Wikipedia:Reference desk archive/Science/2006 October 4

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[edit] Hello I Need Hlp With Thses Two Questions Please

differentiate btwn cells that have a high or low surface area-to-volume ratio

understanding of the significance of surafe area to volume ration in a cell

contact me emeditly (sic) at (email removed)

Do your own homework. --Bowlhover 02:31, 4 October 2006 (UTC)
Read the article Sa/vol. --Canley 03:16, 4 October 2006 (UTC)

...and learn how to spell "immediately", immediately. StuRat 03:40, 4 October 2006 (UTC)

u cnt get hlp on hmwrk qstns hr on wkpdia. The noly wya is to rd ur txtbk or srch wkpdia fr infrmtn on the sbjct -- Wikicheng 08:10, 4 October 2006 (UTC)
  • The instructions at the top of the page mention you should check back for answers as they're not answered by email... - Mgm|(talk) 09:24, 4 October 2006 (UTC)
Fu cn rd ths msg , u 2 cn dbl yr incm w spdwrtng Edison 17:09, 4 October 2006 (UTC)

[edit] Why did all the Soviet missions to Mars fail in one way or another?

...whereas many of the American missions succeed?

The article Mars probe program lists the reasons for each mission's failure. --Canley 03:12, 4 October 2006 (UTC)
But, to assign a root cause, I would say funding is the issue. The Soviet, and later Russian, budgets for space exploration didn't allow for the type of testing and redundancy needed to ensure a high probability of success. Those low budgets, in turn, were due to their less successful economy versus the US, which, in turn, was due to the failure of their economic model (communism). StuRat 03:30, 4 October 2006 (UTC)
Isn't testing a spacecraft much less expensive than building a new one? If the Soviets could afford to build that many Mars landers, why couldn't they afford to do some more testing? --Bowlhover 16:15, 4 October 2006 (UTC)
No, because doing it right requires that multiple copies be built, tested (and quite possibly destroyed in the proces), redesigned, and rebuilt. It's far cheaper to send up one untested rocket and cross your fingers for luck. StuRat 19:59, 4 October 2006 (UTC)
Perhaps the Soviets were unable to exploit advanced space navigation technology because they were denied access to the Roswell UFO incident artifacts.Edison 07:16, 4 October 2006 (UTC)
Yet they were the first ones to put a satellite into space, to put a person in orbit, to land a spacecraft on another world, to soft-land on another planet, and to robotically retrieve a sample from the surface of another solar-system body? Are you serious? --Bowlhover 16:15, 4 October 2006 (UTC)
In essence, I ask myself this question: If you (Soviet Union) are the sole player on the market, does your economy (whatever that means when you are alone) really make a difference (for, say, going to Mars)? Isn't the capabilities of your workforce all that matters? Put differently: If everyone (in Soviet Union) works together to achieve a goal (send probes to Mars), who cares about money? The reason I ask is because I imagine that the government of the Soviet Union could have ordered every citizen to come work on the space projects, couldn't they? As I see it, the reson you could need money is if you need to buy parts from, say, companies, but if you can just decide everything yourself, why not just give orders to those companies to manufacture the things you need and give them to you? Of course, through all this, food and such will have to be provided to all workers, but that could just be seen as a part of the space program.
Is the right conclusion to draw that the Soviet Union did have trade relations outside the country, and so wasn't alone on the market? (As you see, I'm not very educated on the subject.) —Bromskloss 08:12, 4 October 2006 (UTC)
If a country has limited resources, then a "command economy" makes no difference. For example, they need to use many workers just to feed themselves, since the equipment is all broken down because nobody gets paid to repair it, so they must make do with less efficient methods. They also need many more factory workers, due to inefficiency. All of this leaves very few workers or other resources left for "nonproductive" activities, like space exploration, training Olympic athletes, etc. So, they end up having to reduce their efforts in some areas. StuRat 20:09, 4 October 2006 (UTC)
That's not how the world works, people want to get rewarded for their work. Also, Russia doesn't have access to everything, they have to import, and since everywhere were not communist, they would want money for their stuff. If you work really hard to be an engineer, and you have the choice of working for Russia, who won't pay you, and working anywhere else in the world, where they will pay you. Which would you choose? --liquidGhoul 13:22, 4 October 2006 (UTC)
We Martians prefer American culture, except for that last War of the Worlds film. We may have to destroy your planet for that one. Clarityfiend 17:47, 4 October 2006 (UTC)
Couldn't you just give Tom Cruise an anal probe instead? - Nunh-huh 19:42, 4 October 2006 (UTC)
Why? He's one of us. Wasn't that obvious? Clarityfiend 20:30, 4 October 2006 (UTC)

[edit] Evaluation of objective type answer sheets

i want that how the objective type answer sheets are being evaluated in computerised manner or either we are using any costly scanner for that. —The preceding unsigned comment was added by 59.95.33.5 (talk • contribs) 07:03, October 4, 2006 (UTC).

