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January 6

Dragonfruit question

What are those things that look like artichoke leaves on the outside of the fruit of a dragonfruit, or pitaya? Wiwaxia (talk) 00:06, 6 January 2011 (UTC)

Bracts. Vespine (talk) 00:54, 6 January 2011 (UTC)

Oscar (fish) question

I've had a single Oscar for about 2 months and now I've just added 2 more. When I approach the tank, all 3 now come right to the top, and when I drop the food in, they all but attack the pellets, etc. But the single Oscar didn't do that when he was alone -- is this how they usually act when in groups? DRosenbach ^{(Talk | Contribs)} 04:20, 6 January 2011 (UTC)

I know really know, but I can only assume that they are running to the food to make sure to get it before it's all eaten. With just one there is no urgency. I assume that in the wild there usually isn't a concentrated source of food, and they just each search on their own for what they can find. (Again, this is just conjecture on my part.) It does remind me of something I read a while ago where someone was trying to breed an animal (some type of deer or gazelle) with no success - the male showed no interest in any of the females. Then one day males from other pens broke loose and the all ended up together - the competition from the other males stirred all of them, and all the females ended up pregnant. (The original author was rather more dramatic in how he described it, it's too bad I don't remember where it's from.) It seems that competition is not just for capitalism. Ariel. (talk) 06:32, 6 January 2011 (UTC)

Absolutely. The impulse towards competition can be absent when potential competitors are absent. 71.198.176.22 (talk) 14:07, 7 January 2011 (UTC)

evolution propaganda

Does anyone know of any evolution propaganda in the same format as the creationist pamphlets that you get from Jehovah's witnesses et al? I'm thinking of making my own but wondering if someone has done it already, I haven't really been able to find anything my self. Searching for "evolution pamphlet" predominantly gives results for the creationist ones. Vespine (talk) 05:38, 6 January 2011 (UTC)

What would be the need for such propaganda? Evolution has the weight of evidence on its side, it doesn't really need loud, garishly colored pamplets with words in all caps announcing that EVOLUTION IS THE DEVIL'S HANDIWORK or something like that. Science is generally publicized via peer reviewed journals and the popular scientific press; something the creationists lack access to, being that what they do isn't really "science". Hence the garish, badly made pamphlets. --Jayron32 05:54, 6 January 2011 (UTC)

Anyways, giving out pamphlets would only further expose the fact that evolution is desperately looking for support and evidence. --T H F S W (T · C · E) 07:04, 6 January 2011 (UTC)

Evolution can not look for support and evidence, it does not have a mind. Scientists have found a lot of evidence for evolution. I think THFSW is correct in the fact that evolution could loose credibility in the public if pro evolution propaganda pamphlets are distributed widely.--Gr8xoz (talk) 10:10, 6 January 2011 (UTC)

I would find such mock-tracts amusing. WikiDao ☯ 10:28, 6 January 2011 (UTC)

Does something that can be observed and there is no doubt about need propaganda?Zzubnik (talk) 10:34, 6 January 2011 (UTC)

In the USA, "no doubt" is the minority view, presumably because more people read Chick Tracts than Nature. --Sean 14:28, 6 January 2011 (UTC)

While those who reject evolution may be stronger in their beliefs [1] for example show it about even with about 20% not sure. Level of support for evolution#Support for evolution in medicine and industry mentions something from 2007 where 49% believe in evolution although only 14% of the total don't believe god had a part. (This may seem to be a minority but I presume there are some 'not sure' there in particular while the citation seems dead the title suggestions it's 45% who believe in creationism.)Nil Einne (talk) 16:19, 6 January 2011 (UTC)

Your first link says, "In the U.S., only 14 percent of adults thought that evolution was "definitely true,"...". "Definitely true" is not a bad synonym for "no doubt", and 14 percent is certainly a minority, so I stand by my statement. --Sean 16:47, 6 January 2011 (UTC)

Apologies, I missed the 'no doubt' part. However I still have strong doubts about your statement. It seems unlikely the reason for the entirety of the 86% of the population who don't have 'no doubts' read or have had much influence from Chick tracts. Perhaps the 45% or whatever who believe in creationism at most. It's also questionable if reading Nature is needed. For starters, understanding journal articles can be difficult for those without much experience in the field. Also the evidence for overwhelming evidence for evolution has existed for so long it's well covered in far more accessible publications and in fact what is in Nature nowadays is often going to be limited and written without any consideration of the possibility of dispute of evolution. Nil Einne (talk) 21:57, 6 January 2011 (UTC)

There's also the question of where exactly 'no doubt' isn't in a minority. Not the UK for example [2]. The survey referred in the earlier link appears to be [3] from the supplementary material [4] it appears in 2002-2003 only Denmark of the 10 countries surveyed had a majority with 'no doubt'. (United States), Poland, Netherlands, Italy, Spain, (Britain), Austria, Germany, France, had a minority having 'no doubt'. In fact France the highest after Denmark didn't even have 40%. So while it may be true the US lags behind most of the developed world in acceptance of evolution and from the ref, also differ in a number of ways, having only a minority with 'no doubt' isn't one aspect that differentiates them. BTW if you look at the main article, it has more countries but without the 'definitely true' part, interesting France is the 4th highest in this list of acceptance, and the UK is 6. Denmark is 2. Of course that doesn't mean at most 3 of the surveyed countries would have no doubt, it's 2-3 years in the future so attitudes would have changed and the different positions of countries tells us not surprisingly that potentially there's greater acceptance in some countries among the population even if fewer who think it's 'definitely true'. Nil Einne (talk) 22:07, 6 January 2011 (UTC)

You could always set up a new religion like L Ron Hubbard did. How about 'The Church of the Evolved Christ' where we have to evolve to get better, give Christ a blue skin too - that looks good. With a few million followers donating a tithe you could easily get them to produce pamphlets just like the creationists' ones and distribute them all around the world translated into a hundred and fifty different languages. How else would you distribute such pamphlets? How else would you get people to do anything with them except put them with the other paper for recycling? Dmcq (talk) 13:50, 6 January 2011 (UTC)

It could be fun to just change the words on Chick Tracts, like this one where Chick demonstrates to his own satisfaction that Jesus -- not gluons -- mediates the strong interaction. --Sean 14:28, 6 January 2011 (UTC)

I'm not sure how possible it is to mock something which is so inherently risible already. (It's not just physics, Chick even fails theology. Here he claims that Jesus's blood was not human blood, which is not exactly mainstream Christian thinking.) Marnanel (talk) 15:54, 6 January 2011 (UTC)

You make it sound like Chick Tracks are the supreme authority for anyone who doesn't believe evolution. The're not. --T H F S W (T · C · E) 17:17, 6 January 2011 (UTC)

Well, that first tract (the one with the irritable douchebag teacher and the tranquil babyfaced student) is a pretty good showcase of most arguments used against evolution. Ok, the gluon thing isn't exactly omnipresent, but open up any anti-evolution site and you'll find things like the ridiculous "six stages of evolution", the "carbon dating is inaccurate" silliness or the endless masturbation over the Piltdown man. TomorrowTime (talk) 18:47, 6 January 2011 (UTC)

Not terribly sure how you got that out of my words, or Sean's. I am sure even such people can see the foolishness of Chick tracts. Marnanel (talk) 18:32, 6 January 2011 (UTC)

I think you're looking to use your creativity to compose a novel joke, and that's not something that a science refdesk can really help you with much. You already have evolutionary theory - what you need is a mock religion to make it funny. Existing groups like the Church of the Subgenius might give you some ideas.

There is not actually any need for a conflict between religious creationism, which occurs in the dimension of time in which God authors and edits the universe, and scientific evolution, which occurs in the dimension of time in the universe as created. Just because the Foundation Trilogy covers many centuries doesn't mean that Asimov took that long to write it, or wrote it all in the order you read it. Wnt (talk) 18:44, 6 January 2011 (UTC)

I'm not trying to compose a joke. The fact that most of North America thinks people magically changed from lower animals is funny enough to me. --T H F S W (T · C · E) 19:10, 6 January 2011 (UTC)

As opposed to being magically created from dust (or ribs)? AndrewWTaylor (talk) 20:59, 6 January 2011 (UTC)

That happened due to an external influence. Different animals changing into one another is supposed to happen by itself. Would you say its weird for the keys on my keyboard to type out this message? No, because there's someone doing it. --T H F S W (T · C · E) 21:09, 6 January 2011 (UTC)

For THFSW: Introduction to evolution. You look markedly un- or mis-informed if you think the modern synthesis of evolution is "desperately looking for support and evidence" or that "people magically changed from lower animals". We have good articles on the subject; read them. — Scientizzle 22:02, 6 January 2011 (UTC)

...and keep reading. Unlike creationism, which is based on one unchanging, not allowed to be questioned, source, evolution is based on an ever growing body of knowledge being observed and interpreted by open minded scientists happy to change their minds when new evidence appears. HiLo48 (talk) 23:28, 6 January 2011 (UTC)

OP here, I was about to write, STICK TO THE QUESTION! I'm not starting a debate.. but i had to run and i thought it might be a little presumptuous, i was obviously wrong! lol.. I don't care if you think such propaganda is needed, i'm asking if it is around. I have some people close to me which have been given the creationist propaganda and it is making an impression on them. I understand "the weight of scientific evidence" is behind evolution, but there are obviously a lot of people not so scientifically literate who find a concise "to the point" pamphlet more convincing then "the weight of scientific knowledge". Thanks.Vespine (talk) 00:51, 7 January 2011 (UTC)

For the record, I agree with you that 1. the off-topic responses here have really gotten out of hand (which is entirely the answerers fault in my opinion), and 2. there's a lot of good reason to believe that good would be served if the basic arguments in favor of evolution could be condensed down into something that a "man off the street" could read, understand, and be convinced by.

