Wikipedia:Reference desk/Archives/Science/2008 April 12

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April 12

Asexual Reproduction and Natural Selection

I recently learned from a video that some lizards and fish reproduce asexually. I was wondering what is preventing these species from becoming extinct since without sexual reproduction, all the individuals of the species are genetically identical clones. So a virus could kill all of the asexually producing lizards, but only some of the sexually producing ones, since the sexually reproducing ones will have genetic variation. Since the asexual lizards can't adapt to their environments as a population, aren't they at an ultimate disadvantage to a population that can evolve? I know that there are some advantages to asexual reproduction, but how can a population that can't evolve survive in the same environment as one that does, what with natural selection? 24.13.115.247 (talk) 00:01, 12 April 2008 (UTC)

I don't know much about the subject, but I would think that genetic mutation would still occur in assexual reproduction, but that the gene pool in general would indeed be a lot less varied. So I imagine they are not all identical clones of one another, although they likely have less diversity than other species that reproduce sexually. Michael Clarke, Esq. (talk) 01:52, 12 April 2008 (UTC)

Many species (notably bacteria) reproduce exclusively asexually . Other species (e.g. mammals) reproduce exclusively sexually. There is a vast middle ground, where sexual reproduction is used when a male is available, but asexual reproduction is used when no male is available. This makes obvious evolutionary sense: when no male is available, the female that requires a male has no offspring, while the female that does not require a male does have offspring. -Arch dude (talk) 02:07, 12 April 2008 (UTC)

Yeah, if anything, sexual reproduction is the deviant method. It's very tricky to justify. For example, why are there two sexes and not anyone with anyone else, as some species do? Imagine Reason (talk) 03:20, 12 April 2008 (UTC)

The anon is right, a single virus or disease can wipe out an asexually producing species. See Banana#Pests.2C_diseases_and_natural_disasters to see how damaging a single disease is to a asexually produced organism. Perhaps the lizard that you mention is just lucky. A sudden change in the environment our an outbreak will wipe them out.--Lenticel ^(talk) 14:23, 12 April 2008 (UTC)

As noted previously, mutation is the key to survival. This is true in sexually reproducing species as well, since sex only produces "variation within a range", not entirely new characteristics. Species can also apparently vary their mutation rate. Here are some advantages and disadvantages to a high mutation rate:

1) The obvious advantage is that it allows for quicker evolution, both on a small scale, to develop an immunity to a disease, and on a macro scale, to evolve new species.

2) A disadvantage is that most random mutations are harmful, and many are fatal. Thus, only species with a large number of offspring can afford a high mutation rate, as they can afford to write-off many defective individuals.

Another factor is the lifespan of the individuals of the species (or technically, the age at which they are fertile). The shorter this period, the more variation will result from a given mutation rate. Thus, short-lived species don't need as high of a mutation rate as long-lived species would, in order to achieve the same overall variation per time period. The conclusion: if you are a short-lived species that produces many offspring but has difficulty finding a mate, asexual reproduction makes senses. If you are a long-lived species that produces few offspring and finds no difficulty finding a mate, then sex makes senses. I do agree, however, with the previous poster that being flexible would seem to be the best strategy of all. There must be some hidden disadvantages to this system, though, or I'd expect it to be nearly universal. It does seem quite common in plants, however. StuRat (talk) 14:44, 12 April 2008 (UTC)

One obvious disadvantage to sexual selection is that efforts must be put in to make a gene carrier--aka organism--sexually attractive. Consider the peacock's tail. One can argue that it fosters health in the long run, but it is a trade-off nonetheless. It's been stated here too that some species find it difficult to find mates, which is a related problem. Imagine Reason (talk) 00:01, 13 April 2008 (UTC)

See Daphnia#Reproduction which exhibits flexibility in reproduction. I think it is a good strategy for their species.--Lenticel ^(talk) 16:42, 12 April 2008 (UTC)

Giant Fish

http://www.npr.org/templates/story/story.php?storyId=7692201 Can someone please tell me whether this fish is a marlin or something else? The description is vague and not very helpful. Any related articles would be greatly appreciated. Thank you. 99.226.26.154 (talk) 02:36, 12 April 2008 (UTC)

see roundscale spearfish Dismas|^(talk) 03:02, 12 April 2008 (UTC)

