advantage to turning male at common temperatures. So selection would actually operate on what nest temperature leads to what gender. In species such as mammals, birds, and fruit flies, the ratio is harder to mess with because it's based on chromosomes, although selection could theoretically still operate on the gamete that carries the sex-selecting chromosome. --Ginkgo100 16:57, 25 May 2006 (UTC)

Two points. One: for maximum population growth, having fewer men than women is favourable. As such a farmer keeps one bull and many cows (there are other reasons for this obviously but i can't think of a better example right now). However, as pointed out above by Ginkgo100, this is not favourable by natural selection. Two: Assuming you're not questing the purpose of sexual reproduction, having people divided into men and women can be seen as a form of specialisation. Otherwise everyone would have to have both sets of reproductive organs, which would not be favoured by natural selection because it will take more energy to maintain both sets than to specialise and have just one. (And if everyone were female, as you seem to be hinting, how would they get pregnant?) There are, however, many species which keep both sets, such as snails and most plants. —Pengo 23:34, 25 May 2006 (UTC)

That's for r-selection, which is basically where the animals do everything they can to make more copies of the species. In K-selection, there is usually a pair-for-life thing where they try to ensure that good copied survive to reproduce and ignore/destroy "extras". --M1ss1ontom a rs2k4 ^{(T | C | @)} 23:59, 25 May 2006 (UTC)

[edit] Cellulose hydrolysis

From time I am facing one problem. I am trying to do 1. the acid hydrolyse of cellulose, Carboxymethyl cellulose (CMC), hydroxyethyl cellulose HEC)and CMC&HEC based Hydrogel. I have to do a complete (100%) hydrolise of them. 2. I want to know, too, which is the best method to analyse and control the % of hydrolyse and to measure from quantitative point of view the reaction products (glucose, carboxymethyl glucose etc)? I've tried the hydrolise of CMC, HEC and CMC& HEC Hydrogel with sulfuric acide 97% having first a swelling phase at 37 °C for 1 hour and then diluting 10 times with water and incubation at 90-100°C for 3 other hours. The results are not good: I arrived till 25 % of Hydrolyse. Mesuring with HPLC and spectrophotometer at 540 nm.Please help me. 25 May 2006 Xh.D (Ph.D Student, Italy)

Ooooh...not many of us are ~~orgasmic~~ organic chem Ph.Ders here. You may want to direct your question to somebody in the chem department of your university. This is rather too hardcore for us. Sorry. --M1ss1ontom a rs2k4 ^{(T | C | @)} 23:56, 25 May 2006 (UTC)

Uh, there are plenty of PhDs who edit Wikipedia. Including the RD pages. But if you don't know the answer yourself, feel free not to comment. That said, a PhD student has no business asking questions on their subject on a page such as this. As a PhD student you're supposed to be able to search for the answer in the literature, or if someone hasn't investigated it, do the research yourself. In this case, there's quite a lot published on acid hyrolysis of ceullolose. I'd suggest reading that. --BluePlatypus 01:20, 26 May 2006 (UTC)

[edit] Dimming and SADness

Does anyone know of any work relating the climatological phenomenon of global dimming with increased clinical depression due to the seasonal affective disorder? If global dimming, according to the Maldives trial, can account for a 10% reduction in sunlight in poluted areas, that surely must have an effect on the mental health of the population. Are there any studies referencing increased prevalence of depression in industrial areas, of which sunlight may be a significant factor? — Gareth Hughes 10:44, 25 May 2006 (UTC)

I think you are grasping at straws for this correlation. The dimming was at 5% and is now improving (hence global baking). A small latitude change in location is much greater. I have a SAD element to my depression, and it is triggered by the very large sunlight dimming in the fall, for the northern areas. --Zeizmic 11:44, 25 May 2006 (UTC)

And there are way more variables to account for as causes of depression than the degree of sunlight. My favorite is "sense of relative wealth or poverty", which study after study has shown to affect general contentment with life and even physical health. Fundamentally, we judge our lot in life relative to those we know. The more you see and know of people a lot richer than you, the poorer you feel. The implications are interesting. Don't hang around with folks much richer than you, don't live next to folks much richer than you, don't work with folks much richer than you. You can make mental compensation for contact with an occasional rich person, but the more contact you have, the more you become aware of your relative deprivation. This is why poor folks in cities seem so much more deprived and discontent than the rural poor. All of us had recent ancestors whose living conditions were more deprived than the majority of people in the world today who seem desperately disconent. Republican econonomic policies that increase wealth disparity have not been healthy for the American psyche. As a contributor to mental health, the amount of sunlight pales before socioeconomic factors. The mental health of the entire world would be better if we got rid of television sets. alteripse 13:45, 25 May 2006 (UTC)

On the other hand, I have heard that Iceland has the highest standard of living with relatively small wealth disparity, but the highest suicide rate in the world. I can't prove either fact, so you can choose those you prefer. alteripse 13:45, 25 May 2006 (UTC)

Fine, but seasonal affective disorder is a well-documented and studied phenomenon, and this is what the OP was asking about. — Asbestos | Talk (RFC) 22:02, 25 May 2006 (UTC)

OK, I wasn't being clear enough. Latitude, indoor work, and sedentary lifestyles are much bigger determinants of sunlight than urban air pollution. Many other aspects of urban life likely have a greater magnitude effect on mood than sunlight exposure. Those were my points, and they are directly relevant to the question. alteripse 23:16, 25 May 2006 (UTC)

[edit] Bears in Africa

Are there wild bears in Africa? Lapinmies 11:19, 25 May 2006 (UTC)

The Atlas Bear, now extinct, was the only bear native to Africa. — Gareth Hughes 11:37, 25 May 2006 (UTC)

[edit] Physics competition problems

I just knew that I have to go to a physics competition this sunday, and I have only a few days to prepare. Here are the major MC questions that got me stuck.

[edit] Fluid dynamic

9 kg of mercury is poured into a glass U-tube with inner diameter of 1.2 cm. The mercury can flow without friction within the tube. Find the oscillation period. (Given density of mercury is 13.6 times 10^3 kg/m^3)

So, assuming a displacement of x m from the equilibrium height, the pressure difference is 2xgp, where g is acceleration due to gravity and is the density constant. I multipiled this with cross-sectional area to obtain net force. Dividing this by the total mass(9kg), I get the acceleration of the fluid. Observing the ratio between this and the orignial displacement, I get the frequency. But somehow, I get something like 0.2s and the five choice are (a)1.2 s(b)3.4 s(c)5.6 s(d)7.8 s(e)8.9 s. Can someone show me where I am wrong and how to do it?

The force driving the oscillation is, as you note,

F = - 2 x A ρ g

. Since it is linear in

x

, we get a simple harmonic motion. Newton's law gives us:

$F=Ma=M\ddot{x}$

where $\ddot{x}$ denotes a second derivative with respect to time. Inserting the force we get a simple differential equation,

$\ddot{x} = -\frac{2A\rho g}{M} x$

Which has a solution on the form given on the SHM page, linked to above and the oscillation has the frequency

$f=\frac{1}{2\pi}\omega$ where $\omega^2 = \frac{2A\rho g}{M}$

This, of course, should also be in your textbook. --Swift 21:25, 25 May 2006 (UTC)

I have been tricked! Actually, my steps of working are just exactly the same as yours, but somehow all my calculation leds to 0.29. Now, here's the catch: it asked for period, and its unit are seconds, but for some reason I'm brain-washed and only take frequency as the answer! All is fine after taking multiplicative inverse, so 1/0.29=3.4s, the answer is b. --Lemontea 01:31, 26 May 2006 (UTC)

THatll teach you to read the question properly!--Light current 13:11, 26 May 2006 (UTC)

[edit] Torque

Oh, this one is so far that it is just 'dot' to me.

A wheel of weight W and radius 0.8 m is placed against a 0.3 m height rectangular block fixed on the ground. The wheel has an axle of radius 0.1 m. A force F is applied tangentially to the axle to lift the wheel. The minimum value of F is?

I would describe the diagram: the wheel touches the rectangular block at its upper left corner. So far I only knew that the center of the wheel will move circularly with respect to the contact point between the wheel and the block(the upper left corner), and that the axle only "scale" the force, so that can safely be left out and simply consider a wheel. But then what? I have no idea how to use torque if it isn't in equilibrium.

Assuming the wheel does not slip against the block, it will undergo rotation about its instantaneous centre which is the point of contact of the rim with the block (seems to be the corner of the block). So all you have to do is work out the downward torque (or moment) due to gravity and equate it to the upward torque (or moment) due to the string acting tangentially and hey presto! Im sure you can do the simple math!--Light current 16:07, 25 May 2006 (UTC)

Assume the torques are in equilibrium! This gives the minimum value of F which is what you are being asked.--Light current 16:22, 25 May 2006 (UTC)

Last night, I suddenly thought(on bed) that I can consider using the contact point as pivot, but extending the arm through the radius to the diameter! Then there are two force - weight on the midpoint, and the pulling force on the end. Another problem(conceptually) - if the wheel is pulled at a single point, does other point on the wheel also recieve a force? If so, what are their magnitude compared to the original force? I think this because by Netwon's second law of motion, even if the original force act on one point only, all other particles on the wheel are accelerating! --Lemontea 01:18, 26 May 2006 (UTC)

After many trials, I finally got one that has an answer that almost match the choices. Resolving component of weight, the torque of that part is 0.8(which is r) times $\sqrt{0.8^2-0.5^2}W/0.8$ (which is F) and thus the torque brought by the pulling force is sqrt(0.039)W. Now the r for the pulling force is (pyth) $\sqrt{0.6^2+0.039}$ , and after resolving component again, I get $F=\frac{\sqrt{0.039}W}{0.6}=0.329W$ . A slight problem though is that the closest choice are 0.32W, which is okay only if it trancate rather than round off the number. Did I make any mistakes? --Lemontea 08:17, 26 May 2006 (UTC)

In what direction is the force F shown as acting? If vertical, you dont need to do any resolving of forces. Also the reacton of the block on the wheel rim is not relevant.--Light current 13:04, 26 May 2006 (UTC)

Some clarifing: the force is applied horizontally, pointing rightward. And the wheel and axle are two circles with the same center. One question through: Since the position the forces act are not all colinear, Do I still goes on by taking the length straight from the pivot point, or is there any catch?(Which is BTW why I wrote 0.6 above, =0.1 + 0.5 as the vertical displacement of the pulling force from the contact point, and then use pyth) --Lemontea 07:14, 27 May 2006 (UTC)

[edit] Hooke's law

Okay, this one is more conceptual: the law states that F=-kx, but what if both end of the spring is unfixed and get pulled? How does the force distribute? Does it happen to be like tension in a string, or am I mistaken?

Thanks. --Lemontea 15:24, 25 May 2006 (UTC)

Yes its like tension in a stretched string. The force is constant along the spring. If you inserted a spring balnce anywhere in the middle of the spring, you would get the same reading.--Light current 16:27, 25 May 2006 (UTC)

What about their magnitude? Do they all measure -kx/l(where l is its total length) or just -kx? Further, for tension in the string, I know that the direction of force are opposite on two end. What about spring? --Lemontea 02:23, 26 May 2006 (UTC)

The concept being tested here is that since the force is linear in the amount streched,

x

, you can break the spring down into smaller ones, each having the same spring constant,

k

. If you split the spring into

n

smaller ones, each will be streched by

x / n

giving you the force

k x / n

As for

- k x / l

: this could not possibly be the answer since the units are wrong. --Swift 19:50, 26 May 2006 (UTC)

Whats the difference between a spring and a stretchy string? 8-)--Light current 13:07, 26 May 2006 (UTC)

[edit] Does every part of the earth receive the same ammount of sunlight summed over a year?

Question/hypothesis: If you live directly on the equater your recieve 12 hours of sunlight and 12 hours of darkness. If you life off the equater you recieve a proportional ammount of sunlight based on the time of year (either more or less). If you sum up all the sunlight received by a selection of points on the earth, starting from the equator and ending near a pole over a 365 day period would the summation of these values all reach the same value? (ie 12*365 for the equator case). I assume so, but may be missing something important!? Thanks!

The poles receive a lot less sunlight (both in duration and intensity). --Kainaw ^(talk) 18:32, 25 May 2006 (UTC)

It'll be close; here are some factors you've not accounted for:

"Daylight" is calculated as any time when any part of the sun is over the horizon, not the center of the sun. Consequently, average daytime is slightly more than 12 hours and average nighttime slightly less. The effect of this measurement system might vary with latitude.
The angle at which sunlight strikes the earth will relate to the energy retained by the earth. You didn't specify, but this is likely an important consideration: it's a primary reason why the poles are much colder than the tropics, even though the sun is visible for an approximately equal length of time at each location.
Local geography will affect direct sunlight. The bottom of the Grand Canyon is in shadow far more than its rims (this, though, is almost certainly outside the scope of your question).

So there you go: some thinking points for variance in sunlight times. Kainaw, do you know of a reference for the poles receiving less by duration? I would have thought they'd get more. — Lomn Talk 18:34, 25 May 2006 (UTC)

Specifically, our article at midnight sun notes that the poles observe a 186-day daylight period, which leaves time for a 179-day "night". If you find an almanac listing the length of day at the equator on the spring equinox, that multiplied by 365 (or 365.25, if you're picky) would confirm or deny the question of latitude affecting duration of daylight. — Lomn Talk 18:36, 25 May 2006 (UTC)

More follow-up: polar night is probably a better article for this than midnight sun, and night provides the answer to duration, noting that at the equinoxes in equatorial regions, daylight is approximately 14 minutes longer than nighttime. A 12-hour 7-minute day, averaged over a year, gives 184 days of daylight annually. However, I noticed that (when I accidentally checked a 12-hour 14-minute day), an easy misinterpretation gives 186 days of daylight, the same as at the poles. So independent verification is probably a good idea to resolve this. — Lomn Talk 18:45, 25 May 2006 (UTC)

If we feel like quibbling over small effects, then we should note that the North and South Pole won't be exactly the same since the Earth's orbit is slightly elliptical and hence moves more quickly during part of its orbit than in other parts. As Southern Hemisphere summer occurs when the sun is nearest the Earth (and hence the Earth is moving most quickly in its orbit), I would expect that the South Pole recieves slightly fewer hours of sunlight than the North Pole per year. Dragons flight 19:07, 25 May 2006 (UTC)

Thanks for the in depth responces!

Please note that the daily total solar radiation incident on a horizontal surface at the top of the atmosphere peaks at 574 Watts per square meter on December 22 at the South Pole. Thus it is obviously true that the poles get less radiation on an annual basis, but on a daily basis that's where the maximum is (for a short period of time). If you have access to a good libray, you can get more details on this topic from the following book: William D. Sellers (1965) Physical Climatology, The University of Chicago Press, ISBN 0-226-74699-2 (reprinted 1972). See pages 16 to 18 in particular. --Michel M Verstraete 22:04, 25 May 2006 (UTC).

The answer is "no". Dragons flight's elliptic orbit is the reason, and it's not a quibbling small effect (do dragons ever quibble?). Taking a refraction effect of early sunrise and late sunset into account (50 sec of a degree), the figures for the north pole (NP) vs the south pole (SP) are:

Sunlight (2006): NP 191 days, SP 182 days.
Sunlight on both NP and SP (2006): 19 to 22 March 2006, and 22 to 25 Sept - one can calculate the above from these dates.

"Amount" of sunlight, would mean duration of sunlight seen. Obviously the energy per square metre decreases as latitude increases. The Smithsonian Meteorological Tables have figures for sunlight by latitude, where one could see what e.g. happens at the equator, but I do not have ready access to these. --Seejyb 23:30, 25 May 2006 (UTC)

It is obvious that the amount of energy received at the poles is far less than the equator. As for the duration, compare something like Nome Alaska to Charleston SC. In Jan, Nome gets about 4hrs sunlight a day. Charleston gets about 10hrs. In Feb, Nome gets about 7hrs. Charleston gets just about 11hrs. In March, Nome is starting to catch up with Charleston with 10hrs. Charleston has 12hrs. In April, Nome is getting just over 13hrs. Charleston gets just under 13hrs. In May, Nome has 17hrs of sunlight. Charleston has 14hrs. By the middle of the year, Nome has 21 hours of sunlight. Charleston still has 14hrs. Then, it goes back down pretty much at the same rate that it went up. If calculate the hours for each and every day, you'll find that Charleston has nearly 30 more days of sunlight than Nome, counting hour by hour. Now, if you consider any day that the sun peeks up a full day of sunlight, then Nome gets more days. However, I was counting the number of hours of sunlight throughout the year. --Kainaw ^(talk) 13:20, 26 May 2006 (UTC)

One more thing: It's not true that the equator gets 12 hours of sunlight and 12 hours of darkness throughout the year. In fact, this equal division would only occur twice a year, during the equinoxes. Loomis51 08:06, 28 May 2006 (UTC)

[edit] computing - hyperlinks

Not sure if this is the right place to ask - couldn't find 'computing desk'.. It seems that it is possible to link to any other web page using hyper links - what I was wondering was - are there any restrictions on linking to other pages - are there any conditions in which permission is needed first etc, or good manners aside - is it a total free for all?HappyVR 18:20, 25 May 2006 (UTC)

What do you mean exactly? Are you referring to Wikipedia, or the web in general? If it's the web in general, anything goes. If it's Wikipedia, please see Wikipedia:External links. Johnleemk | Talk 18:30, 25 May 2006 (UTC)

It is absolutely a free-for-all. You can link to any page you like whenever you like. In fact, you can do this: Google-Extreme. --Kainaw ^(talk) 18:34, 25 May 2006 (UTC)

I believe there's been court cases over deep linking into the depth of another's web site, and possibly over including images from others' servers. However I don't follow these things because the stupidity of it all gives me a headache. —Pengo 23:38, 25 May 2006 (UTC)

Deep linking is not a huge issue anymore because it's easy to block. So, for example, if I wanted to use a picture from the NYTimes on my homepage, I could code in an image request, but their servers may choose to block it since the request isn't coming from a page in their domain.

See the article for a little history on the law and deep linking. I found this on Wired News also:

"Hyperlinking does not itself involve a violation of the Copyright Act," Hupp said in his ruling. "There is no deception in what is happening. This is analogous to using a library's card index to get reference to particular items, albeit faster and more efficiently." [16] -Quasipalm 15:41, 26 May 2006 (UTC)

[edit] Boiling temperature of blood?

What is the boiling temperature of blood?

I read somewhere that Fahrenheit originally based his scale off of human parameters. Therefore, he assigned 0 degrees to the freezing point of blood, and 200 degrees to the boiling point. Yet, it doesn't mention this in said article. I would've figured that the freezing point of blood would be very close to that of water (32 F), considering blood is mostly water. But perhaps I'm mistaken. I'll try to find you a source. - R_Lee_E (talk, contribs) 18:52, 25 May 2006 (UTC)

It is extremely unlikely that Fahrenheit used the boiling point of blood as a 200 degree point for a couple of reasons.

The boiling point of water is the same everywhere at atmospheric temperatures, is easy to measure, and does not depend on the speed of the temperature rise.
On the other hand, blood is a complex substance with many potential changes in response to different methods and rates of heating. For example, the proteins coagulate and cells would lyze before reaching a boiling point. You would have to anticoagulate it even to keep it liquid for any length of time, and continually mechanically mixed to keep the cells from separating.
Blood is a much less standard substance than water, with many variable components.
Most of all, this fails the common sense test: I cannot even imagine someone thinking blood would be easier or more pleasant to work with for developing a standard. alteripse 19:11, 25 May 2006 (UTC)

Your points are noted alteripse. But I can imagine, if someone were intent on creating a human relevant scale, then they would go through the trouble. This is not to say that I agree with the idea. I'm merely keeping an open mind. - R_Lee_E

(talk, contribs) 19:22, 25 May 2006 (UTC)

Remember - salt lowers both the boiling point and freezing point of a liquid, and human blood is *VERY* salty. Raul654 19:04, 25 May 2006 (UTC)

After two edit conflicts (don't those just make your blood boil ?):

Zero F was supposed to be the freezing point of ocean water and 100 was supposed to be normal blood temperature (however, the person he measured must have been running a slight fever). StuRat 19:12, 25 May 2006 (UTC)

See Fahrenheit. After all, this is Wikipedia. We have everything. --Eh-Steve 19:17, 25 May 2006 (UTC)

Not quite, Steve. 8*) - R_Lee_E (talk, contribs) 19:27, 25 May 2006 (UTC)

Isn't this quite OT, the wikipedia article about Fahrenheit says nothing about the boiling temperature of blood.

Hello! The freezing point of 1/2 salt and 1/2 water is 0°F. The human body temperature was supposed to be 100°F, but it's actually 98.6°F. This made boiling point of pure water to be 212°F. I don't remember where I got this; I'll have to verify it. I know my freezing point reason is correct; I'm not sure about the other end. --M1ss1ontom a rs2k4 ^{(T | C | @)} 23:51, 25 May 2006 (UTC)

The version I read was different from the ones given here and in the article. That was that Fahrenheit simply took the boiling point and freezing point of water, divided into 180 degrees (This was in days when base-60 was the norm) and then offset this by 32 degrees as to make the (supposed) body temperature a round 100 degrees. But that's the extent of how human-based it is. Another reason for that is he probably also wanted to avoid negative numbers (mentioned in the article). The idea that it's based in any way off the properties of blood seems pretty ridiculous though. --BluePlatypus 01:07, 26 May 2006 (UTC)

0°F was at the time considered to be the coldest temperature possible (ie; the coldest temperature that could be replicated in a lab), and 100°F was meant to be body temperature, but as he read the thermometer by firelight, the temperature rose by about a degree before he could measure it. smurrayinchester ^(Talk) 08:48, 26 May 2006 (UTC)

I feel compelled to point out to the original questioner that his choice of "blood" is arbitrary. What's wrong with a phlegm-based temperature scale? Perhaps we can think of something yet more disgusting and impractical? - Nunh-huh 00:04, 26 May 2006 (UTC)

The boiling point of blood would be higher than that of pure water, and of course depend on ambient pressure. What would be boiling would be a salty solution left after cells have lysed and proteins have coagulated and presumably settled out of solution. If one knew the osmolality of the resulting mixture, one could venture a prediction. The simplest solution to the question would be to obtain a sample of blood from a local butcher, and see at what temp it begins boiling. I do not think human blood is necessary for any such endeavour.

The boiling point of blood does not feature in any explanation of the temperature scales. It says here why Fahrenheit chose those temperatures. Shortly: 32 was melting point of ice, and his wife's armpit was 96. The article looks researched, and one can look up the references quoted on the page. However, this site gives a different story, but no references. --Seejyb 01:05, 26 May 2006 (UTC)--Seejyb 01:05, 26 May 2006 (UTC)

So... What is the boiling point of blood? I at least attempted to answer that question. No one has done any better since. - R_Lee_E (talk, contribs)

Several of us have explained in detail why there is no single reproducible "boiling point of blood". You have just told us all our keystrokes and explanations were wasted. alteripse 02:33, 26 May 2006 (UTC

Some people are saying that salt lowers the boiling point and some say it doesn't. Most people are discussing the Fahrenheit temperature scale, and such discussions are best saved for a place where it is appropriate to have them, because the original question was and still is "What is the boiling temperature of blood"!!

Why waste all this time arguing over it, its a relatively simple experiment. Just get a small pot, a thermometer, a heat source, a knife & a vein & try it out. Please also patch up the vein you open quickly otherwise you won't be able to tell us the boiling point. AllanHainey 11:28, 26 May 2006 (UTC)

I'm more curious now to know the boiling point of phlegm (although I don't know why). I would attempt to do the experiment myself, but I'm afraid my wife would beat me to death with the cooking pot for ruining it so. I suppose I could put something in my will requiring her to therefore do the blood boiling experiment... 71.113.119.174 16:53, 26 May 2006 (UTC)

Calculate Blood Boiling: taking plasma osmolality = 300 mmol/kg, and the molal elevation constant for water = 0.512 °C/mol (a colligative property plus look up in a table), the boiling point for blood at 101.3 kPa ambient pressure works out to 100.1536 °C. Hemolysis can be assumed not to change osmolality significantly, since intracellular = extracellular osmolality. Proteins are similarly insignificant with these calculations. These figures can be calculated from info in Wikipedia.

Freezing point of NaCl/H2O solution: The eutectic point temperature that I have is -21.12 °C, (approx -6 °F) which is different from what Sodium Chloride says, and from what M1ss1ontomars2k4 says. --Seejyb 20:07, 26 May 2006 (UTC)

That depends--is the 1/2 NaCl by mass, volume, etc.? --M1ss1ontom a rs2k4 ^{(T | C | @)} 05:05, 29 May 2006 (UTC)

[edit] Idiopathic vs Cryptogenic - Round 1

Is 'idiopathic' the same as 'cryptogenic' and if so, should cryptogenic link to idiopathic? --Username132 (talk) 22:42, 25 May 2006 (UTC)

There is a difference, but it is a subtle semantic connotative one as much as a denotative one. And there are probably contexts in which either term could be used. The greek root of cryptogenic literally means "of hidden cause" and usually refers to a single specific condition thought to have a single cause that is currently being hunted or at least thought about. The greek roots of idiopathic literally mean "of their own individual disease", and is typically the term for conditions not caused by the known causes with perhaps more awareness that there are many causes of most idiopathic conditions. It more often is used in contexts when the cause is not of specific interest or investigation but the testing phase is over. The overlap is that both terms are used for conditions of unknown cause. Nothing wrong with a redirect as long as someone wants to more painstakingly trace the usage differences-- the foregoing is off the top of my head and I am not warranting accurate enough for article text without verification. alteripse 23:00, 25 May 2006 (UTC)

So according to your explanation, would you say that the following instance of 'cryptogenic' from the epilepsy article ought to be changed? "Approximately 50% of cases are cryptogenic – there is no cause for epilepsy that is detectable even with currently state-of-the-art investigations." --Username132 (talk) 00:03, 26 May 2006 (UTC)

To be honest, I would say, "In 50% of people with seizure disorders, a cause cannot be determined even by thorough investigation. This is sometimes termed idiopathic epilepsy." In this context, cryptogenic sounds made-up because someone couldn't think of the usual word. alteripse 02:33, 26 May 2006 (UTC)

"Cryptogenic" could be interpreted by the educated layman as being a reference to cryptococcus infection, and the diagnosis of AIDS. One of our "Radio Doctors" - a very senior physician - suggested that the word should not be used at the present, to avoid disastrous misunderstandings. I agree, "Idiopathic" is quite clear. --Seejyb 20:47, 26 May 2006 (UTC)

Someone ought to go to the Epilepsy page and change it...

I did it. --Ginkgo100 17:37, 27 May 2006 (UTC)

[edit] Callus

How is the suggested treatment for a callus, a thickening of the skin that occurs in response to damage or abrasion, to remove the skin through further abrasion? --Username132 (talk) 23:59, 25 May 2006 (UTC)

First, you talk about a callus as if it's a disease, it's actually a normal response to protect the body from further damage. That said, you can abrade off the thick dead skin, without causing any more. However, don't go and abrade down into the live flesh, or they will regrow. StuRat 00:45, 26 May 2006 (UTC)

And it'll hurt. —

The Mac Davis] ⌇☢ ญƛ. 05:18, 26 May 2006 (UTC)

There's a better way, that I've discovered rather by accident. Take a long hot bath, then scratch (with fingernails, if you have them) the dead, softened outer layer off. Do this for a week or so. And, of course, stop doing whatever caused this, or it'll come right back. And see Callous. Black Carrot 18:05, 26 May 2006 (UTC)

I don't get whats wrong with calluses, they just stop whatever you did that caused them, from hurting as much. Philc _T^E_C^I 19:27, 26 May 2006 (UTC)

And they look great, too...

I think of calluses like fingernails, a little bit is good, and helps protect you, but an excessive amount causes problems. In the case of calluses, they can crack and provide a place with no active immune system for things like warts to get a "foot-hold". I've also used hydrogen peroxide to dissolve them and safety razors on especially thick ones to cut off the outer layers. I agree that they are easier to deal with after soaked with water and somewhat softer, but thick ones are still too hard to scratch off with fingernails alone. A pumice stone may be quite useful. StuRat 14:54, 27 May 2006 (UTC)

[edit] May 26

[edit] Untitled (15 yr ol girl abuse case)

What became of the 15 year old girl who had been locked in a room by her parents and never taught anything? --Username132 (talk) 00:12, 26 May 2006 (UTC)

I don't know specifically, but if she wasn't taught to speak, the prognosis is quite bad. If you don't learn a first language while young you lose the ability, after a while. The same goes for basic social skills. Most likely, if she was truly taught nothing, she would need to be institutionalized for life. StuRat 00:39, 26 May 2006 (UTC)

You might want to take a look at Feral children for more information. Nrets

It happens more often than you think. Saddening. —

The Mac Davis] ⌇☢ ญƛ. 05:17, 26 May 2006 (UTC)

It sounds like you're refering to Genie. She is currently an adult living in a foster home in California. --Ginkgo100 18:50, 26 May 2006 (UTC)

For social skills, it would be good if she did a lot of volunteer work. Helping in a hospital, home for the aged, street feeding, etc. --Jondel 07:32, 2 June 2006 (UTC)

[edit] Laptop vs Desktop

I am interested in purchasing either a laptop or desktop. Can someone tell me if a laptop computer with a 15 inch screen is more energy efficient than a desktop. Do laptops consume less energy than desktops?

Yes, they do, but the differences are extremely marginal. You won't ever make the difference in purchase price back. --Robert Merkel 03:09, 26 May 2006 (UTC)

Unless you actually need the portability of a laptop, get a desktop. You get much more price performance per buck with a desktop. --Cyde↔Weys 03:22, 26 May 2006 (UTC)

If you're concerned about energy efficiency, worry more about how you use your computer than if you should go with a desktop or laptop. If you buy a desktop, buy an LCD screen, not a CRT. Go to the control panel (assuming you're buying a windows PC) and set the monitor, hard drives and system to turn off after a short period of non-use. (I have mine set to 5 minutes.) Also, set your computer to go into stand-by mode after a longer period, like 30 minutes. -Quasipalm 15:28, 26 May 2006 (UTC)

If you're worried because you want to be environmentally conscious, then get a second hand laptop (or desktop) or at least consider the full product cycle of your purchase.—Pengo 11:59, 27 May 2006 (UTC)

[edit] Microwaves destroy electronics...is it possible?

I have heard that in the past, people have used Microwaves to desroy bugs (covert listening/recording devices) on PEOPLE by flooding them with low-intensity microwaves. Is this just some story made up by someone, or is it really possible?