There's plenty of evidence that the Chick tracts have been compelling; heck, even when I read some of them, I think, "gosh, this guy is a clever manipulator of emotions, even if he is a nut." Throwing scientific papers at laymen (even intelligent ones) doesn't do anything; appealing to scientific authority only gets you so far; and dismissing the "lay" opinion as unchangeable or, worse, irrelevant is dangerous and wrong as well. As for having examples of said good "propaganda" (which is really an unfortunate word to use because of its negative connotations), the National Center for Science Education produces a good number of pamphlets and short books that are aimed for this purpose. I'm not sure they have them posted online, and when I saw them (in the late 1990s, in their Oakland location), a lot of them were moldy golden oldies of an earlier time (arguing against Henry M. Morris and other, uh, transitionary fossils). But I'm betting if you wrote them or sent them an e-mail they'd send you some samples; they're a pretty generous bunch and I seem to recall the pamphlets being free anyway. --Mr.98 (talk) 02:38, 7 January 2011 (UTC)

Try "An Introduction to Evolution" from UC Berkeley's "Understanding Evolution" project. There are printable links on each page. I'm pretty sure it's as close as you're going to get to a religious tract about evolution, without the appeals to emotion, authority, or circularity. 71.198.176.22 (talk) 13:04, 7 January 2011 (UTC)

Or here! http://www.scientificamerican.com/article.cfm?id=evolution-the-story-of-life-on-earth 71.198.176.22 (talk) 14:29, 10 January 2011 (UTC)

Rotating momentum exchange tethers in LEO, drag and space debris

Does there exist a altitude range in low earth orbit were a rotating tether (Tether_propulsion#Bolo) for launch assist cold be placed?

I am thinking of a tether with the tip 50 km from the centre of mass and a tip speed of about 2 km/s relative to the centre of mass and an allowed load of at least 80 kN (1000 kg). It should be used by gaining orbital momentum by moving incoming objects from a high orbit to a lower unstable orbit and then give that orbital momentum to payloads launched by suborbital launch vehicles. The tether need of curse to be constructed with multiple strands for redundancy like the Hoytether. This would be part of a larger transportation system.

It must be operated at an altitude below most of the space debris in order to get a useful expected survival time. At the same time it will have high surface area and need to operate at an altitude where the atmosphere are thin enough to not generate a prohibitive high drag. Does such a altitude exist?

Would (micro) collisions with the tether generate a significant amount of new space debris? --Gr8xoz (talk) 11:07, 6 January 2011 (UTC)

I don't think we should assume that a tether needs to passively accept collisions with debris or other micrometeorites, given sufficiently effective sensors. To take a simple example, suppose that a tether has two cables separated by a few meters. If a piece of debris heads for one of the two cables, it temporarily relaxes its hold (perhaps at the expense of tightening in several other segments upward and downward). As a result, the loosened cable can be pulled out of the way toward that which is still taut, and the space debris flies through the hole. True, this requires a 2x redundancy factor, but only temporarily, and in case of catastrophic failure of the taut cable the lax one may still be able to hold the elevator while a repair module is dispatched to the site. And in practice I suspect that there would be quite a few more cables than just two, lowering the required strength-to-weight ratio needed for redundancy in all cases. Wnt (talk) 18:35, 6 January 2011 (UTC)

The ability to avoid collisions is very useful but I think there exist a gap between the debris that reasonable can be detected and the size of debris that can cut the tether. [5] on page 180 or according to the pdf-reader 187 estimates that debris as small as 0.2 mm can cut a 1 mm strand. I think it is hard to detect so small debris if it is approaching at 15 km/s (page 164 or 171) --Gr8xoz (talk) 20:22, 6 January 2011 (UTC)

How do you plan to detect debris or micrometeoroids on the order of millimeters in dimension moving thousands of meters per second, especially far enough in advance to calculate the probability of impact and take action to move the tether? The tether WILL be hit with MMOD. I doubt that these small pieces would pose a new debris risk, though damage would accumulate over time and threaten the tether. A large, undetected object would also threaten the tether. So for any space elevator, this is a real problem with no easy solution. anonymous6494 19:56, 6 January 2011 (UTC)

To me, it seems absolutely unbelievable that people can track a satellite in Earth orbit, or even smaller bits of lost materials. Getting down to 0.2 mm is not that many orders of magnitude of difference. Also, pieces that are isolated specks and cut only a single cable should not really be so dangerous, because there should be periodic cross-struts between several cables, and repair modules that fix one broken cable while the others hold the structure together. After all, there will be spontaneous ruptures in the cables due to defects in manufacturing or deployment or during use, and the system will have to be ready for those. Wnt (talk) 06:32, 8 January 2011 (UTC)

"periodic cross-struts between several cables" is very important in order to get a useful expected survival time. I think that in order to not add to much weight this cross linking will need 100 m or so to spread the load evenly between the strands when a strand is cut. The problem is that the cross linking can not be allowed to pull the strands to close together since that would reduce the redundancy. I think repair modules requires a much more advanced technology and would increase the cost, remember, they need to climb in a acceleration from 0 to 80 m/s^2 and have to be mobile over about 70 km tether. They requires a rather good power supply to climb at any reasonable speed. I think a tether could handle between 100 and 1000 cuts during its lifetime without repair. For a lifetime of 10 years that translates to about 0.02 to 0.2 cuts per km strand and year. An additional problem are that each cut could produce new derbies and accelerate the problem.

--Gr8xoz (talk) 12:42, 8 January 2011 (UTC)

In practice, the performance of tethers in orbit has been very poor. They have failed spectacularly in several high profile incidents, and orbital dynamicists are so frustrated with their inability to accurately and usefully predict their behavior that they have been avoiding the use of tethers for at least the past two or three decades in microgravity orbital and outer space applications in favor of rigid, propulsion, formation flight, and balloon-based solutions to the same problems. Many if not most of the orbital tether failures are still not well understood, except that people now realize that they depend chaotically on initial conditions far more than was originally thought. I am pessimistic about the long term outlook for tether-based orbital dynamics solutions which do not make use of substantial propulsion and tension systems to stabilize them. It's not clear that the bolo launch assist mechanism couldn't be effected by a set of rigid structures. 71.198.176.22 (talk) 16:00, 8 January 2011 (UTC)

It would be interesting to read more abut these problems, do you have any useful links? I have not found any information on failures due inability to predict the orbits. There have been some failures in electrodynamic tethers and some single strand tethers have been cut by debris/meteoroids. Some very low budget experiments has had problem with deployment and telemetry. None of the these problems seems unsolvable to me except maybe space debris.--Gr8xoz (talk) 23:54, 8 January 2011 (UTC)

• http://articles.latimes.com/1992-08-09/news/mn-6218_1_shuttle-lands
• http://nssdc.gsfc.nasa.gov/nmc/spacecraftDisplay.do?id=1996-012B
• http://articles.sun-sentinel.com/1996-03-04/news/9603030189_1_tether-columbia-returns-space-shuttle-columbia
• http://www.youtube.com/watch?v=JuFBUS0kiSA lol
• http://www.vectorsite.net/tarokt_5.html#m2 says "most experiments were successful" and lists many of them. 71.198.176.22 (talk) 14:00, 9 January 2011 (UTC)

Cause of vibration of a string

Project of “ ANKITIUM ” , The Unit Of Life :---------- When we make an approach to the string, we assume the mass, charge and energy as the fundamental properties of a particle. In this way of approach all of our thinking ends up to the Big Bang. We could not be able to know that how does it occurs or what was the situation before it occurs. But if we change our approach by considering the cause of producing mass, charge in an electron (or proton) from a string vibration, we might be able to find out the reason lying behind the Big Bang or the situation before the Big Bang.

Every mass contains some atoms. An atom contains a nucleus and some electrons. Nucleus contains protons and neutrons. Protons are positively charged, neutrons are neutral and electrons are negatively charged (It is our convention to assume that the charge in protons is positive and the charge in electron is negative.).

As all we know that vibration is the only way to transfer energy (such as thermal energy, sound energy etc.) from one place to another, we can conclude all of the energies can be created from vibration. As vibration takes place in different mode, different kind of energy can be produced at different mode of vibration.

Now, consider one electron. The electron is negatively charged. But from where does the charge come from or rather I would say where does it produce from? We can assume an electron as a negatively charged spherical cloud (as per electron’s wave nature). The radius of the spherical cloud is equal to the radius of an electron when it is considered as a particle. The spherical cloud implies the area of the electric field, produced due to the negative charge, in which it acts. In between this spherical cloud, there exists a vibrating string according to the String Theory proposed by Sir Stephen Hawking. The vibration is at one direction (say in anti-clockwise direction). This vibration produces some amount of energy. A part of which converts into a mass which is equal to the mass of an electron, obeying the famous equation E=mc2, of Sir Albert Einstein. Another part of this energy gets converted into some amount of charge, equal to the charge of an electron. This amount of charge produces a spherical shaped electric field which is called an electron in particle theory and electron cloud in wave theory, owing to the dual nature of the electron. Now, from where does the vibration of the string produce? In account to solve this problem, we can assume a string consists of many infinitesimally small units which are continuously getting compressed and elongated in success. These units can be called as the unit of life or rather I could name it after my girl friend, “Ankitium” (“Ankitia” in plural). But why does an Ankitium get compressed and elongated in success?

