Wikipedia:Reference desk/Archives/Science/2008 April 15

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April 15[edit]

small cities[edit]

i am not a person who complains often, but i am not happy because of the simple fact that i cannot find any type of information/research reffering the city of San Antonio Tariacuri, in Michoacan Mexico. I have searched for many hours trying to find any information at all an i am still nto capable of finding anything. The only anwser that i can think of to my simple question, "why am i not able to aquire any information on the city thta i am trying to find?", and the anwser the only anwser i have is.. because it is because the city that i am looking for is too small. i refuse to believe that such a detail that small denies anyone the simple request to find information on such a simple request!!!!!! so basicly my question to you is, can you please add information about the city, San Antonio Tariacuri located in Michoacan Mexico? —Preceding unsigned comment added by No one can judge me (talkcontribs) 01:02, 15 April 2008 (UTC)

  • A Google search gave me this: [1]. It gives the location, population, and elevation, with schools listed at the bottom.
  • Here's the phone info: [2].
  • Here's the maps, airports, nearby towns, and weather: [3].
  • Beware that the town is often called simply "Tariacuri" (or "Tariácuri").
What other info do you need ? StuRat (talk) 01:29, 15 April 2008 (UTC)
Maybe the OP was complaining the is no information on Wikipedia. In which case the OP is welcome to start an article. SpinningSpark 16:17, 15 April 2008 (UTC)

Picture of Blubber[edit]

Does anyone know where I can get a picture of blubber that's usable for wikipedia? FromFoamsToWaves (talk) 01:23, 15 April 2008 (UTC)

In the future if you have any kind of question related to Wikipedia, use the help desk. With that said, please feel free to read WP:IMAGES and fair use criteria for images. Wisdom89 (T / C) 01:33, 15 April 2008 (UTC)
The best way, of course, is to find somebody willing to release their rights on the picture to the public domain. Also, I know that it's unlikely, but, ideally you yourself could be the copyright holder/owner of the image if it is self-made. Wisdom89 (T / C) 01:35, 15 April 2008 (UTC)
This pic any good to you? --Kurt Shaped Box (talk) 22:21, 15 April 2008 (UTC)
Oh boy! Blubber!FromFoamsToWaves (talk) 00:12, 16 April 2008 (UTC)


Okay, you may speedy-delete this question if you want to (part of the answer could be medical advice to give you some good reasons), but I nevertheless mean this dead serious. Why is it that I am sitting here, doing lots of unuseful stuff (like writing this question =) and simply cannot motivate myself to do all those things that I really really want to do to be successful? I have a huge library about personal motivation, I've read, heard and researched lots and lots of this stuff, I have a clear goal (maybe too many?), there are plenty of "carots" and "sticks" in my life, I'm pretty intelligent (Mensan if that matters), I have enough time and talent, cool friends and many good opportunities in almost every area. Judging from what others tell me I could be almost anything I want (as of now), but I'm still sitting here, in the middle of the night, depressed of everything I've missed and done wrong. I'm at a point to believe there may be nothing more that I could do, as I've read and tried pretty every motivation trick/programme/guru/medication/etc that I could think of. With every time I fail to be the self-disciplined guy I so desperately want to be I'm more afraid of moving on and/or trying again, but I simply don't know why. In my native language I'd say that "I'm at the end of my latin". So if you ever were in a similar situation or you've got anything that could help me out, I owe you. And I mean that. Thanks in advance. Endymi0n (talk) 02:31, 15 April 2008 (UTC)

I'm not going to comment on anything that relates to prescription medicine and the like. However, I will say that I understand where you are coming from. Here is some trivial (but helpful) advice. Try approaching the day in steps/small strides. Instead of thinking what ultimately needs to be done, or worrying about the final product, concentrate on the steps. Make yourself a small to do list, and follow it sequentially. I know this sounds cliche, but it's useful. Cheers mate. Wisdom89 (T / C) 02:56, 15 April 2008 (UTC)
And to go along with small steps, I propose small rewards. The eventual rewards of, say, establishing a succesful career, may be years away, with much hard work before you get there, and you may not be willing to work for such a distant reward. So, set sub-goals with rewards at each level. StuRat (talk) 13:01, 15 April 2008 (UTC)
I must have read your very advices more than a thousand times, yet it seems these techniques (small steps, small rewards) were the only ones that really helped me. Maybe it's really like "repetition is the mother of skill" (Tony Robbins =) and I have just have to apply it to my life over and over again. Many thanks though, I hoped for a different answer (one that I didn't know or think of), but you pointed out a very important fact for me! Endymi0n (talk) 15:40, 15 April 2008 (UTC)

