Wikipedia:Reference desk/Archives/Science/2007 December 30

From Wikipedia, the free encyclopedia

Science desk
< December 29 << Nov | December | Jan >> December 31 >
Welcome to the Wikipedia Science Reference Desk Archives
The page you are currently viewing is a transcluded archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.


Contents


[edit] December 30

[edit] muscle building

hi, does anyone know some muscle building/strength training exercises that don't need weights? (n are efficient...) thanks! —Preceding unsigned comment added by 203.78.33.137 (talk) 02:15, 30 December 2007 (UTC)

If you look at our Strength training article, you'll find there are many forms of strength improving exercises that do not involve weights. What's best for you is going to depend on what effect you're really trying to achieve, and I recommend reading through the more specific articles mentioned in the link I gave you. Someguy1221 (talk) 02:20, 30 December 2007 (UTC)
Push-ups, running, and sit-ups --n1yaNt(~Cpt. Obvious~) 09:46, 30 December 2007 (UTC)
Not running. Too much cardio can actually decrease muscle mass. Malamockq (talk) 15:20, 30 December 2007 (UTC)
Hmm, you got a cite for that? Even if it's true though -- and this is strictly my own personal prejudice -- I think that anyone who's backing off on cardio to pack on the last pound or two of muscle should reexamine his goals for fitness training and consider re-prioritizing them. Training for maximum strength is not necessarily the same as training for maximum health, maximum longevity, or maximum quality of life.
Tangentially related rant: Yes, childhood obesity is a real problem. No, the solution is not to get more kids into team sports, especially football! Take a look at the line of any NFL team and tell me you think those people are healthy. Physical education at the K-12 level is important, but the power of the sports teams needs to be broken, also so that school can start and end later in the day, when the kids are actually awake. --Trovatore (talk) 19:56, 30 December 2007 (UTC)
I'm sure if school opened an hour later, kids would stay up an hour later. But also, did I read you wrong, or is a Flem actually suggesting we play less sports? Someguy1221 (talk) 21:53, 30 December 2007 (UTC)
Fleming Hovse was a lot of fun, and I had great friends there, but it's not actually a cult, contrary to what the rest of the campus may think. Yeah, kids would stay up later, but it's not just when you go to bed -- circadian rhythms are synched to the Sun, and there's plenty of evidence that we're getting kids up too early in the day. --Trovatore (talk) 07:31, 31 December 2007 (UTC)
Surely we need to mention Charles Atlas and isometrics as the classic form of no weights strength training. Rmhermen (talk) 18:02, 30 December 2007 (UTC)

[edit] What do volcanoes smell like?

If there were an eruption, what would you smell? How strong would it be? Malamockq (talk) 04:15, 30 December 2007 (UTC)

It could smell like lots of things. Can't say how strong, but certainly you would be interested in the strength of the smell at some given distance from the volcano, like the distance at which volcanic gas concentration becomes lethal or otherwise dangerous. Someguy1221 (talk) 06:30, 30 December 2007 (UTC)
I'd guess of the parts you could smell - rotten eggs from the hydrogen sulfide. - Carbon [Nyan?] 06:42, 30 December 2007 (UTC)
From being around the fumes from Kīlauea volcano in Hawaii off and on, I would agree that the fumes (at least from that volcano) are variable. Some days they would smell a certain way, and other days they'd smell different. The smell also varies by how close you are to the volcano - the further away, the less "sulpher-like" the smell gets. The best way I can think of to describe the typical smell of a volcano from, say, about 50 miles or so away would be that it is like very bad air pollution in a crowded city on a high alert smog day. If you cross that with the smell you get from being downwind from an oil refinery, then you are close to the mark, I think. It is definitely NOT a nice smell. -- Saukkomies 11:16, 2 January 2008 (UTC)

[edit] Aluminum tubing used in a distillery

I read that copper was the only acceptable material to use for piping in a distillery. Can aluminum or stainless steel also be used, if not for making alcohol to drink what about alcohol for fuel? 71.100.6.70 (talk) 07:36, 30 December 2007 (UTC)

Wikipedia:Reference desk/Archives/Science/2007 April 27#distillation may help Nil Einne (talk) 11:38, 30 December 2007 (UTC)
See our article Still for more info on thisny156uk (talk) 11:39, 30 December 2007 (UTC)

[edit] Fermentation of starch versus sugar

Is starch fermentable directly or must it be converted prior to and external to the process of fermentation itself? —Preceding unsigned comment added by 71.100.0.104 (talk) 08:22, 30 December 2007 (UTC)