As we all know that the photons (unit of energy) are absorbed in multiple integrals of a quantum, energy of which is equal to ‘hv’ (h= Plank’s constant and v= frequency of the incident light). Our universe consists of different types of rays with different frequencies. Let, the different rays in this universe are of frequencies v1, v2, v3, v4....... and so on. Let us assume that v1=v. Hence, from Plank’s theory E=hv=hv1. An Ankitium absorbs the amount of energy in multiple integrals of ‘E’ or v1. When an Ankitium absorbs energy from the rays having frequencies which are of multiple integral of v1, the total energy of an Ankitium increases and the Ankitium reaches to a higher energy state. As a result, the Ankitium tries to elongate and a tensile force is built up. But all the frequencies must not be a multiple integral of v1. So, energy will not be absorbed by the Ankitium when the frequency of the incident photon are not of a multiple integral of v1. As a result, then the energy state of the Ankitium gets lowered and it comes across with a compressive force. Thus an Ankitium gets elongated and compressed in success. In case of protons, the vibration of the string must be at opposite direction that of in an electron. As a result, an amount of positive charge is produced. In the neutrons, the vibration must take place in such a way that it only produces an amount of energy which totally converts into a mass equal to the mass of the neutron. As a result, no kind of charge is produced in neutrons.- 61.11.120.66 (talk) 11:23, 6 January 2011 (UTC)

Is there a question in there? I didn't see it. SpinningSpark 11:42, 6 January 2011 (UTC)

I think the questions are 1) Where does an electron get it's charge from, and 2) Where does a string get it's energy from Zzubnik (talk) 11:56, 6 January 2011 (UTC)

I can't answer the questions because not even Stephen Hawking knows the answers. The charge of the proton is known to come from the arrangement of quarks, but that only moves the question one stage back and doesn't explain the charge of leptons. I don't think the "ankitium" will ever be discovered because strings are not believed to consist of matter, or to be in any way "divisible" (or even "real"), they are just mathematical constructs. The vibration modes of the strings are the mass, energy and charge. Alternative theories are M-theory and loop quantum gravity. Dbfirs 12:43, 6 January 2011 (UTC)

I agree, Dbfirs. This is somewhat like asking for a grand unification theory, or the answer to the question of life, the universe, and everything. Although, the answer to that last one is known to be 42. — Preceding unsigned comment added by Zzubnik (talk • contribs) 18:38, 6 January 2011 (UTC)

I asked a similar question just last month: Wikipedia:Reference desk/Archives/Science/2010 December 24#Why do superstrings "vibrate"? -- œ^™ 19:13, 6 January 2011 (UTC)

What's the single best case for evolution?

The conversation about evolution above makes me think that we should pick out a single best case for evolution, a situation so well studied with so many different techniques that it provides a more than compelling argument. Of course, no evidence from the natural sciences can disprove that the world could have been affected by supernatural means, but the point to prove is that if someone made the world, it was deliberately made to look like it has a single consistent history going back millions of years which includes evolutionary change.

The case I want involves:

• Two points on opposite sides of the Atlantic Ocean, in places which visibly look like the continents once fit together there.
• The currently measured rate at which these two points are drifting apart closely matches the established breakup of Pangaea.
• Magnetic field reversals in the crust have been observed close to the line separating these two points, confirming a large number of reversals which match the time frame (though this is a weak argument, as a skeptic will argue the presumed reversal rate is only inferred from the data)
• A land species has been found fossilized near each of the two points.
• The radioactive dating of these fossils matches one another and the time at which Pangaea was breaking up.
• According to radioactive dating, fossils of this land species are found only during a narrow interval of time. However, transitional fossils closely link it to later species which continued to thrive on either side of the ocean, which are different on either side of the ocean. There should be as little confusion about this ancestry as possible.
• DNA analysis of modern living descendants of this species from either side of the ocean reveals differences between them. Modern phylogenetic analysis concludes that they diverged at about the period of time shown by the fossils, assuming mutation rates that are typical judging by those observed today.

I know that there are many situations where a few of these points are met. But I'd like to see an argument with sledgehammer strokes in which we show that geology, paleontology, radioactive dating, and conventional and molecular taxonomy all come together and show the same time frame over and over. That way the skeptic has to try to prove that most if not all of these disciplines are simultaneously wrong or conspiring to conceal the truth, an argument which becomes exponentially harder with each type of data that needs to be ignored. I know that finding such a case is very difficult, even for the expert - I'm just curious if people have in the course of disputations on the subject managed to hit across a good case that is suitably convenient and well-studied. Wnt (talk) 20:00, 6 January 2011 (UTC)

Peppered moth evolution is a common example, perhaps not as spectacular as you hoped for but it did take place in the blink of an eye rather than aeons. 92.24.188.182 (talk) 20:27, 6 January 2011 (UTC)

(ec): How about this paper on E. coli long-term evolution experiment? --Dr Dima (talk) 20:29, 6 January 2011 (UTC)

Guys! Neither of those examples have anything to do with the above post other than the heading. Did you read the post? Please don't bother posting an answer if you haven't read the question! --Mr.98 (talk) 20:56, 6 January 2011 (UTC)

The OP lists so many criteria that its unlikely that anything can fulfill all of them. So in the abscence of that, other examples of evolution were given. 92.24.188.63 (talk) 00:22, 7 January 2011 (UTC)

No, I did read the question. The OP asks for "single best case for evolution", and both my reply and that of 188.182 give examples of some of the best cases for the evolution. I simply do not think that "combining many different techniques that it provides a more than compelling argument" is a good educational strategy in this case. The reason is, whatever scientific evidence of evolutionary history -- no matter how compelling -- you present to a person who thinks the world was created as-is 5800 years ago, fossils and all, it will not alleviate that person's doubts. But if you show this person a colony of bacteria that has actually evolved to metabolize citrate literally in front of researchers' eyes, you may actually have a compelling argument that evolution does happen. --Dr Dima (talk) 21:27, 6 January 2011 (UTC)

The question qualifies very heavily what it means by the "single best case", and your answer ignored that completely. That's what I meant by it appearing not to have read the question. --Mr.98 (talk) 21:29, 6 January 2011 (UTC)

Regardless of the example, this attempt will fail miserably. People who do not want to believe in evolution will not believe in evolution. Another way to put it is: You cannot reason a person out of a belief that they formed without reason. No matter what you attempt to prove, the response is simply, "God made it look like that" - the religious equivalent of "a wizard did it." -- kainaw™ 20:31, 6 January 2011 (UTC)

Your arguments seem more in favor of Plate Tectonics Theory than the Theory of Evolution. As for the strongest support for evolution, I'd have to go with dinosaur bones. There are many skeletons of nearly intact dinosaurs, which are completely inconsistent with the Biblical record. The number and variety of those skeletons shows that there were many eras of dinosaurs. So, which day of Biblical creation were these created ? It just doesn't fit. And, unlike radiocarbon dating, the Big Bang Theory, etc., it really doesn't require any great scientific understanding to look at a T-Rex skeleton and see that it is very different than anything in human experience (or Biblical accounts). StuRat (talk) 21:10, 6 January 2011 (UTC)

Creationists have long made their peace with dinosaurs. (They would have been created on the same day as the other animals, incidentally.) See e.g. this particular discussion. What the OP is asking for is something that is totally scientifically air-tight, not something that appeals to the common man. --Mr.98 (talk) 21:29, 6 January 2011 (UTC)

But that doesn't explain why the Bible didn't mention them (how about a full inventory, just like the "begets" ?). Also, are they supposed to have all died on that same day, too ? If so, why ? And are we taking the Bible literally, so that they only existed for 24 hours ? StuRat (talk) 22:42, 6 January 2011 (UTC)

It doesn't mention a lot of animals, either, and in fact, as the page points out, big, dinosaur-like creatures (and dragons) are mentioned far more than a lot of other common world critters. It's not meant to be an atlas of all animals. I'm not a Creationist at all, but purposefully misreading the Bible (like the idea that they existed for 24 hours, which nobody contends) just sets up a rather foolish straw man, which is convincing to none. If you want to be truly convincing, you argue against the best oppositional case, and show why it is wrong. Not the worst. --Mr.98 (talk) 00:35, 7 January 2011 (UTC)

OK, then, just what is the strongest Biblical case ? The other one I've heard is that dinos were around until The Flood and didn't make it onto The Ark. That seems even more absurd though, if they were supposedly running around with people, as in The Flintstones. Is there also an idea that they were around with Adam and Eve, but died out soon after ? StuRat (talk) 04:09, 7 January 2011 (UTC)

It's creationism that's based on a single, unchanging, unquestioned source. Evolution, like all science, is based on an ever accumulating set of knowledge, combined with an ever questioning community of scientists. The knowledge is massive. Heck, Darwin's voyage in the Beagle took five years! Those who want to believe in creationism are missing most of that knowledge, or choose to ignore it. They oppose letting children have the former and will continue to ignore. HiLo48 (talk) 21:24, 6 January 2011 (UTC)

As the form of the question makes clear, the dispute about evolution is really a surrogate for a dispute about a far more important question, the age of the Earth (and the Universe). The two contending hypotheses for the age of the Earth are (1) about 4.5 billion years (modern science); (2) about 6000 years (biblical literalism). As an argument in favor of the scientific age, the one given above is pretty strong, although not necessarily the strongest possible. It is basically impossible to support an age of 6000 years without assuming that the visible universe is at most 6000 light years in size, which pretty much trashes modern physics. Looie496 (talk) 21:26, 6 January 2011 (UTC)