Thank you —Preceding unsigned comment added by 99.226.39.245 (talk) 18:16, 12 April 2008 (UTC)

Sodium Hydroxide page safety

I was reading the safety section of the sodium hydroxide article and noticed that it said wash any areas that come into contact with the chemical with water, I was almost positive that it should be vinegar but I dont want to change the page if I am wrong so I was wondering if anyone else knew the answer to that, I just dont want anyone getting injured due to a small discrepancy. (sorry if this is the wrong place to post this question) http://en.wikipedia.org/wiki/Sodium_hydroxide#Safety Pascha mit futbol (talk) 03:33, 12 April 2008 (UTC)

If your skin comes into contact with it, water should be used immediately to throughly rinse away anything residual. However, if there is a large spill, the sodium hydroxide should be neutralized with a weak acid (e.g acetic acid). Try this link [1]. Wisdom89 _{(T / ^C)} 03:58, 12 April 2008 (UTC)

If you should happen to have an open bottle of vinegar in one hand while spilling sodium hydroxide on the other, by all means rinse with the vinegar first. However, in most situations water is more likely to be available quickly and in sufficient quantities than vinegar. In cases of skin contact with sodium hydroxide, or any other caustic substance, it is generally more important that it be washed off as quickly and as thoroughly as possible than exactly what one should wash it off with. In most cases running water will be the best option, but if that's not immediately available, use whatever you have. —Ilmari Karonen (talk) 06:54, 12 April 2008 (UTC)

Here is a much more common situation. You are in the kitchen and you burn your finger by touching a hot pan. What to do? You can open the freezer and plunge you hand into a pile of ice, or go to the sink and run cold water on your finger. The second choice is better. Copious amounts of water will remove heat from the burned finger more quickly than the ice will, because the water is in better contact with the burned area. The excess heat in the burned area continues to do damage until it is removed: every second counts. In theory, ice (being colder) will remove heat more quickly. In practice, running water will always win: quicker to get to and much better fit to the affected surface. This is exactly equivalent to the chemical problem. Every second that the chemical is touching the skin, the skin is being damaged. Running water cannot neutralize the chemical, but it will begin removing the chemical instantly, while going to the cupboard, opening a bottle of vinegar, and then pouring it will take many seconds. In addition, your habits are such that you have no problem using copious amounts of water, but you are unlikely to be willing to dump the entire bottle of vinegar onto your finger. -Arch dude (talk) 00:17, 13 April 2008 (UTC)

name for dysfunction

I am researching the ability of people from separate culture groups to comprehend differences in meaning, usage, inflection and other subtleties of language. In all of the languages of Western Civilization one would not expect to find misunderstanding in the difference between the words "view" and "pay." Members of some non-Western cultures, however, appear to be unable to comprehend the difference. For instance, most utility companies have web sites where customers can login to view their bill from the home page. Any web page developer would naturally be expected to entitle a link for the customer "view their bill" link as a "View your bill" link. Members of some non-Western cultures, however, are invariably unable to comprehend the difference between a "View your bill" and a "Pay your bill" title. The only similar situation I have encountered is with the same non-Western cultural group who are likewise unable to make or use the distinction between the words "ask" and "axe." Although manifested in language is there a scientific, psychological or medical term for this dysfunction? 71.100.160.37 (talk) 03:52, 12 April 2008 (UTC)

First, if a trait is shared among entire cultures, it would probably not be considered a "dysfunction" by modern, educated researchers. Second, I doubt your claim that large numbers of people cannot understand the difference between the meanings of the words "view" and "pay". Do you have a reference? Third, while some people do pronounce the word "ask" the way most English speakers pronounce the word "axe", do you have evidence that these people cannot hear the difference between the two pronunciations? Like many people from my own region of the USA, I pronounce "pen" the way many English speakers pronounce the word "pin", but that doesn't mean I can't hear the difference. --Allen (talk) 05:32, 12 April 2008 (UTC)