Please sign your posts with four tildes, like ~~~~. In this profile you can read something about a low-cost optical mark recognizer using a digital camera and software for evaluating objective type answer sheets. I don't know whether this is actually used.  --LambiamTalk 07:58, 4 October 2006 (UTC)

Do you mean questions on Wikipedia? They're all answered by humans, not computers. You can add a response by clicking "edit" on the right. Gary 13:24, 4 October 2006 (UTC)

I think the questioner is asking about computer-graded score sheets for multiple-choice exams, the kind requiring a #2 pencil, which I have always called "Scantron" sheets. --Ginkgo100 talk · e@ 18:09, 4 October 2006 (UTC)
Oh, I see, I'm pretty sure the scanner that grades Scantron sheets looks for the reflective pencil lead. Anywhere that doesn't reflect light doesn't have an answer. Gary 18:18, 7 October 2006 (UTC)

[edit] Dr. Roger Kornberg

Please provide me with the high school Dr. Roger Kornberg attended.

Thank you.

You might (also) want to ask on the talk page for his wiki page. DMacks 21:46, 4 October 2006 (UTC)

[edit] ground parrot

I have a circa 1810-1815 painting of a ground parrot but on the back the artist has callet it P terrestis ..when did the name change?

Ground parrot. Is that what they use to make parrotburger patties?  --LambiamTalk 01:24, 5 October 2006 (UTC)
Only since I started going to the supermarket to buy meat for my cowburgers.  freshofftheufoΓΛĿЌ  11:49, 5 October 2006 (UTC)

[edit] Blood

Is blood a Newtonian fluid Or Non - Newtonian fluid?

It looks like the answer may appear in a table on Non-newtonian fluid. I would have guessed that anyway, since blood contains a lot of complex things in it that are likely to screw around with any kind of simple approximation like the one governing Newtonian fluids. Confusing Manifestation 14:01, 4 October 2006 (UTC)
It is most definitely not a Newtonian fluid. InvictaHOG 18:44, 4 October 2006 (UTC)

[edit] molarity of water

what is the molarity of water?what happens to that molarity if i add 58.8gms of NaCl to it?

What is the purpose of doing your own homework? What happens if you read our molarity article first? (And if that doesn't help, ask again but letting us know exactly where you get stuck.) Confusing Manifestation 13:57, 4 October 2006 (UTC)
Water is 55.5M. It's pretty concentrated stuff! --G N Frykman 19:34, 4 October 2006 (UTC)
Knowing the molarity of water will not likely assist you in this situation. The molarity of NaCl in water that has none in it is zero. - Rainwarrior 19:53, 4 October 2006 (UTC)


[edit] Great Black-backed Gull carrying off (and presumably eating) baby?

This is a story that's been related to me by various people I know - it usually comes up in conversation when I mention my interest in gulls. It'd be an interesting addition to the GBB gull article, *if* it were actually true and I could find a reference for it. Based on what I've been told, it supposedly happened in Scotland in the 1970s/80s - the gull picked up the baby from a pram and flew off with it, never to be seen again. Anyone here able to recall hearing about this in the news, or even better know of an online reference to the incident? --Kurt Shaped Box 14:21, 4 October 2006 (UTC)