There is a fundemental flaw in the question itself, in that it assumes that theories like evolution are built on isolated pieces of evidence, and that some of those pieces of evidence are better than others. This isn't how science works. The theory of evolution is a working theory, and has been for the better part of a century. No one works at building evidence for it, they just use it as background understanding for their research, and the research works. In a sense, all of biology and its subdisciplines has evolution as one of its cornerstones, and insofar as every experiment in biology and subdisciplines works, that's the evidence. All of life is itself the evidence for evolution. The flaw in the question asked in the title of this thread is why the creationist/intelligent design crowd always ends up fighting the wrong battle. There is a belief that evolution (and indeed science) works only if every single piece of evidence that exists is correctly interpreted, and completely true. If you can find one error, or find one single thing that does not yet have adequate explanation, then the entire system is completely and utterly wrong. This sort of reasoning showed up in the defendant's testimony at Kitzmiller v. Dover Area School District, the most important trial case since the Scopes trial in this area, and forms a major part of what is known as the Wedge strategy known as Irreducible complexity. The idea being that certain key elements of living systems, as yet unexplained by science (classic examples are the eye and the flagellum) can be used as the point of the "wedge" to drive into evolution, and prove it wrong. The OP's question presumes the same sort of misguided reasoning, that there are "best examples" and "wrong examples" and that we merely need to put forth the "best examples" to prove evolution or the "wrong examples" to disprove it. --Jayron32 21:33, 6 January 2011 (UTC)

Furthermore, all observational evidence is moot, because it is fundamentally impossible to verify the existence of "reality." This isn't new; Allegory of the Cave predates Christian thought; and the philosophical concept has been re-hashed out by every major school of thought, from rationalism to post-modernism. If somebody doesn't want to accept observational evidence as proof of reality, it doesn't matter how solid your observational evidence is. At best, we can prove that "I perceive something." The next step, "I assume that my perceptions represent a real, natural, material world" is completely unfounded. Religious belief attacks scientific thought at this level by presuming that a supernatural reality exists beyond anything which we can perceive. So, purple unicorns, space teapots, and all that. Nimur (talk) 21:45, 6 January 2011 (UTC)

(Pedant) I think you mean pink unicorns and purple oysters [6]. CS Miller (talk) 00:19, 7 January 2011 (UTC)

Burn the heretic! --Stephan Schulz (talk) 09:52, 8 January 2011 (UTC)

The case for evolution is the same as the case for any other well established scientific theory: It is a simple explanation for our observations. There is no other explanation that even comes close. --Tango (talk) 00:10, 7 January 2011 (UTC)

The best argument I can find against young-Earth creationism is varves. Unlike dating based on radioactive decay, varves provide a very direct, very simple to understand measure of the geological passage of time, even to people with a very weak understanding of any branch of science. And the six million varve depth of the Green River Formation shows that the Earth is at least six million years old, which although that's only a small fraction of the total age of the Earth, is still vastly older than is thought by anyone who measures the time since creation in the thousands of years. However, I still had no luck convincing some Jehovah's Witnesses I talked to that the Earth is at least millions of years old. They didn't have any explanation for the six-million varve depth of the Green River Formation, but they really didn't care. Some people are just going to believe what feels good to believe, regardless of what the evidence says.

What I think is one of the best arguments for evolution are the Australian marsupials (Australidelphia). There are scads of different species of them, but there are biological similarities among them that aren't found elsewhere in the world. Why all those different species of biologically similar animals happen to only be found in Australia is easy to explain with evolution, but hard to explain if all of those different species independently made their way to Australia somehow from Noah's ark. But like with the varves, although the Jehovah's Witnesses I talked to had no explanation for the geographical isolation of the Australidelphia, that didn't actually affect their beliefs. They just didn't care. Red Act (talk) 01:47, 7 January 2011 (UTC)

All observational evidence, even varves, is counteracted by "God made it that way". It's a pointless arguement. Either people are prepared to accept that God created the world as it really exists, with evolution and the Big Bang, and all of it, or they believe that God created the world as they wish it to exist, on a Tuesday morning about 6000 years ago. If they believe the latter, the believe it without any need to look for evidence for how God really made the world. So any evidence you provide is pointless. --Jayron32 02:56, 7 January 2011 (UTC)

Your third sentence is a false dichotomy, in that it assumes that all possible belief possibilities include the belief in the existence of a God that created the world one way or another, which is not a valid assumption. Red Act (talk) 05:28, 7 January 2011 (UTC)

True, you could take God out of the picture and have the same arguement though; he's optional for the point of argueing the validity of evolution in this case as an aside, I do not find God personally optional; as an evangelical Christian myself, I find God pretty mandatory to any of my own belief systems. I also recognize, however, that it isn't necessary for this particular arguement, and so I won't belabor the issue. However, if your point is to help those who believe in God also accept the validity of evolution, its probably more helpful to show how evolution is not fundementally contradictory of anyone's religious belief. If you imply that God and evolution cannot coexist in the same belief system; then you fall into the same exact faulty thought processes that make it so that the strongly religious refuse to accept evolution. Argue the important point; which is the reality of evolution, not the unimportant point, which is the existance of God. unimportant, I might add, to the validity of the case for evolution, not in general. See my aside above. --Jayron32 06:21, 7 January 2011 (UTC)

If God's so smart, why does He simply not tell us what we should believe about evolution? Why leave us guessing? He dosnt reply to prayers etc, has no address, no telephone number, no webpage, no nothing. Do you think He has passed on? On the other hand, when I pray to Santa Claus at the right time of year, He (Santa I mean) brings me presents. Next time I see Santa, I will ask him what the trutrh regarding evolution is. 92.24.183.6 (talk) 16:58, 7 January 2011 (UTC)

Well, he doesn't reply to YOUR prayers. Or maybe he does, and sometimes his reply is "No". --Jayron32 20:06, 7 January 2011 (UTC)

Is the pronoun "He" for Santa and "he" for God ? Cuddlyable3 (talk) 01:56, 8 January 2011 (UTC)

For the OP, a good start would probably be a book like The Greatest Show on Earth: The Evidence for Evolution by Richard Dawkins. If anyone is going to summarize the best arguments in support of evolution it is Dawkins. You might also want to look at our article on biogeography which briefly discusses some evidence based on paleogeography, plate tectonics, and molecular analysis of fossils. --- Medical geneticist (talk) 03:08, 7 January 2011 (UTC)

I had a feeling it would end up in Dawkins... I'll have to actually read him the next time I happen across a copy. I should clarify though that I understand that such a perfect example is not necessary to justify the idea scientifically, and it is also not sufficient to disprove the religious idea of creation. The point is to justify to creationists the idea that the universe is truly a four-dimensional work of art - a story for which a very long past has been written. The creationist does himself an injustice when he fails to consider that if God wanted our planet to have a consistent, logical, richly detailed history stretching back hundreds of millions of years, it means that there is something to be learned from it. Wnt (talk) 10:13, 7 January 2011 (UTC)

You won't find such an arguement in Dawkins. His stance on Evolution is a pretty good read, however he's rather intolerant towards any religious worldview. His writing on religious issues is quite bitter and angry, and not at all "rational" if you ask me. The God Delusion, for me at least, comes of as no less dogmatic than any religious apologetic text. --Jayron32 14:09, 7 January 2011 (UTC)

As an aside, if you want to read someone who DOES do a good job of balancing the religious worldview with the scientific one, might I recommend Stephen Jay Gould, especially Rocks of Ages. --Jayron32 14:14, 7 January 2011 (UTC)

The Speciation article has some concrete examples of natural and artificial speciation which make the case pretty well. 71.198.176.22 (talk) 13:12, 7 January 2011 (UTC)

Wnt - that's a significant comment about time being a critical factor. Evolution has created the complexity we now see through having 3 billion years in which to do it. And there's one of the big stumbling blocks. A creationist argument is that evolution couldn't have created what we now see in the pathetic 6,000 years which they think their god tells them it's had. And they're right. It couldn't have happened in 6,000 years. Dunno what "single best case" we could use to get over that hurdle. HiLo48 (talk) 04:01, 8 January 2011 (UTC)

Even a much less than omnipotent god could get past the physics difficulties if it were required - you could say, he just blew on the continents early on to separate them much more quickly than in the current day. But the difference is that such a minor deity would leave no field reversals in the part of the ocean that was separated in some rapid semi-cataclysmic fashion. Now a suitably powerful deity can get all the tricky little details right, but doing that displays a deliberate intent to make the result match what would occur from the physical processes observed by natural scientists. The point is not to show that the natural science model is absolutely true, notwithstanding supernatural intervention. It is to show that it is meaningful - that even God thought it was important to keep the theory consistent! I should point out that even a run-of-the-mill atheist can read Hitchhiker's Guide to the Galaxy and at least suspend disbelief on a model in which an alien species perfectly recreates the Earth after it has been destroyed - for people on such an Earth a nonreligious creationism is actually the truth, and yet one supposes that it is still useful for them to study evolution. Of course, with anything less than an omnipotent, omniscient deity, the errors will eventually show. Actually, it has sometimes been my speculation that this really isn't the original Earth, but a historical recreation of the first period of history that was recorded well enough to make a decently accurate simulation, and occasionally I am prone to wonder whether certain details are errors in it. (For example, I've wondered whether a primate species capable of such amazing feats of acrobatics truly could not manage to put one of a few keys into a lock without fumbling around for half a minute; perhaps the original humans did this only as a matter of politeness? But I digress!) Wnt (talk) 04:57, 8 January 2011 (UTC)

I am prepared to believe in a God that has created the world, by Intentional Design, so that it very cleverly in all its details is entirely consistent with modern Evolutionary biology (and Evolutionary psychology, too, and so on).