I would guess yes although it would depend on the type of organism used for fermentation. Most would have amylase so should be able to break down starch. In any case, not surprisingly it appears amylase is usually added or comes from a source external to the organism used to fermentation (such as the grain itself). See Ethanol fermentation and also amylase and also [1] and [2]. This isn't surprising, relying on amylase from yeast itself is likely to take to be too efficient for most commercial purposes. Nil Einne (talk) 11:39, 30 December 2007 (UTC)
If you ferment malted barley, you have to let it steep in water at particular temperatures to allow the amylase in the barley to convert the starch to sugar before you can ferment it. Likewise, in African tribes where they ferment millet (wheat) they must chew the grain so the amylase in their saliva can break down the starch into fermentable sugars. The process of converting starch to sugars with loads of amylase, either from the grain or elsewhere, takes in the order of an hour or so; brewer's yeast isn't capable of anything like that - I suspect it'd take years for the normal sort of population of yeast in a 20 litre (5 gallon) fermenter, at the end of a normal fermentation, to process a tablespoon of starch. So yes, you need to convert starch. [This link] shows the process of fermenting starches: the first step: convert the starch to sugar. --Psud (talk) 02:02, 1 January 2008 (UTC)

[edit] Coma and pregnant

What happens if a pregnant woman goes into a coma? Can they still give birth while comatose? mattbuck (talk) 14:45, 30 December 2007 (UTC)

  • Yes, it has happened. I don't know about the birth, but assume they use caesarean section since the mother could not help in the delivery. --Sean 15:22, 30 December 2007 (UTC)
Babies have survived caesarian section from dead mothers (in fact the term "Caesarian" comes about from it's use in that situation) - so certainly the procedure will work on comatose mothers - but I doubt anyone in their right mind would risk attempting natural childbirth with a comatose woman. SteveBaker (talk) 20:11, 30 December 2007 (UTC)

[edit] Localised blushing

What is the cause of a patch of blushing? Why does it happen in areas instead of other? —Preceding unsigned comment added by Bastard Soap (talk • contribs) 15:12, 30 December 2007 (UTC)

  • Check out rosacea. --Sean 15:20, 30 December 2007 (UTC)

[edit] Scale to measure pleasure

Is there a scale to measure the amount a pleasure a human is receiving? So as to compare what stimuli creates more pleasure to a human. 220.239.112.220 (talk) 15:24, 30 December 2007 (UTC)

I don't know of any serious ones - but the article List of humorous units of measurement includes definitions for the 'Happy' and the 'Puppy' which claim to be units of measurement for happiness and the 'Hedon' as a unit for pleasure. SteveBaker (talk) 16:37, 30 December 2007 (UTC)
Felicific calculus never really took off. William Avery (talk) 16:47, 30 December 2007 (UTC)
It should be possible to have a self-reported scale, opposite to the Pain scale. Rmhermen (talk) 17:57, 30 December 2007 (UTC)
Perhaps one of the problems may be the vast differences in the types of pleasures which IMHO is greatly different from the types of pain. Sure pain does vary in type, being kicked in the testicales and dropping hot oil on your hand may feel resonably different but they are ultimately resonably comparable and it's just OMFG that fucking hurts. On the other hand, how do you compare an orgasm, to eating incredibly good chocolate, to winning the lottery, to the eureka moment when you suddenly solve a problem you've been working on for years? Nil Einne (talk) 13:30, 31 December 2007 (UTC)
There's a humorous scale for bad things (that's the first page only, it's four pages total). – b_jonas 21:36, 30 December 2007 (UTC)
I've heard of the DALY and QALY. I think they're the same thing, but I'm not sure. The DALY is used here: [3]. — Daniel 22:35, 30 December 2007 (UTC)

[edit] When did the first star form, and how is it doing today?

Just wondering. MalwareSmarts (talk) 17:35, 30 December 2007 (UTC)