Most GBBs in Scotland life largely off a diet of chip-wrappers and discarded marathons. As a result they are morbidly obese and have congestive heart disease, and it seems very unlikely one could muster the strength to carry of any baby, never mind a scottish one (where babies are known for being large, bad tempered, and ginger). It's nonsense. They have, however, apparently learned to 'gang mug' people (apparently large men) for their fish'n'chips - one gull will harass the man, he'll lash out at it and (distracted) the second gull will grab the poke of chips and fly off. Middenface 14:28, 4 October 2006 (UTC)
Plenty of fat gulls round here too. I've never heard of these stealing food from humans but they do sometimes stand near you if you're eating outside, begging and whining to be fed, getting noisier and noisier if you ignore them. The 'regulars' I feed in my garden are waiting for me on the fence, first thing in the morning, going 'keyow' 'keyow' 'keyow' until I go outside and throw them some scraps. On a couple of occasions, I've had one of them tapping on my windows when they can see me inside the house. --Kurt Shaped Box 17:43, 4 October 2006 (UTC)
Right. Even if a gull did attack a baby, which I might just believe, I just can't imagine any bird smaller than a full-grown eagle lifting up and carrying off even a small human baby. GBB gulls are big, but they're not quite that big. Also note that gulls, unlike eagles, have no gripping talons, so the only way they can carry things is with their beak. I'd think that much front-loading would make trying to fly off with a baby pretty difficult. —Ilmari Karonen (talk) 13:15, 8 October 2006 (UTC)
Why do you presume it was eaten? It turns out, that the gull raised the baby and he grew into a gull-fond adult... (sorry I just had to) --Jmeden2000 14:50, 4 October 2006 (UTC)
Might explain why I was found in a cardboard box at the local dump... ;) --Kurt Shaped Box 17:43, 4 October 2006 (UTC)
Perhaps it was a stork. Edison 17:16, 4 October 2006 (UTC)
Well, if a five-ounce swallow can carry a one-pound coconut, why not? Clarityfiend 17:36, 4 October 2006 (UTC)

[edit] Garlic Spoilage

In what ways can garlic spoil? What are the signs that a garlic clove is unsafe to eat? What do the diseases that attack garlic plants look like? --Dfeuer 17:18, 4 October 2006 (UTC)

Garlic doesn't have much to say on the issue, except to warn against garlic oil preparations, which have been known to spread botulism. Wrinkly cloves indicate dehydration. If the shoot inside the clove turns green and begins to grow, the garlic will be more bitter. Fine black spots could indicate mildew. --Ginkgo100 talk · e@ 18:00, 4 October 2006 (UTC)
Food network was not able to help me much, but I would add that if your garlic does not look good (e.g. brown or black spots, moist or slimy spots, etc.) it's best to throw it away. It is inexpensive, at least where I live, so better to be safe and replace it. --Ginkgo100 talk · e@ 18:04, 4 October 2006 (UTC)
One common defect is brown splotches that are not soft. What might these indicate? Where might I look for information to add to Garlic? --Dfeuer 23:11, 4 October 2006 (UTC)

The fussy garlic chefs don't like the brown marks. --Zeizmic 00:33, 5 October 2006 (UTC)

I've recently bought garlic in supermarkets that seems to have been denatured. It's yellowish and has a texture like hard jelly (jello to the Americans). My gut feeling is that it's been frozen, but that may not be the explanation. It smells odd, and tastes even worse, decidely non-garlicky. I threw it out. I think it was imported from Mexico, which is a further mystery. JackofOz 03:11, 5 October 2006 (UTC)
Jello is a brand name. Jelly is a wobbly substance. Even in US America!  freshofftheufoΓΛĿЌ  11:45, 5 October 2006 (UTC)
I've always wondered about this. If jelly is the stuff you make with jelly crystals, then why do Americans also call the stuff you spread on bread "jelly". We call it "jam", because it is a different thing, made in a completely different way, and deserving a different name. JackofOz 23:41, 8 October 2006 (UTC)
It must be jelly cos jam dont shake like that! From an old (American) song whose title I forget--Light current 01:45, 9 October 2006 (UTC)

[edit] renal cell carcinoma

A patient had a one side of renal cell carcinoma and was resected. A few years after the surgery, the patient developed to another site of renal cell carcinoma. do you think it was mets from old site or it was a new primary cancer?

Thanks.

Most likely a metastasis from the original tumor. DIscovery of metastases years after the resection of a renal cell carcinoma is, unfortunately, not uncommon, because the tumor can grow so slowly. About 50% of patients develop such metachronous metastases after treatment for their primary tumor, and about 10% of these are solitary metastases. In renal cancer, sometimes such solitary metastases can be very effectively treated surgically. A delayed, or metachronous, metastasis actually has a better prognosis than one discovered at the time of diagnosis of the original tumor (a synchronous metastasis) [1] - Nunh-huh 18:26, 4 October 2006 (UTC)

The caution I would add is that our ability to provide general information about medical conditions may or may not apply to an individual case and this casual opinion should not be considered authoritative enough to contradict information offered by real doctors with access to more detailed individual evidence. Much of the medical information here is worth what we charge for it. alteripse 00:06, 5 October 2006 (UTC)

Agreed. - Nunh-huh 02:04, 5 October 2006 (UTC)

Thank you very much for your information. I am collecting clinical data and met this case. Of course, I will query doctor to confirm with it.