But the overwhelming weight of all the available evidence, and the learned consideration of it, supports -- is consistent with -- the possibility that it has all occurred the way it has over the course of aeons without any need for any "Divine Guidance" of it according to some divinely "Intelligent Design" of it.

But, still, God, for reasons of God's own, could have made it just look that way – exactly as if there is no need for a God even though there really is a God! Right? But... what difference would the existence of such a God make? And why would God want to do that? If it is the God of the JudeoChristian bible that you believe to be behind such diabolical trickery, could it be because that God is a very "jealous" God, and just wants to test to see if we will still "believe" even though there is absolutely no good reason to do so on the basis of the evidence that God has seen fit to make available to us...? Do you think a God capable of "creating" this whole world in all its unimaginable vastness and complexity would really be inclined to such childish games?

I am prepared to believe in any God in Whom there is any good reason or cause or use to believe in. That God is welcome to make Its existence known to me at any time. If you have some reason to believe in the God you believe in -- well, God bless you and more power to you. But don't assume that reason or that God must necessarily exist for anyone else - and I recommend just leaving it at that, especially here at the Science desk. WikiDao ☯ 05:26, 8 January 2011 (UTC)

The "no need for God" part is tricky. Very tricky. The universe could have operated "spontaneously" with a set of physical laws that didn't allow for life. The strong anthropic principle suggests that we just happen to see the universe which allows us to exist. But what does it mean for us to exist? To perceive things? Why doesn't a fire, say, count as having a perspective that it devours fuel and responds? Why aren't its ever-changing currents as capable of feeling and experiencing as our brains' electric currents? (Then again, I suppose I don't know for sure that they're not...) The point is, this idea that things can be experienced comes from somewhere. The ideas that there's such a thing as space, such a thing as time, such a thing as perception, such a thing as thought, where do these come from? The materialistic idea that matter just exists and knows what to do by some laws of physics, all without any designing intellect ... it seems like a shell game. God has just been swept into tidy little corners, The Mind's I kind of stuff, where we find the philosophy so hard to think about that we ignore it. But it's not a meaningful settlement.

The simplest way to describe the difference between the purpose of religion and that of science is to picture the universe being intelligently designed in stages, like a draft that is gradually written and revised by an author. If you picture space as a movie, and take one "frame" of three-dimensional space frozen in time, then the relationship of that frame to the ones before and after it as defined by physical laws and perceived by mundane consciousness is one temporal dimension. God's involvement in that dimension is deliberately very small, and may not be distinguishable from the indeterminate laws of physics. But another dimension of time links a frame to a different frame in which a process of divine authorship and revision is going on, according to its own supernatural laws. Thus there is a linear succession of parallel universes in a fifth dimension, which is defined as "God's sense of time". This is particularly consistent with Christian theology in particular, which postulates that the universe was created on a succession of days (in God's time only, as there are no humans described to see the first few days) leading to a small, simple, easy universe, which is then replaced by a series of more complex universes, and where even the current universe is not the final form, but is to be replaced by a perfected version. Wnt (talk) 06:25, 8 January 2011 (UTC)

For most religions the thing you have to get across is that their religion does not require them to believe evolution is wrong. Some of their teachers think it which is a different thing altogether. They don't have to believe in a God who is scheming to test them with tricks like having layers and layers in the mountain dating back millions of years when it is only their teacher who believes in the six thousand years dateline. Do they really want a God that plays silly tricks? Dmcq (talk) 14:34, 8 January 2011 (UTC)

I agree, Dmcq: it is important not to try to just rip a person's religion away before they have a better sense of how they could get along just as well or better without their beliefs. Permit God, but explain the Science... and then let them come to question their notion of God on their own.

In your case, Wnt, I get the impression you've already got some Science and would like to keep your God, too. Fair enough. I suppose the main criticism I would have of your comments above would be the extent to which you are implicitly anthropomorphizing God. Perhaps this stems from that "created in the image of" business in the Bible, I don't know. But if you are going to believe in a God that thinks (which implies not just "knowing" some things at some times) like us and feels (including "jealousy") like us and acts (including "designing") like us – well, first of all, that's a really imperfect God! If you waive that apparent imperfection away as part of a mystery that is beyond us – well, what good is the concept of a mysteriously imperfect "perfect being"? It sounds more like just sloppy thinking to me.

Any Absolute Being should be beyond "personality" in any comprehensible sense. In fact, saying anything at all about such a Being artificially limits that Being into belonging to our own personal, cultural, etc. conceptual categories and linguistic usages. Which is why, presumably, Buddha, for one, refused to even say a word on the subject: you say a word, you get it wrong, and trying to say anything just causes endless confusion, so why bother? Similarly with Science: there is no need to understand how the universe works by appealing to some person-like Creator and Designer, and doing so just is not very useful, so why bother? There is no need; and eg. Evolution can be understood better without having to do so!

That still leaves room for various personal beliefs in God, in which, depending on the person, there may be some utility. But the Universe does not require it. It works just fine whether you believe in it or not. (And no God I would care to believe in would be so weak and emotionally clingy as to "need" me to believe in It!) WikiDao ☯ 18:10, 8 January 2011 (UTC)

Actually, you're wrong about the order of things. Twenty years ago or so, I was very close in thinking to Richard Dawkins, frequently denouncing religion as a virus and so on (when I began the word "meme" hadn't been invented yet). I was greatly appalled by the use of religion to promote injustice, arbitrary restrictions on behavior, and mindless cruelty. But a large number of things came to change my mind. One was the sterility of libertarianism - despite the goal of people to promote freedom in a general sense, the rhetoric sours into lunatics who want to copyright every word of every sentence and defend their right to "respond to violence" if someone infringes that. It is a philosophy that starts on the right track, but doesn't have any sense of direction, and hasn't led people anywhere. Meanwhile, one appreciates the tremendous strength of movements like the SCLC and Martin Luther King, Jr. which were not afraid to look for a broader spiritual basis. I should also mention Peter McWilliams' Ain't Nobody's Business If You Do, a surprisingly strong defense of libertarian Christianity, and a protester at an abortion clinic who withstood my tirade and convinced me of his inner sincerity, as well as a highly ill-considered foray into the genuinely paranormal. After some evaluation I concluded from the history that the belief in individualism, free speech, and liberty in general was derived in large measure from the message of universal and absolute love in Christianity, with some important additions from Laozi via Gandhi and Martin Luther King, Jr. Secular enlightenment, by itself, is like a vehicle that one can drive some distance - but the religious background ultimately provides the sense of purpose that is the fuel. I don't mean to say anything negative about atheists in this context, because as we've all seen, one can (all too easily) have a conception of God that has no inner reality, and likewise one can have a view of atheism that leaves room for a sense of deity under some other name.

Now as for the meaning of a personal God, this is a very sectarian issue - even many Christian groups did not consider the Old Testament as part of their doctrine prior to Constantine I, who began the persecution of heretics as once all Christians had been persecuted; it was part of an all too commonplace effort of a government to take a religion and use it for its own purposes. But to make an imprecise analogy, the Earth is vast, and yet personal - we go here and there, and touch the stones and the soil, and see many different facets of its beauty and also of its pain; and yet we shall return to it, our atoms commingled with all the others. [Some part of this conversation might best be transferred to the Humanities section...] Wnt (talk) 19:12, 9 January 2011 (UTC)

Well as Laplace said I have no need for that hypothesis. If other people want to believe that sort of thing it's fine by me. I do think it is a pity though for people with their finite span on earth to obscure their minds with weird stories. Dmcq (talk) 21:39, 9 January 2011 (UTC)

All very interesting, but yes I agree we are now not only way off-topic but way off-desk, too. ;) Regards, WikiDao ☯ 01:23, 10 January 2011 (UTC)

As a parting shot I should point out that the "finite span on earth" is itself a religious view: in modern materialism it is assumed that everything that happens to a person is perceived (even if it is forgotten in an alcohol blackout or subsequent Alzheimer, stroke, etc.; but that nothing that happens to another individual is sensed by a person. The "person" is defined as a physical brain, rather than as, say, a general process or algorithm, such as an Atman like universal force of consciousness. I would say thus that materialism also is a story that obscures the mind, because while the "person" or soul may be a piece of software that should be developed and made worthy of being preserved in a future release of the universe's operating system, they nonetheless all run on the same core processor. Wnt (talk) 15:47, 10 January 2011 (UTC)

Wnt, there are plenty of places for the publication of sophomoric musings and irrelevant memoir. This isn't one of them. Self-edit, please. 63.17.76.203 (talk) 03:21, 11 January 2011 (UTC)

Lost in taxonomy

Resolved

A Pliosaur discovered in Stretham in 1952 and discussed briefly in that article is causing me some nomenclature concern. In his 1959 paper, Tarlo argues that "... the characters of the anterior cervical vertebrae show that the Stretham specimen belongs to the species P. macromerus Phillips ..." then goes on to suggest "... a new generic name [is] necessary for P. macromerus. The name Stretosaurus gen. nov. is chosen as it seems fitting that the village of Stretham where this giant skeleton was discovered should be commemorated".