Well, it was probably a red supergiant, which would have burnt out fairly quickly - maybe under a billion years - at which point it would have exploded as a supernova, creating in the process the heavy elements that we need for life. This all happened around 13-14billion years ago. mattbuck (talk) 18:00, 30 December 2007 (UTC)
If you are looking for really old non-defunct stars, red dwarfs can live to be as old as 50 billion years. That just ignited the age of the Universe problem, because a suggestion that the universe of 8-12 billion years old meant that it was younger than some stars. Of course, since red dwarfs can have very long lifespans, they are all still alive today, except for the few ones that got into mishaps and became annilated. There are red dwarfs alive today that are 13 billion years old or older. Hope this helps. Thanks. ~AH1(TCU) 18:18, 30 December 2007 (UTC)
The very first stars (known as Population III), were very massive, very short-lived blue giants. The mechanics of star formation were different in a universe before the formation of the first heavy elements. According to theory, the heavy element-free stars would have accreted much more mass before igniting than modern stars, leading to masses of 10s to a few hundred times that of the sun. Such stars would supernova very quickly (less than a million years for the largest). Dragons flight (talk) 18:39, 30 December 2007 (UTC)
AH1, Are you sure about there being super-old red dwarfs? I couldn't find it on the red dwarf article or age of the universe article. — Daniel 22:16, 30 December 2007 (UTC)

[edit] What are the chances of this?

Is it possible that there is a virtually infinite amount of universes, but there is an uncrossable border between each? MalwareSmarts (talk) 17:37, 30 December 2007 (UTC)

See Multiverse. Such a situation is outside the realm of science, since any theory about unaccessible universes is untestable by definition. --Bmk (talk) 18:23, 30 December 2007 (UTC)
(edit conflict)Well, there are a large number of theories that describe multiple universes. For example, some people say that cosmic foam causes universes, big and small, to spring into exsistence. Others say that black holes result in wormholes that result in new parallel universes. Remember that most people are saying that the universe is infinite, so you would have to travel an infinite distance, over an infinite period of time, to reach the edge of the universe which is constantly expanding, and by then the universe would have ended anyway. Well, some theories like cosmic foam say that the universe may bump into other ones, wormholes mean a connection between two universes or a pathway from one end of the universe to another, and yet other theories state that the universes are like water droplets flowing down a shower curtain, and our universe is just one that have laws of physics that make sense to us. Since we don't know anything about what's outside of our own universe, anything is possible, so we can only guess. Who knows, maybe one of the other universes will cause a total existance faliure, which is apparently significantly more likely than a googolplex to one. Hope this helps. Thanks. ~AH1(TCU) 18:29, 30 December 2007 (UTC)
It is certainly possible that the Many worlds hypothesis is true - and in fact, if it were true, it would explain some difficult problems in quantum theory rather elegantly which makes me suspect that it probably is true. However, it's annoyingly unfalsifiable - which makes proof either way impossible. Physicists (justifiably) don't like unfalsifiable theories - so any other explanation of this wierd stuff would be more satisfying. Sadly, nature isn't always cooperative in such matters. If the hypothesis is true (and we'll probably never know that) then it is assumed that nothing can cross between universes. SteveBaker (talk) 20:02, 30 December 2007 (UTC)

Is there anyway at all to observe anything about a black hole? MalwareSmarts (talk) 19:23, 30 December 2007 (UTC)

No information about a black hole can emerge from it's event horizon. However, one could do various experiments to determine what the electrical charge and the rotation rate of a black hole might be. The mass may be inferred from the size of the event horizon. You can see many of the effects the black hole has on surrounding matter. But you can't take a photo of one (for example). SteveBaker (talk) 20:02, 30 December 2007 (UTC)
It's currently unknown whether or not information can leave a black hole. See black hole information paradox. You could take a picture of a black hole, as it emits Hawking radiation, but no one knows if it will tell you anything besides stuff you mentioned. — Daniel 21:57, 30 December 2007 (UTC)

[edit] CR123 Lithium Ion batteries and cheap immatations Does Amp output meet requirements??? for Flashlight

I just purchused 50 CR123 Lithium Ion batteries for a flashlight, that is rated at 5.8 Watts. It takes 2 3.0 volt batteries in series. The batteries I purchaced are limmited to .500Amps each. So do I need to retract my order if possible, take my losses and try to order a higher current battery or am I misaken and these will suffice?

It seems like an easy problem two dc power souces at 3.0 V .5A in series, with an unkown R since it is L.E.D. ; will these provide 5.8 watts??, I don't belive so but would apreciate any input before I cancil the order of 50 units of these batteries, I know that some CR123 lithium ion batteries put out over 1.0A!