I know microwaves can destory technology to some degree, if the circuitry is intricate. Is it possible to use them on a person to remove bugs without cooking them to death? 68.52.56.111 04:23, 26 May 2006 (UTC)

If it transmits on a microwave frequency (like cellphones do), then enough noise at that frequency could prevent the signal from getting through, but I don't see how microwaves could "destroy" anything without being strong enough to cook someone. —Keenan Pepper 17:16, 26 May 2006 (UTC)

On the other hand, maybe a short but intense pulse of microwave energy would do the trick. I'm not sure. —Keenan Pepper 17:17, 26 May 2006 (UTC)

Guys Guys... It'll only cook you if the microwavelength (not a real word) is around 122mm, corresponding to the resonant frequency of water molecules in liquid water. Otherwise, microwaves do (seemingly) no harm, regardless of the intensity of the radiation, so they won't cook you. BUT, they will "fry" electronic circuitry by inducing high currents (relative to electronics), which destroy sensitive components, (provided the radiation is of high enough intensity). -- Eh-Steve 04:23, 29 May 2006 (UTC)

Wow. Very informative. Thanks! 68.52.56.111 19:52, 31 May 2006 (UTC)

Very misinformative. "It'll only cook you if the microwavelength (not a real word) is around 122mm" Can you quantify that "around"? I believe the frequency is not so precise, and what about the first harmonic? 61mm, the Second harmonic,.... etc? And it's not JUST the water that absorbs , it must be a somwhat wide band. "Otherwise, microwaves do (seemingly) no harm, regardless of the intensity of the radiation,..." That is false. "regardless of the intensity"--that's a pretty blanket statement, don't you think? And what is "seemingly no harm", that phrases seems to contradict itself. "... they will "fry" electronic circuitry ... provided the radiation is of high enough intensity)" Sorry, you're being nonquantiative again. Of course if its "high enough intensity", it will fry stuff , but how high it that? And isn't that high enough to hard the person? The original question was about whether "low-intensiy", ie convert, levels would do it. It would depend on the construction of the device, I don't see how you could relie on it. The original story sounds bogus. Maybe it's been tried, by idiots, but they couldn't be sure it even worked. And that kind of microwave transmission is probably not legal, anyway. I am skeptical. Better to find the bugs with metal detectors, etc. See Bioelectromagnetics microwaves etc --GangofOne 06:12, 2 June 2006 (UTC)

[edit] Dynamically changing onSubmit in Internet Explorer

Hi all. I'm trying to get Google Analytics to work with a tricky web application that insists on writing its own form tag; the conversion goal is on a seperate secure server, but I can't use Google's instructions for dealing with the situation, because, again, I can't alter the form tag. I thought I could use Javascript to deal with the sitation, and wrote the following test:

<html>
<head>
<body>

<form name="holy" action="" method="post">
<input type="text" name="Blah..." />
<button type="submit">SUBMIT!!!!!</button>
</form>

<script language="JavaScript" type="text/javascript">
<!--

var allforms;
var i;

allforms = document.getElementsByTagName("form");

for (i = 0; i < allforms.length; i++) {
                allforms[i].setAttribute("onSubmit",'javascript:alert("Thank you!")');
                document.write(allforms[i].getAttribute("onSubmit"));
                } 

//-->
</script>
</body>
</html>

This works in Firefox and Opera, but not in Internet Explorer. Is there any other way of dealing with this problem? Is this some kind of bug in IE? - RedWordSmith 04:26, 26 May 2006 (UTC)

The more common way to set onSubmit (and onClick, onMousedown, onLoad...) is object.onSubmit=functionName. So, it would look more like:

function sayThanks() { alert("Thanks"); }
someObject.obSubmit=sayThanks;

I can't remember right away if you need sayThanks() or just sayThanks. --Kainaw ^(talk) 19:01, 26 May 2006 (UTC)

Thank you, although I still have a small problem: in all browsers I tested (Firefox, IE, and Opera) the functions runs not only when the form is submitted, but also when the document initially loads. Except for having a wrapper function with a static variable to test that the real function I wanted called is only run the second time the browser calls it, is there any other, more graceful way to deal with this? - RedWordSmith 04:05, 28 May 2006 (UTC)

The only reason the function would run when the document initially loads is if you have explicitly called the function in the JavaScript code. When the document loads, it runs through all the JavaScript in the script tags. As long as your code is encased in functions, and the functions are only called onSubmit, nothing should run. I think the problem may lie in the way you put all the form elements on the page into an array; surely it would be easier just to say:

theholyform = document.getElementById("holy");
function confSub() { alert("You submitted!"); }
theholyform.onSubmit=confSub;

As long as your form is named holy (which it seems to be), that should do. Complicating things seems to make way for too many logic errors, and logic errors make things happen that you didn't expect to happen. Note that this solution only applies if you have one form which you know the name of. If you have an unspecified number of forms and unknown form names, your original code would be best. -- Daverocks (talk) 05:42, 28 May 2006 (UTC)

Thanks Daverocks! I think I've got everything figured out now. I misunderstood the original response and the alert function was actually only being called on load; I knew something was amiss when I saw that I had copied Kainaw's "obsubmit" typo! It looked like things were working because the form submitted to itself. - RedWordSmith 20:19, 28 May 2006 (UTC)

You want answers without typos! Who do you think we are!? --Kainaw ^(talk) 16:19, 29 May 2006 (UTC)

[edit] Writing simple video games

What is the best free program that I can download in order to write and play simple video games, and where can I download it from? --elpenmaster

Do you know some programming language? What kind of games are you interested in? E.g. there are tools for creating computer role-playing games. Maybe look into creating a game mod to an existing game you have? And be sure to check the article on game programming and the links in there. Weregerbil 12:23, 26 May 2006 (UTC)

You might look at SCUMM, since you don't say what type of video game. --Kickstart70-T-C 04:30, 27 May 2006 (UTC)

I want to write those kind of 2D games that you look at from above and move a character around and shoot bad guys and stuff --elpenmaster

[edit] Extinction of men

If all women became lesbians or otherwise started disliking men, and if they discovered a way to reproduce among themselves (by combining DNA from two egg cell nuclei or something), then would men become extinct and if so, what would be the evolutionary process causing that? Thank you

Well, I don't see that happening anytime soon. There's still too many women that want a boyfriend even if the guy in question is a complete jerk, but if it did happen, the thing causing men to go extinct would be that they can't get their genes into the kids. If they can't share their Y gene, no boys will be born, hence men would disappear. - Mgm|^(talk) 10:34, 26 May 2006 (UTC)

Ah yes, thank you. How did that not come to to my mind... it seems obvious to me now, too. It's not exactly about genes, though, but the fact that unfertilized, haploid egg cells have no Y chromosomes. And I don't expect that to happen either, ever. :-P

Of course they don't, Y chromosomes are passed through the direct parental line. Eggs can only have Y chromosomes if a man fertilizes them, so boys can only be born when a man passes that gene on. Without man all children would receive XX chromosomes. - Mgm|^(talk)

Lesbians don't dislike men.--Sonjaaa 14:08, 26 May 2006 (UTC)

As I understand it, there is (or possibly was) a small but somewhat notorious strand of feminist thought that advocates lesbianism and separation from men, see lesbian separatism. I'm sure that's very much a minority view, perhaps a tiny minority view, though. --Robert Merkel 00:09, 27 May 2006 (UTC)

If women found a way to recombine their DNA with each other, and disallowed all male DNA, then we males would use the same method to make recombinant DNA. We'd have the added difficulty that we don't have wombs, so we'd have to artificially incubate. But in this hypothetical future where such a level of genetic engineering is possible, why not also artificial wombs? We men would have to make sure we didn't accidentally combine two Y chromosomes, which doesn't lead to a viable fetus, but otherwise, we could do without women just as easily as women could do without us (which is to say, not very easily). -lethe ^{talk +} 16:02, 26 May 2006 (UTC)

Also see parthenogenesis. Science fiction author David Brin wrote an interesting novel entitled Glory Season about a world in which parthenogenesis was the main method for human reproduction, although there were still men and sexual reproduction as well. --Ginkgo100 18:55, 26 May 2006 (UTC)

Note that wombs are not essential for childbirth. An rare but notable birth "defect" is a child that becomes attached outside the womb. There isn't a lot of danger to the child, but the mother (or father) risks a lot of organ damage as the child grows and starts kicking everything. --Kainaw ^(talk) 18:57, 26 May 2006 (UTC)

We made a film about this: 's called Seksmisja. --Ouro 21:26, 26 May 2006 (UTC)

Male pregnancy is fiction.
Ectopic pregnancy is nearly always fatal to the fetus, although there are a few reported cases of full-term ectopic pregnancy resulting in a living baby. --vibo56 10:41, 27 May 2006 (UTC)

[edit] What is "mass psychosis"?

Is "mass psychosis" even a medical term? Is there a condition in social/group psychology that this phrase refers to? --83.252.190.162 11:40, 26 May 2006 (UTC)

Mass hysteria —

The Mac Davis] ⌇☢ ญƛ. 11:43, 26 May 2006 (UTC)

See [17] - Nunh-huh 11:56, 26 May 2006 (UTC)

[edit] (continued) Area on a sphere

This is the problem. It's not a homework question and I just need to know how to work it out. Length of the square is 10 cm, find the shaded area (the curved lines are the loci of the 4 corners) $Image:math-problem.jpg$

As you just want to know how to do it, I will not carry out actual calculations. Call A, B, C, D the vertices of the square in a clockwise fashion starting from the bottom left one. Let E be the top point of intersection between the four circumferences, and let F be the right one. Then one can show that the segments AE subtends pi/6and AF divide the right angle BAD into three equal angles, each of them measuring

π / 6

. Hence, if you set up Cartesian cohordinates so that A=(0,0), B=(0,1), C=(1,1) and D=(1,0), the x-cohordinate of F is just sin(

π / 6

)= $\sqrt{3}/2$ . The equation of the circumference centered in A being

x 2 + y 2 = 1

, the area you are looking for is $4\int_{1/2}^{\sqrt{3}/2} \sqrt{1 - x^2} - 1/2 dx$ (using symmetry to simplify things). Cthulhu.mythos 14:48, 26 May 2006 (UTC)

That's quite funny. There's a much easier way to figure this out. I won't give the details just in case it is homework, but the approach looks like this: let a be the area coloured yellow area, and b be the area of one of the four curvy arrowhead-like shapes in the corners. Express the area of the whole square in terms of a and b. Express the area of a quarter circle in terms of a and b. This gives you simultaneous equations in a and b which you can easily solve for a. Gdr 15:33, 26 May 2006 (UTC)

Your method doesn't account for all the areas. In addition to "a" and "b" there are is also the pointy area between two "b" areas. 199.201.168.100 15:37, 26 May 2006 (UTC)

Yes, you're quite right. So call the thin area at the side c and make three simultaneous equations in a, b and c. Gdr 15:55, 26 May 2006 (UTC)

There's certainly a way to avoid calculus. It's easy enough to get the cartesian coordinates of the four vertices of the yellow area. (e.g. the top one is at (1/2, sqrt(3)/2) just because it makes an equilateral triangle with the bottom two vertices of the main square.) Then take the yellow area to be a square joining its four vertices (aligned diagonal to the coordinate axes), plus four vaguely lens-shape pieces. The area of each of the lens-shape pieces is obtained by considering drawing straight lines connecting its two vertices to the opposite corner (i.e. to the center of the arc): it's the area of the sector of the circle minus the area of the triangle. Hope this makes some kind of sense. Arbitrary username 20:56, 26 May 2006 (UTC)

Like the person posing the question, I am not a mathematician. I suspect that the responses so far have not given enough practical detail to be helpful to the questioner. Based on the original question, and on this repost, I'll have a go at reformulating what I think the questioner had in mind: We are working on the surface of a sphere. We have two pairs of great circles. The angle between the first pair of great circles, expressed in radians, is 10cm/r, where r is the radius of the sphere. The angle between the second pair of great circles is equal to the angle between the first pair. The plane defined by the axes corresponding to the first pair of great circles is perpendicular to the plane defined by the axes corresponding to the second pair of great circles. At two opposite locations on the surface of the sphere, "squares" are formed, as illustrated in the image. Is it possible to express the area of one of these "squares" analytically, such that the area tends to 100cm² as r tends to infinity? --vibo56 21:26, 26 May 2006 (UTC)

I love math problems that have multiple approaches. I'll wave my hands a bit and assert that the corners of the yellow area cut the arcs in thirds. Call A the yellow corner on the left, and B the one on top. Construct segment AB. Figure out the area between segment AB and arc AB, and add four of 'em to a square of side AB. I think the result will look something like

$(2R\sin \frac{\pi}{12})^{2} + (2R^2(\frac{\pi}{6} - \sin\frac{\pi}{6}))$

but that's only because I looked up the formulas for the circular segment on mathworld.

Signed, math degree 30 years ago next month and am rusty as all hell. --jpgordon ∇∆∇∆ 05:41, 27 May 2006 (UTC)

The question was related to the area of a square on the surface of a sphere, and the preceding answer appears to be plane geometry (correct me if I'm wrong!). I think we can be reasonably sure that this is not a homework question, because of the vague way in which it was formulated. I believe what the questioner had in mind was the area illustrated in yellow here:

The red curves are supposed to represent great circles.
Is anybody able to come up with a formula for the yellow area in terms of r, the radius of the sphere? Also, it would be nice if the person that posed the question confirmed that this is what he/she is looking for. --vibo56 09:19, 27 May 2006 (UTC)

- Oh, it doesn't matter what they're looking for -- this is fun! Probably belongs over in WP:RD/Math. I ignored the sphere thing, for some reason or another. But isn't there insufficient information to calculate this? (Is this a solid angle on a sphere?)--jpgordon ∇∆∇∆ 16:13, 27 May 2006 (UTC)

Yes it is a solid angle of a sphere type question - the missing info. is the radius r of the sphere - without that answers will need to be functions of r. By the way if the interior angles of a triangle drawn on a sphere are a,b and c then the solid angle covered by the triangle (spherical geometry here) is a+b+c-pi in steradians. HappyVR 16:32, 27 May 2006 (UTC)

My question, and possibly the original poster's question, was if somebody could provide a formula for the area, in terms of r. --vibo56 16:43, 27 May 2006 (UTC)

I have posted a follow-up in the maths section. --vibo56 14:32, 28 May 2006 (UTC)

[edit] The science of bread at Netto

Why is the bread at Netto and Lidl always stale? If they stopped producing it for a couple of days, demand would catch up on supply and it would be fresh, right? --Username132 (talk) 12:56, 26 May 2006 (UTC)

Two possible answers: Either you should stop buying bread at 9pm, or they may possibly getting their stock of bread from the bread store down the street that doesn't sell day-old bread. freshofftheufo ΓΛĿЌ 16:10, 26 May 2006 (UTC)

Netto and Lidl are real budget-grocery chains though. I think this may be a case of getting what you pay for. They probably sell bread that has more preservatives in it, so that they can keep it on the shelf longer, which means cheaper, but unfresh, bread.--BluePlatypus 18:02, 26 May 2006 (UTC)

[edit] Spina bifida of S4 and S5

I am 30 years old. I am dealing with back pain. My X-ray result says 'spina bifida on S4 & S5'. I have treated with electro-theraphy for 20 days and with electro-Acupanture for 1 month. But the problem still persists, specially when i spent more time with computer.Who can help me to relieve from this pain? what cares should I take? What effects it will have for the future?

The place to start looking is at the Spina Bifida Association. Ask and join the mail groups and chat, but don't blindly follow what everyone says. Don't just accept "Oh you've got spina bifida so you'll have a sore back". Discuss that with your doctor, or request that you be referred to an interested doctor. Or change doctor. That is your right. You cannot be cured, but you are responsible for trying to find the best help you can. We at Wikipedia are strict about not giving medical advice for specific person's medical problems, so we could not help you much further here. We wish you success in your endeavour to solve your problems. --Seejyb 21:50, 26 May 2006 (UTC)

[edit] Mail in future.

Hi, could u plz tell the name of some free websites which offer services like "reminders" on future dates. Like i could add a reminder about xyz's birthday on dec 28 of every year. So now this service would remind me of this say 3 or 5 days earlier than dec 28 of every year. And it should be free. Than you.

I suspect you would forget to visit the website when the time comes. Gmail has a calendar feature built in, but you need to visit it (not your email inbox) to be reminded. I suggest you take a look at the software at http://www.spacejock.com - Mgm|^(talk) 14:41, 26 May 2006 (UTC)

Since the poster used the title "main in future" -- I think he or she had reminder emails in mind. Here's a list of sites that do just that. -Quasipalm 15:19, 26 May 2006 (UTC)

FWIW, I use Yahoo Calendar. It sends email reminders. - RedWordSmith 19:04, 27 May 2006 (UTC)

While not a web-based program, I use this freeware program to remind me of upcoming birthdays, anniversaries etc. It runs on startup and shows you upcoming events. — QuantumEleven 09:46, 28 May 2006 (UTC)

[edit] Budgerigars

Why are most of them so skittish, flighty and bad-tempered when compared to other domesticated birds? Even a budgie that's tame and used to humans is still prone to 'snapping' and attacking for no apparent reason, or flying around in a blind panic and crashing into things.

It's partly due to the fact that most budgerigars are parent-raised and often not even handled until they are nearly adults. It's partly temperament. It may be partly because these small birds in their native habitat are small flocking birds, individually more vulnerable than many larger parrots, but that's just a guess. And it may be partly due to the fact that they are bred in high numbers by sometimes unscrupulous breeders. That said, I never thought my budgerigars were bad-tempered, especially compared to some large parrots I know. --Ginkgo100 19:08, 26 May 2006 (UTC)

I've owned/own a few different birds (lovebirds, cockatiels, parakeets and an African grey parrot) and out of them all, the budgies have been the most spiteful and vindictive towards humans and the other birds. With other birds, you can tell when they're annoyed - wheras budgies just 'flip'. One minute the bird will be sat on your hand, allowing you to stroke him, fluffed up and contented - then you touch *one* feather that the bird doesn't want touched and his beak is clamped around your finger, drawing blood. They like to hold on too.

As for interacting with other birds, budgies can have a very cruel streak. They'll harass anything, even if it's much bigger (e.g. they were trying to bite the African grey's feet through the bars, seemingly just for the hell of it).

Are there any birds particularly well-noted for good disposition and comportment with humans? What bird would you recommend for a household with cats (if any)... something able fto fend for itself, probablyl a big bird? - Nunh-huh 01:30, 27 May 2006 (UTC)

Doves and pigeons are supposed to be good with humans - they tend to allow their owner to stroke/cuddle/play with them more than a parrot would. Parrots of all species tend to have a wild streak just below the surface but budgies do seem worse than most - and have the bite of a much larger bird. On the other hand, a large parrot/cockatoo may be slightly more docile and forgiving but if it does lose it's temper, it could easily break your fingers or tear a hole in you with its beak. If you own one, you have to learn how to gauge its moods as they never really give much of a warning that you're annoying them before they resort to biting. I guess it's because they've not been domesticated for that long, compared to other pets.

I'm not sure about cats and birds together - it's probably not a good idea, whatever species you choose. Instincts have the habit of bubbling up when you least expect. --Kurt Shaped Box 01:48, 27 May 2006 (UTC)

[edit] how to get alerts

I would like to read whenever something containing the name 'Kerala' appears on any Website. Is there a way I can get such alerts?

I doubt there is such a service as it would require following changes in the "whole WWW", which is practically impossible. But a Google search every now and then should do the same trick, I guess. –Mysid^(t) 15:36, 26 May 2006 (UTC)

Google Alerts will (more or less) do this. Dragons flight 15:40, 26 May 2006 (UTC)

Holy macaroni! –Mysid^(t) 16:10, 26 May 2006 (UTC)

== How often do people get sick? Also, how many sick days are used by the average person in a year? == 199.201.168.100 15:11, 26 May 2006 (UTC)

In the US, there is no standard way a company gives sick-days, so it would really depend on how many you're allowed. However, I found a table on the Bureau of Labor Stat. that shows the average number of paid sick days an employee gets a year, as of 1996: [18] (That doesn't really answer your question, I know.) -Quasipalm 15:55, 26 May 2006 (UTC)

[edit] Natural Gas Flame Temperature

At what temperature does methane burn at? --Chris 19:03, 26 May 2006 (UTC)

It can burn at many temperatures, depending on the ambient temperature and pressure, but the answer you are looking for is probably either the flash point or the autoignition temperature, both of which are listed in the infobox in the methane article you linked to. Oldelpaso 19:17, 26 May 2006 (UTC)

If you mean the flame temperature I suggest googling for methane flame temperature; you'll find slightly different figures for different assumptions (starting temperature of the methane, whatnot; your BBQ grill will burn at a slightly different temperature from "ideal lab standard" conditions.) Weregerbil 19:26, 26 May 2006 (UTC)

It seems that the autoignition temperature of methane is 537 degrees, but Google says that it burns in temperatures over 1000. How can that be? --Chris 19:31, 26 May 2006 (UTC)

The autoignition temperature is just the lowest temperature at which a flammable mixture of methane and air will start to burn (no spark required.) Once the gas starts to burn, it heats up rapidly and reaches much higher temperatures. TenOfAllTrades(talk) 19:51, 26 May 2006 (UTC)

[edit] Mysterious powers of two

Why is it that the different speeds for DSL connections are nearly always powers of two: 256, 512, 1024 etc. kbits/sec? I know powers of two are like round numbers for computers, but what does it have to do with seconds? –Mysid^(t) 20:04, 26 May 2006 (UTC)

I guess there's no fundamental reason, it's just what people have chosen to do. Exactly as you suggest, if a quantity is non-dimensional (i.e. is expressed with just a number), then its numerical value may have some fundamental significance, but if a quantity is dimensional, i.e. has units, then its numerical value depends on the choice of units. So for example, you could legitimately quote the speed in kbits/minute, and then the speeds you've quoted wouldn't be a power of 2 any more. Arbitrary username 20:38, 26 May 2006 (UTC)

It's not a representation of time. It's how much information can be transferred in a certain period of time, much like miles per hour is used for vehicles. The reason they're in powers of 2 is because data is represented with binary numbers. --Sporkot 22:23, 26 May 2006 (UTC)

I don't see a connection there. It could be 256 kbit/min as Arbitrary username said above – that would make 4.2666... kbits per second which is not a power of two, but the data would still be represented by binary numbers. I was wondering about the connection of bits and the SI unit of time, second. But perhaps it's just the way it's done, like said above. –Mysid^(t) 22:27, 26 May 2006 (UTC)

I suspect it's at least partly because powers of two have become round numbers for computer and telecommunications engineers, as well as computers themselves :) --Robert Merkel 07:45, 27 May 2006 (UTC)

The DSL infrastructure (although not the modem technology) is descended from ISDN, which worked at multiples of 64 kbps. That bit rate was chosen in the 1960s to give 8,000 8-bit samples per second, which Bell Labs decided was enough for digitizing voice signals. There's a really good tutorial on the subject by the IEC here. I suspect that all DSL bit rates are multiples of that original 64 kbps. --Heron 09:53, 27 May 2006 (UTC)

Thanks for the great answer, clarified the matter completely. –Mysid^(t) 10:13, 27 May 2006 (UTC)

You have to be careful with the units. With ISDN, the "kilo" stands for 1000, so its transfer rate is 64000 bps[19]. I believe with DSL, "kilo" means 1024 (I find no source for this, but it just seems silly to mix powers of two and kilo=1000). —da Pete (ばか) 08:19, 28 May 2006 (UTC)

This last point isn't just a problem with connection speeds, it used be a bit of a pain with hard drive capacities. There are moves afoot to standardise it once and for all - take a look at binary prefix. — QuantumEleven 09:38, 28 May 2006 (UTC)

Dapete, AFAIK, DLS speeds are also expressed using the SI kilo prefix. By reading the answers to my first question it becomes clear that the numbers 256, 512, ... in DSL speeds are actually powers of two by coincidence. (Also Binary prefix#Usage notes states that decimal kilos are used when measuring bitrates.) –Mysid^(t) 07:30, 29 May 2006 (UTC)

[edit] Bicycle Ergonomics

Which is the most appropiate configuration for a bike for minimal damage to the human body? --Username132 (talk) 23:14, 26 May 2006 (UTC)

I'm amazed that the frothing-at-the-mouth fans of the recumbent bicycle haven't answered this question yet...

Sorry I'm late, I was out for a ride! Seriously, though, there's two basic categories of damage caused by bicycling; strain injuries and accidents/trauma. A minimal damage bike would reduce both of these. Honestly, the recumbent bicycle article does a good job of discussing the pros (and the few cons) of this style. On a conventional bicycle, I'd think that the first two areas of concern would be to look at the seat, which is uncomfortable (and pinches all the wrong nerves), and the handlebars, where an upright rider puts a lot of their weight, particularly with a Mountain bike. I think that a suspension fork would help mitigate wrist and forearm damage. But not as much as a recumbent! Trauma, due to accidents, is harder to prevent by bicycle design, and is more a function of the rider and the road. While I'd rather be doored in my recumbent, a more serious accident like being T-boned by an SUV would be bad news no matter what's under you. --ByeByeBaby 09:35, 27 May 2006 (UTC)

Seriously, the conventional bike seat can get uncomfortable and doesn't do wonders for the male reproductive organs - see pudendal nerve entrapment - so if you're looking for improved ergonomics that's probably not a bad place to start. --Robert Merkel 07:09, 27 May 2006 (UTC)

A pair of cycling gloevs and cycling shorts can help a lot to make the ride more confortable. However, it's definitely accidents that can cause the most damage, so always use a helmet, and front and back lights if you're riding in the dark. – b_jonas 13:16, 28 May 2006 (UTC)

[edit] May 27

[edit] domain name hijacked

Today I started receiving numerous e-mail bouncebacks from e-mails sent using my personal domain name, let's call it halcatalyst.com (non-existent). Evidently some spammer got access to it. I've notified the service through which I acquired the domain. Is there anything else I can do to stop it or at least protect the reputation of the domain name? Thanks, --Halcatalyst 00:19, 27 May 2006 (UTC)

You might want to get actually start using the domain.:D.Anyways, try and find the spammer/hacker's IP and use a block system (probably ineffective). Another way you might go is to overlay some server security sofware. --hello, i'm a member | talk to me! 01:13, 27 May 2006 (UTC)

There's no hacker. It is just a spammer. Spemmers don't use their own domain names when sending spam (obviously). So, the just pick a few thousand at random and cycle through those. What can you do? You can look at the bounced emails, find the site that they are trying to sell stuff through, buy something so they have to charge your credit card, refute the charge so your bank tells you who charged you, get the company information from there (most likely a foreign company), try to find out who owns that company, hire an inspector to find the home (or family) of that person, then fly there and kill them. Sure, you'll go to prison for life (which may be very short after getting murder charges in many countries), but we'll have one less spammer to worry about. --Kainaw ^(talk) 01:17, 27 May 2006 (UTC)

Sounds fair to me. Except for the prison part, of course. I've always wondered if spammers could be charged with under harrassment laws. If I sent the URLs of porn websites to a hundred thousand people per day after being told to stop, I'd expect to be locked away. Howard Train 05:15, 27 May 2006 (UTC)

Actually, I'm pretty sure those bounce-backs use the "From" field, which is easily forged. The spammer might not have access to it at all. --AySz88 ^-^ 15:19, 27 May 2006 (UTC)

That's what happened. The spammer used my domain name with random fake names in front of the @. The domain is set up so that anything @domainname comes to me. So I get the bouncebacks instead of the spammer.

Next question: who gets the bad rap? My domain name or the server the spam is sent from? --Halcatalyst 21:40, 27 May 2006 (UTC)

What sort of bad rap do you mean? If someone sends e-mail pretending to be someone else it can of course harm the reputation of the person being impersonated; the same can extend to entire domains. While savvy users understand about faking, enough will be taken in. The worst case is where a spammer sends millions of e-mails using your address as the sender. There will be hundreds of thousands of replies, enough to snarl up your e-mail system for a long time to come. Notinasnaid 09:16, 28 May 2006 (UTC)

One of the failed delivery notifications included this information about the message sent: Received: from unknown [71.225.167.171] (HELO mydomainname.com). Is this the spammer's server? Is there a way I can look up the owner of the server? --Halcatalyst 18:09, 28 May 2006 (UTC)

Not really, and it's not worth pursuing. As someone probably already told you, many spambots forge email headers, often trying to make the "From" line appear to come from the same domain as the "To" line. You should look into spam blocking and consider this kind of thing to be spam. ---CH 05:52, 3 June 2006 (UTC)

[edit] Sibelius scorewriter software problems

Midi playback won't work on Sibelius (it used to). Everything else seems fine. I haven't made any modifications to the midi driver or anything like so. Suggestions? (help system, tech support used) --hello, i'm a member | talk to me! 01:13, 27 May 2006 (UTC)

Big face, I forgot what it is called. When you first started Sibelius, you got a screen that asked you what MIDI thing you wanted to use. Change it if the sample doesn't play. For me only the Windows one worked. Kontact player is better though I think. —

The Mac Davis] ⌇☢ ญƛ. 02:46, 27 May 2006 (UTC)

I use the Windows one, and it used to work. More Suggestions? (BTW, Thank You :))--hello, i'm a member | talk to me! 02:51, 27 May 2006 (UTC)

What speakers does the playback play to? I've worked with Sibelius on three windows computers, and have had a perhaps related problem before, and I seem to only be able to use the computer-integrated speaker in the back of the box, instead of the connected MIDI keyboard's speakers on all three. —

The Mac Davis] ⌇☢ ญƛ. 06:19, 27 May 2006 (UTC)

You need to do some diagnostics. Are you able to play midi files using other software, such as the windows media player? If yes, the problem is related to settings within Sibelius, if no, there is either something wrong with the windows settings (midi volume turned up?), a driver problem, or a hardware problem. --vibo56 10:54, 27 May 2006 (UTC)

[edit] Name of area between Lake Erie and Lake Ontario?