What does Tarlo mean? Is he suggesting Stretosaurus gen. nov. is a synonym for P. macromerus or even P.? Confirm P. is the genus and in this case is Pliosaurus. How should I refer to this extinct animal? Is it a Stretosaurus, a Stretosaurus gen. nov., a Pliosaur, a P. macromerus, a Pliosaurus, all of the above or a what?

yours sincerely, very confused --Senra (Talk) 21:19, 6 January 2011 (UTC)

You will find further reference to this question, which may or may not clarify, in the article Liopleurodon. 87.81.230.195 (talk) 15:52, 7 January 2011 (UTC)

Thank you 87.81,230,195. Just to be very clear here, I am refering to the specimen with the Sedgwick Museum catalogue number: J. 35990 a–z, aa–zz, A–Q. I have looked at Liopleurodon which seems to suggest

Stretosaurus macromerus Tarlo 1959 -->

Liopleurodon macromerus relegating Stretosaurus to a junior synonym of Liopleurodon Halstead 1989 -->

Pliosaurus macromerus Noè 2004

implying (to me) I should refer to this animal as a Pliosaur, P. macromerus? Am I correct? --Senra (Talk) 00:08, 8 January 2011 (UTC)

The Pliosaurus article mentions the species with no content on a dubious classification, so yes, I think you're right. Crimsonraptor | (Contact me) Dumpster dive if you must 00:21, 8 January 2011 (UTC)

Having now tried to read the minefield which is represented by the Wikipedia articles on Taxonomy, Alpha taxonomy, Biological classification, Author citation, Synonym and International Code of Zoological Nomenclature, I feel the need to modify this particular Pliosaur species references to P. macromerus Phillips, 1871 --Senra (Talk) 14:13, 9 January 2011 (UTC)

Followup on element symbols

In chemical symbols like ¹⁴
₆C
what is the purpose of the left-hand subscript (6 in this case)? Chemical symbol says it's the atomic number, but that's already known from the element name. Why the redundancy? --Sean 22:17, 6 January 2011 (UTC)

Chemical formula#Isotopes notes, "This is convenient when writing equations for nuclear reactions, in order to show the balance of charge more clearly." DMacks (talk) 22:30, 6 January 2011 (UTC)

(ec) Nobody needs that for Carbon, because "everybody" remembers the atomic numbers of the first twenty or thirty elements. But Yttrium and Ytterbium, now that's a whole other story! Heck if anyone can remember the atomic numbers of all hundred or so elements. Particularly in nuclear chemistry when we have a lot of nuclei on the paper, and a lot of changes and intermediate products, it's convenient, albeit redundant, to annotate the atomic number. Nimur (talk) 22:31, 6 January 2011 (UTC)

(ec, continuing my thoughts) In general, if the whole focus of some discussion is centered on the nuclear charge (for whatever reason), may as well just state it instead of having to look it up, and especially for cases where the atomic symbol is not universal (systematic vs eventually blessing by IUPAC, or international language differences). DMacks (talk) 22:37, 6 January 2011 (UTC)

As an addendum, nuclear physicists also draw the periodic table a little differently than regular chemists: Table of nuclides (complete); it visualizes the information differently and makes it easy to draw decays and reactions on the chart. Nimur (talk) 22:38, 6 January 2011 (UTC)

It's not strictly necessary, and you'll find lots of instances where it is dropped. But it's convenient. --Mr.98 (talk) 23:14, 6 January 2011 (UTC)

Why does a grape soda stain on a white paper towel look like a bird map?

A small paperback book I've had since I was a child has pictures of familiar American birds and shows a map of where they live. The summer range is pink, and the winter range is blue. Some birds can live in certain areas year-round, so the area where the ranges overlap is purple.

One would think a grape soda stain would be purple.Vchimpanzee · talk · contributions · 22:41, 6 January 2011 (UTC)

The pink/blue map overlay sounds characteristic of the Peterson Field Guides A Field Guide to the Birds; I have found those to be better than the official National Audubon Society bird guides. Do you have a question? Nimur (talk) 22:59, 6 January 2011 (UTC)

The question is hidden in the section title (annoying but common) and would appear to ask about the separation via paper chromatography of the various pigments in grape juice. -- 119.31.126.67 (talk) 00:33, 7 January 2011 (UTC)

It is really a shame that that article has no illustration in it. I seem to recall endlessly doing this experiment as a child, where you separate out black ink into its component colors. It's a very vivid illustration of a basic concept, and easy to do if you have the right materials (e.g. a bottle of blank ink). Anyone game? --Mr.98 (talk) 21:07, 7 January 2011 (UTC)

India ink ? Cuddlyable3 (talk) 01:51, 8 January 2011 (UTC)

No, as that's made of soot, it won't separate. Thin layer chromatography has a pic which shows it, but I've done it before with a circular filter paper + a black felt tip. SmartSE (talk) 14:53, 8 January 2011 (UTC)

ER

can anyone tell me the names of tv show's where they take you into the emergency room and show whats going on ? example

http://www.youtube.com/watch?v=j0p74MgfV-8 — Preceding unsigned comment added by Tommy35750 (talk • contribs) 22:54, 6 January 2011 (UTC)

Sorry to be blunt, but what has this got to do with science? You'd be better off asking the uploader of the video on youtube. SmartSE (talk) 23:11, 6 January 2011 (UTC)

Why the need to bite the questioner? The link to science seems pretty obvious: a desire to see examples of the science (admittedly sometimes considered an art) of emergency medicine in practice. Edison (talk) 00:41, 7 January 2011 (UTC)

We have many entries in Category:Medical television series. ER sounds a lot like what you describe? DMacks (talk) 00:24, 7 January 2011 (UTC)

I think the OP is looking for documentary material, not drama. SpinningSpark 01:23, 7 January 2011 (UTC)

I think it's Trauma: Life in the E.R. APL (talk) 00:45, 7 January 2011 (UTC)

The OP does not make it clear whether he wishes to know about actual medical emergency departments or fantasy fiction. Richard Avery (talk) 07:43, 7 January 2011 (UTC)

I don't think they are asking about this show, but any show that covers the subject. 72.2.54.34 (talk) 01:01, 8 January 2011 (UTC)

It is a fact that the OP chose not to post the question at the Entertainment desk. Cuddlyable3 (talk) 01:47, 8 January 2011 (UTC)

January 7

Yellow zinc passivated screws and chrome-6 carcinogen

I've bought some "yellow zinc passivated" woodwork screws, and after looking up on the internet what "passivated" means, I've found information like this page http://www.ewes.se/doc.asp?M=100000096&D=600000326&L=EN which says that some kinds of passivation use a "grade 1" carcinogen, described as chrome six, and are in the process of being banned by the EU.

The screws I've got look reddish with a little pale green rather that the "yellow" of the label. Have I bought the bad kind that are beginning to be banned? Thanks 92.24.188.63 (talk) 00:15, 7 January 2011 (UTC)

See zinc chromate. --98.221.179.18 (talk) 01:19, 7 January 2011 (UTC)

I understand that what is to be regulated are the exposure of industrial workers to the carcinogenous chemicals, and use of the plated surfaces in medical or food preparation applications. The woodwork screws may one day be marked Unsuitable for these but I doubt that sale of them will be banned.Cuddlyable3 (talk) 02:11, 7 January 2011 (UTC)

The answer appears to be "probably". Hexavalent chromium and passivation are relevant. 92.24.178.121 (talk) 11:11, 7 January 2011 (UTC)

I agree; avoid exposure to hexavalent chromium. If you're just using a handful of screws, wear gloves and/or wash your hands. If you're a carpenter, buy galvanized screws or screws passivated with a different oxide instead. 71.198.176.22 (talk) 14:00, 7 January 2011 (UTC)

It is better to get other types of screws like galvanized ones. --98.221.179.18 (talk) 21:48, 7 January 2011 (UTC)

The passivateisation (sp?) is applied on top of the zinc galvanisation, and is said to reduce the corrosion by several times beyond that of plain zinc galvanisation. There are various treatments that can be used to do the passivateisation, and I'm not clear which are believed to be harmless. Dipping the screws in paint might be an alternative to passivatisation, although I don't know by how much this would reduce corrosion. 92.15.24.121 (talk) 11:31, 8 January 2011 (UTC)

Of course it's a cost-benefit analysis with corroded screws on one hand and decreased lifespan and medical bills from cancer on the other. It just seems inconceivable to me that there isn't a nontoxic alternative of approximately equivalent cost and effectiveness in this case. 71.198.176.22 (talk) 16:39, 8 January 2011 (UTC)

New Jersey Department of Fish and Wildlife field guides

I would like to know if these are copyrighted. --98.221.179.18 (talk) 01:19, 7 January 2011 (UTC)

Probably. In the U.S., the only things which are safe to assume are in the public domain are those a) expressly released into the public domain by the rightful copyright holder b) published before 1923 or c) published before 1978 whose copyright was not registered or renewed properly before 1978. Anything created and published since 1978 is presumed to be under copyright to someone unless expressly released into the public domain. --Jayron32 02:45, 7 January 2011 (UTC)

Things created by an employ of the federal government, as part of their capacity as a federal government employee, are also considered non-copyrightable: Copyright status of work by the U.S. government. However, this does not apply to state governments or employs. The State of New Jersey specifically claims copyright to the NJDEP Division of Fish & Wildlife webpage (at the bottom), so I think it's likely that they'd claim copyright to the guides as well. I don't see a specific copyright claim on the guides, but as Jayron pointed out, there doesn't need to be a claim to copyright to be copyrighted. It also remains unclear whether the state of New Jersey holds the copyright to the work, or the authors ("Schwartz, V. & D. Golden", as attributed). I am not a lawyer, but in general, I believe it's only the owners of the copyrighted material that are allowed to sue (or issue Takedown notices)