The batteries I ordered are around 1500mAhr, Please help!!! --Aaron hart (talk) 21:27, 30 December 2007 (UTC)

The math says P=EI, which means that I=P/E. Two 3-volt batteries in series will give you 6 volts (E). The flashlight wants 5.8 watts (P). The device will draw about one amp (I). I suppose they mean that the batteries you ordered will get too hot and give less voltage at anything over a half an amp, although they could just be playing it safe and providing a conservative figure. But I wouldn't be too hopeful that the ones you ordered will be satisfactory given the current rating. --Milkbreath (talk) 01:29, 31 December 2007 (UTC)
Is it 0.5A or 0.5Ah? It's not very common for batteries to be marked with their max current (and 0.5 is quite low for max current), but (much) more commonly the capacity. If it is Ah, then it will probably work, but will not last as long. --antilivedT | C | G 04:57, 31 December 2007 (UTC)
The problem with that theory is that Lithium CR123's have a capacity of 1500mAh (1.5Ah) and Lithium-Ion CR123's manage 700mAh (0.7Ah) - so the number of 0.5 doesn't sound like it could be Amp-hours either. If I had to pick a number that I disbelieved it would be that an LED flashlight could consume 5.8 watts. That seems like an awful lot. CR123's are those camera batteries - they are expensive...even if you found a pair of batteries that could produce an amp at 6 volts, the batteries are going to die within a couple of hours at best. WHy would you design your flashlight to chew through such expensive batteries? Why not pack four AAA's or AA's in there instead? They have much higher Ah ratings and are vastly cheaper. To require CR123's suggests that the designer was fanatical about making the flashlight small and lightweight - but didn't give a damn that it would be hideously expensive to run. Personally, I'd cancel the order for the batteries and buy a better flashlight! SteveBaker (talk) 17:06, 31 December 2007 (UTC)
Googling for a 5.8 watt flashlight suggests that Aaron is using an Inova XO3 or similar (see review). 5.8 watts is the rating of the bulb, but the review says that the bulb is driven at 3 W. I confirmed this figure elsewhere. This conveniently suggests a current of 3 W / 6 V = 500 mA, so your rechargeable batteries might just work. However, you would be running them at their maximum current, so you would not get anything like the 2 hours that you would get from primary cells.
As a back-up calculation, running the bulb at 5.8 W would draw nearly 1 A. The manufacturer says that the light will run for 2 hours, and this is confirmed by the review I linked to. This would require a cell capacity of nearly 2 Ah. The capacity of CR123 cells is 1.5 Ah or less, so this suggests that 5.8 W for 2 hours is impossible and therefore 3 W is the more likely figure. --Heron (talk) 15:19, 1 January 2008 (UTC)

[edit] How now transgenic cow?

I notice that transgenic cow is a red link, yet several articles reference the existence of transgenic cows, and I recall seeing something on PBS talking about a company that engineers cows that have been genetically modified to produce pharmaceutical precursors. Is the transgenic cow for real?--69.118.143.107 (talk) 21:32, 30 December 2007 (UTC)

I think you'll find there are a few different strains of transgenic cow, depending upon what the goal was. Check out Google, yo. There are ton of transgenic animals - why not cows? --Seans Potato Business 23:09, 30 December 2007 (UTC)
To be honest, I was kind of hoping this question would inspire someone to create the article.. it's so far down on the list of requested articles no one is even going to see it there.--69.118.143.107 (talk) 14:06, 1 January 2008 (UTC)
I'm kind of busy at the moment with other projects, otherwise I would take it up. You can find everything you need on Google though, right? Sorry to disappoint. You could register and start it yourself? The more people contribute, the faster the place grows. ----Seans Potato Business 16:18, 3 January 2008 (UTC)

[edit] Identify this dinosaur?

I've been trying to identify exactly what dinosaur Diego Brando turns into. The article claims it's a velociraptor, yet he has no feathers. Here's some pictures:

[4] [5]


Any help would be appreciated, this is really bothering me! SprayTape (talk) 23:22, 30 December 2007 (UTC)