Probably because you've been told since you were about five that you need to be a 'successful' person in order to have an enjoyable life, but your subconscious just doesn't believe it. Your subconscious is more concerned will real issues like food and sleep and warmth and social contact than these constructed fabrications of value like 'having a succesful career', 'having a successful marriage'. All that stuff is just filler for your obituary, and no one really cares about it. They just give it lip service because that's the way it's always been. I mean, by all accounts Bill Gates is the most successful man in history, yet who really respects or admires him? They may superficially admire his wealth and intelligence and business acumen, but he's not exactly a role-model and I doubt if anyone would want to be just like him. Vranak (talk) 04:38, 15 April 2008 (UTC)

Yes, Bill gates is truly an evil, evil man, whom no person should look up to. Maelin (Talk | Contribs) 06:42, 16 April 2008 (UTC)
Thanks Vranak - to clarify myself: I don't want to be as "successful" as Bill Gates and I don't measure success in money. You have to pay a price for everything and all money, no life and fun isn't a life that I'd be comfortable with. Though, to quote a line from one of the best songs I've ever heard (Switchfoot-This is Your Life, go hear it if you've ever felt like me!): "This is your life - are you who you wanna be?" - and I'm clearly not. I don't want to get religious here, but whoever gave me the gifts I was born with wanted me to do something good with it. My problem is that I don't know what I really want as I love so many extremely different things and I just wished I could do them all. I have worked as an author, church musician, graphics designer, film score composer, business consultant, flirting coach, film director, radio anchorman, web designer and singer/songwriter while studying engineering physics, musicology and media technology, but nothing to a level where I was ever satisfied with my life and/or achievements. I start something, get enthusiastic about it, finally get a bit bored when everyday life kicks in and then find something new that draws my interest. I feel so torn every day because in all those fields there's something I like that I just don't want to give up. I've made lists, spreadsheeds, mindmaps... but I just cannot decide what's my ultimate goal, the one that's "all or nothing", to get me started. So I'm sitting here, having aborted two study disciplines, watching all my peers and friends getting finished and starting a "life" while I'm still stuck in my self-built cage of missed opportunities. That's the story =) Endymi0n (talk) 15:40, 15 April 2008 (UTC)

Well, if you'd like to analyze your problem from a mathematical angle you might want to look at Game theory, risk and related pages. On a psychological basis unconscious mind and deferred gratification are worth a look. Simply put, your logical analysis does not coincide with your subconscious assessment. You know there's a healthy carrot in your future if you work hard, but your subconscious/unconscious mind sees and eats the chocolate cake in front of you. There are techniques like mind control to get the rest of the troops to agree with your reasoning. That's why breaking a big task into smaller ones sometimes works. The reward is moved a bit closer to the effort. If you are suffering from adult ADHD quite a few of those techniques won't work. As for depression, if you are talking of the non-clinical type, you might want to reexamine your goals and Value theory. Looks like your glass is always half empty instead of half full. Try this one: Tape a list somewhere so that it often falls within your field of vision. (The mirror so often recommended actually doesn't really work that well) Write on it "I'm a great guy/gal." and 3 things you have achieved or like about yourself then at regular intervals add 3 things you've done. (Every evening's recommended but not practicable for the busy/disorganized. Once a week's more like it). Start with little things like "I took out the trash." and head for the "got my dream job" once you've got the hang of it. —Preceding unsigned comment added by Lisa4edit (talkcontribs) 08:29, 15 April 2008 (UTC)