The difference in sound for the Homonyms "pin" and "pen" is that "pin" is spoken somewhat more crisply than "pen" is spoken. The difference in sound between "ask" and "axe" is far more different. Its the kind of error one might make when learning a new name so if never corrected then at some point it may be impossible to correct. I can't think of an example this far past my bedtime but many languages seem to have syllables that are pronounced differently in the native language such that "ask" may be a word that was impossible to pronounce correctly, although the culture I am referring to is like a stem cell in that native pronunciation should not be a problem. Large numbers in this case simply means of those persons hired to write copy or perform other literary tasks. A high percent of persons hired from the culture had a similar misunderstanding regarding phases like "large number" in that they had only learned one sense. In this case the phrase "large number" meant eight out of ten persons hired rather than a statistically significant number like fifteen hundred. Although the "trait," as you call it, is more prevalent within a certain subgroup of the culture perhaps there is a correlation with those who have technical training and lack English skills. Until we became aware that there was a problem we did not screen for English skills and unfortunately for some if this is not a known dysfunction then disability compensation would not be an option. 71.100.160.37 (talk) 07:37, 12 April 2008 (UTC)

Are you sure about the 'ask'/'axe' thing? [2] [3]? In any case, I'm not sure if you answered the question from Allen, are you sure that the people are not unable to make the distinction as oppose to simply a pronounciation difference while still being able to make the distinction? BTW, who defines what's the correct pronunciation of a word? Nil Einne (talk) 19:41, 12 April 2008 (UTC)

I suppose that following the American Revolution Americans began to identify with specific pronunciations, for instance skedjewl versus shedule, the later being a pronunciation associated with the enemy or former enemy. Same word, different pronunciation atypical of national affiliation. Both references above BTW are excellent and by the same token (BTST?) may only indicate affiliation with one region or another versus affiliation with a particular culture, although in all but one case I have never heard "axe" pronunciation spoken outside of the particular culture due possibly to the potential confusion with the noun "axe." The particular culture that uses "axe" pronunciation seems oblivious to the fact that the noun and the verb can be confused resulting in unintentional meaning. For instance, was he fired, (he got axed) or was he consulted (he got asked). Hence the assumed illiteracy of the speaker and of his region or cultural. 71.100.160.37 (talk) 10:22, 13 April 2008 (UTC)

You seem to be repeatedly assuming that this unnamed culture is unable to do various things without evidence to back up your assumptions. They "seem oblivious?" To "the fact that the noun and the verb can be confused?" According to Stanford linguist John Baugh, "[aks] never occurs in linguistic domains where it is truly ambiguous with 'ax.'" (Beyond Ebonics, page 94) The Wikipedia reference desk is really for asking questions and answering them, citing reliable sources. I think your question has been answered: As far as anyone here knows (or, at least in my case, can possibly imagine) there is no scientific term for the "dysfunction" you posit. A little digression and speculation here is usually tolerated, but I think it would be nice if you backed up with references any more negative claims about other cultures, and nicer still if you restricted such claims to direct answers to others' questions. --Allen (talk) 17:13, 13 April 2008 (UTC)

You seem to forget that the Wikipedia reference desk does not work in real time, forcing the OP to return again and again in hope of finally getting an answer. In the meantime discussions break out. Start providing realtime answers and your desire for no interaction might have merit. The kind of references and evidence you demand are only necessary if one is trying to make a point while my goal is merely to determine if the failure of one culture to fully comply with the requirements of another culture can be defined as a dysfunction so that members of that culture might seek disability compensation rather than blaming the other culture for rejecting them on some false and projected basis like cultural prejudice. But then I realize if you belong to that culture, have been so rejected without opportunity for disability compensation, that your bitterness is in fact evidence that I'm wasting my time. 71.100.160.37 (talk) 05:27, 15 April 2008 (UTC) —Preceding unsigned comment added by 71.100.171.178 (talk)

You seem to be confusing many different issues:

1) Some languages don't distinguish certain sounds. For example, Orientals tend not to distinguish between L and R.

2) Some words sound alike in some accents of the same language, but not other accents.