Velociraptors were TINY.
Velociraptors were TINY.
I can barely see it, but it might be a Deinoychus, but those are now believed to have feathers too. Malamockq (talk) 00:16, 31 December 2007 (UTC)
Hm, yeah, that seems about right, or as best of an answer I could find. Thanks! SprayTape (talk) 01:12, 31 December 2007 (UTC)
It's just a cartoon - what makes you think it's any kind of real dinosaur? The odds are good that the author just drew his idea of a generic 'human-sized' dinosaur. Anyway - it can't be a velociraptor - the velociraptor was only "human-sized" in the minds of the author of Jurassic Park - in reality they were about the size of a chicken. The lesson here is that it's very dangerous to try to translate the ideas of fiction writers into real animals! SteveBaker (talk) 01:20, 31 December 2007 (UTC)
Err, what's your basis for those assertions? Check out Utahraptor; you guys must have some mighty big chickens in Texas! I jest, of course, Utahraptor is a seperate genus from Velociraptor, but both are closely related and it wasn't specified in the cartoon that the dino was in fact a V. at all. I recall when the Utahraptor was discovered; it was shortly after Jurassic Park was in the theatres and there were jokes it should have been called Spielbergosaurus or somesuch since he'd "identified" the genus before the actual palaeontologists. In fact, U. is actually much bigger than the raptors in the movie - not something I'd care to tangle with! Matt Deres (talk) 01:56, 31 December 2007 (UTC)
...but Utahraptor was BIG.
...but Utahraptor was BIG.
Whoops; I guess it is claimed that it was supposed to be a V. after all. Maybe I should read questions before answering them! Matt Deres (talk) 02:02, 31 December 2007 (UTC)
Be aware that the feathers on those raptors was only really well known as recently as 2007. So it's not unlikely that they were basing the idea on earlier conceptions (like the ones seen in Jurassic Park). --67.180.134.53 (talk) 03:41, 31 December 2007 (UTC)
Yeah - Michael Crichton can be forgiven for not including feathers on his velociraptors - but making them human sized was a calculated distortion of the truth - he even admits making the decision to ignore the real size of his 'raptors. Why on earth he couldn't have picked a bigger dino - or just invented a new one is not at all clear. It was actually a pretty terrible thing to do because an entire generation now believes that Velociraptors were monsterous 6' tall killing machines - rather than somewhat vicious chickens. If proof were needed, this cartoonist evidently believed the movie and didn't bother to spend 10 seconds to click on Wikipedia and type 'Velociraptor' into the search box! SteveBaker (talk) 04:15, 31 December 2007 (UTC)
I bet the answer is that the word "velociraptor" sounds cool. --Sean 14:48, 31 December 2007 (UTC)
Looking at the tail of the first linked picture, could not be identified as Velociraptor, even allowing for error of scale. The tail is long and whippy and comes to a narrow point. Can't be Utahraptor either for the same reason. This guy though seems like a better match for the tail. The overall size and lack of frills on the head are still not right though. I vote with SteveBaker, the author made it up. Spinningspark (talk) 17:12, 1 January 2008 (UTC)

It looks like a generic large dromaeosaurid (Dromaeosauridae is the family Velociraptor, Deinonychus, Utahraptor etc. belong to). It has an enlarged claw on the foot, and the way the hip bones stick out at the bottom is distinctive, too. There's creative license as well (lack of feathers, tail that can bend, etc.). The picture above, though, is Othnielosaurus, a small inoffensive herbivore\omnivore. J. Spencer (talk) 17:56, 1 January 2008 (UTC)

[edit] Can it be possible to keep a budgerigar and an eclectus in the same cage???

Anyone know? —Preceding unsigned comment added by 84.71.65.59 (talk) 23:31, 30 December 2007 (UTC)

I know and the answer is an emphatic "no" in the real world while being hypothetically possible. If the eclectus was raised a a chick, hand-fed, and a budgerigar kept with it in the incubator, the two might appear friendly enough that someone not knowing better one would attempt to house them together in the same cage. Hand-fed birds might learn to associate with one another even after they are past the incubator stage. An eclectus might decide that the budgie is a baby eclectus and take it "under its wing." But parrots naturally spar with one another -- I've got scars to prove what happens if one does not have the reflexes the parrot thinks one has. I would fear the eclectus might accidentally kill or maim the budgie if they squabbled. If the eclectus ever got night frights, the budgie might be killed by a flapping wing. In the world of "What if?" the birds might be kept together, but in practice, I would only permit them together for short, supervised times. Placing the birds together in a cage is asking for tragedy. --UnSpace (talk) 16:11, 31 December 2007 (UTC)
Agreed. A budgie and an eclectus in the same cage is just asking for a 'big bird, little bird, little bird lost' scenario. Budgies can be bad-tempered little scrappers - I've personally seen them trying to attack larger parrots and cockatoos with little apparent regard for their own safety (it's reminiscent of a yappy little lapdog snapping at a human's ankles), requiring immediate human intervention. It wouldn't take long for the eclectus to become enraged at being pecked and inflict a possibly fatal bite. Even the standard psittacine 'beak duelling' could be dangerous with such a size difference - my friend has a budgie with a permanently misshapen upper mandible as a result of a minor beak squabble (lasting a matter of seconds) with his Alexandrine Parakeet. --Kurt Shaped Box (talk) 00:14, 1 January 2008 (UTC)