You say you are "sitting here, in the middle of the night". You could try changing your sleep pattern so that you get more sleep (even if you don't think you need it) - this could improve your motivation, mood and energy levels. Gandalf61 (talk) 09:54, 15 April 2008 (UTC)
Mm-m, Circadian rhythm. Try to turn off the looking at the past thing. Nothing you can do about it, let it go. Julia Rossi (talk) 12:16, 15 April 2008 (UTC)
Thanks. Conciously I DO know both of that. But when I'm in the wrong state (see below), I just don't care. I wish I could. Endymi0n (talk) 15:40, 15 April 2008 (UTC)

I relate strongly to what you wrote. Not that long ago I was diagnosed with Attention deficit disorder (non-hyperactive type). The diagnosis suprised me (I never considered myself inattentive) but it fits. Maybe it also fits for you? moink (talk) 12:24, 15 April 2008 (UTC)

Didn't want to mention it in the first place in fear of being speedied but yes, I'm diagnosed with ADD (non-hyperactive), bipolar disorder with ultra-rapid cycling and high IQ. I believe I was always kind of ADD, since that's not an illness but a different way of experiencing and doing things. BPD likely came from my way of (not) dealing with it, as I was nothing like that in my teen years. As a type, I'm rather optimistic =). Endymi0n (talk) 15:40, 15 April 2008 (UTC)

Majahapit civilisation[edit]

<already at Humanities desk - please do not crosspost>

Why does the sun make people happy?[edit]

After living in Alaska through a few long, dark winters, I learned from direct experience and observation that not having the sun around makes things pretty gloomy. One time during such a winter I walked into someone's house and they had one of those full-spectrum "happy-lights" and I immediately felt better. It really shocked me. I didn't even notice the light until after I felt its effect. Why in the world does the sun's light, or light similar to it, do this to humans? Wrad (talk) 02:14, 15 April 2008 (UTC)

See seasonal affective disorder. Vranak (talk) 04:33, 15 April 2008 (UTC)
You might take a look at the "pathophysiology" section of the Seasonal affective disorder page; it describes some of the theories about what relationship the sunlight has with psychological effects from a biochemical perspective. Note of course that SAD is an extreme form of the general observation. --Captain Ref Desk (talk) 02:40, 15 April 2008 (UTC)
This question is really a Science question, but I'd also remind you to beware of SAD. Imagine Reason (talk) 03:02, 15 April 2008 (UTC)
Sorry about that. It is a science question. I must have clicked the wrong thing. Wrad (talk) 04:18, 15 April 2008 (UTC)

Moved. BrainyBabe (talk) 06:44, 15 April 2008 (UTC)

I am not so sure it does make people happy. If you look at the world map for the Human Development Index (a good proxy for human well being), you will notice that generally it increases the further away from the equator you go. There is a very strong inverse correlation between temperature and wealth in the world. For possible explanations of this correlation (including some that more sun does indeed have a negative net effect on happiness), see the article Geography_and_wealth. Cambrasa 13:38, 16 April 2008 (UTC)
As someone who moved from Australia to Sweden, I can certainly agree the phenomonen exists! One very real reason is Vitamin D. Vitamin D is produced when sunlight of the right wavelength hits the skin. Except close to the equator, this does not happen in winter. Vitamin D deficiency has been linked to seasonal affective disorder and other mood disorders. What's more, it only takes 10 or 15 minutes of the right kind of light for your skin to produce enough Vitamin D to boost levels significantly. Vitamin D levels have been hypothesed to be linked to the creation of serotonin[4]. --Insider201283 (talk) 19:40, 21 April 2008 (UTC)

What will happen if there would be an Ebola Pandemic[edit]

I was inspired by Dismas' post here and my seredipitous find in using the Random article button. Suppose the monkey infecting Ebola Reston virus mutated into a human infecting virus. Unlike its sisters, which is transmitted via bodily fluids, this one is airborne. What do you think would happen to society? Would all of humanity be wiped out? How fast would the infection be? I for one know that I would be dead by now if the virus did mutate as the strain is found here in the Philippines. I just want your opinions. Thanks.--Lenticel (talk) 08:43, 15 April 2008 (UTC)