What is the political, geological and any other name for the land area that separates Lake Erie from Lake Ontario? ...IMHO (Talk) 02:56, 27 May 2006 (UTC)

The Niagara River connects the two lakes, not a land area. However, there are two rather prominent islands in the river, Grand and Goat. --Kainaw ^(talk) 03:03, 27 May 2006 (UTC)

Great Lakes: System Profile

Image:Great Dam.PNG

The Great Dam

The land area between the two lakes is nothing less than a Great Dam which Canada has failed to develop to its full electric power generating potential and thereby eliminate the long term energy crisis for the greater public good. The United States should therefore apply its world wide view of Immanent Domain to this region, invade Canada, confiscate the land and end the long term energy crisis! ...IMHO (Talk) 04:36, 27 May 2006 (UTC)

Oh dear, This guy better not be remotley serious in any way whatsoever regarding the motives or the action or the sincerity of what he just said. Either he's making a very subtle yet synical dig at americas foreign policy in proposing they invade canada, destroy the niagra falls for financial gain, and playing on americas percieved 'blame canada' atitude. Or if not.... just oh dear.... --Philc _T^E_C^I 14:45, 27 May 2006 (UTC)

Now don't get your bloomers all up in an uproar. This "guy" happens to know that Americans have no interest in the area West of an imaginary straight line drawn between Hamilton and Port Dover. ...IMHO (Talk) 03:25, 28 May 2006 (UTC)

I believe the potential energy is used rather effectively, given the constraints of not wanting to drain Lake Erie (which would cause massive transportation and water supply problems) and not wanting to completely shut off Niagara Falls (which would cause loss of tourism dollars). We have the ability to completely divert the entire flow over the Falls to hydroeletric generators, but rarely use this ability, as it makes the Falls rather ugly. StuRat 15:19, 27 May 2006 (UTC)

Drain Lake Erie??? And exactly what rate of flow do you compute that would make this happen? ...IMHO (Talk) 03:25, 28 May 2006 (UTC)

They wouldn't have to drain it much to cause water supply and transportation problems, and over the course of years it wouldn't take that much of a flow rate (when compared to the flow rate needed to supply all of the power needs of the Eastern US and Canada) to reach that level. StuRat 14:34, 29 May 2006 (UTC)

Hey, I'm in that business. There is a very nice treaty that regulates how much water can be used by both countries. If they turned on all the available taps, there would be no water over Niagara Falls, very bad for the honeymoon business. As it is, they wait until all the newlyweds attack each other in their beds, and then turn on the taps. This fills up a giant reservoir at night. There is actually some water that is not being used, because many old plants have fallen into the river, or have been squeezed out by the rock. That is why they are now making a second tunnel on the Canadian side, to suck out more water. --Zeizmic 00:09, 29 May 2006 (UTC)

I'm having trouble keeping up with who's actually being serious and who's just being an ass with a lame sense of humour. In any case, for any of you worried about the Americans "invading" Canada, just think of the consequences. The American administration can't even invade a country run by a brutal dictator who massacres his own people and those of his neighbours in completely unprovoked acts of aggression (estimates range between 500,000 and 2 milion dead during the "Saddam Years"), without being criticized as being "warmongers" waging an "illegal" war (whatever the hell that means). In any case, my point is that, hypothetically, if the American's decided to invade a placid, docile (overly docile in my opinion), peace loving nation like Canada, the political furor in the US would be unprecedented, leading to political upheaval the likes of which the US has never seen, and, dare I say, the likes of which would cause a near revolution among the American populace. Just think of the massive protests resulting from America's decision to attempt to stave off the spread of communism half a world away in Vietnam. Invade Canada? The resultant political upheaval could and likely would spell the end of the United States as we know it (and I'm not exaggerating here).Loomis51 01:25, 30 May 2006 (UTC)

It's just a joke. StuRat 21:36, 30 May 2006 (UTC)

On another topic brought up: Since Lake Erie is located upstream from Lake Ontario (via the Niagara River), wouldn't the damming of that river, to the extent that it would hypothetically drain one of the two lakes, drain Lake Ontario and not Lake Erie? If anything, wouldn't the dam actually cause the water level of Lake Erie (as well as possibly the other three Great Lakes, all even further upstream) to rise rather than fall? Loomis51 11:25, 30 May 2006 (UTC)

It's true that a hydroelectric generator usually requires a difference in water table heights, and where none is present initially (or a very slight difference), damming a river is one way the achieve this difference. However, as a rather substantial difference in water levels already exists between Lake Erie and Lake Ontario, it's not necessary to dam the Niagara river, unless the dam is just used to redirect the water from the Falls to the generators. In this case, the typical goal would be to keep the total average flow rate about the same as it is naturally, in order to prevent drastic changes in water level in either lake, which, as discussed previously, would be disastrous. StuRat 21:36, 30 May 2006 (UTC)

But Stu, I am right, am I not, that if any lake were to be "drained", even ever so slightly, it would be Lake Ontario, not Lake Erie? And how do you know the above nonsense was a joke? I know it sounds like a joke, but I've heard more absurd comments. Did you make that post? Loomis51 23:59, 30 May 2006 (UTC)

A dam alone would only reduce the flow rate, and so cause Lake Erie to enlarge and Lake Ontario to shrink, yes. However, putting in a dam alone would be rather foolish, and they would likely also cut a deeper and/or wider channel than the Niagara River, and put generators on the channel (I believe much of this has already been done). This would increase the flow rate from Lake Erie to Lake Ontario and would (if the increased flow rate was sufficient) drain Lake Erie over time. The increased water in Lake Ontario might increase it's level slightly, but most of the excess flow would likely just flow out to the Atlantic at an increased rate. StuRat 12:34, 31 May 2006 (UTC)

How do I know it's a joke, because of it's level of absurdity, like all satire. I hope you don't take Jonathan Swift's A Modest Proposal as a genuine endorsement of murder and cannibalism of the Irish ! StuRat 12:34, 31 May 2006 (UTC)

Please forgive me for not clearing up this question sooner. The idea here is not to dam the Niagara river but rather to label (or name) the total land mass which stands between the two lakes as the "Great Dam." (Understand now? Great Lakes ----> Great Dam.) As for humor the Canadians would probably be all to happy to see the American's build more reservoirs on the previously Canadian side not to mention finally getting rid of Hamilton once and for all. ...IMHO (Talk) 10:21, 3 June 2006 (UTC)

Perhaps what you want is Niagara Escarpment ? That extends well beyond the land mass you described, but it does run through it, at least. StuRat 18:59, 3 June 2006 (UTC)

[edit] What the heck was this creature?

The other day I was walking over to the grocery store and saw a strange animal. It was climbing, rather clumsily, down a tree headfirst. Its head looked very much like a squirrel though a little larger, but its hindquarters looked very much like a rabbit. When it moved forward, both back legs moved forward at the same time, much as a rabbit does. It had no tail at all as far as I could tell, and it was black (fur was a little mangy).

It seemed wary of me, but not afraid. This was in a well-trafficked area, so I'm not surprised at that. What I am surprised at is that no one else was freaked out by this to not kill the thing before I ever saw it. This was in the Vancouver, BC area if that helps at all. --Kickstart70-T-C 04:23, 27 May 2006 (UTC)

The only animal I can think of is a black Manx. –Mysid^(t) 09:07, 27 May 2006 (UTC)

Maybe a Marten of some sort? Like a Fisher? Maybe a Pika? --ByeByeBaby 09:24, 27 May 2006 (UTC)

Perhaps it's a large black squirrel which lost it's tail in an accident (run over by a car ?). The lack of a counterbalancing tail would make it's motion rather clumsy. Are there other black squirrels in the area ? StuRat 15:09, 27 May 2006 (UTC)

Hi all, unfortunately none of the above look like this creature...the head really looked pretty much exactly like a squirrel (though larger), and the whole creature was at least twice as large (maybe three times) as a regular black squirrel. Maybe it was a tailless black squirrel with gigantism? I'll try to get a pic and ask again. --Kickstart70-T-C 16:55, 27 May 2006 (UTC)

Could have been a squirrel with Down Syndrome? 12.183.203.184 17:19, 27 May 2006 (UTC)

[edit] E-mail IDs

Can any1 plzz give me the email IDs(real) of stars like John Abrahim—The preceding unsigned comment was added by 59.162.193.165 (talk • contribs) 05:23, 27 May 2006.

Probably not. Wikipedia is an encyclopedia. Wikipedia is not somewhere you're likely to find such information. If you need to get in touch with somebody famous, I recommend contacting their agent (www.imdb.com is a good source for info on film and TV personalities), their publisher if they are an author, their university if they are an academic, or their club or team if they are a sporting personality. Hope this helps. Howard Train 05:33, 27 May 2006 (UTC)

The fact they have fans means celebreties are swamped with emails on a daily basis, and there's a good chance they don't read enough of it to keep up. On top of that, those email adresses are often outdated. Try sending their agent a letter. It has a lot better chance to get through. - Mgm|^(talk) 13:58, 27 May 2006 (UTC)

[edit] next generation of geothermal energy plants…

Mention geothermal energy [plants] and the reaction you will get is that they are far too expensive to build and only after a relative short period of operation extract all of the sufficient energy necessary to generate power for many, many years. The solution? There is a new type of geothermal power plant being proposed that would overcome this obstacle while substantially lowering the cost of building such plants. What is this new technology? You may already be familiar with it if you have every assembled your own personal computer in the last few years. The idea is to drill wells deep enough to tap such power but instead of injecting or extracting super heated water a sealed pipe is lowered into the well and filled to the upper limit of the geothermal area liquid carbon dioxide. The super heated gas that then rises to the top as with any gravity based heat pipe is used to power turbines directly or indirectly using the heat at the top of the pipe to make steam. ...IMHO (Talk) 05:37, 27 May 2006 (UTC)

Do you have a question?

If your point is that we don't have information about this new technology in Wikipedia, well go ahead and add some. We already have an article on Hot-dry-rock; this sounds like a different method to tap the same resource, so maybe that article is an appropriate place to do so. Remember to cite your sources.--Robert Merkel 07:03, 27 May 2006 (UTC)

Probably as useless as hot, dry rock heat extraction. The problem with rock is that it is a poor conductor of heat. Only well-opened, soggy, steamy places are good. --Zeizmic 00:12, 29 May 2006 (UTC)

[edit] Omega iris - biologists etc please check?

Hello, I've just created a page 'omega iris' (and associated redirect page 'omega eye'). This was in response to a red link on the plecostomus page.

I previously asked for more information Wikipedia:Reference desk/Science#Biologists/Catfish/Plecs/Omega eye - that request still stands.

Also if anyone wants to check this page for obvious or other errors please do. In addition I'd like to put a request in for 'better' picture links - ideally a series of photos showing the eye in light/dark conditions for the same animal/species. Thanks.HappyVR 12:30, 27 May 2006 (UTC)

I was thinking about this, and a very perfunctory search turned up no articles about different eye and iris shapes and structures among different species. I think Interspecific eye anatomy or something like it might be a good article, and "omega eye" could be incorporated into it eventually. What do you think? --Ginkgo100 17:46, 27 May 2006 (UTC)

Yes, the article eye is good but lacks (specific) info. on the eye structure in different animals, there is an article on compound eyes but for non compound eyes not much - however outside the sheep and goats example (see Wikipedia:Reference desk/Science#Biologists/Catfish/Plecs/Omega eye) I don't know of many examples of obvious differences - clearly the accuity, rod/cone ratio, colour sensitivity, field of view varies between species and to some extent is dependent on the adaption of the animal eg hunter/hunted, nocturnal/diurnal etc. The suggested article definately sounds like a good addition.HappyVR 18:26, 27 May 2006 (UTC)

However in terms of an interspecies eye comparison article I wouldn't be suprised if the 'omega eye' is just a footnote or curiosity and would still require a separate page - that really depends on how such a page turns out.HappyVR 18:31, 27 May 2006 (UTC)

[edit] Ovulation

Oocyte

The page on oocytes says that a sperm has to penetrate the oocyte to make it divide by mieosis. The picture depicts a secondary oocyte becoming a mature ovum after meiosis. If the ovum is the gamete, and it is the gamete that interacts with sperm, why does the oocyte (a stage before the ovum) involve sperm? The ovulation page complicates everything further by saying that an ovum is an oocyte is a gamete. What on Earth is going on? --Username132 (talk) 12:52, 27 May 2006 (UTC)

I agree wholeheartedly, the two taken together are confusing as hell. Take the ovulation one as the one easier to understand. Both articles needs clarification. Check in a few hours' time. --Seejyb 17:26, 27 May 2006 (UTC)

Won't someone please think of the children. --Username132 (talk) 11:14, 29 May 2006 (UTC)

It weems, after extensive reading, old and new sources, that no such "thing" as an ovum exists, there are but different stages of oogenesis from in female fetus to fertilised oocyte undergoing it's final meiosis. What I thought was clear fact is confused and darkling plain. I will discuss this with our local prof of infertility at the university, he is an acknowledged expert, at least. And yes U123, I will remember children. --Seejyb 04:39, 30 May 2006 (UTC)

[edit] Difference b/w "Specific" Latenet Heat and Latent Heat

Help needed.

Latent heat = Specific latent heat (times) mass. Period. --Lemontea 14:42, 27 May 2006 (UTC)

LOL @ Latenet in title, sounds like my perpetually slow Internet. StuRat 14:58, 27 May 2006 (UTC)

[edit] question regarding a laptop

Upto how many degrees (angles) can I turn open a laptop? For example, screens in a desktop are kept at 110 -120 degrees to the table in front. In a laptop, can I turn the laptop so that the screen would be some 150 degrees to the keyboard in th elaptop? Or is the screen only turnable to a point much smaller than 150 degrees?

I want a laptop in which I would be able to rotate the screen sothat screen is 150 degrees to keyboard.

Do you know any laptops like that? please specify company , model name.

Thanks

Have you seen tablet PCs? Their screens rotate every which way. Isopropyl 14:35, 27 May 2006 (UTC)

Just about any laptop allows turning to 180°. - Dammit 16:45, 27 May 2006 (UTC)

[edit] Question regarding figuring out the yield of vinegar

If one has a bottle of vinegar that contains 5% of the active ingredient, how would on figure out how many grams of said vinegar one needs for every gram of baking soda that contains 100% of the active ingredient.

Thanks

The active ingredient of vinegar is acetic acid. The active ingredient of baking soda is sodium bicarbonate. The sodium bicarbonate article has a reaction equation that shows they react in molecular ratio 1:1. It also says the molecular mass is (about) 84 g/mol. So one gram of baking soda will contain (1/84) mol, which will react with (1/84) mol of vinegar, and the acetic acid article shows the molar mass is 60 g/mol, so this would be (60/84) g of pure acetic acid, about 0.71g. The bit I'm not sure is exactly what's meant by the vinegar containing 5% of the active ingredient. Is that by weight? If so, then you'd need about 20 times that, i.e. about 14 grams. Arbitrary username 22:23, 27 May 2006 (UTC)

[edit] monitor viewing distance

Its a well known fact that we must view the monitor by keeping the monitor approximately in an arm's distance. That translated to some 27 to 30 inches. What i want to know is that should the same distance be maintained while using a 12" laptop? For example, take the case of Acer travelmate C200. It has a 12" screen and the screen stands at approximately 45 degrees to the horizontal table while using it like a laptop. I just want to know what distance must be maintained between our eyes and the screen in such 12" devices.

Should it be the same 27 inches or less than that. If its less than that, whats the ideal distance?

I don't think it matters how far your eyes are away. Whatever's good for you. —

The Mac Davis] ⌇☢ ญƛ. 00:08, 28 May 2006 (UTC)

I've never heard of the supposed "well known fact" that we must view a monitor at an arm's length. I suspect that that's just a rule of thumb representing a compromise between conflicting goals. On one hand, you want to be farther away from the monitor so as not to force your eyes to focus on close objects for long period of time. On the other hand, you want to be able to read smaller fonts and graphics with ease. (The two goals can be achieved at the same time, but if one's limited to an ordinary monitor, there seems to be only a few things one can do to balance the two, and other, considerations).--68.238.243.228 04:33, 28 May 2006 (UTC)

If the whole problem with putting your face too close to screens is that the muscles in your eye grow stiff and you become nearsighted, then why not alternate distances, essentially working out your eyes? I'm doing it right now, alternating every 5 seconds between distances ranging from 20cm to about 200cm and my eyes feel better already. freshofftheufo ΓΛĿЌ 00:17, 29 May 2006 (UTC)

[edit] Earthquakes in the middle of plates

How are they possible? I was under the impression that collision, transformation, diversion and conversion were the only things that could cause quakes. How can you then have earthquakes in regions near the middle of a tectonic plate?

See Intraplate earthquake. --Heron 22:30, 27 May 2006 (UTC)

[edit] Gray Matter

Other than medicine, what kind of food can increase the amount of gray matter in our brains? Is there any exercise can increase the amount of gray matter?

Its matters more not how many neurons, it is how well they are connected. And how well you can use them. —

The Mac Davis] ⌇☢ ญƛ. 00:11, 28 May 2006 (UTC)

Gray matter contains mostly cell bodies of neurons and glia; of the two, only glia are generally capable of dividing in the adult nervous system. I suspect you're more interested in the growth of new neurons, but currently this isn't possible outside of certain regions of the brain (ie, the olfactory bulb and hippocampus)—and even then the physiological significance of such growth is poorly understood. Why do you ask? --David Iberri (talk) 00:19, 28 May 2006 (UTC)

My question is what food, like lithium, can possibly increase the amount of grey matter, if we eat them? What I am looking for is somethings specific, like what kind of fruits or what king of exercises?

The brain is composed mostly of fat not gray matter. Let the first reply be your guide. Laziness can not be compensated for by increasing physical gray matter. What you need to do is to increase logical gray matter. There is a picture of a kid somewhere who got shot in the head and lost over half of his brain and yet he only had minor physical and mental incapability as a result! One of the TV documentary programs showed him being fitted with a prosthesis that was bigger than a grapefruit! The brain is like a wild cat - it may be born with physical agility and prowess and a bunch of other amazing attributes but if nothing is going on and it is sleeping all the time then those attributes only represent potential that is subject to atrophy. Put that same cat on a hot tin roof and all of those attributes will come alive and be put to good use dealing with a problem. Each time the cat is stimulated in such a way it is challenged to learn a better and faster way to deal better with a similar problem. What you need to do is look for challenges that will force upon you to the need to increase your logical gray matter. ...IMHO (Talk) 04:58, 28 May 2006 (UTC)

I very much doubt that any serious research has been done relating the amount of gray matter to nutrition. The only way to get this information would be do mri scans of a large number of people, calculate the gray matter volume (which I suspect in itself would be a difficult task), and do in-depth interviews of each person about their lifetime dietary habits. What has been done, however, is to study the correlation between nutrition and cognitive functions. There is no doubt that childhood malnutrition is related to lower scores in measurements of cognitive function. Omega-3 Essential fatty acids such as EPA and DHA are probably important. I suggest you follow this link to do a medline search. A search for "(epa or dha) and (cognitive functions)" gets some interesting hits. You might also want to try simply "nutrition and (cognitive functions)". As for exercising the gray matter, isn't that the same thing as using it? --vibo56 10:47, 28 May 2006 (UTC)

[edit] Another new page - aeration - a mostly science and technology term?

In response to a 'red link' I have created a page entitled aeration. A number of questions arise:
Is it ok?
Could it be improved (yes)
Have I missed any notable examples of aeration?

In addition a similar but subtly different usage of the term aeration exists in terms of gardening/soil science - the aeration of a soil - have I dealt with this disambiguation properly?

Please change my mistakes etc etc. Thank you.HappyVR 19:36, 27 May 2006 (UTC)

[edit] Lotsa Stem Cells

"We identified a rare cell within human bone marrow mesenchymal stem cell cultures that can be expanded for more than 80 population doublings" - does this mean that after 80 doublings, there is something wrong with the cells to make them stop? If it's their telomeres shortening, then they're no use for therapy. If it's mutations occuring, then they're no use for therapy. What is causing divisions to stop - the research paper doesn't say? --Username132 (talk) 20:18, 27 May 2006 (UTC)

Shortening of telomeres in the nucleus causes the cell to no longer be able to replicate properly. So the cell can't reproduce anymore, even if it's healthy. This is fixed in sexual reproduction using telomerase. --M1ss1ontom a rs2k4 ^{(T | C | @)} 23:05, 27 May 2006 (UTC)

[edit] life cycle of plastics

what is a plastic?

Try typing "plastic" into the search box. —Keenan Pepper 21:15, 27 May 2006 (UTC)

[edit] AIDS dementia complex – an autoimmune disorder?

I was reading about AIDS dementia complex, which is a disease of the CNS that is apparently induced by the HIV virus causing monocytes and macrophages to attack neural tissue. Would this mean that ADC is a form of autoimmune disease? Peter G Werner 21:14, 27 May 2006 (UTC)

Well, I guess so. Fits the definition. --M1ss1ontom a rs2k4 ^{(T | C | @)} 23:03, 27 May 2006 (UTC)

[edit] plastics

how does polyethylene change its life cycle from raw material to finished product to recycled product????

Ethene is an unsaturated (the third point on unsaturated is the relavent one) hydrocarbon that can be mined, using polymerization you can changed this into polyethene (aka polyethylene), as it is not a thermosetting plastic you can re-use it, because there is not bonding between the chains. Philc _T^E_C^I 22:57, 27 May 2006 (UTC)

That means that PETE can be melted down and poured into a new mold to get a new object. Neat, huh? --M1ss1ontom a rs2k4 ^{(T | C | @)} 23:02, 27 May 2006 (UTC)

I thought PETE stood for polyethylene terephthalate. —Keenan Pepper 23:13, 27 May 2006 (UTC)

That's usually just "PET" though. Polyethelene is just "PE" or optionally "HDPE" or "LDPE" depending if it's high-density or low-density. (And a bunch of others listed in the article) Just to add a fact, industrially LDPE is produced using the UNIPOL process developed by Union Carbide, IIRC. We seem to be missing an article on that, though. --BluePlatypus 23:43, 27 May 2006 (UTC)

Also, I forgot to mention, the ethene may be acquired by catalytic cracking a much larger relaitvely useless hydrocarbon. Philc _T^E_C^I 23:22, 27 May 2006 (UTC)

[edit] What circumstances does Dioxygenyl arise under?

I understand what dioxygenyl is (O₂⁺). But where and why does it occur? What is it's lewis structure?

It occurs when you ionize oxygen (photochemically for instance) and let it react with something forming a (meta)stable compound. It takes a bit of energy, the ionization energy of oxygen is pretty high (1164 kJ/mol). It's a radical ion and has one unpaired electron. You should watch out with Lewis structures for ordinary oxygen - While it is correct that it's double-bonded, oxygen is paramagnetic. Two of the electrons are unpaired. As for synthesis: cursory search turns up J. Shamir, J. Binenboym, "Photochemical synthesis of dioxygenyl salts", Inorg. Chim, Acta. 37, 1968. --BluePlatypus 00:05, 28 May 2006 (UTC)

[edit] Budgerigars and mirrors

Why do budgerigars love staring at their own reflection in a mirror so much? Some of the birds I've had can sit for hours, just admiring themselves, singing and tapping the glass. Do they think that it's another budgie, or are they just really vain? --84.71.42.75 23:54, 27 May 2006 (UTC)

Very, very few animals can recognize that a creature in the mirror is them. It's probably not black and white, though. Somehow my cat seems to know that her in the mirror isn't anything to worry about =( --mboverload @ 06:04, 28 May 2006 (UTC)

Since the mirror doesn't smell like a cat, your cat knows that it isn't a cat. AFAIK birds tend to see rather than smell. Henry ^Flower 14:23, 28 May 2006 (UTC)

As an interesting example of this, my cat mostly ignores his reflection, but he did once try to jump through a mirror that was positioned so that he didn't see his own reflection in it (until it was too late). —Ilmari Karonen (talk) 23:00, 29 May 2006 (UTC)

The usual answer is that budgerigars are social, and enjoy "interacting" to their mirror friend. I don't think any animal has a self-concept that makes it possible for them to realize their reflection is actually an image of themself. My son doesn't even have that self-concept yet. --Ginkgo100 16:34, 28 May 2006 (UTC)

The first time I showed our cat her image in the mirror she got quite excited. After trying to touch it in vain, though, she learned it was nothing to get upset about, and afterwards she ignored it. --82.207.206.54 23:41, 28 May 2006 (UTC)

Ours is the same; initially tried to see what it was (as a baby will do), then seemed to mostly ignore it unless she's in the same mood as when she chews her own tail, or has something on her head. Skittle 01:49, 31 May 2006 (UTC)

I know (from TV) that some primates in fact can recognize themselves in the mirror, and use it to pick up lice from their back and stuff like that. VdSV9•♫ 17:27, 1 June 2006 (UTC)

[edit] May 28

[edit] Comic book characters

Why do male comic book characters seem so impossibly muscular? --HappyCamper 00:10, 28 May 2006 (UTC)

See Muscular comic book characters. Anyway, well, they have to! What if superman was just another computer nerd?? They couldn't do all those heroic things without excessive amounts of muscle mass. —

The Mac Davis] ⌇☢ ญƛ. 00:14, 28 May 2006 (UTC)

I don't get it. --David Iberri (talk) 05:47, 28 May 2006 (UTC)

Odd link there, Mac. You might as well ask why the villians are generally "ugly" or disfigured in some way. Or why the females are back breakingly busty. Or why the bad cowboys in the old westerns always wore black hats while the good guys wore white. They're stereotypes. Dismas|^(talk) 05:50, 28 May 2006 (UTC)

[edit] Turbine

Could someone please refer me to a site or maybe somewhere on this site that can tell me how to builed a turbine that generates electricity. Thank You

What kind of turbine? A steam turbine? A gas turbine? A water turbine? A wind turbine? --Robert Merkel 01:08, 28 May 2006 (UTC)

Wind probably, there's a site on NASA bout it. Check wind turbine. —

The Mac Davis] ⌇☢ ญƛ. 03:47, 28 May 2006

(UTC)

Wind Turbine, but is there a site that has building plans?

Try these: [20][21]. Weregerbil 07:50, 28 May 2006 (UTC)

THANK YOU!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! With many more exclamations.

Well, I hope you checked Wind_turbine#References... it had several sites with plans on it for you. —

The Mac Davis] ⌇☢ ญƛ. 10:32, 4 June 2006 (UTC)

[edit] How many cows in a bottle?

I live in a city of about 4 million people. I go down to my local suburban supermarket and buy a 2 litre container of milk. Roughly, how many cows contributed to the contents? JackofOz 01:35, 28 May 2006 (UTC)

4 million. —

The Mac Davis] ⌇☢ ญƛ. 03:47, 28 May 2006 (UTC)

Just click the "history" tab on the label and ... never mind. —Zero Gravitas 04:00, 28 May 2006 (UTC)

It could be literally thousands. Having never been to a dairy farm in Australia, I can't swear to the way things work there. But I have been to several dairy farms in the U.S. and know many dairy farmers here as well. I don't imagine it works too different there than it does here though. The way milk is produced here is that the milk comes out of the cow, goes into a pipeline, and gets dumped into a bulk tank at the farm. Every day/every other day the milk truck comes and pumps that milk out of the bulk tank. That is then taken to the milk company where it is then dumped in with milk from other farms and the whole thing is then pasteurized and bottled. One company will have dozens of farms from which they pick up milk and each farm has anywhere from 20-2000 cows. Of course, this depends on the area, California has much larger farms because they simply have more available land whereas Vermont has smaller farms. The largest farm that I know of in Vermont is about 650 cows. So there are literally thousands of cows in that bottle, brick of cheese, stick of butter, etc. Dismas|^(talk) 05:44, 28 May 2006 (UTC)

Everything is mixed together to get a consistent taste for every day. Many food production processes do it. --mboverload @ 06:02, 28 May 2006 (UTC)

I suspected that was the case. I thought it was possible the maximum number of cows per bottle might be limited by the size of the largest vat used in the pasteurisation plant. But if the milk is already pre-mixed from various places before it ever gets there, then I see how the number is much larger. Thanks. JackofOz 09:40, 29 May 2006 (UTC)

In addition, spreading the milk for each cow out among a large volume of other cow's milk ensures that no one bad/infected cow will end up hurting the consumer. Contrast this with the old days where it was more likely that you would be drinking the milk from a single cow who could be infected. Bad news for you! Nailed 20:36, 31 May 2006 (UTC)

Isn't that the role of pasteurisation? The mingling seems to actually increase the chances of infecting humans, not decrease it. If a large volume of unpasteurised milk contained milk from an infected cow, then my intuition says that everybody who drank any of the mixed milk would be exposed to the infection. But since it's all pasteurised, the infection is killed off before it gets to the consumer. JackofOz 00:29, 3 June 2006 (UTC)

[edit] P=NP

Why does it matter whether or not P=NP? What does it mean for computers? I know the answer probably is in the P=NP article but I have no idea what that article is talking about since I don't have a doctorate in computer science. It really needs to be simplified a bit. A Clown in the Dark 01:54, 28 May 2006 (UTC)

To give you just one example, the password-checking system on most computers uses a cryptographic hash function to transform the password into a number, and matches that number with a stored one. Even if you know that number, it's practically impossible to get a password that hashes to it, because the hash function is designed that way. If P=NP, however, then it's always possible to compute a password with a given hash in a "reasonable" amount of time, and thereby break into the computer system. ("Reasonable" is in quotes because it's a precise mathematical condition that doesn't always correspond to the common-sense meaning of "reasonable".) —Keenan Pepper 02:48, 28 May 2006 (UTC)

From the formal problem statement by Stephen Cook for the Millennium Prize Problems:

Although a practical algorithm for solving an NP-complete problem (showingP = NP) would have devastating consequences for cryptography, it would also have stunning practical consequences of a more positive nature, and not just because of the efficient solutions to the many NP-hard problems important to industry. For example, it would transform mathematics by allowing a computer to find a formal proof of any theorem which has a proof of reasonable length, since formal proofs can easily be recognized in polynomial time. Example theorems may well include all of the CMI prize problems. Although the formal proofs may not be initially intelligible to humans, the problem of finding intelligible proofs would be reduced to that of finding a recognition algorithm for intelligible proofs. Similar remarks apply to diverse creative human endeavors, such as designing airplane wings, creating physical theories, or even composing music. The question in each case is to what extent an efficient algorithm for recognizing a good result can be found. This is a fundamental problem in artificial intelligence, and one whose solution itself would be aided by the NP-solver by allowing easy testing of recognition theories.

The consequences of the discovery of an efficient method to solve NP-complete problems (either through the discovery of a practical algorithm to solve them on conventional computers or the development of a quantum computer even more advanced than the ones presently under consideration), would be, in my opinion, more profound than Einstein's discovery of relativity. --Robert Merkel 00:48, 29 May 2006 (UTC)

[edit] Intelligence

Is there any statistical database about IQ score or EQ score of countries? What I can find is the estimated score for one year only, but I need at least 5 years.