Of course, depending on what you're using the material for, copyright may or may not matter. Something like Wikimedia Commons will only accept work that is truly under a free licence, but in many cases, if you're confident that the copyright holder won't sue, you can do whatever you like with the material, irrespective of the law. I'm not sure if the state of New Jersey (if they are indeed the copyright holders) is likely to sue anyone over some obscure field guide, even if they don't do find out. If you intend to use the material in any serious way, it would be a good idea to seek the advice of a lawyer. You could also send a polite e-mail to the New Jersey Department of Fish and Wildlife inquiring about the work. Even if they aren't willing to release the material under a free licence, they may be willing to grant you permission to use it in specific ways. Buddy431 (talk) 03:38, 7 January 2011 (UTC)

Edit: NJ Division of Fish and Wildlife Contact Info. Buddy431 (talk) 03:46, 7 January 2011 (UTC)

Edit: I did find one example of a New Jersey government agency suing Youtube for a copyright infringement, [7], so I guess they're willing to protect their copyright if they want to. I'll let you interpret the article as you will, but I think it's likely that the copyright concerns were not the NJTA's chief concern in trying to get the material removed from Youtube. Buddy431 (talk) 03:44, 7 January 2011 (UTC)

Speed of gravity

If nothing escapes from a black hole,how does gravity which also travels at the speed of light?02:09, 7 January 2011 (UTC)118.208.93.193 (talk)

John Cowell

Although perturbations to the curvature of spacetime, i.e., gravitational waves, are thought to travel at the speed of light, the curvature of spacetime in the vicinity of a black hole is in a steady state. As physicists say, "black holes have no hair". There's no gravitational information to escape. Red Act (talk) 02:18, 7 January 2011 (UTC)

And the gravity field starts before the black hole is formed, and perhaps the black hold never forms in the reference frame of those outside it. Graeme Bartlett (talk) 07:58, 7 January 2011 (UTC)

Some things can escape a black hole: see Hawking radiation, which is an effect of quantum-theoretical behaviour. However physicists don't fully understand quantum gravity, so the precise nature of gravity isn't fully explained under existing theories. --Colapeninsula (talk) 13:58, 10 January 2011 (UTC)

Alan Guth's inflation period.

If matter,time and space were created in the big bang and Alan Guth claimed everthing accelerated beyond the speed of light then; What force accelerated it? What did it expand into? If it exceeded the speed of light then it would be travelling into a past that never existed, What FTL force decelerated it.

John Cowell118.208.93.193 (talk) 02:30, 7 January 2011 (UTC)

The expansion of the universe is not the result of a force moving matter around. It's not the objects themselves moving. It is the actual space itself being created. See Metric expansion of space. There's nothing pushing because matter itself isn't being moved. It's the space between the bits of matter that is getting bigger. And space, lacking a mass, requires no force to make it accelerate. --Jayron32 02:40, 7 January 2011 (UTC)

Nothing has really accelerated to a speed greater than the speed of light (c). The rate at which the distance between very distant objects increases can be a faster rate than c, but that's because the space itself is growing, not because any objects are moving faster than c within space. All objects are locally traveling at a speed less than c, as measured in any (local) inertial frame of reference. Red Act (talk) 04:04, 7 January 2011 (UTC)

The balloon example is often used to explain this (and to make physics students cringe at the absurd oversimplification of the example). Blow up a balloon. Place two dots on the outside of the balloon. Those are two points in space. By law, nothing can travel across the outside the balloon faster than a certain speed (c). All is well. Now, blow up the balloon some more. The dots move apart, from your perspective of looking at the whole balloon, but from the view of the points, they haven't moved at all. So, the speed limit wasn't affected by blowing up the balloon. Continuing, you can blow up the balloon faster than the speed limit, making the two points move away from each other faster than c. From your point of view of looking at the whole balloon, they are breaking the speed limit, but they aren't really. The speed limit states that nothing can travel across the surface of the balloon faster than c. The two points aren't moving at all from their perspective. All in all, it is has to do with what the speed is relative to - hence relativity. With that understanding, you can see how a person can say that the dots on the balloon are expanding faster than c, but they aren't actually moving at all. So, there is no concept of force involved. Therefore, asking what force moved them is missing the point of the expansion theory. -- kainaw™ 14:40, 7 January 2011 (UTC)

At what temperature does the volume of water decrease, regardless of whether your increase or decrease the temperature?

Assuming 1 atmosphere of pressure.--70.122.125.20 (talk) 03:23, 7 January 2011 (UTC)

See Properties_of_water#Density_of_water_and_ice. Its right in the first paragraph, and in the chart at the right. --Jayron32 03:40, 7 January 2011 (UTC)

You are really just asking the temperature at which water has the minimum density (at 1 atmosphere), right ? StuRat (talk) 04:00, 7 January 2011 (UTC)

Maybe I'm misreading - but there is no temperature where the volume decreases when the water is either warmed or cooled. At 4 celcius, the density will decrease in either direction on the temperature scale; volume will increase. Nimur (talk) 04:02, 7 January 2011 (UTC)

Ah. That is what he said. In that case liquid water has a minimum density at the boiling point. Gaseous water has no minimum density, due to the fundemental nature of gases. Solid water (ice) has numerous allotropic forms, each with their own behavior in regards to temperature, so its difficult to answer. --Jayron32 04:08, 7 January 2011 (UTC)

Liquid water at 100°C isn't a right answer, though, because if you increase the water's temperature a bit, it will turn to gas, and the water's volume will increase.

The question specifies a pressure of 1 ATM. If you freeze liquid water at 1 ATM, it will form ice I_h (normal ice). Normal ice at 0°C has a density that's at a local minimum (volume at a local maximum), because if you increase its temperature a little, it will turn into liquid water and shrink, but if you cool the ice, it will also shrink (see Ice#Characteristics). Red Act (talk) 05:02, 7 January 2011 (UTC)

ball bearing

what kind of link a ball bearing forms(a turning pair,a spherical pair etc..,what?). i know its higher pair. —Preceding unsigned comment added by 115.248.161.154 (talk) 04:27, 7 January 2011 (UTC)

It's called a rolling pair[8][9]. Red Act (talk) 06:36, 7 January 2011 (UTC)

gravitational acceleration

what is the relation between gravitational acceleration and gravitational constant? — Preceding unsigned comment added by Dev follower of maths (talk • contribs) 08:27, 7 January 2011 (UTC)

We have articles on Gravitational constant (denoted G) and Gravitational acceleration (usually denoted g), and the approximate relationship (ignoring rotational effects) is

g = GM/R² (where M is the mass of the earth, and R is its radius). The second article explains the subtleties. Dbfirs 09:54, 7 January 2011 (UTC)

electronics

describe of ac and dc? — Preceding unsigned comment added by Dev follower of maths (talk • contribs) 08:28, 7 January 2011 (UTC)

The articles on Alternating current and Direct current should answer your question (basically DC is electricity that flows one way, whereas AC changes direction), but please come back to ask again if you don't understand them. Dbfirs 09:59, 7 January 2011 (UTC)

Ceramic flat iron

Can someone explain to me how,infrared ceramic flat irons work? I bought one in Europe and it makes a humming noise but no detectable "heat" the brand is ASCET...the iron came with no instructions............. —Preceding unsigned comment added by 24.127.222.196 (talk) 10:15, 7 January 2011 (UTC)

Are you using it on the recommended supply voltage (i.e presumably the same as the country in which you bought it)? If not, it will never work.--Shantavira|^{feed me} 12:09, 7 January 2011 (UTC)

...or at least not work well. Europe has (nearly?) universal 230V/50Hz. The US has 120 V. As a consequence, unless there is a universal power supply, a simple heating element will dissipate about 1/4 of the expected power on a US mains outlet as opposed to a European one - it might become warm, but very probably not hot. And if it has more complex electronic components, it will probably not work at all. --Stephan Schulz (talk) 12:46, 7 January 2011 (UTC)

Removing a mole

This question has been removed. Per the reference desk guidelines, the reference desk is not an appropriate place to request medical, legal or other professional advice, including any kind of medical diagnosis, prognosis, or treatment recommendations. For such advice, please see a qualified professional. If you don't believe this is such a request, please explain what you meant to ask, either here or on the Reference Desk's talk page.

This question has been removed. Per the reference desk guidelines, the reference desk is not an appropriate place to request medical, legal or other professional advice, including any kind of medical diagnosis or prognosis, or treatment recommendations. For such advice, please see a qualified professional. If you don't believe this is such a request, please explain what you meant to ask, either here or on the Reference Desk's talk page. --~~~~

Please speak to your family physician or another qualified medical professional if you have any questions about how to perform a medical procedure on yourself or others. TenOfAllTrades(talk) 15:03, 7 January 2011 (UTC)

To remove a mole, put a hose down it's hole and fill with water. :-) StuRat (talk) 19:10, 7 January 2011 (UTC)

Those who do not write well do not read well. Cuddlyable3 (talk) 01:42, 8 January 2011 (UTC)

Cuddlyable3 vs. It's; 2011 court case. --Chemicalinterest (talk) 14:10, 8 January 2011 (UTC)

Ha! I see you also followed the Internet Spelling Flame Rules, in that your comment itself contains a speling mistake:) Court cases are "X v. Y" not "vs.". DMacks (talk) 18:34, 8 January 2011 (UTC)

The loneliest thing in the universe

Hello,

Imagine a lone elementary particle which is so far away from everything else that it interacts with nothing and is beyond the reach of any force. What effects would this total release from outside influence have on properties such as charge, spin, etc.? To what extent does interaction with the elementary forces shape the properties of elementary particles?