The worst-case scenario could be the collapse of civilization (or reduction of it to a less developed level), but humanity would most likely survive due to genetic diversity. -- (talk) 10:54, 15 April 2008 (UTC)
I suppose it depends on how much the virus mutates in that time. It's not inconceivable that, being airborne and highly fatal, if it mutated quickly enough to counteract genetic diversity and outbreaks happened simultaneously all over the world then it could wipe out a significant portion of humanity. But I'd expect there to be some survivors, even if it's only astronauts and people who have their own clean rooms. If the Black Death couldn't kill us off before medicine was really a science, I doubt any disease will be able to completely eradicate humanity nowadays. But we could be looking at a collapse-of-civilisation type scenario, and the airborn nature of the virus means it could linger in other animals, killing us off later. But I'd say that even if it did mutate incredibly fast there are always likely to be carriers. But I'm no Virologist. Michael Clarke, Esq. (talk) 22:05, 15 April 2008 (UTC)
All this talk reminds me of 12 Monkeys. Imagine Reason (talk) 22:19, 15 April 2008 (UTC)
Really? I thought Outbreak. Confusing Manifestation(Say hi!) 22:57, 15 April 2008 (UTC)
That was a good film, but c'mon, how can you put them in the same category? Imagine Reason (talk) 02:55, 16 April 2008 (UTC)
The incubation time for ebola is quite short: about 24 hours. After this time, the victim is quite ill and not really able to wander about and spread the virus. Combined with the high mortality, this attribute makes it somewhat more likely that the illness' spread would be largely self-limited and restricted to a few populated areas. – ClockworkSoul 00:26, 16 April 2008 (UTC)
I thought it was very short as well, but our ebola article says (without citation) that the incubation period can range from 2 to 21 days and is usually about a week. Dragons flight (talk) 12:59, 16 April 2008 (UTC)
It does however also say "In the early stages, Ebola may not be highly contagious. Contact with someone in early stages may not even transmit the disease. As the illness progresses, bodily fluids from diarrhea, vomiting, and bleeding represent an extreme biohazard." Obviously things will be different for an airborne strain but it wouldn't surprise me if it's similar enough. Nil Einne (talk) 20:25, 16 April 2008 (UTC)
Ebola appears to transmit from humans to human only via exposure to body fluids, so yes, in the early stages one would indeed be much less contagious. – ClockworkSoul 01:51, 18 April 2008 (UTC)

Do hands get bigger with age?[edit]

If you buy a ring when you are 18, will it still fit perfectly when you are 50? I'm referring to men specifically, but women too. Thanks. (talk) 09:08, 15 April 2008 (UTC)

I think bone growth stops when you achieved young adulthood so hands wouldn't grow bigger. However, it might grow bigger if you become obese.--Lenticel (talk) 09:31, 15 April 2008 (UTC)

Finger size can certainly change if you put on or lose weight, by enough to make a previously well-fitting ring difficult to remove or too loose for comfort. Resizing plain gold or silver band rings is very straightforward - the process is described here. Resizing rings with stones is more difficult, but possible. Our article on ring sizes says that rings made of titanium or tungsten cannot be resized. Gandalf61 (talk) 09:41, 15 April 2008 (UTC)
Possibly hands develop size through muscle increase and skin thickening as the body matures/ages. A ps – about men, there seems to be a bulk thing happens around 30. If you won't be able to fit into clothes you had when you were 20, I guess the ring is a similar thing for the hands. Julia Rossi (talk) 12:09, 15 April 2008 (UTC)

White dove?[edit]

What species of dove is a pure white dove such as the kind in the Noah's Ark myth of the Bible? (talk) 13:27, 15 April 2008 (UTC)

I'm not aware of a dove species that is normally pure white in the wild. According to this page, Streptopelia risoria has a common mutation that makes it white, and then there's the white homing pigeon, which is a rock dove bred for whiteness and other traits. But I'm also not aware of a translation of Genesis that specifies the color of the dove. --Allen (talk) 18:00, 15 April 2008 (UTC)
Actually, looking at the Wikipedia article for Streptopelia risoria, it doesn't sound like that mutation occurs in the wild either. --Allen (talk) 18:00, 15 April 2008 (UTC)
Possibly you are thinking of the artistic representation of the Holy Ghost such as seen in Piero della Francesca's Baptism of Chist [5]? Any all-white dove would be a white variety of the domestic rock dove (pigeon) [6].--Eriastrum (talk) 21:10, 15 April 2008 (UTC)


Rather specific question: how rigorously reviewed are articles submitted for the geology newspaper Eos? It says on their website [7] that "Eos is a newspaper, not a research journal" but the Wikipedia article says that its articles are "refereed," and I'm sure you couldn't just send them an article saying the earth is flat and have it printed. So, would any passing person with experience in these matters know the level of "peer-review" (if that term is even applicable) that Eos articles go through?