There is IQ and the Wealth of Nations. However, that particular book is, um, "contraversial". In my opinion, the book's data is so clearly onsensical as to make it useful only as toilet paper and fire accelerant. The question of race and IQ is heavily politicised, with some unable to accept that there is any genetic component to intelligence at all, and a lot of racist bullrinky from people claiming that intelligence is almost exclusively genetically predetermined, that there are clearly identifiable categories of "race" in which there are wide statistical difference in intelligence as measured by IQ, and that this explains racial minority and third-world disadvantage in large part. The only place where there is much good data is within racial groups in the United States, and even that is heavily disputed. I don't know why you want this data, but if this is for some kind of undergraduate or high school essay I'd strongly suggest you rethink your approach after reading some of the articles I've linked to. --Robert Merkel 12:14, 28 May 2006 (UTC)

The "IQ and the Wealth of Nations" is what I was talking about. It is the only source I can find with estimated IQ score, but I only can find one year of it. Moreover, I had read those articles. IQ and EQ are the best I can think of to go with, because others seem so difficult to find date to prove whether people are getting smarter or dumber. Any suggestions of what direction I can go with and the source of data? Thanks.

Ah, right. Are people today more educated than in the past? Yes, just about everywhere in the world. Smarter or dumber is a harder question, but see Flynn effect. --Robert Merkel 22:46, 28 May 2006 (UTC)

[edit] How To Sort Through all that Computer-Buying Jargon

I realize this to be a really open-ended conversation, but surfing the web has left me paranoid that if I could understand any of the writing about computers I read, I'd simply be soaking in propaganda artfully disseminated among various customer-review sites by Dell. Wikipedia searches are generally too history and science related to answer any of the questions I'm interested in. And since I know the guys who hang out at the wiki help desk are here to answer questions anyways, I wanted to ask a two-part one. First of all, can somebody explain all that technical computer lexicon: gHz, ram, the difference between intel and AMD, what one needs for a high-quality computer that's capable of dealing with a lot of information (mostly music - but lots of it, and a bunch of programs too.) What is an excessive gHz number if I'm not really a major gamer or anything but my current computer (which is not great but not crappy) is dying under the weight of all the crap it has to deal with. Same with ram. And, second part of the question, what is the intelligent way to go about getting a moderately light laptop capable of dealing well and quickly with abou 100 gigs of music and then some other stuff? Everyone seems to be talking about Apple. Is it really any better? The way it's organized (really, prohibitively, user-friendly) irritates me. Is Alienware overkill (I'm not a gamer)? So, from a non-Dell-bought perspective, could anybody recommend a good computer that isn't inordinately expensive, but weighs below 8 pounds, costs under 3000, and can deal with 120 gigs or so of info quickly and withoutwithout freaking out on me? Am I just dreaming? Oh, and also, will the new Windows program make everything more guarded and difficult? Should I just avoid it altogether and go for Apple or Linux, or does Microsoft own enough material that it's stupid to buy anything else right now? Thanks so much, Sasha

Processors are basically the brain of a PC. The speed of a processor is measured in hertz. 1024 hertz=1 kilohertz. 1024 kilohertz=1 gigahertz. Processor speed is usually around 2.5-3.5 gigahertz. Clock speed really isn't all that important these days, it's mainly the processor itself that matters. Celerons and Durons are the really bad processors for businesses and budget computers. As long as you don't get one of those you should be fine. RAM is where the computer keeps its short term memory such as what is on the screen right now, numbers that are being used etc. 512 MB to 1024 MB should suffice very well. Intel and AMD aren't really all THAT different. Intel processors tend to run really high in hertz but in my personal opinion I'd say AMD is better anyway. Mac laptops are pretty good due to the fact that their processors are nice and they can run both Windows and OS X. Alienware is VERY overkill if you don't game. You probably don't want Vista in my opinion, it really seems like a rip-off and it can't do anything that XP can't already do. I'd say go with a Macbook from Apple, more specifically one of these [22]. A Clown in the Dark 04:55, 28 May 2006 (UTC)

If your present computer is no longer coping with what you want it to do, there are three likely reasons:

insufficient RAM. You can probably increase your RAM quite cheaply. If you have less than 512 MB, then this is worth looking at. The simplest way to upgrade would be to take your computer (just the main box, not the monitor, keyboard and mouse) into some small computer shop and ask them if you can double your current RAM.
insufficient disk space. You can probably fit a second hard drive, which will appear to Windows as "D:". Again, just take your computer to a small computer shop and explain what you want. You say you have about 120 gigs of music, so buy at least a 200 Gb drive (unless you have a very old BIOS or operating system, which may not be able to recognise such a large drive).
spyware slowing down your computer. Run a program such as Lavasoft Ad-Aware on your computer. It's free to download. Check the Wikipedia article before downloading any program which claims to remove spyware as some programs claiming to remove spyware are themselves spyware. Some spyware is very difficult to remove, so you might need to try several anti spyware programs, or even reinstall the operating system. If it's that bad, buying a new computer makes sense, but you need a strategy to make sure the new computer doesn't also get infected.

If you do buy a new computer, my rule of thumb is to make sure the speed in GHz is twice as high as the old one, the RAM is twice as large, and so is the hard disk space.

All this advice assumes you have a machine which is a couple of years old, but not more than about five years old. If you're already running a recently-made machine, you don't need to buy a newer one, and if your machine is ancient, then upgrading it probably isn't sensible. If you tell us more about your current machine we may be able to give better advice.-gadfium 05:22, 28 May 2006 (UTC)

you guys are awesome. thanks so much for the help

so i think i'll buy a new computer. i've got a dell dimension 8400 which isn't all that old or anything (i don't quite remember, but i think maybe 3-6 years) but it's started going crazy on me. I have an internal extra 40 gigs, and one day it suddenly crashed, so i had some computer wiz recover the files and i got another internal and installed it, and now it will from day to day decide whether or not to function. so sometimes my internal drive just wont open at all, and if i restart it'll function just fine. but the computer's also making disconcerting noises since my internal drive crashed, like every now and then a fan (though nothing's obstructing the fans) is being blocked by a piece of rubber that flaps out of the way noisely perhaps three times a second for a couple seconds, which doesn't sound very good. I'm going off to college soon anyway, so i think I'll just buy a new one. apple? do i need higher gigahertz for more memory? is there any way other than defragmenting to get everything better organized, because the more information i have the slower it takes since the computer's searching through everything every time i try to open a file. opening a music player can take a minute and causes the player to crash about 50% of the time. it's infuriating

oh yeah. and why did the person who suggested AMD over intel suggest that if intel has more gHz?

and how does one check how much ram is on a computer? you guys have been tremendously helpful. thanks

If you know the model of your computer and haven't changed the RAM, the easiest way is probably to go to the vendor's site and look up the technical specifications. Isopropyl 06:10, 28 May 2006 (UTC)

Heehee--I'd try to give you advice, but instead I'd start acting like an Apple salesman. --M1ss1ontom a rs2k4 ^{(T | C | @)} 06:12, 28 May 2006 (UTC)

Defragmenting does help a lot. It's possible that you don't have enough free RAM to run, say, a music player. In this situation, adding more RAM helps greatly. On Windows XP, it's relatively simple to check the amount of RAM. Just do a right-click on "My Computer", and select "Properties". The total amount of RAM you have available should appear there. Regarding your question "do i need higher gigahertz for more memory?", the answer is that you don't need a higher GHz processor to add more RAM. Also, about the AMD and Intel processor difference, the reason a lot of people prefer AMD processors is because they have a different architecture to Intel ones; in other words, they are built differently. AMD supporters, of course, say it is built better, even if it has less GHz in general, and a lot of people would probably agree. -- Daverocks (talk) 06:20, 28 May 2006 (UTC)

last question. i promise. so i have fine ram (512), good gHz (2.99), and my computer's only 4 or so years old, but it's just dying. i don't have much spyware, bc i've checked pretty recently, but the computer's just so slow. i tried opening the start menu, and when my mouse hovered over "programs," it loaded up a blank gray panel (as if in any second this list of programs would fill in) but nothing happened. for about a minute my mouse stayed there, but the damn thing wouldn't load, so i clicked out, and a half a minute later, the start menu closed. I just have, including additional external and internal harddrives, about 120 gigs of stuff on my computer. is that why it's running so slowly? any other ideas for why? any way to fix all this temporarily? i've defragmented recently as well. it's bizarre, and frankly this has all be pretty recent. it was working a lot better two months ago (i've gotten a lot more music since then too, but not THAT much)

oh. and when a computer specification page lets you choose between the same size hardrives with different rpms, does that just mean that the one with more rpms is faster?

For hard drive speed: Yes, but for playing music it shouldn't really matter to you.

You say you don't have much spyware, but it's starting to sound like a spyware problem to me. Try a different spyware checking program, no single program can find or remove everything. The other possibility is that you are running too many background programs, even though each program by itself is harmless. I've seen people who run three different antivirus programs all at once because they feel safer that way. One other thing that occurs to me is that your system is running in a partial "safe mode" due to some device conflict. Right click "My computer", select properties, then choose the hardware tab, and press the "Device Manager" button. Are any of the devices showing a question mark or a red cross?-gadfium 06:45, 28 May 2006 (UTC)

About why I suggested AMD over Intel, clock speed really isn't all THAT important. There's a lot of factors that go into a processor's speed and quality such as its amount of cache, transistor count, temperature, power consumption, etc. A Clown in the Dark 07:05, 28 May 2006 (UTC)

Always check your FSB (front side bus) because even if everything is a fast as it can be, if this is slow everything is slowed. It will most likely be a decent fsb, as they are relatively cheap, but its worth the check, as it also a general indication to how good the motherboard is. There is a table on the FSB page that tells you how much frequency you need for a given processor, my recomendation would be an athlon 64 processor with atleast 800MHZ fsb, 512mb ram, what ever hard drive you want, but make it a decent speed if you want to find all that music quickly (i.e., no loading time) and that should be it for the minimum spec for what you described, unles i forgot something... Philc _T^E_C^I 10:21, 28 May 2006 (UTC)

I have no idea what you guys with computer trouble are talking about. I have an apple. :P Its birthday was April 9, 2002 2:22 AM, and it has NEVER given me any trouble at all. Its only 770 MHz, with 512 Mb RAM, and 40 Gb hard disk space. I'm going to need a new one in a year or so though, because of hte new Intel-ness. —

The Mac Davis] ⌇☢ ญƛ. 10:48, 28 May 2006 (UTC)

would replacing the CPU be a major operation? would there be easier ways of upping the Ghz of my pc? would it be particluary nesscary to incease speed and ability cuss i'm slowly upgrading my pc currently have 1.8 ghz athlon--Colsmeghead 13:35, 28 May 2006 (UTC)

I was going to answer your question, but i'm actually an undercover agent working for dell--152.163.100.74 23:23, 28 May 2006 (UTC)

Ahem... to answer Colsmeghead's question in a non-trolling way ( :P ), it depends what you consider a "major" operation. Replacing the CPU typically involves opening up the computer case, removing the current heatsink and CPU from the motherboard, and replacing it with a new CPU (preferably higher GHz) and heatsink. This is the traditional way to "up the GHz", but if it's too much for you, a technique called overclocking exists. Essentially, overclocking involves forcing the CPU to run at a higher frequency (higher GHz) than the manufacturer specifies. If you don't know what you're doing, you can stuff up, and even if you do it correctly, overclocking tends to reduce the overall life of your CPU, so I don't recommend it. Then again, it's also possible to stuff up replacing a CPU. But there are probably other ways to dramatically increase your system's performance without having to upgrade the processor, such as adding more RAM. -- Daverocks (talk) 12:44, 29 May 2006 (UTC)

Something that has not been mentioned, related to strange performance, and to the funny fan noise you hear: Apart from software, check that your CPU is not overheating. You may be able to monitor it inside your operating system, or may have to use the initial setup (CMOS - the thing you get when you press "Del" key as the machine boots). A new or clean cooling fan, heat sink and enough thermal grease sometimes solves all these things that seem to bother you. Check the integrity of the memory. You can either plug your memory into some other machine, or ask a shop to test your machine with known good memory. As above, adding more RAM can improve things remarkably.

Replacing a CPU is simple, but follow the instruction (re touching, static eletricity, gentle positioning) accurately. First get the specs for your main board (you can find them on the net, if necessary), then see what kind of CPU it can accept, before buying anything. A number of failed DIY upgrades that I've needed to fix had to do with inadequate thermal coupling between the CPU and it's heat sink, or not putting in a new fan. --Seejyb 20:30, 29 May 2006 (UTC)

I'm troubled by the apparent underlying conviction that you're being railroaded/hoodwinked by the assorted NewSpeak proponents at (Dell, or Gateway, or whatever). There certainly is a good bit of madison Avenue content free manipulation going on, but not at the level of CPU speed (it really does make a difference), RAM sizes (more certainly is better), ... That's just engineering, and if you're willing to learn, there are numerous sources of information. On the Web (though the good ones are perhaps harder to distinguish among), in books, and in user groups (though again the uninformed are too loudly prominent). If you feel lost on these matters, you can simply educate yourself. The Thompsons (eg, PC Hardware in a Nutshell, O'Reilly Assoc, and their Web site as well) have written on these matters (not exhaustively, it's true, but perhaps more than you want to know), but your distaste for that sort of thing leaves you at the mercy of others and their biases. Anonymous comments here are much better, in my opinion, than the average 'computer whiz' from down the street or the 'smart kid' at school, but that's only my opinion, and I might be completely bonkers. How would you distinguish between my bonkers opinion, and my possibly hugely informed and neutral opinion? In this, as other consumer decisions, it's your responsibility to make the best choice you can and bet your funds on it being more correct than not. Consumer Reorts is awfully generic in its recommendations (has to fit in a small article, no?), but you'll hardly be completely fleeced if you follow their suggestions. Won't get a machine well suited to your particular needs either, but...

The hoodwinking about which your subconscious suspicions are warning is not really about the hardware engineering, though if I were designing those standards there would be fewer odd corners, but in software. This is not constrained by very many real world limits, nor by a necessity for elegant sensible and as stable as possible design. There are significant disadvantages to the software standards in use (in many respects), and yet the weight of the market presence of some of these is such that alternatives are nearly invisible. This is the side of things you should be worried about being misled on.

One of the reasons the minor manufacturer that is Apple is a significant alternative is that the software they use is entirely out of the mainstream. Not without its problems, even so, but at least more than a little different. In fact, Mac hardware is largely inflexible, choices having been made for you by the folks at Apple. They have, for instance, abandoned floppy drives as a standard device many years ago. And for several years, they didn't include USB ports in their machines, using instead the much less important Firewire interface. The reason Apple is significant presence is that they are now using a very different design of operating system than does the majority of other suppliers. It is, underneath the Apple specific trappings, Unix. And Unix, from its very beginnings, was designed for multiple users and to keep those users out of each others stuff (files, hardware, ...) even when running on the same machine. This remains true for many of the current *nixen, including mac OS X, the various distributions of Linux (I favor SuSE), the BSDs (OS X is one, but I prefer FreeBSD or NetBSD), or more commercially, Linspire (an entry level sort of Linux) or Syllable (another entry level *nixen). Knoppix provides a way to check it all out, running entirely from a CD without disturging anything at all on your current PC; doesn't even touch the hard drive unless you explicitly tell it to. Those responsible for machines running such operating systems must understand enough about the OS to manage it effectively. That means that such folks must learn something, and a great many people don't want to do so. I'm not sure that it's possible to manage this without good luck in choosing the people whose ideas and advice you will (blindly) follow.

We humans don't know how to design complex systems (eg, software) which do what you need, even if you don't quite know what you want, and furthermore do it safely and securely too. What we can do, at least in this instance, is to help you with learning what you need to learn. Linux is the most comprehensively documented operating system that has ever existed. There are books and magazines (I think Linux Journal and Linux Pro Magazine are pretty much the best of the lot), and there is the Linux Documentation Project, all of whose docuemnts are online and freely downloadable, rather like almost all the Linux distributions themselves. In particular, they have produced two particularly excellent full books which are worth the download: The System Administrator's Guide, and The Network Administrators Guide. There are also lots and lots of smaller documents (HowTos and such which cover single topics -- mostly well, but sometimes less than clearly or completely). And Paul Sheer's Rute Guide to Linux is a fully professional, soup to nuts, introduction to Linux and freely downloadable as well. The Linux Cookbook by Stutz isn't free, but is very easily approachable, being short recipes which can be tried in a few minutes. Good practice and easy incremental learning. And there is lots of introductory mateial on the Web (eg, linux.org (follow the pointers), and even linuxchix (again, follow the pointers). Learning, it's a good thing. Perhaps especially in one who is going off to school. ww 18:46, 30 May 2006 (UTC)

[edit] Female N-Type connector gender question

Hi,

Why does the N-Type Female connector has a pin been a female?

Thanks,

Does Gender of connectors and fasteners help?-gadfium 05:49, 28 May 2006 (UTC)

Or maybe N connector.-gadfium 05:52, 28 May 2006 (UTC)

Although it looks like a shemale, it is actually a long thin socket. Compare the male of the species, which has an even thinner pin that will fit snugly inside the female.--Shantavira 07:56, 28 May 2006 (UTC)

[edit] DVD Movie Creation

Which program would I use to burn a WMV movie file to a DVD in perfect quality so that it would work on a DVD player (as good as the movie at least)? I know Nero works but i'm pretty sure the quality isn't maxed out with it. Respond ASAP please--154.20.89.16 04:44, 28 May 2006 (UTC)

Completely impossible. Transcoding is a lossy process. Sorry! =) --mboverload @ 06:01, 28 May 2006 (UTC)

The Windows Media Video format is itself a lossy format, so any WMV file has probably already lost some of its original quality. The format is surprisingly good, however, and you shouldn't notice the difference. Concerning recording the movie to DVD, Nero should do the job fine. But if you're still interested in other software, this is a short list of some other DVD authoring suites. -- Daverocks (talk) 06:01, 28 May 2006 (UTC)

Thanks a lot.--154.20.89.16 19:11, 28 May 2006 (UTC)

[edit] Lawn grass length

What's the optimal length of lawn grass for water conservation, assuming one wants a lawn that is at least somewhat green (not allowed to dry out completely/seed)? I guess some of the considerations are: a) quantity of plant matter that requires water to survive; b) length of roots that can draw up water from deeper in the soil; c) quantity of ground cover minimising evaporation; d) quantity of roots minimising runoff.--Anchoress 05:55, 28 May 2006 (UTC)

I'm no pro, but it really depends what kind of grass you have. --M1ss1ontom a rs2k4 ^{(T | C | @)} 06:10, 28 May 2006 (UTC)

Could you be more specific?--Anchoress 06:42, 28 May 2006 (UTC)

I don't think a, b, or d will have any effect on the equation. c is all important, as is the "leakage" of moisture from a cut stem. For "optimal" moisture retention don't cut the grass at all. --Shantavira 08:02, 28 May 2006 (UTC)

Conservation for whom? The water is not being lost, it is just moving from one place to another. You seem to want all your water in your grass? —

The Mac Davis] ⌇☢ ญƛ. 10:43, 28 May 2006 (UTC)

Water hog. Quit hogging all the water. --Username132 (talk) 17:58, 28 May 2006 (UTC)

Thanks for all the replies so far. Shantavira, I agree with you that uncut grass is best, but as I'd stated this is assuming that the grass is cut, just trying to figure out how long. Mac Davis, sorry for not being more clear. In some parts of the world water shortages necessitate watering restrictions, so the conservation would be added water. --Anchoress 10:59, 28 May 2006 (UTC)

I was assuming conservation of mains water supply, as there is currently a much-publicized drought in the south of England.--Shantavira 10:54, 28 May 2006 (UTC)

As long as possible for maximum water conservation, as you'll find with really long grass, even in the height of summer, the ground will still be moist. Philc _T^E_C^I 15:10, 28 May 2006 (UTC)

For bluegrass lawns, three inches is considered a good length for water conservation. That's around 7.5 cm. Also keep the following tips in mind: Don't cut more than a third of the blades' height at a time, or the plants will suffer from the sudden loss; be sure your mower blade is very sharp; and water deeply but infrequently to develop deep roots. --Ginkgo100 19:38, 28 May 2006 (UTC)

Yippee!! Thanks Ginkgo100, that's *exactly* the kind of answer I was hoping for! Thanks very very much for taking the time to reply, and thanks again to everyone else who took the time to post something on my question.--Anchoress 22:52, 28 May 2006 (UTC)

Wow, do you grow your lawns to 8cm? Down here in Africa we call that lush pasture, for fattening sheep for Christmas dinner :).--Seejyb 18:48, 29 May 2006 (UTC)

I do. I live in Colorado, U.S.A., which is hot and quite dry in the summer. I'm so accustomed to long grass that I consider it more aesthetic than the short grass one might find in lawns elsewhere. --Ginkgo100 21:59, 29 May 2006 (UTC)

[edit] First electronic theory of valency

Is this parapgraph correct? Is it true?

By 1904, the first electronic theory of valency was developed by Thomson. A revision of Berzelius ’s electrochemical scheme and Maxwell’s electromagnetic theory, he came up with chemical bonding being nothing more or less them a simple electrostatic attraction. Thomson concluded that a bond was formed when one or more electron was exchanged or transferred between two atoms. The “donor” atom then becomes positively charged and the atoms that receives that electron then becomes negatively charged.

Thank you

Sounds like a somewhat oversimplified explaination of Thomson's theory. Second, "true" is a relative term. But chemical bonding cannot be explained solely in electrostatic terms. It cannot be described in any classical terms, because strictly quantum effects like the Pauli exclusion principle (electrons being fermions) are critical to correctly describing chemical bonds. However, as a model, it does give at least a little bit of insight, in particular to ionic bonds. --BluePlatypus 14:28, 28 May 2006 (UTC)

I don't understand? is it correct or not?

If you don't understand that "true" is a relative term, then I can't help. Otherwise, you'll have to be more specific about what you don't understand about it. --BluePlatypus 23:03, 29 May 2006 (UTC)

I understand what "true" means offcourse. when i said i don't understand i meant that i don't understand your reply in saying whether my paragraph is correct or not!

[edit] California as ancient impact (comet) creator?

I know there have been many studies of soil samples an other impact creator indicators of California but I can't help but look at all of the rock and other geological formations coming into LA from Bakersfield in addition to those in Chatsworth and just about everywhere to the point almost that you begin to be unable to see the trees for the forest. Furthermore if you travel through areas as far North as Montana and through Arizona, New Mexico and even as far away a Texas you can spot mountain size piles of what looks like it could be the debris that returned to Earth after such an impact - one big enough to carve out the great California basin. Maybe I'm crazy but I don't believe for a minute that it is the result of Tectonic plate Subduction but rather that only the original creator has been distorted by motion of the Pacific and North American plates. Again call me crazy but I can't seem to explain all of the geological features to my own satisfaction in any other way. Call me crazy. ...IMHO (Talk) 09:38, 28 May 2006 (UTC)

So... where'd all those mountains in south america come from? must be one really huge impact..oh and, you're crazy IMHO (Talk)--152.163.100.74 23:22, 28 May 2006 (UTC)

Hello crazy! --DLL 18:38, 28 May 2006 (UTC)

I'm positive that if this were true the literal HOARDES of geologists in California would have noticed =) --mboverload @ 20:45, 28 May 2006 (UTC)

Impact creators are extremely dangerous. Do not go near one! Some say California is full of impact creators. Do not go near it! --Zeizmic 22:23, 28 May 2006 (UTC)

No, it's just full of the home-secuals =D --mboverload @ 05:39, 4 June 2006 (UTC)

[edit] "The car wheel rim analysis"

how to do the car wheel rim analysis by using the ansys tool? wher i can get the informations on wheel rim<web>?

         --Shridhar vd 11:12, 28 May 2006 (UTC)shridhar

[edit] ventilation

When something says to use adequate ventilation, how much ventilation would be considered adequate? KeeganB

I'm not an expert, and I hope you will get advice from some, but when I'm doing anything that requires 'adequate ventilation', like using spray paint, bug spray, or corrosive cleaners, I use the following rule of thumb: I want as much ventilation as would be necessary to prevent a kitchen smoke detector from going off if I really badly burnt a couple of pieces of toast. I think the idea is sound: you're as sensitive to contaminants as a smoke detector, therefore contaminated air exposed long enough and in enough concentration to irritate a smoke detector would also irritate you. :-) What it means to me is either several windows that open all the way (on at least two different walls for a cross-breeze), or a strong suction fan (like a bathroom fan, not just a ceiling fan) plus an open window, or an open window and door. Other ideas include: call the manufacturer (they usually have 1-800 numbers) or call a poison control centre.--Anchoress 12:22, 28 May 2006 (UTC)

If in doubt, use a fume mask - even if only one of the cheap plastic/papier mache type. And work outside if at all possible. Grutness...wha? 12:41, 28 May 2006 (UTC)

Good advice Grutness, but the problem is it's not only the safety of the person using the chemical; flammable products can build up enough gas to ignite if sparked, that's one of the other reasons adequate ventilation is so important.--Anchoress 13:00, 28 May 2006 (UTC)

Mmm. good point. I'd forgotten to consider that. Grutness...wha? 01:52, 29 May 2006 (UTC)

[edit] Is a Home Team Win a "Proven" Boon for Souvenir Shacks?

This is pro-ball season. The souvenir kiosks at the ball park seem to be busier just after a home team win than after a loss. Has there been a formal study that shows a positive correlation between home team wins and souvenir sales?--JLdesAlpins 12:39, 28 May 2006 (UTC)

[edit] L-number, fishkeeping, copying, and editing info

I recently added a page L-number which may need tidying.. This is not my main point - I have found a list of L numbers with associated info. eg scientific classification - it is an external link on the page - what I can't seem to find out is whether it's ok to copy and edit this info into an article (it would provide a usefull cross reference in future) or whether it's some sort of copyright violation etc. I would add wiki markups to the data but otherwise it would be pretty much a straight copy - can anyone advise whether this is a right or a wrong thing to do?HappyVR 12:49, 28 May 2006 (UTC)

Wow, great! I noticed you're contributing a lot to pages about armored catfish, and wondered if you would do L-numbers, which confused me a great deal when I first ran across them. However, I would recommend asking this question on the Help Desk, as it's more a question about copyright than a technical question. In general, though, you should contact the original publisher and ask them to license the text under the GFDL before using it on Wikipedia. I have done this with images but not with text. --Ginkgo100 19:45, 28 May 2006 (UTC)

Thanks I'll try that.

If you're interested in L numbers the best place to try would probably be http://de.wikipedia.org/wiki/L-Nummer the german wiki page for the same thing - just needs translating. (or use a translation tool such as 'babel-fish' here - http://babelfish.altavista.com/babelfish/trurl_pagecontent?lp=de_en&url=http%3A%2F%2Fde.wikipedia.org%2Fwiki%2FL-Nummer) which sort of works...HappyVR 20:35, 28 May 2006 (UTC)

[edit] nuclear energy

status of nuclear energy in india and the world--Mudasir dar122

Status: up and running. Do you need to know something specific the article on nuclear power does not address? (And there is an article on nucular. Amazing.) Weregerbil 15:42, 28 May 2006 (UTC)

but there is on nucular weapon. I'll add the other. You never know when George W. Bush might be searching Wikipedia. DJ Clayworth 17:23, 29 May 2006 (UTC)

[edit] Why are all these computing related questions still here?

I thought we reassigned those to the math reference desk?--Frenchman113 on wheels! 14:15, 28 May 2006 (UTC)

Possibly because Computer Science doesn't want to be shoved over with the math geeks. In my opinion, if it is computer science, it belongs in science. If it is math, it belongs in math. When it comes down to it, we speak English in the science RD and they speek math geek in the math RD. Just try to decipher one of their answers (or any math article on Wikipedia) without at least a BS in math (and the term "BS" really fits in this case). --Kainaw ^(talk) 20:44, 28 May 2006 (UTC)

Believe me, Computer Science isn't about computers. It's about math =( Most of the computer questions are not computer science related, though --mboverload @ 20:51, 28 May 2006 (UTC)

Yeah, almost all the questions we get are how to use software or what RAM to get. —

The Mac Davis] ⌇☢ ญƛ. 23:54, 28 May 2006 (UTC)

In Science Bowl, before the Big Recategorization, all comp-sci questions were...er...science. After that they became "general science". Math is a category too.

As Edsger Dijkstra once said, "Computer Science is no more about computers than astronomy is about telescopes." --KJ 12:21, 29 May 2006 (UTC)

I agree with Kainaw; I liked the Science reference desk much better when computer science was officially included in it. Now I have to check the Math reference desk too to be sure I'm not missing out. I mean, Slashdot includes Science-related articles in their repertoire, and yet not Math-related ones. Surely we can do the same? :) -- Daverocks (talk) 12:51, 29 May 2006 (UTC)

<---

Pshaw, guys! Theoretical computer science is indeed mostly math, but anything other than paper and pencil work immediately becomes engineering, albeit a mixture of electronic and applied math, with more than a modicum of shopping theory (ie, attempting to find good combinations of this or that product (subsystem) design). Since most folks think (wrongly) that things with math and measurement ARE science, putting these questions in the non-existent engineering categoy wil cause more trouble than not. Given popular convictions on what 'science' is, we should probably stick with the current situation. ww 17:38, 3 June 2006 (UTC)

You have it backwards. Theoretical math is mostly computer science. Theoretical computer science is mostly trial and error - no math required. Of course, there are people who consider programming to be math. I am not one of them. --Kainaw ^(talk) 23:51, 3 June 2006 (UTC)

[edit] Malpractice In The Scientific Community

How frequently do people fabricate their results and what motivations do they have for doing so? Are they scared of loss of funding if they don't show results - is it therefore the funders who are to blame for applying too much pressure? Did that Korean guy just do it to embezzle money? What other forms of malpractice occur? --Username132 (talk) 14:20, 28 May 2006 (UTC)

Big Science has lots of pressures, mainly 'publish or perish', and funding. I don't have any links on the general philosphy, or ethical issues, but I'm sure there will always be a few who fall by the wayside. --Zeizmic 00:40, 29 May 2006 (UTC)

Fall by the wayside? You mean scientists? That's probably what'll happen to me :'( --Username132 (talk) 02:40, 29 May 2006 (UTC)

Scientific misconduct --GangofOne 05:18, 29 May 2006 (UTC)

[edit] Google earth and browser feature

I viewed Google earth sometime back and found interactive navigation features that I thought were impossible in a web browser. What feature of the browser is it using? How can I turn the feature off (in Mozilla Firefox)? —Masatran 14:21, 28 May 2006 (UTC)

Do you mean Google earth which is a separately installed executable program and doesn't run in a browser, or http://maps.google.com/ which does run in a browser? The latter uses something called Ajax (brace yourself for a flood of TLAs and ETLAs if you click the Ajax link). Weregerbil 15:36, 28 May 2006 (UTC)

[edit] Mosquitoes vs. Ticks

I have read many times that when a tick is sucking your blood you must remove it with care to avoid its head or mouth getting stuck in your skin. This piece of information leads me to my question: when a mosquito is sucking your blood, and if you smack it, will the proboscis get lodged into your skin? If so, does this increase the risk of getting a disease? Thanks--71.98.16.114 14:54, 28 May 2006 (UTC)

Mosquitos only stick their syringey thing into your skin. Ticks tend to lodge themselves into you so they're hard to remove. Mosquitos have no such problems. - Mgm|^(talk) 17:00, 28 May 2006 (UTC)

Ewww. Kilo-Lima|^(talk) 18:24, 28 May 2006 (UTC)

Actually, there was mention if this regarding the West Nile virus by the Canadian health authories. They tried to get people to not smack-and-kill mosquitoes because of a concern of leaving virus-laden mouth parts in the flesh. I think this might have been a little fear-mongering without known concern however....though I have no medical proof either. To say nothing, of course, of people like my brother who like to pinch the skin around the bite while the mosquito is there, to trap it and force it to suck blood until it explodes on it's own greed. --Kickstart70-T-C 21:44, 28 May 2006 (UTC)

[edit] Innate Cancer Treatment

I learned that the property of aging is there so that a cancer dies after its tolomeres get too short. How likely is it that a cancer will meet its demise because its cells have devided too many times? --Username132 (talk) 17:54, 28 May 2006 (UTC)

Consideirng the number of 30+ pound external tumors I've seen (I think one was ~200 pounds) I don't think that's a factor. Interesting idea though. --mboverload @ 20:53, 28 May 2006 (UTC)

I think I've read somewhere that cancer cells have fixed the telomere problem and are effectively immortal. My notion, which I don't have any real confirmation for, is that it takes at least two mutations to make a cell cancerous—one to remove the controls on division, and another to turn off the telomere clock. If a cell suffers the first but not the second, its line simply dies out as the telomeres expire. If that's right, then the purpose of the telomeres may very well be to prevent cancer; it could be that the first sort of mutation happens reasonably frequently, but usually harmlessly.