3) Some concepts only exist in certain cultures and are difficult to understand in others. Inanimate objects having a gender is one example. StuRat (talk) 03:11, 13 April 2008 (UTC)

Good points StuRat. No doubt if you did a study of misunderstandings resulting from such differences you might come to the conclusion that for particular groups made up of mixed cultures that the language they use needs to be standardized according to specific rules which some members may be unable to follow resulting in their necessary exclusion from the group. "I told you to ask the prisoner, not to axe him!" 71.100.160.37 (talk) 10:32, 13 April 2008 (UTC)

Muscle stiffness, weakness and soreness

I have muscle weakness, stiffness and soreness in my back and legs. What could be causing it? I have been through several physicians and have only medical bills and debt to show for it. —Preceding unsigned comment added by 63.237.114.10 (talk) 07:43, 12 April 2008 (UTC)

See our Wikipedia:Medical disclaimer - we cannot offer any form of medical or legal advice that would otherwise be provided by a professional. You need to depend on your physicians. Wisdom89 _{(T / ^C)} 07:58, 12 April 2008 (UTC)

Indeed, if you've only been seeing GPs, you may want to see a specialist of some sort although I'm not really sure what sort. Nil Einne (talk) 13:34, 12 April 2008 (UTC)

specific gravity

A body weighs 3 kg in air. If it is submerged in a liquid, it weighs 2.5 kg. What is the specific gravity of the liquid.Jalaludeen (talk) 13:59, 12 April 2008 (UTC)

I don't think there's enough info. We'd need to know the density of the object, or it's volume, since we could get density from it's mass and volume. Consider submerging two 3 kg objects in water. If you submerged 3 kg of styrofoam it would actually have a negative weight in water, or in other words, it would float. On the other hand, 3 kg of lead would still weigh close to 3 kg, since it's density is so much higher. StuRat (talk) 14:07, 12 April 2008 (UTC)

"3 kg of styrofoam...have a negative weight...3 kg of lead...still weigh close to 3 kg"

That means that knowing the initial weight and final weight, it's possible to calculate density. Buoyancy from water applies an upward force of 1 g per g/cm^3 of the submerged object, since water's density is 1 cm^3. Because the 3 kg body's weight became 2.5 kg, a reduction of 500 grams, that must mean the volume is...the rest is left as an exercise to the OP. :) (If this isn't a homework question, sorry for my misunderstanding, but the final answer should be easy to calculate.) --Bowlhover (talk) 22:29, 12 April 2008 (UTC)

The OP didn't say the liquid was water. The question was to find the SG of the liquid, so the liquid is the unknown. There still is not enough information. Sure, 500g of liquid has been displaced, but the only way to know what volume that occupied is from the density of the supermarket trolley or whatever it was that was thrown into the local swamp. By the way, is there any liquid that styrofoam will sink in? SpinningSpark 23:04, 12 April 2008 (UTC)

Sorry. I should have read the question more caref...well, I should have the question. --Bowlhover (talk) 02:34, 13 April 2008 (UTC)

I speculate that Styrofoam would sink in liquid Helium, but we would very rapidly get into obscure arguments about the definition of Styrofoam at 4.22K, because Styrofoam is a composite material one of whose components is air. If you can believe Tom Clancey, there is a tradition in the deep-diving community of presenting a new passenger of a deep-diving submersible with a Styrofoam cup that had been placed in the external sample basket prior to the deep dive. After the deep dive, the cup is dramatically smaller because all of the air was forced out of the interstices during the dive. An equivalent phenomenon would occur as the air froze when the Styrofoam was immersed in liquid helium. -Arch dude (talk) 23:57, 12 April 2008 (UTC)

I've seen one of those crushed cups (divers should concentrate more on what they are doing in such a dangerous profession instead of fooling around) but I am not convinced liquid helium would have the same effect. The cup under water has the great pressure of the depth to crush it after the air has been forced out. In fact, the air is coming out because it is being crushed rather than the cup is crushed because the air has come out. In liquid helium, there is no change in pressure (unless you are postulating a VERY large tank). It would be more a case of the air dripping out. The vacated space would be replaced by helium and the cup structure would maintain integrity. SpinningSpark 22:18, 13 April 2008 (UTC)

Having now looked up the density of styrofoam, I also dispute that it would sink in the first place. The densities I found quoted for commercial styrofoam ranged from 35 to 45 kg/m³. According to our article liquid helium has a density of 125 kg/m³. SpinningSpark 22:35, 13 April 2008 (UTC)

The helium page states (and cites) that styrofoam floats on normal liquid helium. DMacks (talk) 05:22, 14 April 2008 (UTC)

Reasoning validity of interesting excerpt...