I'm not interested in submitting an article to them, of course. Just curious--it's a long story. Thanks in advance to anyone who replies.Schmitty120 (talk) 15:02, 15 April 2008 (UTC)

Eos content may or may not have been externally reviewed, at the discretion of the editors. All articles will have been internally reviewed by the editors, several of whom are practicing scientists. In general however, Eos is not intended for the publication of new scientific results (though they don't always adhere to this consistently), it is meant to summarize publications in journals. Dragons flight (talk) 18:14, 15 April 2008 (UTC)
Thanks! I'm still curious though. Maybe this is a better way of phrasing my question: compared to, say, an article being written for the New York Times, how closely will an Eos submission be scrutinized before it is accepted? Will the editors carefully check for flaws in reasoning or questionable interpretations of the data, or no? Would the review process be closer to that of, say, Discover magazine or more like that of Science magazine? Thanks (again) and thanks in advance to whomever responds. (edited once to make my question even more clear) Schmitty120 (talk) 00:57, 16 April 2008 (UTC)

Water in space[edit]

Suppose you open a window of the International Space Station, take a cup of room-temperature water and empty it out in space (or more formally: you instantaneously reduce temperature and pressure from room conditions to 3K, 10-11 Pa). What would happen to the water? Would it instantly freeze and then sublime away, would it instantly boil away, would it first boil a bit, then freeze, then sublime, or any other combination of the above? Thanks, AxelBoldt (talk) 18:09, 15 April 2008 (UTC)

It's not an exact an answer to your question, but DamnInteresting has a excellent article on human exposure to outer space:
In the absence of atmospheric pressure water will spontaneously convert into vapor, which would cause the moisture in a victim's mouth and eyes to quickly boil away. The same effect would cause water in the muscles and soft tissues of the body to evaporate, prompting some parts of the body to swell to twice their usual size after a few moments. This bloating may result in some superficial bruising due to broken capillaries, but it would not be sufficient to break the skin. DamnInteresting
-- MacAddct  1984 (talk &#149; contribs) 19:35, 15 April 2008 (UTC)
This article might prove helpful: [8] --Prestidigitator (talk) 19:37, 15 April 2008 (UTC)
In Project Mercury when the astronauts dumbed urine into space, it froze into droplets which they referred to as "Constellation Urion." It was shown in National Geographic as such April, 1966, page 548, in the article "Space Rendezvous" by Kenneth Weaver per[9]. Edison (talk) 23:12, 15 April 2008 (UTC)
You can't open the windows on the ISS (at least I hope you can't)--Shniken1 (talk) 04:10, 16 April 2008 (UTC)

Thanks a lot, you guys rock! AxelBoldt (talk) 20:32, 17 April 2008 (UTC)

Can positronium be liquified[edit]

Returning to the question of finding a liquid that can sink styrofoam and pursuing it to the point of pointlessness. Summary so far (to save linking way back up the page):

  • Density of styrofoam: 35 to 45 kg/m3
  • Density of liquid helium I: 125 kg/m3 (so aint going to do the job, says so in article)
  • Density of liquid hydrogen: 70 kg/m3 (oh so close but still not there)


  • can positronium be liquified?
  • if it can, anyone know how to calculate density?
  • if you do, will styrofoam sink in it?