But then again it's not clear that the numbers really work out. I think you start with a count of about 50; 2⁵⁰ cancer cells is clearly more than enough to kill you. So maybe the situation is more complicated. If anyone knows more, I'd be interested to hear it. --Trovatore 21:02, 28 May 2006 (UTC)

If you plot the incidence of cancer against the age it occurs (in a double-logarithmic plot) you will find out that on average six mutations are needed for cancer to occur. Dr Zak 03:39, 29 May 2006 (UTC)

There are actually several things that have to happen to a cell (or a line of cells) for it to become malignant; see carcinogenesis. The problem of telomere shortening is addressed in the majority of cancers by the reactivation of telomerase, an enzyme which lengthens the telomeres. There's also an alternative pathway that's activiated in a minority of cases; both pathways allow cancerous cells to maintain their telomeres and evade the Hayflick limit. TenOfAllTrades(talk) 01:53, 29 May 2006 (UTC)

[edit] Why aren't people with AIDS treated like

people with Severe combined immunodeficiency? They seem to be really similair, it should be pretty effective for them to just get in a bubble. A Clown in the Dark 20:23, 28 May 2006 (UTC)

Because AIDS isn't that acute; SCI usually kills within a year, while those affected by AIDS can live decades. Also, while SCI only affects 1 in 100,000, AIDS affects 1 in 150, most living in countries which couldn't afford to provide sterile bubbles and associated treatment. And a lot of the infections that can affect those with AIDS were already present in the body, but lying dormant or latent, such as Toxoplasmosis. Incidently, the bubble treatment is now largely depreciated; bone marrow transplants can allow the body to start producing the white blood cells again (this won't work for AIDS however). smurrayinchester^(Talk) 21:32, 28 May 2006 (UTC)

Why wont it work for HIV? If the virus is in the T4 cells, total body irradiation will kill all of those. Then you just hit them with enough antibodies to sequester the loose virus particles and give the patient more bone marrow. In fact, if you just use the haematopoetic stem cells, you could give someone an autologous transplant of the stem cells they need to get back on track.

Even if you failed to sequester all the virus, it would still revert the patient to an earlier stage of infection, right? --Username132 (talk) 22:03, 28 May 2006 (UTC)

Aid's doesn't kill people, that lack of an immune system does, so total body irradiation would surely accalerate this process, making it worse. Also, there will be alot of the virus in the blood stream anyway the will just repopulate as more cells come back into the stream. Philc _T^E_C^I 19:35, 29 May 2006 (UTC)

I'm not sure you read everything I said. Firstly, sequester the virus using antiviral antibodies (viral titres are usually low until late on anway) and secondly I didn't say "leave them without an immune system". I said to give them an autogenic haematopoetic stem cell transplant to replace their immune system. --Username132 (talk) 22:30, 29 May 2006 (UTC)

Ok, im my web-crawls trying to understand what you said, bacause in all fariness, I did misread your earlier comment, so my inital response was unfounded, I don't really understand the science of it, i keep getting long words mixed up but I did find this [23], which doesnt say much on the subject but it does say this, "One case has been reported of a patient with AIDS who contracted lymphoma and underwent syngeneic bone marrow transplantation while being treated with zidovudine. Although the patient died from recurrent lymphoma, autopsy revealed no evidence of persistent infection from HIV; however, the absence of subsequent reports on the use of HSCT in treating AIDS suggests that this approach has not been able to permanently eliminate the virus.", which implies people are aware of what you are trying to say, but they either don't believe it works, or haven't found a way to make it work. But it does raise another interesting point, if you are going to save people with AIDS, you need to do it quick, because they can contract anything at any point. Philc _T^E_C^I 00:09, 30 May 2006 (UTC)

Ahh, but they didn't use Sean's patented formula. zidovudine just stops the virus trying to insert it DNA into T4 cells. If you mop up the loose virus first with antibody AND use zidovudine, then it will maybe be like they just got infected. I'm gonna email my immunology lecturer and see if he laughs at me... --Username132 (talk) 01:14, 30 May 2006 (UTC)

Thats pretty bitchy, patenting something that could save the lives of millions, and most of africa, who wouldn't be able to afford it if some dude wants a cut off everytime someone buys it. Philc _T^E_C^I 23:58, 31 May 2006 (UTC)

Mahwell, thats capitalism for ya. Philc _T^E_C^I 11:48, 1 June 2006 (UTC)

Well a) I'm left wing and I'm in this for the people, b) it's probably a bad idea anyway (I don't think you could sequester the virus easily due to all the variations) and c) you can't patent (I don't think) and idea that's already been disclosed to the public. --Username132 (talk) 16:47, 1 June 2006 (UTC)

Yeh, sorry, I misread your post, and as a result you misunderstood mine, Zidovudine is patented and as a result, despite the fact a single dose costs in the region of 30p to make since the patent holder monopolizes the market, they refuse to sell it for less than £5 per dose. Philc _T^E_C^I 17:52, 1 June 2006 (UTC)

[edit] Two new pages at least for biologists

Hi. I've two new pages for biologists and similar organisms to check. L-number and Pterygoplichthys. Please be gentle.HappyVR 21:28, 28 May 2006 (UTC)

I Wikified and copyedited your Pterygoplichthys article and wrote it out in prose. You should avoid making articles of lists as they are difficult to read and notoriously inaccessible to the new user. Biology is my weakest science so I might have misunderstood a couple of your statements; please check my copyedit and make sure it's scientifically correct! Also, check some well made articles on similar topics (another genus article would be best) and it might help if you follow the same style, also including similar information. Other than that, thanks for being bold and keep creating useful articles! freshofftheufo ΓΛĿЌ 03:19, 29 May 2006 (UTC)

Thanks for that - I actually used otocinclus and ancistrus as a template for this genus - it used a list. It's very difficult to judge the readability of something oneself has written so thanks for looking at it. As far as I can tell your conversion is good - might have to make a subtle change regarding feeding but the original article was ambiguous in that respect.- I'm tempted to space it out a bit - Wikipedia: ‎Wikipedia:WikiProject Fishes suggests separate paragraphs for each subtopic. I just wanted to get the data in including the references.

Thanks to everyone for working on it - especially whoever added the greek characters.HappyVR 10:02, 29 May 2006 (UTC)

[edit] Human powered hydraulic system

I might be cutting my own throat but I need some answers to continue my project. I am attempting to buid a hydraulic bike.I have the plans,the witness of the plan. What I need is where to find the equipment.I need...

1 small hydraulic pump (motor)peddel crank powered
1 accumulator
and verious actuators and check valves. —The preceding unsigned comment was added by 172.162.62.9 (talk • contribs) 22:40 UTC, 28 May 2006.

First of all, put the knife down. Second of all, I think the question you wanted to ask was, "How could I go about obtaining such parts?" freshofftheufo ΓΛĿЌ 00:20, 29 May 2006 (UTC)

How would you do gears, without using gears, and then defeating the point of the project?.... Philc _T^E_C<sup>I 19:43, 29 May 2006 (UTC)

I suppose a hydraulic intensifier, something like this: http://www.hydraulicspneumatics.com/200/FPE/Pumps/Article/True/6404/Pumps would do the trick. I'm pretty intrigued by the design problem, now! One could use several intensifiers and a valve system to select which intensifier (gear) is powering the rear wheel. The drawback will be weight... hydraulic systems are heavy, finding miniature hydraulic components will not be easy. 71.112.123.204 18:59, 30 May 2006 (UTC)

[edit] Cooking With The Door Open

If the grill is built into and enclosed in your cooker/stove, why grill with the door open? A lot of people do and it says to on the front of the cooker but I never do. Surely it is better to use a lower setting and cook with the door closed for energy efficiency? --Username132 (talk) 21:58, 28 May 2006 (UTC)

The old top-grills on ovens didn't have a temperature control. Thus, you would control the heat by the amount you left the door open. For modern counter-top ovens, etc, you leave the door closed. --Zeizmic 22:16, 28 May 2006 (UTC)

Sometimes in baking with new counter-top ovens you are to leave the door ajar so the temperature does not vary. When the oven gets to a certain heat it turns off, then turns on again. —

The Mac Davis] ⌇☢ ญƛ. 23:55, 28 May 2006 (UTC)

I don't really care if the temperature varies. I can't taste it when I bite into my fishfingers... --Username132 (talk) 02:38, 29 May 2006 (UTC)

If you're cooking something fatty - like sausages - with the door closed you can create a serious fire hazard, since the very hot fat will catch alight when it's suddenly exposed to air.--Peta 04:45, 29 May 2006 (UTC)

Who you callin' fatty? --Username132 (talk) 10:46, 29 May 2006 (UTC)

And leaving the door open exposes it to less air!? Philc _T^E_C^I 19:33, 29 May 2006 (UTC)

It's less sudden. If you leave the door open, you get a steady stream of fresh air moving into the oven, and a steady stream of smoke from burnt fat moving out. If you leave the door closed, the little bit of oxygen in the oven combusts with a little bit of fat, and by the time the sausages are done, you've got a nice cloud of superheated, aerosolized fat just waiting for oxygen to react with, and opening the door could give you a fuel-air explosion. --Serie 21:50, 30 May 2006 (UTC)

Fishfingers?? Are you from the UK? In the US we call them fish sticks, because they're little sticks of fish. —

The Mac Davis] ⌇☢ ญƛ. 10:48, 29 May 2006 (UTC)

Yeh and we call petrol petrol, because it is petroleum, and a liquid, not a gas. Philc _T^E_C^I 19:33, 29 May 2006 (UTC)

Ah, but we also eat chicken fingers, not chicken sticks, here in the States. --Ginkgo100 22:07, 29 May 2006 (UTC)

Tomato / tomato (that doesn't quite work as well when not vocalised, but you get the point) Rockpocket 20:18, 29 May 2006 (UTC)

I thought the question was about grilling. Taking a steak as an example: By "grilling", I assume you mean you want to use infrared electromagnetic radiation to sear one side of your steak to a controllable depth, then turn it around and do the same on the other side. This would be analogous to grilling over coals. Heat is applied only on one side of the food. That way you can have grilled/black outside and rare/red inside. If you close the door, you change the mode of cooking. The whole oven heats up, and you are cooking by convection plus radiation, so that your steak may be cooked through before you've even turned it around (plus you'd have extra loss of juices). So the idea of leaving the door open is that you cook by radiant heat only, not by convection. As a test, put an oven thermometer inside your "grilling" oven with the door closed, placed below your food to be shielded from the EM radiation. You'll see you can bake a cake at the air temperature found underneath your steak. So by closing the door, you are using the oven as a mixed grill plus bake/convect device. Nothing wrong with that, but don't expect gourmet blue steaks. --Seejyb 18:59, 29 May 2006 (UTC)

I don't like steaks. --Username132 (talk) 22:43, 29 May 2006 (UTC)

[edit] May 29

[edit] spyware

people talk about needing more than one spyware program to remove everything. if i have the free version of ad-aware, does anybody have a suggestion for a good (FREE) other program i could use in conjunction with ad-aware to take more of those buggers out?

Spybot - Search & Destroy. TheMadBaron 23:27, 28 May 2006 (UTC)

What operating system are you using? —Keenan Pepper 23:30, 28 May 2006 (UTC)

Hahahahh!!! What Operating System is he using?? —

The Mac Davis] ⌇☢ ญƛ. 23:56, 28 May 2006 (UTC)

Yeah, that's a good one! --Zeizmic 00:16, 29 May 2006 (UTC)

Would you mind explaining the joke? Is it funny because non-Windows operating systems rarely get spyware, or because ad-aware is a Windows program? --Bowlhover 01:23, 29 May 2006 (UTC)

i don't get the joke either, but i'm using windows xp

lol, Windows is the only OS that gets spyware. —

The Mac Davis] ⌇☢ ญƛ. 10:40, 29 May 2006 (UTC)

The joke is, the operating system is obviously Windows something because no other operating systems are known to get spyware. So Keenan's question was kind of weird. Also, Ad-Aware is Windows-only (TMK). --M1ss1ontom a rs2k4 ^{(T | C | @)} 04:52, 29 May 2006 (UTC)

I don't think it was weird. If only Windows systems ever got spyware, the answer to all spyware problems would be obvious. —Keenan Pepper 05:49, 29 May 2006 (UTC)

Its obvious— get an Mac. :) —

The Mac Davis] ⌇☢ ญƛ. 10:41, 29 May 2006 (UTC)

Obviously. Everybody should get a Mac, like every self-satisfied Mac-head is forever suggesting. Then, when the majority of computer users are all hooked on Mac, you might actually be able to get software for it.... and all the virus writers, spyware pushers, spammers, crackers and script kiddies can go bother you guys, and leave those of us with real computers alone. ;) TheMadBaron 14:06, 29 May 2006 (UTC)

There are a number of reviews of these programs. My suggestions are in Boldface. My opinion: Microsoft's own anti-spyware (now called "Windows Defender", specific for XP) is free, seems as good as any, and better than most, in that I have not seen a review where other programs outperform it (even the ones you have to buy). It updates itself regularly. You may wish to install something like "Prevx" (home version) to try to prevent some of the rootkit problems - it detects attempted changes to registry settings and other basic OS files (get the "old" one, the new one is grossly intrusive, IMHO). Combine with an anti-virus such as "Avast!" (the home version is free), and you're about as secure as you can be. The distinction between anti-spyware, anti-virus/trojan, and rootkit detecting programs seems to be becoming less clear. A single intruder often get detected by all three the "different" programs that I use. Keenan is perfectly right about asking what system the questioner was enquiring about. We are never impregnable - Linux, Mac or not. Anyone who thinks otherwise is living in a fool's paradise. You can check the web for "virus Linux" and "virus Macintosh OS X" to see how virus-writers are taking up the Mac challenge - they have already succeeded (contrary to info given above; references are available) and will do so more in the future, especially as the users are deluded that they can be spyware or virusfree just because of an OS - which is why Apple downplays the security issue, so that virus-writers do not see it as so much a challenge. --Seejyb 18:43, 29 May 2006 (UTC)

I must say that I have never had a good experience with a Mac. I My school has an Mac in the art class (becuase, apparenty, Macs are the best at architecture/drawing things et al) and I had finished my drawing and I wanted to print. I did so, and the printer wouldn't work (the almighty "chooser" function is horrible). After finally getting the paper into the printer, it got stuck half way through and then the computer crashed. I done this twice more to no avail. I finally got the solution to the problem by not moving the mouse, which is totally useless and barbaric. Nice little anecdota. I have never used the Mac since. Phew! Kilo-Lima|^(talk) 14:34, 30 May 2006 (UTC)

Was it running OS X? OS X is fundamentally different from all previous versions. —Keenan Pepper 16:43, 30 May 2006 (UTC)

You don't need antivirus. You don't need antispyware. Shit, you don't even need a firewall if you have a NAT router. Just stop downloading exe's on Kazaa. I haven't run it for over a year. I run some online checks every few months and I'm always clean. No point in slowing down you computer. --mboverload @ 05:44, 4 June 2006 (UTC)

[edit] Living for 1000 years??

I heard something on the radio last week about a medical procedure that will enable a person to live for "500-1000 years". Apparently it will be available in roughly 75 years and will be a result of the completion of the human genome project.

I can't remember all the details but it was something to do with cells in the human body that stop being produced around the age of 25, thus starting the slippery slope towards old age. This procedure will supposedly keep these youth cells firing for several centuries more than normal.

Firstly, I'm not insane (as far as I know) and secondly this comes from quite a reliable source on the BBC in England. Is this even possible and has anyone else heard of a such a thing? --Ukdan999 02:16, 29 May 2006 (UTC)

Are you sure it's nothing to do with telomeres? --Username132 (talk) 02:37, 29 May 2006 (UTC)

A lot of bible figures in Genesis and Gilgamesh epics lived up to 900 years but these are religious stories and legends. Hmmm.--Jondel 02:44, 29 May 2006 (UTC)

Somatic cells continue to be produced throughout your lifetime. It is absurd to think that they simply stop propagating at 25, otherwise your parents would no longer to be able to heal papercuts and things of that nature. Isopropyl 03:49, 29 May 2006 (UTC)

If it is at all true (I believe your sources are a little bit mixed up) I find it funny that they use the figure "in 75" years, which is basically like saying "right after all of you die". freshofftheufo ΓΛĿЌ 03:59, 29 May 2006 (UTC)

I expect you are referring to the beliefs of Aubrey de Grey, which were reported on the BBC recently because he is involved in some contest called the M-Prize: a $3.4 million award available to any scientist who can slow or reverse the effects of aging in mice. For the record, it is currently only in the realm of speculation. Rockpocket 04:14, 29 May 2006 (UTC)

Yeh! what a way to keep the world population under control, increase everyones life span ten fold. Philc _T^E_C^I 19:37, 29 May 2006 (UTC)

Preferably we wouldn't do it for everyone, Phil. Just for me. -lethe ^{talk +} 02:28, 30 May 2006 (UTC)

[edit] Soundwaves

if a sound is loud enough, could it shift the planets? I know that sound cannot travel through space, because space has no particles in it. But planets are just a big cluster of condensed particles and, perhaps, if the planets acted as a single massive particles it would be possible?

As I understand it, sound requires the reverbration of molecules within the matter of the surroundings. If you are modeling the planets are single massive particles, your model would need to have collisions between the particles in order to propagate a wave. Isopropyl 03:47, 29 May 2006 (UTC)

well why couldnt there be collisions between the planets?

I dunno. The point is, sound waves can't travel through space, so they can't vibrate planets. Ask a planetary physicist, perhaps. --M1ss1ontom a rs2k4 ^{(T | C | @)} 04:50, 29 May 2006 (UTC)

Outer space is a vacuum, so there can't be any oscillation of molecules, as sound waves require. Planets have collided before, though: see Giant impact theory and Comet Shoemaker-Levy 9. Tito xd^{(?!? - help us)} 04:52, 29 May 2006 (UTC)

I know about space being a vacuum and i acknowledged it it my question, but waht about if the wavelength of the sound was similar to the distance between the planets, or if the sound was even bigger could it shift galaxies? Thank you all for the quick responses and just one more question, where does the average planetary physicist 'hang'?

Sound is particles vibrating. In order for a wave of sound to travel through a material, the particles have to interact by some force. For everyday situations, this is the electromagnetic force (e.g. when air molecules collide it's the repulsion of their electrons that stops them from going right through each other). The electromagnetic force between stars and planets is very small, because they are so far apart and have so little electric charge for their size. On the other hand, vibrations could travel between astronomical bodies by the force of gravity. Does anyone know of research into this area? —Keenan Pepper 05:41, 29 May 2006 (UTC)

seems my question wasnt quite as stupid as first perceived.

Keenan: gravity waves? Tito xd^{(?!? - help us)} 07:57, 29 May 2006 (UTC)

Gravity waves: We're working on it. LIGO, LISA and Einstein@Home are some attempts at current to detect. —

The Mac Davis] ⌇☢ ญƛ. 10:32, 29 May 2006 (UTC)

No, gravity waves are waves in the field of gravity (spacetime) itself, right? Gravity waves can propagate in the absence of matter, so they're not analogous to sound. I'm talking about one star shaking and causing another star to shake because of the gravitational interaction between them, and so on. —Keenan Pepper 00:28, 30 May 2006 (UTC)

Seems to me that in order for a gravitational phonon to propagate, it should have a very low frequency. I don't see why they shouldn't exist, gravitational waves from the Big Bang have cooled just as much as EM waves have, so the cosmic background gravitational radiation may have some slow oscillations. But I guess the problem is that the amplitude of oscillation would be so small as to be drowned out by random oscillations, collisions by specks of dust, that sort of thing. Gravity is really weak, after all. NB: I'm speculating here, I haven't done any back-of-the-envelope calculations to even guess at orders of magnitude.

Yeah, Keenan, that is right. For the guy right above me: Gravitational phonon? According to the article, a phonon is quantization of vibration occurring in a rigid crystal lattice. If you are pretty knowledgeable of the subject, can spacetime be treated as a rigid crystal lattice in this context? I don't see why not, its just that I've never heard that before. —

The Mac Davis] ⌇☢ ญƛ. 07:57, 31 May 2006 (UTC)

Just some thoughts here: We're talking sound here, not EM radiation. You postulate that the wavelenght of the sound would be similar to the distance between the planets. OK. So a physical thing - a molecule, stone, rock, planet - physically moves "forward" from Earth (say) up to Mars (say), bumps it, and then returns to Earth (ignoring any oscillation or overshoot). Meanwhile the bumped molecule (Mars?) would travel "forward" on in space for the same mars-earth distance, sort of hoping it meets something solid to hit - to be able to propagate before it has to come back to Mars (i.e. at the far end of it's oscillation). Convenient if there were objects of similar mass at the right distance. Would that fit in with being a sound wave? I cannot see that that could be called sound by any stretch of the imagination, nor could it be detected by any sound-detecting device. What manner of thing would it be? Note the loudness of a sound is not caused by it's wavelength, but I think that your question may have implied that. The question would make more sense to me if the sound word were not there. --Seejyb 19:14, 29 May 2006 (UTC)

Not all space is empty, of course, there exist dust clouds in which small sounds could propagate a short distance. Black Carrot 20:39, 29 May 2006 (UTC)

The interstellar medium is composed mostly (by volume) of hydrogen atoms, at a pretty density. (~2 atoms/m²?). By mass it is mostly composed of dust. —

The Mac Davis] ⌇☢ ญƛ. 21:12, 29 May 2006 (UTC)

[edit] Looking for a particular perennial plant

I'm trying to help a friend find a plant. She thinks it's called something like "homburger". It's a perennial, and it has little green leaves. Unfortunately, that's about all she could tell me about it, so that didn't leave me much to search on. Can anybody suggest further avenues of research?

Thanks muchly.--Sar e kOfVulcan 04:39, 29 May 2006 (UTC)

With just that to go on, see if she recognises: Lobelia erinus. Cultivar: Hamburgia. Family: Campanulaceae. Size: Height: 0.33 ft. to 0.75 ft. Width: 0.33 ft. to 0.5 ft. Plant Category: annuals and biennials, perennials. Plant Characteristics: low maintenance. Foliage Characteristics: small leaves. Foliage Color: dark green. Flower Characteristics: showy, unusual. Flower Color: blues, pinks, purples, whites. --Seejyb 20:02, 29 May 2006 (UTC)

I'll pass that on and let you know. Thanks!--Sar e kOfVulcan 15:50, 30 May 2006 (UTC)

HI, I'm the person Garrett was asking for. THank you very much!!!!

[edit] quantum physics

why, when electrons are fired one by one at a sheet with two slits, do the electrons hit the screen at the back in a wavelike scattered pattern. Why isnt there just two slit patterns left on the screen?

See Double-slit experiment, Wave-particle duality, and philosophy of quantum mechanics -- SCZenz 07:33, 29 May 2006 (UTC)

i dont understand them, can you put it in a more simple way?

Because electrons act like waves, rather than like particles, whenever you're not looking at them. In fact, everything does that, although the lighter a particle it is the more pronounced its wave-like properties are. Weird, isn't it? -- SCZenz 07:37, 29 May 2006 (UTC)

why though, how can an electron interfere with itself? sounds so sexual.

We don't really know. Yes, it is sexy. So sexy!! Excuse me, I need to interfere with myself. —

The Mac Davis] ⌇☢ ญƛ. 10:28, 29 May 2006 (UTC)

Because it is a wave and not a solid particle. --Swift 03:04, 1 June 2006 (UTC)

Its just diffraction isn't it? Philc _T^E_C^I 00:17, 30 May 2006 (UTC)

If I may, I'd like to add a rider to this question. In The Dilbert Future, he mentioned an alleged experiment (which he pointed out he didn't remember well and was probably misquoting) in which, when the light passing between two slits was measured, it came out one way, and when it wasn't, it came out another. To find out whether it was the act of measurement causing this or the existence of information itself, the alleged scientists involved decided to program their computer to erase any data coming in and tried again. It was, apparently, as though it wasn't being measured at all. Anyone familiar with this? Black Carrot 20:36, 29 May 2006 (UTC)

lol, that part is just a joke, but yes, there is some animosity in the physics community to whether observation of an action actually makes it happen. —

The Mac Davis] ⌇☢ ญƛ. 21:10, 29 May 2006 (UTC)

Schrödinger's cat and Wigner's friend deal with this. Conscious 08:17, 31 May 2006 (UTC)

[edit] Outlook Express print size

Does anyone know how to change the font size that prints from Outlook Express (plain text emails)? It went small a few weeks ago and I can't get it back to how it was. I can change the font size on screen just fine but this makes no difference to the printout. Thanks. --Shantavira 07:49, 29 May 2006 (UTC)

I don't know about Outlook Express, but in Outlook it's File, Print, Page Setup.--Anchoress 11:43, 29 May 2006 (UTC)

Thanks Anchoress, but that doesn't seem to be an option in Outlook Express.--Shantavira 14:09, 29 May 2006 (UTC)

That's too bad. Sorry I don't have OE installed, I'd check around for you. Another thing to check is if you've got a setting for something like 'scale to fit page'. Also, note that in Outlook you can get radically different menus when you have an email open versus being in the inbox; you might try checking the print menu (thru the drop menus, not the print icon) in both views. Or just check around the print dialog (if you haven't already).--Anchoress 14:17, 29 May 2006 (UTC)

[edit] Aufwuchs and Periphyton

What are the differences between aufwuchs and periphyton if any. Are aufwuchs just epilithic periphyton? or does 'aufwuchs' include periphyton as well as larger animals (ie aufwuchs live in periphyton?). Should there be a link between these two and are there any related terms? HappyVR 09:49, 29 May 2006 (UTC)

[edit] High-elevation aircraft

Is there a specific name for airplanes designed for extremely high elevations (the kind where the pilot has to wear breathing apparatus)? High-elevation aircraft doesn't seem to be it. Angr (talk) 11:39, 29 May 2006 (UTC)

In aviation-talk, it's altitude, not elevation (that's for land-lubbers). --Zeizmic 11:42, 29 May 2006 (UTC)

Okay okay, but High-altitude aircraft doesn't seem to be it either. Angr (talk) 12:46, 29 May 2006 (UTC)

That's when Googifying comes in handy! You will find that this does not merit an article, since all jet aircraft can top Mt. Everest where breathing equipment is necessary. If you go through the trouble of pressurizing the cabin, then you don't need anything, but fighter jets worry about bullet holes. The first really high high jet was the Lockheed U-2.--Zeizmic 12:53, 29 May 2006 (UTC)

Well, the first jet for sustained flight at those altitudes. Interceptors like the F-104 Starfighter got that high first, though. Rmhermen 21:04, 29 May 2006 (UTC)

I'm a little surprised we don't have an article on HALE aircraft, that is, aircraft designed for High Altitude and Long Endurance. moink 02:35, 30 May 2006 (UTC)

[edit] First Amendment Ruling

Just an interesting fact: I got from a blog that footnote 16 of the recent Apple Ruling cited Wikipedia (specifically Bulletin board system). I searched the rest of the ruling, and it turns out a couple more articles, including Firewire, Breakout box, Garage band, Asteroids (game), and Breakout were all cited in footnotes. Doesn't Wikipedia have a list of media references to itself? Another interesting note: the judgement mentions a "memetic marketplace" of ideas.JianLi 14:42, 29 May 2006 (UTC)

Wikipedia:Press coverage does. You could also check out the signpost. --HughCharlesParker (talk - contribs) 19:35, 29 May 2006 (UTC)

[edit] Government signature for public key?

Is any government or other trust-worthy entity signing public keys of individuals? —Masatran 15:26, 29 May 2006 (UTC)

Interesting word, trustworthy. It's reification from one abstract concept we can't handle very well to something even more so. Easy to think of (maybe), but impossible, or near so, in practice.

No government is doing so that I've heard of, at least for the public. Government run PKI systems (if sanely designed) must have something comparable, of course. But consider the problem. Governments have trouble coping with the variations in the population. private arrangements (and military ones, too) can work to the extent they do because they have filtered out those to whom their 'solution' to <whatever> doesn't apply. The general problem is x orders of magnitude harder, where is a medium sized integer.

In the US, Congress has passed a bone-headed law requiring all states to include 'standard' informaiton on unforgeable ID cards (ie, driving licenses). but they've passed it in a rosy glow of (everyone knows the ivory tower types can deliver what ewe demand, so we'll demand unforgeability) fantasy. Any such system for the entire popularion, is, I think, doomed to have so many problems as to fail, more or less quickly. They passed such a law about vote recording in elections in the aftermath of the Florida debacle in 2000 (didn't prevent a similar debacle in Ohio in 2004, though). Wishing it's so, passing a statute requireing it to be so, allowing interested company lobbyists to write legisation, ... doesn't make it so. And so the result has been technical buffonery as incompetence and marketing driven 'engineering' have produced voting machine after voting machine which doesn't work -- where work is not losing actual votes, not adding phantom votes, and making attack difficulty so high it will, in practice, be impossible. Everything works where work is defined as something that looks like it works long enough to cash the check. Very different definition of 'work'. Cynical pessimism is certainly justified. ww 18:19, 3 June 2006 (UTC)

[edit] Disabled Physicst

I want to know the name of the famous British Physicst, who is disable. What kind of Diability has he?