In my hot-air balloon bunting adventures around the internet in eighty aeons, I recently came across the following passage, and wondered what sense to make of it:

Today, physics is explained in terms of group symmetry, for example U(1) for electromagnetism, SU(2) for spin in three dimensions or electroweak force field, and so on. On the other hand all symmetries must merge at least at the so called Planck's elementary scale, near 10-33 cm. from quantum mechanics, the smaller the scale the larger the energy. So, the planck's unit is something as 10^29 times (ten billions of billions of billions) more energetic than the simple photon of visible light.

From modern physics experiments, it seems the electroweak force field must fuse with nuclear force at a scale near 10 000 Planck's units. A light radiated at that level would not see an Universe with an infinite number of directions, for it the world would be a sphere made from small Planck's unit surfaces. The surface of a sphere is given by the formula: 4 x Pi x R^2, or 1 256 000 000 for R = 10 000. The biggest possible energy for a photon gives it a view of the Universe with something as one billion possible directions.

Quantum mechanics produces a strange phenomena: the so called state superposition: A photon radiated at the elementary scale will goes in one billion directions at the same time! It will get to one billion different places after one crossing time, the time it take to travel at light speed a distance equal to R ( 10 000 Planck's units). Such a quantum process can works with virtual particles using no net energy at large scale. That is to say, it will take place continuously everywhere in each space element 10^-29 cm long and on a time scale near 10^-39 second.

I would verily appreciate if the veritable brainsponge thinkclouds that inhabit this vast elysia of edification could grant me the boon of explaining, with specific reference to points in the passage, whether this line of inference would be well-recieved in the court of physics comprehension, and if not, at which syllogistic leap the jester might fear for his position. This I entreat of you, my good fellows, in the assurance that I will not soon forget my benefactors, when after many leagues and perils, I complete my journey and return with the trove of ages. Most lostentatiously, Ernst Valiance de Fargowellsenstein, esq. —Preceding unsigned comment added by 85.194.245.82 (talk) 16:23, 12 April 2008 (UTC)

You could start by taking a look at our article Symmetry in physics. For a more mathematical point of view (but still readable) there is Symmetry group. For electromagnetism and the U(1) and U(2) groups in particular, take a look at Gauge theory. For a deeper mathematical understanding there is Special unitary group which will tell you about SU(3), needed for quarks and the strong nuclear force and if you're really brave you could leap into Standard Model (mathematical formulation) which will tell you about SU(3)xSU(2)xU(1) - basically the theory-of-everything-except-gravity.

Many in science are coming to believe that symmetry is what lies behind it all and to make further progress in our understanding we should be looking for deeper and simpler symmetries. Oh, and your questions on quantum theory, look at Quantum mechanics. SpinningSpark 16:41, 12 April 2008 (UTC)

One was rather hoping that the trouble might actually be taken to read and attempt to explain the passage, as the object of my mission is the assessment of its veracity, rather than a expenditure of time perusing the background of the subjects alluded to, which fascinating as they might be, would be of no immediate assistance in determining the credibility of the syllogistic in question, and would detract immeasurably from my various aviational adventures and epic travails. Which is to say, dear friends: does anybody else care to assist? E. V. de F., esq. —Preceding unsigned comment added by 85.194.245.82 (talk) 00:48, 13 April 2008 (UTC)

Herewith is my humble assessment of the veracity of your quoted passge.

The first paragraph is a summary of standard physics. In particular, the Planck energy is about 2x10⁹ Joules, which is about 10²⁸ times as energetic as a typical light photon.

The second and third paragraphs are a veritable pile of unicorn droppings, especially the parts about light "seeing the universe" in a number of directions and photons going in "one billion directions at the same time". It might be a (not very good) attempt to describe quantum foam. However, in the absence of a consistent theory of quantum gravity, any current statement about physics at the Planck length scale will be mostly speculation. Gandalf61 (talk) 10:03, 13 April 2008 (UTC)

Good and wisened mage, of long and venerable lineage, I thank you for your gracious and esteemed counsel. My travelling companion, though feathered and vulgar-of-tongue as any not-long-since buccaneer's shoulder-mate he may be, did study for some time under a greatly learned and erudite master the ars physica, and his reckoning, at least while sober, I trust above all unplumaged bipeds. He proposes that the intended sense of "direction of seeing the universe" might refer to the maxima on the spherical surface of the light-cone extending from a photon emmision event after a propagation time of 10,000 planck units (equivalently, radius of 10,000 planck lengths), the number of which indeed grows as the square of radius. The reference to "all direction at once", my squalking sea-faring sidekick suggests, is equivalent to sum-over-histories formulation of QED, in which all possible paths within a light-cone contibute to the quantum amplitude of the EM transmission. What say you, sir, to these comments? E. V. de F, esq. —Preceding unsigned comment added by 85.194.245.82 (talk) 20:06, 13 April 2008 (UTC)