[edit] Blue sea near Bahamas

Why is the sea so blue in satalite pictures of the Bahamas? Here's the Google map: Bahamas. The article Geography of the Bahamas has a similar picture, and doesn't explain it. Thanks! --Mary

The compounds in the water, I think for that blue you need limestone and something copper based in the local rocks. Philc TECI 21:43, 4 October 2006 (UTC)
Might not the coral be involved? --jpgordon∇∆∇∆ 04:55, 5 October 2006 (UTC)
Not as far as I know, coral isnt uniformley pale blue.... I think it is possible source of the limestone but I dunno. Philc TECI 17:28, 5 October 2006 (UTC)

Light blue colors typically arise when the substrate (water bottom) is white - in this case, because of the abundance of shell fragments all over. Other examples include Bear Lake (Idaho-Utah) and the Little Colorado River, which is very turquoise in color when it isn't at high, muddy flows. It's all because of the way light refracts, I'm sure there is an article about that somewhere. Geologyguy 22:11, 5 October 2006 (UTC)

[edit] The gyroscope movement

I recently made brand new images for our gyroscope article using POV-Ray. I made the gyroscope you see at the right in a way I could specify the angle for each gimbal isolately, and the overall orientation of the giroscope. This way I could animate it showing the behavior of a gyroscope as it rotates, and all I need is the equations that describe the angles of the gimbals during time.

Thing is, I'm having big troubles with it. It's pretty hard for me to get the rotation in three axis right. Is anyone interested in helping? ☢ Ҡi∊ff⌇↯ 21:36, 4 October 2006 (UTC)

Which are you having trouble with, understanding the equations, or applying them to POV-Ray? For the second, you could try asking at the POV-Ray newsgroups: http://news.povray.org/ or news://news.povray.org/ --Serie 22:20, 4 October 2006 (UTC)
I'm having problems in describing the motion of the gyroscope based on the relative angles of the gimbals. If I get that right, I just feed the formula in POV-Ray, what isn't a problem. ☢ Ҡi∊ff⌇↯ 22:24, 4 October 2006 (UTC)

Just move the base using the centre of rotation of the disk (on a sphere). Keep the spin axis steady (which is what a gyroscope would do). You can resolve the motion along the 2 gimbals. --Zeizmic 00:29, 5 October 2006 (UTC)

A gyroscope in operation
A gyroscope in operation
That's what I'm already trying to do man. You see, imagine you have that gyro floating in zero gravity, and you start to spin the frame around in several angles. The gimbals will have to rotate accordingly in order to keep the spinning axis steady. The angles of rotation for gimbals (which rotate in only 1 axis) are then relative to the rotation angle of the giroscope, but this relation is what's tricking me. I suppose this is more of a maths question, so maybe I should take the issue to the maths reference desk... ☢ Ҡi∊ff⌇↯ 01:53, 5 October 2006 (UTC)
Yay, I did it. It was all about the orientation of the spinning axis. Since I was too lazy to change that, I just changed the order to rotate the axis and it worked! Now I just need to figure a cool movement for everything. :) ☢ Ҡi∊ff⌇↯ 03:20, 5 October 2006 (UTC)
There's the animation I was trying to do to the right. I guess our article on gyroscopes has enough images to explain the concept now. :) ☢ Ҡi∊ff⌇↯ 05:12, 5 October 2006 (UTC)
Good work! *Wikiprops*  freshofftheufoΓΛĿЌ  11:43, 5 October 2006 (UTC)

I like it. I'm doing all my wiki-illustrations in 3D using Art of Illusion. Now that I got the concept, I should move to animation. --Zeizmic 11:52, 5 October 2006 (UTC)

This is a great animation! Two things it would be good to show: 1) the dreaded gimbal lock which was referred to in the Apollo 13 movie, as in "Caution, you are approaching gimbal lock." and 2)The precession seen in a toy gyroscope, which has only the innermost gimbal. If you try to force the axis to rotate, the device rotates inthe resultant direction. Nice work.Edison 14:11, 6 October 2006 (UTC)