Stephen Hawking —Masatran 15:43, 29 May 2006 (UTC)

And as the article details, he has motor neurone disease (specifically, amyotrophic lateral sclerosis) GeeJo ^(t)⁄_(c) • 18:16, 29 May 2006 (UTC)

Known in the US as Lou Gehrig's disease. --HughCharlesParker (talk - contribs) 19:23, 29 May 2006 (UTC)

Known in wikipedia as a redirect to Amyotrophic lateral sclerosis --205.188.116.74 21:21, 30 May 2006 (UTC)

[edit] Sturcture of compound

Hi,

Does anybody know what the structure of the active ingredient (i.e. P57) in hoodia is?. I will like to know. If you do kindly contact me on <email removed to prevent spam> Thanks

Dr Kay Akinnusi —The preceding unsigned comment was added by 137.122.187.99 (talk • contribs) 16:55 UTC, 29 May 2006.

The hoodia article is probably a good place to start. --HughCharlesParker (talk - contribs) 18:55, 29 May 2006 (UTC)

Except that the article doesnt answer the question. Meaning that this was the right place to ask. A quick google search doesn't reveal anything though, and PubChem isn't going to be much use with such a proprietary and experimental compound. I'll keep looking for a bit. GeeJo ^(t)⁄_(c) • 19:12, 29 May 2006 (UTC)

It looks like this PDF is an FDA application for a supplement in which Hoodia Gordonii extract is the active compound. My Adobe Acrobat is out of date though, so I can't see the text. Your answer is likely buried in there somewhere. GeeJo ^(t)⁄_(c) • 19:21, 29 May 2006 (UTC)

Try Foxit. It's what Acrobat Reader should be. Also freely available. ww 18:21, 3 June 2006 (UTC)

It's supposed to be a plant steroidal glycoside (digitalis is another), see [24] and [25]. As with other drugs of this type, it is likely to be lethal if used incorrectly. There is a clump of Hoodia Gordonii growing in a reserve 1km from my house, and the South African Defence Force taught of it's use in survival courses 30 years ago, so it's not that new. I wouldn't touch the stuff with a barge pole, until at least the FDA has looked long and hard at what messing with inter alia your CNS eating control neurones does to a human in the medium to long term. The South American people chew coca leaves, but cocaine ain't a "natural remedy". --Seejyb 23:46, 29 May 2006 (UTC)

[edit] Suckermouth fishes

As there was a 'red link' I have created this new page - not sure if it will need to be changed to "Suckermouth (fish)" in the future. Also not sure of the absolute necessity of this page. It does make a useful 'node' though. If I have missed any obvious species with 'suckermouths' please alter it or tell me, also the page might be a bit 'wordy' at present - needs a quick look - any volunteers?HappyVR 17:33, 29 May 2006 (UTC)

We can just move it if a disambig or a more popularly known species is found to be needed there. —

The Mac Davis] ⌇☢ ญƛ. 20:45, 29 May 2006 (UTC)

[edit] identifying a web server

I have the numeric address [71.225.167.171] of a web server I believe to have been used when my domain name was forged as the FROM: address on spam. How can I find out ownership, location, etc. for this server? --Halcatalyst 17:37, 29 May 2006 (UTC)

Doing a whois 71.225.167.171 from here, I got:

Comcast Cable Communications, Inc. JUMPSTART-5 (NET-71-224-0-0-1)
                                  71.224.0.0 - 71.239.255.255
Comcast Cable Communications, Inc. PA-30 (NET-71-224-0-0-2)
                                  71.224.0.0 - 71.225.255.255

# ARIN WHOIS database, last updated 2006-05-28 19:10
# Enter ? for additional hints on searching ARIN's WHOIS database.

I don't know if this helps, maybe it's more of a lead than you had. Good luck. --The Gold Miner 18:30, 29 May 2006 (UTC)

Comcast are a broadband ISP, and a Reverse DNS lookup makes it look as if this IP is in Denver. Wikipedia hasn't been edited from that IP (unless the user logged in). --HughCharlesParker (talk - contribs) 18:46, 29 May 2006 (UTC)

What is the reason to assume that the IP address in question belongs to a web server. The common way to send spam is to infect millions of computers with a IRC bot and then command the bot to send your spam. The easiest computers to infect are ones that are connected to the Internet all day every day. So, a home PC connected to always-on broadband most likely has a bot on it that sends spam (or does DOS attacks or cracks passwords or tries to infect other computers...) --Kainaw ^(talk) 22:43, 29 May 2006 (UTC)

Thanks for the reference to DNSStuff.com, which I followed up. According to this search, Comcast is a domain name server. It reports that there is no pointer (PTR) from the numeric address to a host name for [71.225.167.171]. Since "all Internet accessible hosts are expected to have a reverse DNS entry," and that such addresses are blocked by many mailservers, this must be a spam server hiding its identity. --Halcatalyst 00:19, 30 May 2006 (UTC)

The search also shows that it's not located in Denver, but Mount Laurel Township, New Jersey. It is most probably a desktop PC hijacked by a spam virus. Comcast is not a DNS server but an Internet service provider (ISP). The DNSStuff lookup just asked some DNS servers about the name of this IP, but couldn't find any. The DNS server belongs to Comcast, because this IP belongs to someone using a Comcast DSL connection. –Mysid^(t) 09:28, 30 May 2006 (UTC)

[edit] Photoelectric effect and current

In the photoelectric effect, the higher the frequency, the higher the max speed of the electron.

So, does this mean that the higher the frequency of light, the higher the current produced by the effect? -- infinity0 20:47, 29 May 2006 (UTC)

See photoelectric effect--Light current 21:17, 29 May 2006 (UTC)

Oh yeah I see, thanks :) It was just hidden away in a passage about the history :S -- infinity0 21:31, 29 May 2006 (UTC)

[edit] High voltage power supplies

Why is it (in UK at least) that all high voltages seem to be based on multiples of 11. For example: 6.6kV?, 11kV, 33kV, 66kV, 132kv, 275kV ? 8-? --Light current 22:02, 29 May 2006 (UTC)

I am not an electrician, but it makes sense to me that all the "standard" voltages would have a common factor, since that means the winding ratios on transformers between those voltages are simple (for example, an 11kV to 6.6kV step down has a winding ratio of 5:3.) As for the specific values, not a clue - multiples of 11 would make sense with a 110V or 220V domestic supply voltage, but in the UK we have a (nominal) 230V supply that is in practice usually closer to 240V (or so I'm told, I don't go around sticking voltmeter probes into power sockets.) -- AJR | Talk 22:54, 29 May 2006 (UTC)

Just a guess, but perhaps it all goes back to the 110 V chosen by Edison, according to Mains electricity#History of voltage and frequency, in 1882. The final message in this thread on physicsforums.com says that Edison chose 110 V for compatibility with his light bulbs. The fact that Edison used DC doesn't affect the choice of voltage, for reasons that are obvious to electrical engineers. --Heron 20:40, 30 May 2006 (UTC)

My meory suggests to me that RMS of 110VAC is not equivalent ot 110VDC for a pure (or mostly so) resistance load like the lightbulbs. in this, as in a few other things, Edison would have been well advised to consult Tesla, however odd he was. As for the 11 factor, I thought everyone knew it came from the Tarot and has been confirmed by Ramtha. ww 18:26, 3 June 2006 (UTC)

This might have something to do with preferred numbers. Ardric47 20:40, 5 June 2006 (UTC)

[edit] Classical mechanics doubt

Say we have a physical system like this one: wall(fix point)|------ m1 ------ m2 ------|wall With m1 = m2 = m being massic objects and the "------" being springs. I'd like to know Newton's Second Law applied to both masses... I've figured something but still I'm not sure if my reasoning is correct... I get somewhat lost when such combinations are made. There's no friction, the springs in the sides are attached to the wall and the spring in the middle can move freely in the x axis. Thank you very much.

You have two coupled oscillatory systems. See damping.--Light current 22:07, 29 May 2006 (UTC)

[edit] Apples

Do apples help keep you awake? --Username132 (talk) 23:23, 29 May 2006 (UTC)

They can do, especially if you try sleeping on top of them! 8-)--Light current 23:31, 29 May 2006 (UTC)

There's nothing about apples being stimulants in Apple, nor in this link. Why do you ask? --Ginkgo100 01:33, 30 May 2006 (UTC)

Yes, if the porno you're downloading onto them is interesting enough.--Anchoress 03:29, 30 May 2006 (UTC)

Or if apples are used interestingly enough in the porno you are downloading. —

The Mac Davis] ⌇☢ ญƛ. 05:52, 30 May 2006 (UTC)

On a more serious note, they do provide water and sugar, and tend to be quite cool when you're eating them. Sugar can provide you with energy and cool water can wake you up a little bit, temporarily. So they could help you wake up a little, if you were trying to be more alert, but would be unlikely to affect your ability to sleep if you ate them just before bed. Skittle 11:00, 30 May 2006 (UTC)

[edit] Terraforming and Space travel???

I have recently been researching both of these on this site and many other sites and I still can't fully understand how terraforming can be done. Can Mars be, in anyway, terraformed (even in future technology)? My other question is if space travel in the future can really be faster and how long would it take to get to another "Earth-like" planet outside our solar system? I'm writing a story about a terraformed planet (in the future, specifically 2163 for terraforming to begin and 2306 to finish). Also, I would like this planet to be Mars but I feel as if it won’t work because Mars, even with terraforming, would still be unsafe, or would it?... Oh, I’m sooo confused! Lol And then I thought I would make it a more distant planet with the same mass and distance from the sun but the problem with that is the time it takes to get there (I need it to be at least under a year). Even if we invent a ‘fast’ spacecraft, then you would be traveling so fast it would affect the people inside the gravitational craft (if that’s even possible) or you would hit something, damaging the ship! So, if you could please offer anything you know in the simplest of words for me on any of this or even links to sites would be great! Maybe a site offering just how this could be possible because I can’t find anything or I can’t understand it.

Please understand that I'm only 17 and don't understand science talk (Not that I'm saying I don't like science, because I love it!) ~Cathy~

It is highly unlikely it is possible for mars to be terraformed, as the earth has a molten core, the spinning generates a magnetic field giving the earth a Magnetosphere, which then deflects powerful solar winds thrown off the sun, these are potentially extremely harmful, and without the

Also terraforming, if possible, is expected to take in the region of 10 to a 100 million years, so don't be expecting anything by 2306. Philc _T^E_C^I 00:44, 30 May 2006 (UTC)

Other people who have studied the problem are considerably more optimistic than PhilC. For instance, the loss of atmosphere would probably be very slow. In the long term, it may well be feasible to retrieve enormous ice-covered asteroids from the outer solar system and take them to Mars to replenish the atmosphere (as a baseline technology for doing this, you could consider nuclear pulse propulsion. But like gadfium says, read our articles. Some other books of interest might be Robert Zubrin's The Case for Mars and Entering Space. Zubrin is an advocate rather than a dispassionate scientist, however, so don't take everything he says as the last word on the matter. --Robert Merkel 01:23, 30 May 2006 (UTC)

[edit conflict] Well, if you want to terraform Mars, you have two major challenges: increase the thickness of the atmosphere, and raise the temperature. Luckily, Mars's existing atmosphere is carbon dioxide, which is a greenhouse gas, so you can do both jobs at once. The problem is, where do you find enough carbon dioxide to do the job? Does Mars have massive amounts of CO₂ trapped under the ground? How would you get it out? How long would it take? How much would you need?

Then, once Mars does warm up enough, you'd need to get all that CO₂ out, because humans prefer not to breathe it. How would you get it out? How would you get the nitrogen and oxygen you'd need? And how would you shield from radiation?

The answers to all these questions are, like most of the good questions, unknown, but hopefully this will give you an idea of where to start. You might want to try some of the links in terraforming, or this article, or this article, or this one. I'd also suggest Kim Stanley Robinson's Mars trilogy. -- Filliam H Muffman 00:59, 30 May 2006 (UTC)

I didn't even think about Venus! I guess it’s because Venus is so hot and Mars is getting all the attention because we can go there NOW and not have to worry about that.

So what would happen if, theoretically, Mars is terraformed after a few (years, decades, centuries???)? Would it start to corrupt and go back the way it was after that time… or I’m I getting all this wrong? When, for example, you send those algae to Mars and it ‘terraforms,’ would it stick? And if it goes back to the way it was or whatever it does, how would it do that? Would the volcanoes erupt, for example? (I’m laughing at myself because I totally have no idea what I’m talking about AND I even researched a lot of this!)

OK, I just thoroughly confused myself, but at least I’m learning something… I hope. lol

~Cathy~

Oh... and thanks for all the links and book suggestions! I'm reading all the articles right now.

~Cathy~

I echo the Mars trilogy - granted, it's science fiction, but most of it is relatively realistic (if a touch optimistic! Liquid water and a breathable atmosphere in 200-odd years...). It even talks about colonisation (and terraforming) of Venus, with some very nifty ideas. You should be able to draw some inspiration from it.

Whether Mars would 'revert' depends on many, many factors - if there are no further active systems (eg plants) then, yes, eventually it will revert to its previous state. I stress eventually - this process could take many, many years. If there are "active" systems going on Mars (eg plants, factories spewing out oxygen and greenhouse gases...), then it should be possible to maintain Mars in its new, terraformed state. But the bottom line is, it depends.

I also noticed no-one took you up on your space travel question - as far as we currently understand physics, we can keep on building faster and faster ships, until we hit speeds approaching the speed of light. Faster than that is not possible (no, no warp drive :)). Stress currently because it's possible that, down the road, we may discover ways of getting around the speed-of-light limit (by curving space, using wormholes or whatnot). However, even staying below the speed of light, we can do some pretty serious exploring - the nearest star is about 4 light-years away, so ~10 years (at a reasonable speed) to get there. That's only about twice as long as the first long-distance ocean voyages in the 15th and 16th century, so it's reasonable. As to the nearest habitable planet, we don't know, we haven't found one yet, but a rough guess would put it at around twice that distance - so we're still in the realms of reasonable travel times.

If you need to get there in under a year, note that as you approach the speed of light, time slows for the travellers (relative to the outside) - so at high relativistic speeds (around 0.9 times the speed of light or so), the astronauts would only experience a year of passing time, while in the outside world, several years will have passed. Might that help you get around the problem of long journeys? Alternatively, generation ships (where the children of the astronauts who leave Earth arrive at the destination) or sleeper ships (where the astronauts spend the voyage in hibernation) are possible solutions.

Welcome to the wonderful world of sci-fi! :) — QuantumEleven 08:18, 30 May 2006 (UTC)

Some amateur advice & a pep talk: Unless you want to do very much more research, use Mars. Much has been written about that already, so you can embroider and assume that many of the present difficulties are amazingly solved. Have you looked at the page How Stuff Works - Terraforming? At the end of the article you will find some useful links about your travel/spacecraft questions. Then come back and reread the Wikipedia articles on Terraforming and Martian Terraforming, it should be easier to follow then. Your 150 years is time for not much more than living inside a self sustaining protective dome environment of some sort - planetwide ecologies are staggeringly complex and slow. But for your tale, the big smash, million year, do the whole planet approach has obviously been replaced by the one small step at a time approach. The difficulty, danger and slow rate of achieving anything may be the very essence of your tale. You worry about ships smashing up; well accidents happen during travels; what about 2 of your 5 ships being enough to establish a "colony"? Earth is unsafe, how could a terraformed place not be unsafe, and the story of humanity is a tale of continuing in spite of dangers, failure and death. There is no reason why your people should be different. Write your about people, and assume solutions where you know of none. Write, instead of about large-scale terraformig, about the first real mars water collecting in a well, the first sheaves of corns growing and spreading in an acre where previously there was dust. The way they stop the oxygen leaching irretrievably into the hungry martian soil. The drops of progress that will one day, far away, coalesce into a river of change bringing life to a place which was once barren and uninhabitable. Write about humans and their strivings, fears, failures, successes, love, determination, evil, all we are, set in the struggle of transforming a world to a paradise they are destined never to see. Write about challenges faced and solved, even if you do not at first know how they could do it. Make a nitrogen machine, a magnetic shield generator, carbon dioxide fixing bug plants. If you identify a problem that needs solving invent a solving machine - like a 20km long particle accelerator that strips oxygen from rocks and CO2. Invent a breed of super-MacGyvers, using tools hitherto unknown. Write, just do it. 25 mins a day. And just carry on writing, don't try to perfect and justify or scientificize yesterday's writing. You will develop a flow. Later, or as you go on, you can ask opinions on the "details" and "impossibilties" from people who have such knowledge, but possibly no writing ability - they'd probably love to help, it's a fair swop of energy! And then you can start again, nothing is perfect first time. Go where your heart takes you, you may never be able to do it again. Stick to your guns. What could force you to stop, what feelings are your enemies? W S Churchill: Never, never, in nothing great or small, large or petty, never give in except to convictions of honour and good sense. Never yield to force; never yield to the apparently overwhelming might of the enemy. --Seejyb 04:22, 30 May 2006 (UTC)

Hear, hear!! JackofOz 13:41, 30 May 2006 (UTC)

OK, I think I’ll go ahead and increase the amount of time for terraforming to complete. I’ll probable be changing the way I’ve gotten it written down about the way they live on this planet (With more of a dependence on technology).

So, roughly how long would it take to revert back to it previous state or could it be any amount of time depending on certain factors put on the planet? Does around 290 years sound good?

OK, let me just tell you what I have planned... Terraforming begins in 2123 and ends in 2317 giving it 194 years to do so. And by that time I need it too be habitable enough for the people on Earth to know it’s secure enough to live on so they can leave (because they definitely do not want to stay!).

So if I put ‘active systems’ on (I’m going with Mars since I discovered Venus has really long days and traveling space outside our solar system will take way too long) Mars and they keep everything going, how long would it take for the population to realize that something is wrong if they break down (Just to give you a hint… they have no idea about any of this. No idea about Earth, technology (to an extent), terraforming, etc. So they would have to know from the way they are feeling physically). I’m not completely dumb to put inexperienced people on a different planet. There’s a whole lot more to it, but I’d rather not tell… But there are a group of people who do know about all of this.

OK, now I’m thinking of just having a section of Mars terraformed…

Just to tell you, I’ve been writing this story for over a year now, so it’s getting kinda hard for me to change things around because if I change one thing, everything changes and it’s a big mess! lol (but it’s not completely restricting. I still change a great deal, but for some things, I just can’t…)

Thanks for the bit of inspiration! It helps, especially after a year of writing!

I’m totally going out and buying those books now! Lol

~Cathy~

Just so you know, its generally accepted that it will take atleast 10 million years to terraform mars, though many believe it to be more like well over 100 million years. Philc _T^E_C^I 22:21, 30 May 2006 (UTC)

Yeah, I know... but it's a fictional world where anything is possible. Plus that does apply to real life too, though. :) Who knows? In a 100 years, maybe it will be possible. I mean, look at airplanes... we can now fly from New York to Switzerland in around an hour! That's amazing and something that people once thought impossible. So, time will tell. Advancements in technology happen every day. Just look at where we were 100 years aago.

~Cathy~

Yeh, but 50 years ago they said we'd be catching space busses to the moon for laughs by now. Philc _T^E_C^I 00:46, 31 May 2006 (UTC)

Well, that is why the future is so great... it is unpredictable. We can try our best at guessing, but it's never 100% accurate, now is it? Kinda like statistics... we can make an approximation of how many people do this or that or get this or that, but the truth lies in the factors that affect that. For example (and this is just some random example)… in Sex Ed. our teacher told us that 1 in 3 teen girls are pregnant before they get out of high school. Well, you can’t just pick 3 random girls and expect just one to get pregnant. What if all three are girls with a motivation to have some great career or their sister had gotten pregnant and they know what it’s like (and I’m talking from experience here for that one)? Well, you just found out more factors that make the chances of pregnancy decrease… And it’s still not 100%.

Plus, I like a great sci-fi show where it doesn’t take itself completely serious, otherwise where’s the science fiction if you don’t add fiction to it? That’s just my opinion…

~Cathy~

Quite the contrary. Assuming that statistic is correct, you can pick three random girls and expect one to get pregnant. It doesn't mean that one will, just that the chances are good that one will. (I'll leave it to you to work out what those chances are.) That's how statistics works. -- Filliam H Muffman 02:48, 31 May 2006 (UTC)

Sorry, read your post badly. -- Filliam H Muffman 02:53, 31 May 2006 (UTC)

I never said that statistics could not get 1 in 3 sometimes, but that doesn't mean it's going to work every time for every three. Let's say every teen girl had a 33% chance of getting pregnant before getting out of high school. Well that, for me anyways, would be lower since I've experienced what a teenage pregnancy does to change your life with my sister. So my chances would be different. Don't get me wrong, I do like statistics... all I'm saying is that you have to consider your factors of 'chance' and they'll be even more accurate because you incorporated those factors. Statistics take the whole population (or what ever you're trying to figure out) and averages.

Besides, I was just trying to make a comparison with the future... the more factors you know about the world right now helps you to predict what might happen.

~Cathy~

If you want recommendations for science fiction books about terraforming, I rather liked Building Harlequin's Moon, even though I've not much liked anything else recent by Larry Niven.-gadfium 09:27, 31 May 2006 (UTC)

[edit] Z Finger proteins

I have been hearing about a recent medical treatment referred to as Z Finger Technology. I would like to know the name of the company in California, U.S.A., currently holding majority of patents. Z Finger, so named as having finger like proteins. Is to have multiple treatment uses in the repair or alteration of genes. 1st technique invented by Dr. Aaron Klug, 1986. Treatments targeted are; Cancer, Diabetes, HIV - AIDs, Alzheimers, Cardiovascular & much more. Thanks, Joe, <-- email removed -->

Zinc Finger (Warning: Very POV): Read [26], and you'll find the company name. It's essentially a way of altering cell protein production, by changing what DNA encodes - switching things on and off at different places. At present something of a monopoly. Presently nothing to deliver (so expect hype and false science), and if anything does pan out, what moral justification for making such treatment - as the company claims it could develop - available only to the rich (which would be a likely end result). The "Treatments Targeted" (I assume you mean diseases targeted for treatment) could as well be a list drawn up by a school kid answering the question: "For what diseases would you like to see cures being developed?" And so much of it based on other peoples' work, a wonderful global co-operation to find out what is inside our genes. I may be cynical, but to me it's money, hype, money, hype, money, money, money. Until proven otherwise. --Seejyb 01:01, 30 May 2006 (UTC)

You would be talking about Sangamo BioSciences. But this link would suggest not to believe everything you read. Rockpocket 00:42, 30 May 2006 (UTC)

Zinc finger proteins? --Username132 (talk) 00:44, 30 May 2006 (UTC)

[edit] May 30

[edit] thought speed

At what speed do thoughts travel? What about emotions: how fast do these travel?

Nervous impulses, which I suppose is what you are reffering to travel at anywhere from 1 to 120 metres per second. Depending on how you define emotions, you may be refering to nervous impulse, or hormones, which take from minutes to weeks to affect. Philc _T^E_C^I 00:39, 30 May 2006 (UTC)

Some hormones, e.g. epinephrine which plays a central role in the short-term stress reaction, take only seconds to affect. –Mysid^(t) 09:15, 30 May 2006 (UTC)

Some believe the brain is a quantum machine, in which case thoughts can be two places at once and even go backwards in time. Weird, huh? —Keenan Pepper 16:29, 30 May 2006 (UTC)

mmm, if it was wouldn't we have unlimited ability to process information and never have to forget anything. As isn't a quantam computer like the holy grail of electronic science or something... Philc _T^E_C^I 00:51, 31 May 2006 (UTC)

No. Quantum computers are weird, but they're still limited. —Keenan Pepper 20:39, 31 May 2006 (UTC)

[edit] Losing your erection after jerking off?

Is this normal? I've read lots of sex stories and read kiss-n-tells in the newspapers where it's said that guy cums and just starts going again straight after with a full-on boner. When I cum, I lose my boner afterwards and can't get it back for a couple of hours.

I'm quite worried about what will happen when I have sex with a woman, that she'll think I'm not up to the job if this happens. Can you help?

Yes, this is entirely normal, and it's called the refractory period. — TheKMan^talk 01:46, 30 May 2006 (UTC)

Which is the reason why most kiss 'n tells are fabricated and stories are just that. The body needs to to 'reset' itself and generate more sperm. Some people believe so called "tantric sex" techniques can assist in enhancing sexual performance. Both in terms of duration and frequency. Sting swears by it. However don't worry about it too much, its highly likely you will be fine with the time, er, comes. ;) Rockpocket 02:25, 30 May 2006 (UTC)

I could be wrong, but I don't think the refractory period is due to the need to produce more sperm. In my short time that I had to search for it, I couldn't find much on sperm production rates or anything like that, but I doubt all the stored sperm is used in one ejaculation. Can anyone expand on this? E WS23 | (Leave me a message!) 05:36, 30 May 2006 (UTC)

Which newspapers?--Anchoress 05:20, 30 May 2006 (UTC)

Yes, you are partly right. I was speaking in simplified generalities (which isn't very helpful when some one asked a specific question, i admit). Sperm is produced continuously and therefore the refactory period is not required to specifically generate more sperm from scratch. However, the number of sperm per ejaculate is significantly decreased when one ejaculation closely follows another, so the time is required for the sperm on the "production line" to mature to optimal levels. The refactory period is also required to generate more semen to carry the sperm. Ejaculate volume is corrolated with the time since last ejaculate. These are all "reasons", but the mechanism is due to a sympathetic override of the parasympathetic nervous system (which is also why, when your mother walks in mid-masturbation, you tend to lose the erection pronto). Hope that is more clear. Rockpocket 06:08, 30 May 2006 (UTC)

I'll note that the refractory period is usually quite a bit shorter than the time it takes to (re)generate significant amounts of mature sperm. TenOfAllTrades(talk) 12:50, 30 May 2006 (UTC)

A girl can keep you going. Or hrm... After reading the refractory period article, maybe I'm just one of the few who can keep it up after cumming. - R_Lee_E (talk, contribs) 07:08, 30 May 2006 (UTC)

Well, the other major factor is youth. I see you are a student. Men aged, say 14-21, will often be able to reachieve, or even maintain, erections soon after orgasm. Sadly, its downhill from there on in, so enjoy it while you can. Rockpocket 07:20, 30 May 2006 (UTC)

What's to enjoy after the fun's been had? --Username132 (talk) 11:55, 30 May 2006 (UTC)

I could tell you but that would spoil the surprise. Just wait and see and you never know what might happen. :--) JackofOz 13:35, 30 May 2006 (UTC)

Where do you live? Your school's sex education seems to be pretty awful. I'm not blaming this on you, this is something you should have been told. --mboverload @ 06:00, 4 June 2006 (UTC)

[edit] Read Only Folders

My entire hard drive seems to have spontaneously been marked as "Read Only", which is a problem. I've tried to uncheck it (and it even asks if I want to do all the subfolders and such) and it looks like it's working, but at the end of the process nothing has changed. Does anybody have any idea how I could correct this problem? I've tried restarting, but nothing seems to work! --ParkerHiggins ( talk contribs ) 02:23, 30 May 2006 (UTC)

Should we assume you're using some Windows variant? Dismas|^(talk) 05:42, 30 May 2006 (UTC)

You give us very few info. The most common cause for this is having a read-only Desktop.ini file in the root folder (C:\, or generally <drive-letter>:\). Try removing the read-only attribute from that file. If it doesn't appear in the Windows Explorer try this at the command prompt:

attrib -r <drive-letter>:\Desktop.ini

Please, let us know if this solved the problem. —Gennaro Prota ^•Talk 12:11, 30 May 2006 (UTC)

I am in fact using Windows XP on a relatively new Dell Inspiron laptop. I tried the fix Gennaro Prota suggested, but even in the command prompt I was told the file was not found. I also checked the desktop.ini files found in the C:\Windows folder and the C:\Windows\system32, and found that they were not checked as read-only. I guess certain files and folders are open to writing, but it looks like every folder I would be using is not. I'm very confused by this. --66.214.253.134 12:44, 30 May 2006 (UTC)

Don't panic, it's Windows :) One thing: when you clear the read-only check box and then choose "apply to all subfolders and files as well" do the contained file attributes change? If so, then you might just use attrib on the folder, for instance:

attrib -r C:\My Folder

Notice, however, that if you remove both the system and the read-only attribute from a customized folder you will lose your customizations; if the problem is that some programs don't allow to save files in such a folder you might want to remove the read-only but leave, or add, the system attribute, as follows:

attrib -r +s My Documents

Don't hesitate to ask again if this doesn't work for you (or if the answer to my initial question is "no"). —Gennaro Prota ^•Talk 18:02, 30 May 2006 (UTC)

[edit] North Star

Can you tell me the simplest way to identify the North Star. I do not know what to look for in order to find. Please spell it out so clear that i can follow step by step instructions on this article in order to find it. Thank you.

The way I normally find it is to locate the Big Dipper and then follow the line that is created by the two stars that make up the edge of the bowl of the dipper on the side opposite from the handle of the dipper. By following this line in the direction of the "opening" of the bowl of the dipper, they point to the North Star which is also the last star in the handle of the Little Dipper. The rest of the Little Dipper is generally harder for me to see since the stars aren't as bright in that constellation. Dismas|^(talk) 05:41, 30 May 2006 (UTC)

P.S. After checking the links I supplied, I see that this is spelled out with diagrams on the page for the Big Dipper. Dismas|^(talk)

But don't use the official flag of Alaska, that is shown on the big dipper page as a map! The north star is nowhere nearly as bright as the flag suggests. Use this link instead, and you will find a better map. --vibo56 19:13, 30 May 2006 (UTC)

The flag of Alaska is NOT provided as a map. Look for the REAL map in the section "Guidepost." B00P 19:42, 8 August 2006 (UTC)

[edit] intrauterine photos that appeared in Life magazine in the ? 70s

I am trying to find the name of the person who did photos of living fetuses. It was the cover photo of Life magazine in , i believe the 70s. I thought his name was Nilson. Cant find this in the LIfe.com site nor by searching google . ANyone have any ideas? thank you!