Is it mere coincidence that, prior to the addition of this non-sequitous comment, the words following that parroty were, "Bird Poop?" ;-) --Prestidigitator (talk) 21:41, 13 April 2008 (UTC)

A most serendipitous synchronicity of jungian justapoxition, one can only surmise. E. V. de F., esq. —Preceding unsigned comment added by 153.1.253.5 (talk) 13:01, 14 April 2008 (UTC)

Bird Poop

<moved from miscellaneous desk>
There is bird poop on my sliding glass door. Who knows how it got there... Anyway the question I have is; Why is bird poop white? 71.142.208.226 (talk) 21:28, 12 April 2008 (UTC)

Because white is a neutral color and because the poo can match the fluffy clouds in the sky. For all I'm concerned clouds are bird poo.

Always

Cardinal Raven

Cardinal Raven (talk) 22:00, 12 April 2008 (UTC)Cardinal Raven

That possibly can't be true. 71.142.208.226 (talk) 22:17, 12 April 2008 (UTC)

Birds do not urinate, instead they secrete uric acid into their droppings which is white and makes up the bulk of it. Nanonic (talk) 22:36, 12 April 2008 (UTC)

Birds don't just drop it, they eject it at an angle, so if one happens to be flying past your window, it can score a hit. Graeme Bartlett (talk) 12:07, 13 April 2008 (UTC)

Thanks for explaining why when I clean my car windows, I do not think of clouds (but will try to in future). Julia Rossi (talk) 02:35, 14 April 2008 (UTC)

Star and Sun

Why do we say the Earth rotates around its sun, but if it was another planet they say Plaid(my example planet I made up) rotates around its star every 8.3 minutes? Why is it Sun for Earth, but star for other planets like Plaid(my made up planet)?

Thank You

Always

Cardinal Raven

Cardinal Raven (talk) 23:21, 12 April 2008 (UTC)Cardinal Raven

(edit conflict)Hi. Well, the reason why our sun is called "Sun" is because, well, it's our sun. Other stars are stars because they're not our sun. If we lived on Plaid, though, the star it orbits might be called "Sun", were we to speak English. Some stars have names, though. Also, if we spoke English and lived on any other planet orbiting the sun, we'd still call it "Sun", although it may be brighter or dimmer than on Earth. However, since Plaid (your example) rotates around a star other than our sun, we say it rotates around a star, but most stars have either a name or some kind of formal designation. Hope this helps. Thanks. ~AH1^(TCU) 23:32, 12 April 2008 (UTC)

But, why is that so? Our sun is still a star. And the stars are still suns. What made it that way?

Always

Cardinal Raven

Cardinal Raven (talk) 23:45, 12 April 2008 (UTC)Cardinal Raven

My guess is that the names of the sun and stars were made before people knew they were the same. —Preceding unsigned comment added by 59.100.167.250 (talk) 00:13, 13 April 2008 (UTC)

That the Sun is a star is not at all obvious. Though a smattering of people thought so early on (e.g. Anaxagoras), it was still a heretical idea well until after the main body of work of the scientific revolution. As for why we call our sun The Sun, well, it has historical antecedents. To call it by a more formal name (e.g. Sol, as some sci fi writers often do) seems silly when we've been calling it The Sun for so long. --Captain Ref Desk (talk) 00:33, 13 April 2008 (UTC)

This is a language question, not a science question. "The Sun", capitalized, is the English name of a particular star. The star's name in latin is "Sol". The (non-capitalized) word "sun" designates the primary of a star system. So: the sun of Earth is Sun, or the sun of Terra is Sol. The sun of Plaid is Fomalhaut. In general, you can replace the (non-capitalized) word "sun" with "primary." The (capitalized) word "Sun" is the (english) name of a particular star whose third planet is named (in english) "Earth." The name of Earth's primary is "Sun." Earth's sun is named "Sun." Earth's astronomers have formal names for most of the 6000 or so visible stars, but the millions of other stars have other designations in several systems. Presumably, the inhabitants of Plaid will name their sun. Perhaps they will name it "Tartan." . If the primary of Plaid is not visible from Earth, the government of Earth will probably acknowledge the new name for the star. If the inhabitants of Earth already have a name for that particular star, there is likely to be a truly silly debate over the correct name for the star. -Arch dude (talk) 00:58, 13 April 2008 (UTC)