SpinningSpark 21:20, 15 April 2008 (UTC)

Positronium cannot be liquified, because the half-life of the stablest form is on the order of microseconds, so even if you had a kilogram of positronium it would be completely annihilated (i.e. not a single atom remaining) in less than a millisecond.
If you assume some magical way of preventing the positronium from annihilating, then it definitely would liquify at low enough temperatures, and the question of its density is interesting. To do it right you'd have to model it as an interacting Bose liquid, which I don't know how to do. If we assume it has about the same particle density as hydrogen, then its mass density is smaller by the ratio of the masses, which is about a factor of 900, so it would be about 80 g/m^3 (so styrofoam would sink like a rock). —Keenan Pepper 21:46, 15 April 2008 (UTC)
All that decay would produce huge energies, enough to make a plasma. Also it would be chemically reactive like atomic hydrogen, so you would need dipositronium. It should have made a very non dense liquid. Next you had better try a foam to get your density down. It takes a foam to sink a foam. Graeme Bartlett (talk) 21:51, 15 April 2008 (UTC)

Maybe you should try the somewhat longer-lived muonium instead of positronium. A question regarding the 2S state of positronium: "Positronium in the 2S state is metastable having a lifetime of 1.1 μs against annihilation" - that's the lifetime against annihilation, but what's the lifetime against decay to the 1S state? (The reciprocal of the total lifetime is the sum of the reciprocals of the individual lifetimes). Icek (talk) 23:43, 15 April 2008 (UTC)

Well, in response to the styrofoam sinking problem, consider this - we have already defied the conventional idea of a "solid" because styrofoam is a compound material containing air macroscopically trapped inside the polymer. So, maybe you should be a little more liberal with your definition of a liquid. Generally, both liquids and gases are classed as fluids; in this sense, gaseous nitrogen will sink styrofoam. If you find a sufficiently dense gas (maybe Argon or some other heavy noble gas), you might even get enough buoyancy to "drift" the styrofoam as it falls. Nimur (talk) 15:53, 16 April 2008 (UTC)

Causes of Alzheimers[edit]

I am looking for the Biological causes of Altzheimers Disease. I have a 10 page research paper due and I cant locate any research articals or anything —Preceding unsigned comment added by Navarro3949 (talkcontribs) 21:42, 15 April 2008 (UTC)

Well I know very little about the disease myself, but you always try the condition's page. Michael Clarke, Esq. (talk) 21:48, 15 April 2008 (UTC)
If you spell it correctly, Google Scholar has about half a million hits[10], or 60000 if you also look for "causes"[11]. The first few already seem apropos. --Stephan Schulz (talk) 07:18, 16 April 2008 (UTC)

Minimum operating temperature of CMOS[edit]

What is the minimum temperature at which a CMOS circuit will continue to function? That is, if I submerge my laptop in a liquid helium bath, obviously the liquid crystals in the display will freeze and the display will stop working, and the hard drive probably won't be happy, but will the CPU and memory keep working? What about millikelvin temperatures? —Keenan Pepper 22:06, 15 April 2008 (UTC)

Don't know about the physics, but you won't get any manufacturer to guarantee those temperatures. Typical commercial spec devices are rated 0o to 70o. Even military spec is only around -55o to 125o, and that's operating temperature, not ambient temperature. However, the problems are likely to be mechanical things like the chip breaking away from the substrate due to differential contraction rather than a fundamental physics obstacle. If you wanted to know when (or if) the actual silicon fails, I would imagine it would be quite happy as the temperature went down, the intrinsic resistivity would be going up and the carrier density would be going down, but silicon designers should be able to make heavily doped devices where this would not be a significant problem. That is, until you reach the region where all those funny superconductivity and Cooper pairs stuff starts to happen, which is where my knowledge comes to an end. SpinningSpark 22:36, 15 April 2008 (UTC)

Sense of Smell[edit]

I have some flowers that really smell strongly. is the smell caused by the flowers giving off a gas, or is it caused by micro-particulates from the pollen? —Preceding unsigned comment added by Pierhead (talkcontribs) 23:40, 15 April 2008 (UTC)

It's a gas, emitted for the purpose of attracting pollenators. See Flower#Attraction methods. ~Amatulić (talk) 00:16, 16 April 2008 (UTC)
WC Fields: "The other day I awoke from a nap in my neighbor's garden to discover this wonderful group of tiny hummingbirds swarming about."
"Really ? How small were they ? Did you need glasses to see them ?"
WC Fields: "Yes, about 9 or 10, I'd say." StuRat (talk) 16:58, 17 April 2008 (UTC)