How about your local - but if possible well-stocked, meaning the larger the better - library? Wouldn't they have an archive of back issues? --Ouro 05:49, 30 May 2006 (UTC)

This one's real famous. The photographer was Lennart Nilsson. --jpgordon ∇∆∇∆ 06:20, 30 May 2006 (UTC)

And the issue is April 1965. I'm surprised there aren't any good scans of it on Google Images. --Fastfission 03:59, 1 June 2006 (UTC)

[edit] Running a fullscreen program in a window

I'm not sure if this is the right place to ask this kind of question, but does anyone know of a way to run a program which usually runs in fullscreen mode in a window? I'm using windows xp, and the program in question is Sid Meier's Alpha Centauri. There is no option within the program to run in a window. Is there anything I can do to get it to run in a window? Thanks. NoIdeaNick 05:17, 30 May 2006 (UTC)

Sorry, I don't know how to do it unless it asks you. Did you check the options, preferences, or controls? In Age of Empires games and Halo you can run it in a window —

The Mac Davis] ⌇☢ ญƛ. 06:07, 30 May 2006 (UTC)

According to the readme, all the options like that are changed using the INI file, but there doesn't appear to be anything useful in it. Some games will load in a window if "-w" (without quotation marks) is added to the end of a shortcut target, but this doesn't seem to work either. smurrayinchester^{(User), (Talk)} 06:20, 30 May 2006 (UTC)

I assume you've tried the obvious Alt-Enter. --Heron 20:22, 30 May 2006 (UTC)

Yeah, I've tried all that, but none of it works. I was wondering if there was a more general solution. I came to the point of downloading Microsoft Virtual PC and running it inside that, but that seemed pretty extreme. NoIdeaNick 23:52, 31 May 2006 (UTC)

[edit] Chromatophores

Hello Scientists. I know this isn't really the place, however, i wonder if i could get a few opinions on the chromatophore article? I requested a peer review, but have had no takers. I'm trying to get it to good or featured article status and would like the opinion of intelligent non-experts, on whether it is too technical, not technical enough or whether anything is missing. Would appreciate it any comments. Thanks. Rockpocket 06:25, 30 May 2006 (UTC)

Looks very nice! Don't see anything wrong with it. Good references, and external links. —

The Mac Davis] ⌇☢ ญƛ. 07:51, 30 May 2006 (UTC)

I agree that the article is well-written, interesting, and visually pleasing. The article contains many technical terms, and it could be made more accessible to non-expert readers by making sure that the meanings of these are explained when introduced, or that there are links to pages defining them. An example: the sentence beginning with "Biochromes, such as pteridines and carotinoids...". In context, I suppose it is clear that biochromes are a subset of chromatophores, but I had to stop and think, and read the sentence a couple of times. There is a page (stub) called pteridines, a link would have been helpful if the link points to the correct molecule. Even a term such as de novo could have confused a non-expert reader, especially because the disambiguation page for de novo had a definition of de novo in the biological sense that was, in my opinion wrong ("newly synthesised", instead of "synthesised from simple building blocks". I have fixed that now.) But all in all, a very interesting and thorough article. --vibo56 19:04, 30 May 2006 (UTC)

Thanks for your comments. Actually, a 'biochrome' is defined as a 'pigment produced by an organism' (as opposed to a schemochrome, which is a colorless organic substance that reflects or refracts light). These aren't types of chromatophore per se, just different ways of generating colour. Its clear that that particular sentence can be improved, i'll work on that. Thanks again. Rockpocket 03:35, 31 May 2006 (UTC)

My pleasure. I have added some additional comments on the Chromatophore talk page. --vibo56 18:31, 31 May 2006 (UTC)

[edit] how do prawns sleep?

After going prawn fishing at a prawn farm my daughter has asked me a question I can't find the answer too:

How do prawns sleep? --S.ferguson 07:39, 30 May 2006 (UTC)

Since prawns are fish, these links will help: [27], [28] and this link (which I think will be the best becuase it is frmo the Discovery Channel, [29]. Kilo-Lima|^(talk) 14:42, 30 May 2006 (UTC)

Actually, prawns are Crustaceans. Mammals, birds, and fish sleep, but I believe prawns do not "sleep". I do believe they undergo some sort of period of inactivity, like most other creatures. — TheKMan^talk 14:47, 30 May 2006 (UTC)

Even if they do sleep, how would one answer the question? How does anything sleep? I guess they just drift off. Perhaps in a crevice with their feet up? In a skampie nightie?--Shantavira 18:08, 30 May 2006 (UTC)

Perhaps they dream of crustacean sheep?

Groan. -- Filliam H Muffman 02:30, 31 May 2006 (UTC)

Thanks for your help -- S.ferguson 08:15, 1 June 2006 (UTC)

[edit] Snails

i heard or read somewhere the snails 'fire darts' at each other in order to have sex, is there any truth in this?

Garden snails do this, although it apparently doesn't matter too much if the darts miss.[30] They just increase the number of sperm surviving in the snail hit by the dart. However snails that miss transfer more sperm, perhaps to make up the difference. [31] -- Avenue 08:46, 30 May 2006 (UTC)

Isn't that also in the snail article? —

The Mac Davis] ⌇☢ ญƛ. 10:36, 30 May 2006 (UTC)

Not that I could see; nor in the Garden snails article. It probably should be. -- Avenue 10:52, 30 May 2006 (UTC)

Well some more trivia then. The organ that the dart comes from is called the dart sac. It deserves an article too.—Pengo 13:30, 30 May 2006 (UTC)

[edit] Screaky sounds

Why do screaky sounds (like hitting a plate with a fork) cause chills? –Mysid^(t) 09:44, 30 May 2006 (UTC)

It is similar to fingernails on a chalkbord. I think it is because our subconcious mind can associate it with a fear but also it is just a plain weird sound that makes me think of an icecold wasteland.

I would be very interested in knowing where these reactions come from, especially because i suffer heavily from the chalk on chalkboard thing. It really gets to me somehow SanderJK 12:13, 30 May 2006 (UTC)

For me, the sound tenses the nerves that run through my jaws - the same nerves that tense when my teeth grind together by accident (or if I bite down on a fork or bone or something similar). There maybe some relation there. --Kainaw ^(talk) 12:58, 30 May 2006 (UTC)

There are some interesting theories on Bill Beaty's Science Hobbyist website here. There is no definite conclusion, but Bill's tooth-scratching theory is the best one I've heard. --Heron 20:19, 30 May 2006 (UTC)

Huh. I thought it had something to do with the resonant frequency of our ear canals... that is, it just sounds louder to us. moink 21:37, 4 June 2006 (UTC)

[edit] Interpretations of Quantum mechanics

how does many-worlds interpretation and transactional interpretation describes the quantum version of the double-slit experiment?

Click on the links. Just type it in the box next time. --Mac Davis 20:56, 30 May 2006 (UTC)

[edit] Measuring percentage in gas

Air is normally 79% Nitrogen. Is this litres, weight or quanta (mol?)? Henning 11:25, 30 May 2006 (UTC)

Volume (litres). See Air#Composition. –Mysid^(t) 11:43, 30 May 2006 (UTC)

My current level of high school chemistry also suggests that proportion by volume and the number of moles are roughly equivalent for gases for a given temperature and pressure, so 79% by volume would imply 79% by moles. This might be an over-simplification though given that it is high school. 81.157.113.170 11:57, 30 May 2006 (UTC)

Avogadro's law says that an ideal gas has the molar volume of 22.4 l/mol, and that real gases "may deviate" from this value. However, mole (unit) states that all gases have the molar volume of 22.4 mol/l, so I guess the deviation is pretty small. –Mysid^(t) 12:33, 30 May 2006 (UTC)

The figure from NASA is 78.084, not 79. It's the percentage of the total number of molecules in a volume of dry air at STP, or parts (molecules) per million divided by 10,000. If you add 5% water vapour, it becomes 78.084% of the part of the air that is not occupied by water vapour, i.e. 78.084% of 95%. --Seejyb 22:50, 30 May 2006 (UTC)

Hilariously, I saw a pamphlet for an Oxygen bar the other day that claimed the air contained half as much oxygen today as it did 100 years ago. In that case, I wondered why everyone wasn't investing in trees and hoarding oxygen tanks. Oh, and I don't recommend inhaling (supposedly) 95% oxygen if you don't need it; it just made me feel ill until I lowered my blood oxygen again. Skittle 01:16, 31 May 2006 (UTC)

An oxygen bar claimed that air used to be over 40% oxygen?! You're right, that is hilarious. There'd be forest fires every five minutes. -- Filliam H Muffman 02:33, 31 May 2006 (UTC)

The composition of air given in the article yields about 75.6% nitrogen by mass. Conscious 07:51, 31 May 2006 (UTC)

[edit] THEME PARK PROJECT

Could anybody help me with a project I have? I need to take 5 rides you could find at a theme park and show how the ride works in a powere point using both pictures and text. The preselected rides for me were: 1)Free Fall Tower 2)Swings Ride (specifficaly the Star Flyer)** 3)Bumper Cars 4)Log Flume 5)and the Swinging ship ride that flips all the way over.

PS: I also need to find the saftey systems such as harnasses and emergency braking systems,power outages etc.

- - Star Flyer

THANX A BUNCH

--Devol4 11:58, 30 May 2006 (UTC)

Have you checked our article on amusement rides? There's a pretty comprehensive list of different rides (at least log flume and bumper cars are there). By the way, people at the Reference Desk are usually reluctant to do other people's homework. :-) –Mysid^(t) 12:28, 30 May 2006 (UTC)

Here are some thoughts on the physics involved in each ride:

1)Free Fall Tower: Free fall under standard Earth gravity (g = 9.81 m/s^2).

2)Swings Ride (specifically the Star Flyer)**: Centripetal force in equilibrium with g (use a force diagram to find the resultant force and direction).

3)Bumper Cars: Perfectly elastic collisions.

4)Log Flume: Buoyancy.

5)and the Swinging ship ride that flips all the way over: Centripetal force which exceeds g.

StuRat 22:04, 30 May 2006 (UTC)

I'm surprised you didn't include a rollercoaster, but I'd sure give you points for originality. - Mgm|^(talk) 09:24, 31 May 2006 (UTC)

[edit] vaccination

dear sir / madam
>
> how many vaccination a year in uk?
> how many people die as a result of not being vaccinated a year in uk?
> what is advantages and disadvantages of vaccination?
> what is the costs a year, if we vaccinated or if we don't?
> should communities get educated on vaccination,"eg schools"?
> what is the future of vaccines for certain disease "eg
> aids,malaria,smallpox"?
> what is the statistic of vaccination to the world?
>
> thanks
>
>
> andy royle
[email removed]

(I have removed your email address to hide it from spambots. –Mysid^(t) 12:30, 30 May 2006 (UTC))

Well, the "homework vaccine" is a common vaccine used to innoculate people against having to do homework. Unlike many conventional vaccines delivered via syringe, the "homework vaccine" is delivered via Internet. Once vaccinated, recipients merely redirect all of their questions to resources like this one and count on volunteers to do their homework for them. The homework vaccine is truly a miracle of modern science! --MattShepherd 13:09, 30 May 2006 (UTC)

This one is worst than most. A mere book is requested. An accurate answer to each of those questions would be the equivalent of a term paper project or a long review article in a medical journal or a textbook chapter. Andy, there are already books on immunizations that have the answers to most of those questions. The answers here are off the tops of our heads in most cases. Here are the equivalent answers to your 8 questions in order: 1. lots; 2. zero or very few; 3. reduced chances of getting a disease versus a jab in the arm; 4. lots of money versus even more; 5. of course; 6. some will be discontinued, some improved, some new ones will appear; 7. the "statistic of vaccination to the world" is 42. alteripse 16:48, 30 May 2006 (UTC)

I'm not sure I agree with your answer to number 2. If someone dies, it's nearly impossible to determine whether it's from not being vaccinated, but enough people don't want to be vaccinated because of religious concerns. To properly answer that question, you'd need to know how many people aren't vaccinated to begin with. - Mgm|^(talk) 09:22, 31 May 2006 (UTC)

PS: Vaccination. --ByeByeBaby 17:27, 30 May 2006 (UTC)

User:Alteripse forgot to provide the link to the statistic you requested in question 7. Here it is. You might also want to browse the WHO web site, this subpage might be a start. --vibo56 21:17, 30 May 2006 (UTC)

[edit] You can't handle the tooth

Why don't we have one tooth that goes all the way around on both the top and bottom instead of all those different teeth? What is the evolutionary advantage here? Is it just so we can have cool-sounding names like molars, incissors, and bicuspids?

Fault tolerance, maybe? Damage to, or a cavity in, one tooth won't necessarily spread to other teeth. Allowing the teeth to move – just a little bit – relative to one another probably helps to spread out loads on the teeth. TenOfAllTrades(talk) 12:47, 30 May 2006 (UTC)

I can only speculate here. It could be that teeth evolved from scales, so they started as individual units and haven't changed from that. Some teeth seem to have fused together from multiple primative teeth (molars) but i'm not sure if that's really the case—They might just be big teeth. Birds have beaks, which is another way of doing it, and so have lost their teeth. —Pengo 13:25, 30 May 2006 (UTC)

Primitive tetrapods had multiple teeth which were replaced when they fell out. Mammals are unique among tetrapods in that our teeth have since become extremely specialized -- so much so that paleontologists routinely study and classify fossil mammals based only on their fossilized teeth. Each tooth is shaped to fit just so with the faces of the teeth in the opposing jaw. This is because the small, warm-blooded early mammals needed the added efficiency of such excellent teeth in order to get maximum energy with minimum expenditure from their food. Mammal teeth are worthless without the perfectly fitting opposing teeth, so mammal teeth have a limited number of replacements -- if they dropped out willy-nilly like the teeth of reptiles and sharks, the mammal would be unable to eat until the new tooth grew in. In many modern mammals such as humans, having perfect teeth (functionally, not aesthetically) is less critical to survival, although still very important. --Ginkgo100 15:10, 30 May 2006 (UTC)

Thowing in some engineering here: Our individual teeth have considerable latitude to move, and mesh with the opposing tooth (on a slow basis). It's an equilibrium system, like Silly Putty. --Zeizmic 17:00, 30 May 2006 (UTC)

Multiple teeth has the advantage that they can adjust well as your jaw grows in childhood. – b_jonas 20:07, 30 May 2006 (UTC)

And losing your baby teeth would be a lot more traumatic if there was just one big one on top and one on the bottom. (... the tooth fairy would need to leave the poor kid a credit card, LOL.) StuRat 21:50, 30 May 2006 (UTC)

"The tooth, the whole tooth, and nothing but the tooth." StuRat 21:54, 30 May 2006 (UTC)

[edit] Converting .rm to other formats

How do one convert realplayer formats to other formats such as .m4a or .wav, .mp3? I tried some softwares but they need RealPlayer to be installed. Are there anyways to convert them without necessary installing RealPlayer? Thanks!

I think you simply click on the file, press F2 to change the file name, remove the file extension you don't want, and then change it to whatever. Just so you know, if you change it to wav or wma, you can't change it out again! Kilo-Lima|^(talk) 14:45, 30 May 2006 (UTC)

Huh? --Ouro 15:04, 30 May 2006 (UTC)

Well, that does a good job of changing the file name, but the data will still remain in RealPlayer format. — TheKMan^talk 15:11, 30 May 2006 (UTC)

Ignore that last answer. Changing the name of a file doesn't change its contents. To convert a RealAudio file to another format you need something that can play RealAudio files (like RealPlayer) and you need some way of making it output to a file instead of your soundcard. There are programs that can capture the data sent to your sound card and save it as uncompressed audio (for example a wav file). To convert to a compressed format like m4a or mp3, you need another piece of software to encode it. Keep in mind that converting from one lossy data compression format to another is never a good idea, because the quality suffers even if the file doesn't get any smaller. —Keenan Pepper 16:25, 30 May 2006 (UTC)

A tutorial is here. –Mysid^(t) 17:02, 30 May 2006 (UTC)

mplayer will do this nicely. Use the -ao pcm option to get raw WAV output, and then reencode that. Dysprosia 22:41, 30 May 2006 (UTC)

[edit] MediaWiki codebase

Just what is its size? A souce would be appreciated. Thanks, Ingoolemo ^talk 15:25, 30 May 2006 (UTC)

The source is available at mediawiki.org. There you can check the size of the compressed tarball, and alternatively unpack and count the total code size yourself. ❝Sverdrup❞ 15:37, 30 May 2006 (UTC)

My copy of 1.6.2 seems to be 8.3 MB, with 4.3 MB devoted to support for other languages. Dragons flight 15:40, 30 May 2006 (UTC)

Hmm... How hard would it be to delete language support if it is an English-only Wiki you want? I think the big problem is that when you upgrade you have to remove the languages again. --Kainaw ^(talk) 17:06, 30 May 2006 (UTC)

[edit] fingerprints

could someone please advise who first started the fingerprint system? and what year. thanks.

Have you read our article on fingerprints yet? — Lomn Talk 18:33, 30 May 2006 (UTC)

no, did not know there was ne. last time i was on wiki was over 3 months ago. sorry.

Interesting as the history seems to suggest that article has been around since 13 September 2002 :P -Benbread 12:13, 31 May 2006 (UTC)

nice, but i did not know about wikipedia until 6 months ago and not having a computer at home makes if difficult for me to access. but thanks for the sarcasm.

[edit] Honey, We're Killing the Kids

The BBC broadcast this show over here, and apparently there's a US version too, in which parents are advised on how to give their kids a healthier lifestyle. One of the more revolting parts of the show is the bit where the parents are presented with CGI images of what their children "would look like" if they carried on living unhealthily. The section starts with a wee montage showing skilled technicians (white coats, spectacles etc) beavering away on Apple Macs.

So, my question is - does this "aging" software exist? Or are they just messing around with Photoshop until they find an image revolting enough? Thanks --The Gold Miner 18:50, 30 May 2006 (UTC)

Sure. It's used by police to guess what people who have been missing for several years may look like if still alive. For a shock-value show like that, though, I wouldn't be surprised if there's a significant Photoshop factor too. —Zero Gravitas 19:24, 30 May 2006 (UTC)

Thanks - so is it, or anything similar, available commercially? --The Gold Miner 21:34, 30 May 2006 (UTC)

Update: for anyone interested - I had a bit of a Google. I didn't find the swanky white coats and spectacles software, but www.infoscotland/experience and www.perceptionlab.com claim to be able to do similar things. The latter also apparently let's you see other changes such as if you were a different race. You upload a photo etc etc. I haven't tried it yet. --The Gold Miner 00:39, 31 May 2006 (UTC)

Also, if I may add, that part of the show is more to scare you and the victims on the show out of leading excessively unhealthy lifestyles, than to be accurate. —

The Mac Davis] ⌇☢ ญƛ. 07:52, 31 May 2006 (UTC)

[edit] Hardness of Coal

Hi,

Could you please tell me the hardness of coal?

Thank You! CAra787

It varies. Hard coal is also called anthracite coal, soft coal bituminous coal. None of those articles gives a specific degree of hardness, however. --Ginkgo100 21:24, 30 May 2006 (UTC)

One of them is pretty hard—like a rock, and the other is pretty dusty and crumbly and soft. —

The Mac Davis] ⌇☢ ญƛ. 07:38, 31 May 2006 (UTC)

Thanks for clearing that up. =) --Ginkgo100 19:13, 31 May 2006 (UTC)

Our mineral article gives a list that form the Mohs scale. Mnemonic for the list : "The Girls Can Flirt And Other Queer Things Can Do". Pick one of each minearl item and rub you coal against to measure the hardness, it should be between 3 and 4. But why that question ? --DLL 17:59, 31 May 2006 (UTC)

[edit] Conversion of Units

How do you convert a number in the units mg/kg to the unit mg/kg-1 (that reads mg/kg[to the power of]-1, read negative one, not minus one)? Thanks.

sorry, I don't --Seejyb 23:07, 30 May 2006 (UTC)

Well, mg/kg=1^–6 (unitless), and mg/kg^–1=mg*kg=1 gram². I suppose you need some sort of constant to convert from one to the other. — TheKMan^talk 23:08, 30 May 2006 (UTC)

mg/kg⁻¹ sounds like an odd unit to use. Are you sure you don't mean mg kg⁻¹? Because that's just another way to write mg/kg. They are the same "unit", though not really a unit but a dimensionless number. –Mysid^(t) 08:06, 31 May 2006 (UTC)

[edit] Quantum Chemsitry

Hi, i was wondering what goes in and out of a blast furnace, also what is what benefits does it have in explaining the thesis of quantum chemistry (reference page 89 quantum chemistry, Chemistry is for life, Dr. John Parker).

Thanks for your help. I look forward to your wholesome replies

-Prof. Martin Alderson

Are you testing us? You shouldn't use your real name, people will just think you're making it up anyway. Googlifying on this rather obscure question leads one to the Earth's inner core, made up of solid iron, and it is a single crystal because of quantum effects. [32] --Zeizmic 00:03, 31 May 2006 (UTC)

All of chemistry is a quantum effect. --BluePlatypus 07:39, 1 June 2006 (UTC)

I must admit I am not familiar with the thesis of quantum chemistry. Can you tell it? For what goes in and out of a blast furnace, see blast furnace. Here is one animated interactive diagram of one kind of blast furnace [33]. —

The Mac Davis] ⌇☢ ญƛ. 07:41, 31 May 2006 (UTC)

Curiously Dr. John Parker (if that is his name) has made some posts here aswell. Both are unconvincing at best regarding wether they are doctors or not. Philc _T^E_C^I 23:42, 31 May 2006 (UTC)

[edit] May 31

[edit] Laptop screen size

Looking into laptops for older users, and wondering what would be best between a 14.x" (1024x768?) and 15.1" (1280x800?) for someone with subpar eyesight. 17" would be best, but lets assume that isn't an option. Much thanks. - Roy Boy ⁸⁰⁰ 00:42, 31 May 2006 (UTC)

IMHO, the text size in your settings is going to be more important than the size of the display. -- Filliam H Muffman 02:36, 31 May 2006 (UTC)

- Well, on the 15.1" screen, for a vertical or horizontal length of one inch you will have 105.8 pixels. On the 14" screen, you will have 91.4 pixels per one inch length. The 14" screen will show details in a slightly larger size relative to the 15.1" screen. — TheKMan^talk 04:30, 31 May 2006 (UTC)

You mean for what laptop, or what size and resolution? If its an old person that is not very tech-geeky, than you should probably get something like the MacBook—you never have to mess with spyware, viruses, internet & wi-fi problems, and it is totally compatible (except with some of the newer hot games) with all PC stuff. My grandmother uses an Apple. —

The Mac Davis] ⌇☢ ญƛ. 07:49, 31 May 2006 (UTC)

So it's a Granny Apple? Weregerbil 10:15, 31 May 2006 (UTC)

Hoo hooo! It'd be funnier if her name were Smith.. --Zeizmic 12:04, 31 May 2006 (UTC)

Thanks all, indeed the font settings would mitigate this discussion; but I was curious as to which indeed ends up being better in its own right for text clarity and detail. - Roy Boy ⁸⁰⁰ 06:05, 7 June 2006 (UTC)

[edit] Sharp-ribbed newt

The Iberian Ribbed Newt was on board Bion 7 and 10 and there are papers about them that back it up, but I can't find strong evidence either way if they were actually on board Bion 9 and Bion 11, or if the space newts were a different species. I'd like the article on the Iberian Ribbed Newt to be more definite and referenced about it. Were iberian ribbed newts (Pleurodeles waltl) on board Bions 9 and 11? Thanks —Pengo 00:58, 31 May 2006 (UTC)

[edit] Branched alkane?

What is the name of the alkane with this diagram? (Treat all the numbers as subscripts.)

       CH3-CH2  CH2-CH3
            |   |
        CH2-CH-CH-CH3
         |
CH3-CH2-CH-CH2-CH-CH2-CH2-CH2-CH3
     |      |
    CH2    CH3
     |
    CH-CH3
     |
    CH3

I think this is just polymeth-2-3-ane aka petroflurochloride

Dr John Parker

To start with, I know you would probably have 3,7-dimethyl-4-ethyl-6-somethingduodecane, with the main line being the one in bold, but what would the something be? I don't see a procedure to handle the multiple branching this would involve. Seahen 02:50, 31 May 2006 (UTC)

I can't remember how to prioritise the different chains, in order to find the main chain. I know you are meant to minimise multi-substituted chains to a certain degree. If the bold chain really is the main chain, then the substituted group is (1,3-dimethylbutane), i.e. the whole thing would be 6-(1,3-dimethylbutane)-4-ethyl-3,7-dimethylduodecane. Note the alphabetical order: normally the numerical prefix ("di" in 3,7-dimethyli-) doesn't count for alphabetisation, but with the multi-substituted group it does. -postglock 05:08, 31 May 2006 (UTC)

Bah. It's way easier to just call it isodoicosane. :D TenOfAllTrades(talk) 14:52, 31 May 2006 (UTC)

It doesn't have a name as it is not possible to make (well, you could, but it would decompose instanaeusly) there are several Carbons in there with 5 bonds. I count at least three. And one with only three bounds, so it would also be an Ion. Philc _T^E_C^I

CH3-CH2-CH--CH-CH2-CH-CH2-CH2-CH2-CH2-CH2-CH3
         |   |      |
        CH3 CH2    CH-CH3
             |      |
            CH3    CH2
                    |
                   CH-CH3
                    |
                   CH3

I've also removed all of the kinks as the do not mean anything, in order to make it less confusingPhilc _T^E_C^I 20:36, 31 May 2006 (UTC)

I think you also removed the methyl group at position 7.

You are right, but it is probably a typo. Carbon 7 and 8 are transposed.

The longest chain is the main chain, this is already in boldface, so that is easy. I think you take the chain closest to the end first. So that would be 3-methyl 5-ethyl 6(1,3 methyl) butyl 7-methyl duodecane, or maybe 3,7-methyl 5-ethyl 6(1,3 methyl)-butyl duodecane, but my memory is kind of fuzzy.

[edit] Pennies

What is a penny composed of? And what is the melting temperature of the combined metals? I want to melt a bunch of pennies and have a giant one, is that possible with limited resources? Would the super-penny be worth how many pennies it is made of?

The article on the United States penny tells what it's made of, if you were thinking of a U.S. penny... though I don't know of any others off the top of my head. Dismas|^(talk) 03:07, 31 May 2006 (UTC)

Well, the US penny is almost entirely zinc, with just a coating of copper. The melting point would likely be close to that of zinc. — TheKMan^talk 04:17, 31 May 2006 (UTC)

Pennies also exist in other places that uses dollars as their currency. Make sure you specify the country. Melting pennies together would almost certainly make them lose their value as a bank would no longer take them. You wouldn't get a single penny back unless you found a collector crazy enough to buy it. Melting money may also be illegal. - Mgm|^(talk) 09:14, 31 May 2006 (UTC)

Not only dollars are divided into pennies. So is the pound Sterling. Also, I know that in Canada melting down money is illegal, but you can ship it to another country and melt it there. (This used to happen with silver dimes when the silver became worth more than ten cents.) Seahen 12:57, 31 May 2006 (UTC)

[edit] Railgun

If I where to build a railgun capable of withstanding the amount of energy flowing through the rods, How much energy would it take to get an objet wieghing 500 tons up to 7.2(or so) miles per second?

500 tons is 453 592.37Kg. To get this mass at 11 587.2768 meters per second use 1/2mv^2. Assuming resisitve forces are negligble which, in the real world they obviously arent, you would need 3.045078607*10^13 Joules of Kinetic Energy. I hope this has helped.

Dr J Parker

Lots. You can get a lower bound using the formula for kinetic energy to figure out how much energy a 500-ton object travelling at 7.2 miles per second has; see joule to see how to adjust for the appropriate units. Any real rail gun will be less than 100% efficient, so it will take more energy than the kinetic energy of the final object. No, I'm not going to do the calculation for you. --Robert Merkel 05:53, 31 May 2006 (UTC)

For interest, I did the calculation; it's smaller than the amount of energy released by Little Boy, but not that much smaller. If you need more precision than that you'll have to crunch the numbers yourself. --Robert Merkel 06:07, 31 May 2006 (UTC)

500 t = 453 592.37 kg; 7.2 mi/s = 11 587.2768 m/s; E_k = ¹⁄₂mv² = ¹⁄₂ (453 592.37 kg) (11 587.2768 m/s)² = 3.04507861×10¹³ J. Of course, you probably have fewer significant digits, but we don't know how many.

For the railgun, B = 2x(u0/2pi)x(I/r), a=ILB/m, and F=ma. B is the magnetic field strength. u (actually mu) is the magnetic constant of free space, I is current, L is length of the rails, m is mass of the projectile, a is acceleration, F is force. Put it whatever values you desire. —

The Mac Davis] ⌇☢ ญƛ. 06:44, 31 May 2006 (UTC)

Thank You... Everyone

[edit] Forecasting weather with emotions

Could you please tell me what is the name of the term for describing the phenomenom of a person's emotions forecasting the weather?

I think the term is bullshit. This clearly doesnt work, get a life

Dr J Parker

P.S The guy below me, do you not think he has already tried this you idiot.

In this web page a related phenomenon is called "Bio-meteorology". Try a google search for (emotion OR emotions OR mood) AND "forecasting the weather. --vibo56 17:00, 31 May 2006 (UTC)

[edit] Osmotic pressure symbol

Hi, is the symbol for osmotic pressure an uppercase or lowercase pi? The article itself says lowercase, but Pi (letter) says uppercase. Googling also brought varying results. Thanks! -postglock 04:59, 31 May 2006 (UTC)

I've only encountered osmotic pressure as lowercase pi (ie, π). The following medical texts/review books agree: Medical Physiology by Boron and Boulpaep, PreTest Physiology by Ryan and Wang (11th ed), Vander's Renal physiology by Eaton and Pooler (6th ed), and BRS Pysiology by Costanzo (3rd ed). Hope that helps, David Iberri (talk) 04:04, 4 June 2006 (UTC)

[edit] colours to make white light

on this site it says you need red, blue and green to make white light but if you look at prisms more colours than that come through. what are the actual colours needed to make white light? thanks --81.151.8.56 09:06, 31 May 2006 (UTC)

In fact, the light mixed from red, blue, and green is physically different from light mixed from all the spectral lines, but both are percieved as white. See white, color vision and trichromatic color vision. Conscious 09:17, 31 May 2006 (UTC)

So basically red blue and green is a minimum recquired to make white, whereas you can use more? Philc _T^E_C^I 20:20, 31 May 2006 (UTC)

Yes, you could make white-looking light from three monochromatic light sources, but it wouldn't act anything like the broad-spectrum white light from an incandescent light bulb or the Sun. Any object that doesn't reflect those specific colors (say, a true purple object) will look black, and objects that reflect one of the colors weakly, while reflecting a similar color strongly, will look strange. A similar effect could be seen with early fluorescent lights (and to a smaller extent even with modern ones), where an object appears to "change colors" when moving from sunlight to fluorescent and back. --Serie 21:32, 31 May 2006 (UTC)

The reason those three colors combined look white to human eyes has to do with the way humans perceive color. We perceive three basic colors, red, blue, and green, and see all colors as a combination of those three. This condition is called trichromacy. Other species see other numbers of colors; for example, most mammals are dichromats, seeing only two colors (blue and green), and some species are tetrachromats, seeing red, blue, green, and ultraviolet. Presumably, to a tetrachromat, a three-color light that looks white to us would look, well, whatever color is opposite to ultraviolet in their vision. And a blue-green, or cyan, light (to humans) would look white to a dichromat. All these organisms would see full-spectrum light as white, however. --Ginkgo100 19:09, 1 June 2006 (UTC)

See this nice introductory article on Colors and colorimetry. – b_jonas 10:10, 1 June 2006 (UTC)

To make light that just looks white red green and blue will do, to make true white light (as from the sun) you need all the colours - ie a rainbow - red orange green blue indigo violet. White might give the answer, don't forget to look at spectrum as well.HappyVR 17:43, 1 June 2006 (UTC)

I believe, by opposite, you meant complement. Black Carrot 22:17, 1 June 2006 (UTC)

[edit] Air intakes for jet engines

How do jet engines (used on aircraft) work even when its raining, snowing, in dust storms etc., and still not damage the internals of the engine? Basically, I want to know how jet engines filter their intake air.