Btw, Earth revolves around the Sun, each complete trip marked as a year. Earth rotates around its axis, creating days. Imagine Reason (talk) 01:18, 13 April 2008 (UTC)

URGENT

Is it safe to??? —Preceding unsigned comment added by 79.122.53.15 (talk) 23:29, 12 April 2008 (UTC)

Hi. Could you please specify if what is safe to? We cannot answer your question if you do not tell us your question. Also we can not give you professional advice. Thanks. ~AH1^(TCU) 23:35, 12 April 2008 (UTC)

NO! It is NOT safe to ?? Stop now. Exit the premises. Call the fire department. Call the police. Duck and cover. Move away from the keyboard. -Arch dude (talk) 23:39, 12 April 2008 (UTC)

Thank you!!!! Your quick advice helped me to avoid certain doom :) —Preceding unsigned comment added by 79.122.53.15 (talk) 01:58, 13 April 2008 (UTC)

Is it safe to question a question? Questioning this Question will cause the author to harm you in all possible ways. Questioning about a question will incite personal descrimination from the questioner. Questioning why questions exist brings up an issue nobody questions but the questioners of all questions. And why do you question so much, anyhow? --99.237.101.48 (talk) 23:28, 13 April 2008 (UTC)

It is not safe to live. You will die doing this. Mac Davis (talk) 06:54, 14 April 2008 (UTC)

If you have to ask, it isn't. Another clue would be the urge to shout "Hey, watch this!" or "Here, hold my beer for a sec..." just before you do it.

Atlant (talk) 12:03, 14 April 2008 (UTC)

Your best clue is that if you have to come to the wikipedia reference desk and say it's urgent, then it's not safe. Relying on random volunteers, who could easily be wrong or worse, fooling around with you, for urgent advice on whether something is safe to do, is never a good idea. Nil Einne (talk) 21:41, 18 April 2008 (UTC)

Protein homology dataset

Where can I get a dataset of protein homology? I searched the Internet and found <http://mips.gsf.de/>, but I am unable to locate any dataset there. Note that I have a Computer Science background, and I have not studied any Biology since joining University. --Masatran (talk) 23:31, 12 April 2008 (UTC)

Since no one's bitten yet: I don't know if it helps, but the science forum of folding@home might be able to help. Proteins are right up their alley. --Lisa4edit (talk) 14:32, 13 April 2008 (UTC)

This any useful? http://webclu.bio.wzw.tum.de/simap/web/simap/fulltextsearchresult --Lisa4edit (talk) 15:19, 13 April 2008 (UTC)

What are you looking for in a protein homology dataset? (To what purpose are you going to employ it?) The standard repositories of Entrez and Expasy have sequences of most all of the proteins know to science, with some cross referencing for homologous proteins. If you have particular proteins you hope to find homologs to, you can always try BLAST type searches. If you are looking for structural similarity, there is always Scop or CATH or FSSP. One issue you're going to run into is the definition of homology - strictly speaking, homology is an evolutionary relationship. Unfortunately, we can only infer evolutionary relationships through sequence and structural similarity. How much experimental evidence of evolutionary relationship do you need? Also, how closely related do two proteins need to be before you call them homologs? There are instances of similar sequences giving different folds, and different sequences giving similar folds. I can't think of specifics at the moment, but I believe that there are structurally and functionally similar proteins which are hypothesized to have arose from separate evolutionary paths. -- 128.104.112.85 (talk) 18:55, 13 April 2008 (UTC)

The mips datasets are still online. Go here: http://mips.gsf.de/projects/funcat, ftp://ftpmips.gsf.de/catalogue/, ftp://ftpmips.gsf.de/catalogue/annotation_data/ etc. As for other databases, I would recommend KEGG first and foremost. --Rajah (talk) 06:05, 14 April 2008 (UTC)