Thanx.

Once again we have an article on anything. See Bird strike. Anything smaller isn't noticed. I like how they once had a cat sucked in at 10,000 ft! --Zeizmic 12:01, 31 May 2006 (UTC)

Basic answer: they don't filter, they just hope that anything they suck in will go through the engine without causing any critical damage. Also, they build the engine fan blades with sufficient strength to widthstand moderate impacts. For rain and snow, it just turns to water and is lost in the large mass of air that flows through the engine. Dust and sand are a problem, as they can clog the engine and cause it to fail (as happened when British Airways Flight 9 flew through a cloud of volcanic dust) - again, the engine is designed so that it can cope with moderate amounts of the stuff, but anything above that is a problem. Large, solid object are a major problem for jet engines, since they act as giant vacuum cleaners and suck up everything in front of them. Birds are a problem (see the article Zeizmic linked), jet engines have to undergo 'bird strike' tests to prove that, if hit by a moderate-sized bird, even though they will fail, they won't damage the rest of the plane. If anything larger hits, you're in trouble - see foreign object damage. — QuantumEleven 11:04, 1 June 2006 (UTC)

[edit] natural resources

ok i am writing a project on natural resources and my topics are :

                                        1)general information
                                        2)conservation of natural resources-practices
                                        3)causes of depletion
                                        4)impact of resource depletion

can somebody please help me out you can mail me at: (email address removed; don't post it or spammers will get it!) thanks

What help do you need? Read the article, read relevant items under the "see also" section and click any of the blue words in the article that look interesting. Any specific questions that remain unanswered? Also remember to google first. Weregerbil 11:38, 31 May 2006 (UTC)

[edit] acanthicus - new fish page please check (biology)

I've added a new genus article - acanthicus - maybe someone could check it for errors etc - also further questions at Wikipedia talk:WikiProject Fishes#Questions about format - new genus article - if there are any comments - maybe you could reply there as this page is big.HappyVR 10:41, 31 May 2006 (UTC)

HappyVR, your contributions are excellent, but this is not really an appropriate use of the reference desk. Does anybody know the right place for this kind of announcement? I'd say don't even bother, because yours are so much better than the vast majority of new articles. =P —Keenan Pepper 20:47, 31 May 2006 (UTC)

You can tell me about it... if its not about fish. :P —

The Mac Davis] ⌇☢ ญƛ. 04:44, 1 June 2006 (UTC)

[edit] blue sky

my question is why the sky looks blue???

Because you probably don't live in the British Isles. Arbitrary username 16:11, 31 May 2006 (UTC)

Try Why is the sky blue?. Weregerbil 11:34, 31 May 2006 (UTC)

"Because it isn't green". --Serie 21:39, 31 May 2006 (UTC)

Because of a phenomenon called Rayleigh scattering (or the Tyndall Effect). Interestingly enough, this process is the mechanism through which almost all blue colours are generated in nature. Rockpocket 05:45, 1 June 2006 (UTC)

[edit] Speed of gravity

Suppose the sun, which is about 8 light minutes away, was to suddenly disappear, the Earth would leave it's orbit and travel into space. But would this effect be instant, or does gravity have a maximum speed, like light does, so there would be a time when the Earth continued to orbit a non-existant star, just as light from the sun would continue to reach us for 8 minutes? I can't find an answer to this at gravity. smurrayinchester^{(User), (Talk)} 11:13, 31 May 2006 (UTC)

Try speed of gravity. Weregerbil 11:33, 31 May 2006 (UTC)

Gravity indeed was missing a "see also" link to speed of gravity, fixed. Weregerbil 11:41, 31 May 2006 (UTC)

The speed of gravity is dependant of the mass of which it is centered around. For example, a much larger mass such as Jupiter has a larger gravitational force than the Earth. Gravity cannot exist without a central mass. The instant the sun 'disappeared' the earth would stop orbiting the Sun. The flux density (S.I unit Tesla) would instantaneously stop. The earth would then continue in the direction of the tangent to its orbit at the specific point it was at when the sun disappeared. The earth would not accelerate into space as there is no resultant force acting upon it but would continue in a specific direction until another force would act upon it. The reason light would continue to reach us eight minutes after us is because the light takes a finite time to reach us. After 8 minutes the light would stop and we would all die!!

I hope this is of some help

Dr J Parker

What are you a doctor of, exactly? --Heron 20:08, 31 May 2006 (UTC)

Yes, either the "sum" was meant to be a pun, or I have sincere doubts about his authenticity. Philc _T^E_C^I 20:18, 31 May 2006 (UTC)

Note to confused, curious parties: 'Dr' J Parker's explanation above is just silliness. Teslas are involved in electromagnetism, not gravity. Skittle 20:19, 31 May 2006 (UTC)

...and that's just scratching the surface. --Ashenai 20:22, 31 May 2006 (UTC)

Ignore "Parker's" comment, it is flat out wrong. Is the speed of light different depending on how bright it is?—

The <font color=#006600>Mac Davis] ⌇☢ ญƛ. 21:00, 31 May 2006 (UTC)

Thanks to all of you. I agree that Doc's response seems confused. It seems to says the speed of gravity is both variable and infinite... smurrayinchester^{(User), (Talk)} 21:20, 31 May 2006 (UTC)

Recently I've been re-reading the book "A Brief History of Time" by Stephen Hawkings, it says that gravity should propagate at the speed of light. VdSV9•♫ 17:49, 1 June 2006 (UTC)

I've heard that. And Speed of gravity confirms it, though if even the people writing the article aren't confident, I'm not sure how reliable it is as a source. Black Carrot 22:11, 1 June 2006 (UTC)

If your desire is to stay within the realm of reality in such a scenerio the entire mass of the Sun must be converted to Gamma radiation. Once you step outside of the realm of reality any answer likewise falls outside the realm of reality. Star Trek anyone? ...IMHO (Talk) 11:21, 2 June 2006 (UTC)

Wow, there's a lot of garbage here. Gravity is an effect from the curvature of spacetime, Newton's laws are approximations. The curvature propogates at the speed of light, so it would take 8 minutes for there to be any effect on the Earth. See general relativity (Cj67 22:40, 2 June 2006 (UTC))

According to general relativity, gravitational waves propagate through a vacuum at the speed of light. Tom Van Flandern is a well known crank. ---CH 05:34, 3 June 2006 (UTC)

The problem in the article is not that WikiProject GTR lacks expertise or confidence :-/ The problem is that Tomvf (talk • contribs) is Tom Van Flandern in real life. See also Some Scientifically Inaccurate Claims Concerning Cosmology and Relativity for some more pointers. ---CH 05:38, 3 June 2006 (UTC)

[edit] First electronic theory of valency

Is this parapgraph true?

Thank you

No saddly it is false. Do your own homework

[edit] River and Stream Widths

Is there a specific definition in the difference between a river and a stream as it pertains to the width of the body of water? I thought I had read somewhere that a stream is defined as being less than four feet across, hence a river being larger than four feet. If not, then at what point does a stream become a river? Curious second graders want to know...befuddled teacher unsuccessful in locating answer...Help!

Thanks, Bridget

You could check our articles at stream and river (also creek, brook, branch, and various others I can't recall offhand) but ultimately, in practical use, there is no hard fast definition. Stream is perhaps most helpful, as it notes that "stream" is the scientific "umbrella" term encompassing such bodies of water (note also the size of the "river" pictured in the article). — Lomn Talk 14:58, 31 May 2006 (UTC)

In order of increasing size, in general usage, creek < stream < river. Nevertheless, there do exist in some places (for reasons of historical accident or tradition) named rivers that act as tributaries to named creeks. Historically, bodies of water have been named by whomever settled in the area.

Legal definitions (based on width, flow rate, navigable depth, etc.) exist in some jurisdictions. If you can tell us what country or state you live in, we might be able to locate more formal definitions. TenOfAllTrades(talk) 15:01, 31 May 2006 (UTC)

Also note that the width of many change over the year, from the dry season to the rainy season and/or snow melt season. Changing the name as the width changes would be a real pain. StuRat 16:31, 31 May 2006 (UTC)

My personal definition is that it's a stream if I'm willing to wade across, but a river if I want a boat or a bridge. --Serie 21:41, 31 May 2006 (UTC)

I follow Lomn: On the one hand, there's the Gulf Stream, but on the other hand, while all streams stream, rivers can't river, creeks don't creek , and I brook serious questions. --Seejyb 03:08, 1 June 2006 (UTC)

I think we need to branch out to a more serious discussion.

[edit] dBmW

The following statement taken from the article dBm seems incorect, Since it is referenced to the watt, it is an absolute unit, used when measuring absolute power. It should not be confused with dB, a dimensionless unit, which is used when measuring the ratio between two values, such as SNR. Are not all decibel scales unit-less (and NOT absolute)? And the statement seems to be a contradiction, seeing that the decibel milli Watt is the logarithmic ratio of the Power being measured over 1 mW?? And would it be better if the page was renamed to deciBell milli Watt? Sorry if i am completely wrong! --LeakeyJee 15:12, 31 May 2006 (UTC)

This is a common logarithmic scale with an equivalence given to W(atts), which is dimensional. The dB paradigm is strong but here we have no dB at all, just a representation for W.

Do not rename the page, create a redirect page if you wish. --DLL 17:45, 31 May 2006 (UTC)

First, when SI units are spelled out, they are lowercase; the only exception I can think of is degree Celsius. Thus the spellings would be "decibel" and "milliwatt". This avoids confusion between the unit and the scientist. It is only when the unit is shortened to a symbol that units named after scientists are capitalized (dB, mW).[34]

Second, you are generally right. Every decibel measurement is compared to some reference power, which may be unique for a certain experiment, or may be a widely used power level such as a milliwatt. So dBm is just shorthand for decibels above 1 millwatt. Gerry Ashton 18:31, 31 May 2006 (UTC)

[edit] amino acids

hello,

why are L-AMINO acids and not D-amino acids used in proteins?

I have searched through google and got only this fact but not the reason......can any one help me out...plz?

This is a fact of evolution. It is an interesting exercise to try and imagine alternative biologies, ~~which~~ with information-carrying molecules different from DNA and RNA, and structural molecules composed of something else than the amino acids we know. And even within the constraints of DNA and RNA, with 64 codons, there could have been 63 different structural building blocks (leaving one for a stop codon). Yet there are only 20.

Amino acids turned out to be good building blocks because of the peptide bond, which links the amino acids together in proteins. Polypeptide chains fold into complex structures. In parts of the chain typical folding patterns like alpha helices and beta-pleated sheets form stable substructures ("secondary structure") within the three dimensional structure of a protein. For such substructures to be stable, all the amino acids have to be of the same type, i.e. either L or D. Therfore, in the primordial soup, nature had to make a choice. And the choice fell upon L-amino acids, possibly for no particular reason. But it had to be one or the other. --vibo56 16:38, 31 May 2006 (UTC)

Are there cases where D-Amino acids are used rarely like reverse transcriptase in certian viruses? Or am I on the wrong track?

I'm not sure about reverse transcriptase, but a medline search for "(D-amino acid)" reveals that D-amino acids are indeed used to some extent for specialized purposes. "(D-amino acid) AND (reverse transcriptase)" gave no relevant hits as far as I could see. This article suggests that D-serine may be a regulator of glia cells, and thus indirectly control the exitability of neurons --vibo56 18:56, 31 May 2006 (UTC)

My read on this enzyme in Wiki suggests it is made from normal L-AMINO acids, but has a reverse function of making DNA out of RNA instead of the normal way of making RNA out of DNA. This is necessary for viruses to hijack the cells functionality.

Since viral proteins are made by the protein synthesising machinery of the host, they would be expected to consist entirely of L-amino acids, and your interpretation of the reverse part of the enzyme's name is correct. What I thought the questioner had in mind was whether there was something funny going on with this particular enzyme, such as a posttranslational modification, but as stated, no hits in medline. --vibo56 21:42, 31 May 2006 (UTC)

Chirality is often overlooked; see thalidomide. Isopropyl 20:32, 31 May 2006 (UTC)

The link should be Chirality (chemistry). --vibo56 21:48, 31 May 2006 (UTC)

I asked this on the Chirality page, but I am sure a lot more people read this one so I will ask it here. Is it possible to have an optical isomer using isotopes? Suppose the Alanine molecule has the Methyl group replaced with Deuterium instead of Hydrogen? Would that create an optical isomer?

Yup (also answered on the Talk:Chirality (chemistry) page wher eyou asked it). The carbon atom would be tetrahedral as usual and would have four different substituents on it, thus it is an asymmetric center. One might expect the optical rotation to be small--I can't find the exact number at the moment. DMacks 21:18, 1 June 2006 (UTC)

The optical rotation is expected to be small because the chemical difference between the two is small, right?

Yeah...from a non-scientific viewpoint, one might say "well, they're both hydrogen, so why is it considered a stereocenter at all (see the initial question), and even if it is in a technical or pedantic sense, would there be any rotation at all?" Until I found the actual ref (see my response below), I only remembered that indeed it was "a small number". DMacks 16:01, 2 June 2006 (UTC)

Tetrahedron 1959 6 338-344 reports measurements of optical rotation of several isotopically-chiral molecules such as RCHDOH, finding [α]_D up to ~1°. DMacks 23:08, 1 June 2006 (UTC)

I read something about serine being special, and only liking to make bonds with the same-handed aas... I can't find it again though, but I thought it was an interesting idea. Aaadddaaammm 07:50, 7 June 2006 (UTC)

[edit] Wiki hosting site

I need a free wiki hosting site that uses inline tex. Does anyone know a good one? ThanksBorisblue 16:10, 31 May 2006 (UTC)

Wikia? Conscious 05:31, 1 June 2006 (UTC)

[edit] Enzyme Kinetics

Hi, I have an exam on firiday and I am really struggling to understand 1st and 2nd order reation rates. The amounts of equations and explanations can get a bit tricky. Any simple explanation which includes the orders of reaction rates would help so much. Also if anyone can just breifly explain allosteric regulation to me...that would also be a help...Thanks a bunch. 196.23.228.155 16:18, 31 May 2006 (UTC)

Mmmmh. I do not work with chemistry, but reaction rates and allosteric regulation might have the answers you are looking for. Cthulhu.mythos 16:47, 31 May 2006 (UTC)

Order of reaction may be what you need. Rmhermen 19:02, 31 May 2006 (UTC)

I actually just passed my college enzymatics course, which is cool. The key thing to remember when writing the mass-action kinetics equations is to look at the big picture first: how things are formed and lost. Isopropyl 20:29, 31 May 2006 (UTC)

Reaction orders are pretty simple. If dA/dt (product A formed per unit of time) is proportional to the concentration of one reactant, then it's first order. If it's proportional to the product of the concentrations of two reactants, then it's second-order. However, enzyme reactions are usually described as neither, but as Michaelis-Menten kinetics. However, real-life enzyme kinetics are actually much much more complicated and not actually well-understood. --BluePlatypus 07:31, 1 June 2006 (UTC)

[edit] Hurray...Google desktop is a spyware! Or is it?

Today, when I monitored my network using network monitoring software, I found that google desktop was constantly sending out data to its servers. I was not warned when I installed google desktop.Or did Google warn me? Your comments.

Did you read http://desktop.google.com/eulauk.html, specifically under "Automatic Updates" and "Information Practices"? Notinasnaid 17:28, 31 May 2006 (UTC)

After reading the google Desktop EULA, I changed to Copernic Desktop search, and have used it for 3 months now with no complaints --Seejyb 02:26, 1 June 2006 (UTC)

A lot of the plugins to the Google Desktop download data (I believe). For example, the web clips, news, Gmail inbox, Google Talk, weather and maps sections all upload and download data without you specifically requesting it. This automation is one of the aspects of Google Desktop that I like. I guess it really depends on your view on allowing the tools into your system. I trust Google not to screw my system, so I don't consider it malware/spyware. --DanielBC 03:34, 2 June 2006 (UTC)

[edit] Moon 8 Orbit

Would it be possible for a satellite to exist in a figure 8 type orbit between the earth and the moon? Thanks. 199.201.168.100 18:56, 31 May 2006 (UTC)

I think so, in the short term, although the loop around the Earth would be larger than the one around the Moon. However, I don't think such a complex orbit would be very stable. Changes in the distance between the Moon and Earth would destabilize the orbit, as would debris which can accumulate in the barycenter/Lagrange point between the Moon and Earth (I think that would be where the figure 8 crosses itself). StuRat 19:24, 31 May 2006 (UTC)

I disagree. The magnetic flux density of the earth is much greater than that of the moon, the satellite would just continue to orbit the earth instead.

"magnetic flux density"? Shimgray | talk | 19:31, 31 May 2006 (UTC)

Are you proposing the pre-Newtonian idea (rejected before him) that objects in the solar system are held in orbit by magnetism? Or are you just playing around with jargon? Skittle 19:39, 31 May 2006 (UTC)

Oh, for those who are wondering if it exists: Magnetic flux density. Skittle 19:40, 31 May 2006 (UTC)

I think our magnetic friend is a hoaxer. See similar comments at 'speed of gravity' above. --Heron 20:11, 31 May 2006 (UTC)

[edit] high blood pressure medicine

Is there a medicine called prinivil used to treat high blood pressure or hypertension?

Please consult your doctor if you require medical advice. Prinivil is a drug used to treat high blood pressure, it is a trade name for Lisinopril. Oldelpaso 21:05, 31 May 2006 (UTC)

[edit] Ant identification

Every year about this time I get a few termites flying around. Some of them are attracted by the monitor and the desk lamp and loose their wings and crawl around looking for a new home but since everything I have is mostly metal or plastic they soon die and require removal. However, for the past couple of years it seems that I also get removal help at the same time every year by a crew of very odd type ants so I was wondering it anyone could identify them and tell me if they also stick around during the winter months and go looking for termites inside of wood. They sure are great little removers of expired termite carcasses. Under a magnifier I can see they have much longer feelers than a normal ant and they have much longer legs and hairs coming out of the back of their Metasoma. Their behavior is what is so different and unique. I call them "Darters" because they dart for distances of between half and six inches as if they were trying to catch a fast moving train. I'm hoping to breed them and market them as termite carcass clean up crews as a hobby project. So if you can help me identify them it will help out allot. ...IMHO (Talk) 21:26, 31 May 2006 (UTC)

Have any photos? Also, what is your general location? — TheKMan^talk 14:33, 1 June 2006 (UTC)

I was thinking about doing a photo but thought the description might be good enough. Lets see where is that camera...? Central Florida is the general area. ...IMHO (Talk) 20:48, 1 June 2006 (UTC)

Whatever they are, I'd hate to see them "marketed" into an area where they are not native and become a harmful invasive species. --Ginkgo100 19:15, 1 June 2006 (UTC)

Oh heck I only see these guys once a year just after the termintes start swarming. I'm sure they must specialize in termite carcass removal. They don't gang up they just each handle a carcass alone. I can't immagine them becoming outrageous and obnoxious pests unless of course you have pet termites and then well I'll put a warning on the label. ...IMHO (Talk) 20:48, 1 June 2006 (UTC)

And I can't imagine cute little Quaker parrots being obnoxious pests, but they are, in places where they've been introduced. --Ginkgo100 03:21, 2 June 2006 (UTC)

One problem with any living creature (especially insects) that many people do not realize is their excrement. Even if you have beneficial instects doing a go job for you unless their fertilizer is also of benefit areas that become highly populated (as with cockroaches and Palmetto bugs) can become quite obnoxious. ...IMHO (Talk) 08:26, 2 June 2006 (UTC)

I think you might have Argentine ants. Apparently they make a habit of attacking termite colonies.[35] — TheKMan^talk 06:15, 2 June 2006 (UTC)

Haven't seen any queens though yet. The article contains a recipe for a homemade insecticide I've been looking for. Thanks. ...IMHO (Talk) 08:26, 2 June 2006 (UTC)

[edit] Expanding Universe...

This has been bothering me a while now, "If the Universe is expanding, then what is it expanding into?" Thanks WizardFusion 21:53, 31 May 2006 (UTC)

Why must it be expanding into something? — Knowledge Seeker দ 22:08, 31 May 2006 (UTC)

Actually you are probably refering to the known or observable or visible universe that is inside the unknown or unobservable or invisible universe. ...IMHO (Talk) 22:53, 31 May 2006 (UTC)

Probably the universe is infinite. So when it expands, it's just that all the distances get larger; there aren't any edges moving "into" anything anyway. -- SCZenz 22:16, 31 May 2006 (UTC)

Actually in Star Trek episode 79 (TNG) the universe is contracting around Beverly where people begin to disappear. I know a girl like that once where the whole universe was only an area with a radius of about five feet from her head until she got some help from a doctor and now her universe has stopped contracting and may have actually expanded a few more feet. (On second though make that only a couple of inches.) ...IMHO (Talk) 22:35, 31 May 2006 (UTC)

Be careful of the popular misconceptions. SCZenz has got it right. It is the spacetime that is expanding, not objects contained. The distances grow larger, but nothing actually moves because of the expansion. —

The Mac Davis] ⌇☢ ญƛ. 04:32, 1 June 2006 (UTC)

Thank you all, I think its a change of thinking that is required on my part. WizardFusion 15:34, 1 June 2006 (UTC)

Remember that if you travel far enough in one direction as straight as you can, you'll eventually come back to where you started... FreeMorpheme 12:19, 2 June 2006 (UTC)

Not proven for the universe. —

The Mac Davis] ⌇☢ ญƛ. 05:51, 6 June 2006 (UTC)

OP: see Frequently Asked Questions in Cosmology HTH ---CH 05:43, 3 June 2006 (UTC)

[edit] discrimination of sound

Which part of the brain is responsible for the discrimination of sound?

See Primary auditory cortex --vibo56 23:49, 31 May 2006 (UTC)

[edit] Explosions in space?

As a matter of interest, how would a large explosion in the vacuum of space (e.g. a spacecraft detonating due to a fuel explosion/drive overload/etc.) actually appear to an observer? I'm pretty sure that the way it's usually portayed in the movies is wrong - forgetting about the whole 'sound in space' issue, how could an expanding fireball exist in the complete absence of oxygen and an atmosphere to carry the blast wave?

Also, would it be possible to detonate an atomic/hydrogen bomb in space? If so, what would the explosion from that look like?

Thanks. --Kurt Shaped Box 23:20, 31 May 2006 (UTC)

You'll still get a fireball, from the material that was consumed and heated by the explosion, but it won't be anywhere near as big or as long-lasting as an atomspheric fireball.

For a nuclear explosion, what it'll look like depends greatly on where the explosion takes place. For an explosion within a strong magnetic field, like what you get around a planet, see the photos at Starfish Prime (a high-altitude atom bomb test). For one in empty space, you'll get a roughly spherical fireball. --Serie 23:40, 31 May 2006 (UTC)

We have an article on high altitude nuclear explosions with some pretty pictures. --Fastfission 02:49, 1 June 2006 (UTC)

There's a picture of a large explosion in space happening right here. --Shantavira 07:54, 1 June 2006 (UTC)

So, what exactly is the 'fire' in those things comprised of? I didn't think that fire could exist without oxygen. Sorry if that's a dumb question... --Kurt Shaped Box 11:59, 1 June 2006 (UTC)

A conventional (non-nuclear) explosive either provides its own oxidizer (combustion explosives such as gunpowder) or involves a chemical breaking down into gas (decomposition explosives such as nitroglycerine). This produces a lot of heat, which causes the gas produced by the explosion, and any debris that is caught up in it, to glow white-hot, producing the "fire" you see. A nuclear explosion also produces a hot-gas fireball, but there's so much energy involved that it can cause light in other ways, such as fluorescence in the upper atmosphere of a planet. --Serie 19:04, 1 June 2006 (UTC)

Note that certain types of explosives, like a fuel air explosive, do indeed depend on atmospheric oxygen, so the only explosion you would see in a vacuum would be from the detonator and (if separate) diffusion charge. StuRat 01:52, 5 June 2006 (UTC)

[edit] One more space question - birds in space...

I remember reading somewhere a very long time ago that astronauts had observed that birds are unable to survive in the zero-g environment of a spacecraft without specialized hand-feeding. I think it was something to do with them being unable to swallow water due to the 'design' of their throats (many birds take water into their mouths and then tip their heads back, allowing it to run down their throats with gravity) - and possibly being unable to swallow solid food either. Does anyone have any more info on this subject? I'd like to read up about it again but I have no idea where to even start looking... --Kurt Shaped Box 23:26, 31 May 2006 (UTC)

That should be predictable, but one would not normally think of that aspect. Afaik the only group of birds that can actually actively swallow water (i.e. drink it while their head is below their stomach, like humans can) is the dove / pigeon group --Seejyb 02:36, 1 June 2006 (UTC)

How much would it suck to be an astronaut from an advanced avian civilization (i.e. the one that will arise when humans end up destorying each other and the parrots evolve and take over)? :) You'd literally have to spend your entire time in space with a tube jammed down your throat (gotta get annoying on those trips to the moon). Still, I'd *love* to see what a spacecraft designed by sentient birds would look like. Hell, their cities (completely unconstrained by the limits of ground-based thought) would be a sight to behold too... --Kurt Shaped Box 11:56, 1 June 2006 (UTC)

How strange. A couple of days ago I saw a clip of a bird fluttering around in a spacecraft, probably the shuttle. I think it was an extra on the Apollo 13 DVD. I'll have another look and see if there's any information we can nick for WP. --Howard Train 03:57, 5 June 2006 (UTC)

Animals in space doesn't include any mention of birds (except quail eggs). If you can find info, please update that article. Rmhermen 02:59, 1 June 2006 (UTC)

They probablly find the vaccum of space to be disorenting since they are used to a certain air pressure when flying. 12.183.203.184 04:08, 1 June 2006 (UTC)

I've never heard of birds in space at all, except possibly some kind of eggs. (They get hungry you know) —

The Mac Davis] ⌇☢ ญƛ. 04:33, 1 June 2006 (UTC)

When I was a kid, I distinctly remember seeing footage on TV of a medium-sized brown bird onboard a spacecraft of some kind. It didn't look very happy in zero-g and it was flying around in circles (it was upside down in relation to the astronauts) and occasionally fluttering off into the walls with its head held at a strange angle. I remember thinking 'how cruel' at the time... --Kurt Shaped Box 11:42, 1 June 2006 (UTC)

Well, there are Pigs in Space, and we all know that pigs can fly, so I guess that means ...... trails off incoherently JackofOz 09:43, 1 June 2006 (UTC)

Perhaps they were birds riding on the Vomit Comet? Rmhermen 14:46, 1 June 2006 (UTC)

Many birds cock their head upward to use the force of gravity to take their catch down their throat. Also, their throat may not be able to actually move food or it does it poorly. For some reason I have an inkling that being able to eat upside down is somewhat unique to mammals. --mboverload @ 06:04, 4 June 2006 (UTC)

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Wikipedia:Reference desk archive/Science/May 2006 part 2

From Wikipedia, the free encyclopedia

Contents

[edit] May 21

[edit] Server Park

[edit] Eat my hair

[edit] Cortical Arousal

[edit] Acetic Acid

[edit] Charge of an electron

[edit] Static electricity

[edit] Construction of Houses and Apartments

[edit] Paralysis causes loss of feeling?

[edit] working model related to astronomy

[edit] about svchost.exe

[edit] plasma containment

[edit] Cashews

[edit] crosse' s acari how is it possible?

[edit] Odontodes

[edit] 1/3 meter

[edit] May 22

[edit] How long it takes to photosynthesise

[edit] How to remove a fluorine based organic grease from aluminum

[edit] Definition File

[edit] Plotting graphs for excel through visual basic

[edit] Evolution?

[edit] Home Made Carbon Dioxide (CO2)

[edit] Siren

[edit] How to hydrolise Cellulose, CMC and other

[edit] how is a football made

[edit] Reason for 25°C "Standard Temperature"

[edit] posterior cervix

[edit] Footballs

[edit] Weird language problem

[edit] Genetic Engineering

[edit] Water protecting against bullets

[edit] My dream.

[edit] Sharp pain in the chest

[edit] Untitled Question

[edit] May 23

[edit] Electrolysis of Baking Soda

[edit] Global Warming- should we worry?

[edit] Transgenics, Genetically Engineered Organisms.

[edit] Ester Based Drilling Fluids

[edit] Question

[edit] The Ultimate Speed Limit

[edit] ROCKET FINS

[edit] RBC'S

[edit] Sweaty drugs

[edit] Lost My Indiglo

[edit] J.Smith (talk • contribs)

[edit] Random Pixel Message

[edit] personalised google home page

[edit] Connecting a single solar cell to a home's power supply

[edit] House cat behavior

[edit] Generic blood pressure medicines

[edit] Molecular weight profile of a mixture of proteins or peptides

[edit] Physics question

[edit] wat kind of frog?

[edit] Linux taking advantage of Windoze device drivers

[edit] SCM

[edit] Is it possible to see clearly underwater by wearing spectacles instead of goggles?

[edit] Leukocytes

[edit] Ivy cuttings

[edit] Ducklings...

[edit] "Tastes like chicken..."

[edit] May 24

[edit] Atmospheric gas spectrographic image

[edit] Computer processing question

[edit] Flower Names

[edit] regrowing limbs

[edit] Numbered lists in word

[edit] Area on sphere

[edit] Microsoft IRC?

[edit] Lifespan of safety razor: affected by length of hair/stubble shaved?

[edit] Extremely thin teacher

[edit] Geometrical construction

[edit] Etching PCBs

[edit] raw egg peeler

[edit] Biologists/Catfish/Plecs/Omega eye

[edit] Another Javascript question...