I know we couldn't observe such a particle if it existed, I just want to know what the theory tells us. Thank you. Leptictidium (mt) 12:33, 7 January 2011 (UTC)

There are no particles within the observable universe which aren't effectively gravitationally and electromagnetically bound to other particles to some extent. The ratio of leptons such as photons to baryons is just too large for a person to meaningfully comprehend. Light from other galaxies is visible to the naked eye. 71.198.176.22 (talk) 13:51, 7 January 2011 (UTC)

This is a "What sound does a falling tree make when nobody is listening?" type of question, isn't it? Any physical measurement requires interaction. As soon as we try to measure the charge, spin, etc. we have to interact with the particle, and therefore we cannot answer your question by measurement. I don't think any theory would predict anything other than that the particle has the charge, spin, etc. appropriate for its type. Anyhow, whatever a theory says, it would be an untestable, therefore from a scientific viewpoint useless, statement. --Wrongfilter (talk) 14:02, 7 January 2011 (UTC)

If such things amuse you, you may look up Mach's take on the bucket argument. Beware, however, that Mach's position on this is nowadays considered to be wrong. Einstein, among others, tried hard to find a way in which it could be right, but with no success. –Henning Makholm (talk) 15:48, 7 January 2011 (UTC)

Holy shit! That bucket argument was what I tried to ask my physics teacher 10 years ago, and they stared at me blankly! Just so I'm clear, is Einstein's position that, if the bucket of water were the only thing in the universe, the water would still have a concave surface because it is rotating relative to the geodesic formed by the mass of the water and bucket? Or is his position that it couldn't be said to be spinning at all, and thus the water would be flat (although I suppose the water might be convex if the only gravity is the water and the bucket, but the question remains of whether it would experience centrifugal 'force')? Perhaps rephrased as 'if a gaseous planet were the only thing in the universe, can it be said to spin, and would it therefore bulge?' And is the situation of a real gas giant bulging said to be because it is spinning relative to the gravity fields of everything else in the observable Universe? Would it bulge less if the Universe were smaller in terms of mass? <sorry if this is threadjacking: I got overexcited. Should I start a subsection? 82.24.248.137 (talk) 22:56, 7 January 2011 (UTC)

Einstein and modern science in general (and the General Theory of Relativity in particular) say, unambiguously, that a rotating gas giant in an otherwise empty universe would bulge. Space itself knows what "non-rotating" means; it is an absolute -- in stark contrast to "non-moving", which has no inherent meaning except relative to a particular frame of reference.

What Einstein felt, on philosophical grounds that he attributed to Mach, is that it ought not be so -- that the universe would be a beautifuller place if it were governed by a theory where "non-rotating" doesn't need to be a built-in primitive property of space. But he never succeeded in constructing such a theory, and neither has anyone else. –Henning Makholm (talk) 02:39, 8 January 2011 (UTC)

Thanks, this is very cool and exactly what I wish my teacher had said :) 86.163.214.50 (talk) 21:28, 11 January 2011 (UTC)

For an actual answer, we can look at the Schrodinger Equation. One of the first exercises in a quantum mechanics course is to take a lone particle in empty space, as you describe, and watch it evolve in time. Basically the particle, without anything to constrain it, expands out into the void. It becomes everywhere and nowhere until it has some constraint, something with which it can interact. If you know some mathematics, picture a Normal Distribution that just gets infinitely wider. The particle is there, but found anywhere with equal probability - it will "stick" to whatever it can find, but if alone it will be without definition forever.

When you expand the situation to include Quantum Field Theory, you get vacuum fluctuations which spontaneously appear and are able to localize the particle. To me, this is the most intuitive aspect from which to "trust" quantum mechanics: the void is equally nothing and anything, for if it were entirely nothing, then the universe is a contradiction. SamuelRiv (talk) 20:39, 7 January 2011 (UTC)

Primordial black hole evaporation as gamma ray bursts

The Primordial black hole article says, "The evaporation of primordial black holes has been suggested as one possible explanation for gamma ray bursts. This explanation is, however, considered unlikely.^{[by whom?]}"

That's what I want to know: By whom? And why is it considered unlikely? Gamma-ray burst#Progenitors cites Cline, D.B. (1996). "Primordial black-hole evaporation and the quark-gluon phase transition". Nuclear Physics A 610: 500.... as supporting the possibility, but doesn't say what the evidence against it might be. The "Related Articles" on that cite include [10], [11], [12], and [13], which don't seem to discount the possibility either. Why is it unlikely? 71.198.176.22 (talk) 13:42, 7 January 2011 (UTC)

A disappearing black hole should give a burst that rapidly rises in strenght and then suddenly stops, where as the burst actually appear to be steady. Also the optical counterparts look like supernovas, you would not expect to see much from a black hole evaporation from a long distance. And finally you have the energy levels involved, the black hole releases far less energy than a supernova and would not be observable half way across the universe. Graeme Bartlett (talk) 22:58, 7 January 2011 (UTC)

Relativity

If time is relative, and speed is relative, then what about size, shape, and distance? —Preceding unsigned comment added by 165.212.189.187 (talk) 14:37, 7 January 2011 (UTC)

In a nutshell: yes, because if time and speed are relative, it affects how you measure length in profound ways. See Length contraction for the full discussion. ("Shape" is only a "yes" if you mean the general dimensions of something, not "it's a square no wait it's a circle." Ditto "size.") So two observers traveling in different reference frames will disagree on the length of space and length of objects in rather striking ways. The Ladder paradox illustrates this rather vividly. --Mr.98 (talk) 14:58, 7 January 2011 (UTC)

Please explain what you typed in parentheses. shape is either yes or no. I mean square vs. circle, duh. —Preceding unsigned comment added by 165.212.189.187 (talk) 15:43, 7 January 2011 (UTC)

An intrinsically circular object will be seen measured as being elliptical in a coordinate system that moves with respect to it. Incidentally, the theory of relativity is more concerned with absolutes or invariants rather than relative (coordinate-dependent) things, and Einstein himself later regretted the name he had given to his theory (I don't have a quotation right now). I struck out "seen" because miraculously an individual observer always perceives a sphere as a sphere albeit rotated. --Wrongfilter (talk) 16:09, 7 January 2011 (UTC)

I've forgotten most of the relativity that I ever knew (and that wasn't much) but I thought that the relative view was effectively a rotation (as mentioned by Wrongfilter), so that a rod viewed from the side would appear shorter, but a sphere would maintain its "apparent shape" , and a cube would appear rotated with the trailing side being visible when it "shouldn't be". What would one "measure" to record an ellipse? Dbfirs 17:57, 7 January 2011 (UTC)

... (later) Oh, yes, I "see", one would measure the distance between two marks on the original sphere at opposite ends of the diameter along the direction of motion in its rest-frame. If the moving sphere had its "pole" pointing towards the observer, and had a circle painted round the equator, the observer would see this circle as an ellipse only if the sphere was transparent, otherwise part of it would be hidden. Is this correct? Dbfirs 17:59, 7 January 2011 (UTC)

Well, measuring means taking the coordinates of various points simultaneously (in your rest frame). Imagine placing two rulers in the path of the moving sphere, one aligned with its direction of motion, the other perpendicular. Then mark simultaneously (in your restframe) the points where opposite sides of the sphere are on those rulers. The marked length in the direction of motion will be shorter than that perpendicular to it. If you trace out a cross-section of the sphere, it will be an ellipse. "Seeing" means perception by an individual observer. Consider two photons that hit your retina at the same time, one from the near side, one from the far side of the sphere. The latter photon will have travelled a longer distance, hence it was emitted earlier than the former one. In fact, it will have been emitted when the sphere was actually farther away. Taking the light travel time into account returns the ellpsoid to a sphere. --Wrongfilter (talk) 18:29, 7 January 2011 (UTC)

What I'm worried about is what you mean by "opposite sides of the sphere". Is that "opposite ends of a diameter in its own rest-frame", or opposite ends as the observer "sees" it. I think these would be different. Dbfirs 08:18, 8 January 2011 (UTC)

Sorry, forget the worry, these are the same if the the observer is at the centre of the sphere but not moving with it. Dbfirs 22:36, 9 January 2011 (UTC)

What about SIZE??? —Preceding unsigned comment added by 165.212.189.187 (talk) 21:21, 7 January 2011 (UTC)

Since no-one else has replied, I'll venture an inexpert opinion that it depends on what you mean by "size". In its own rest-frame, an object's dimensions do not change with speed, so size is unchanged. In an inertial frame that is moving at speed with respect to the object, the dimension along the direction of the speed appears is measured as contracted, but islooks as if it is "actually just rotated". If the observer measures just that dimension then it seems to be reduced in "size", but if the observer "looks" and interprets what he "sees", then the moving object will just appear the be the same "size" of object, but rotated. One interpretation of this might be that "size" and "shape" have not changed, but that "orientation" has changed. Distance perpendicular to the direction of motion is unchanged in any interpretation. As pointed out by Wrongfilter above, there is a difference between "seeing" and measuring just one dimension. Perhaps an expert can comment on my "actually just rotated" interpretation. Dbfirs 10:14, 9 January 2011 (UTC)

Um, no, that is backwards. In the non-comoving frame, the object is actually contracted, but may look "just rotated" to an observer that is not too close to it. The rotation is a purely optical effect; length contraction is real. –Henning Makholm (talk) 17:08, 9 January 2011 (UTC)

Yes, perhaps you are correct, though it all hinges on simultaneity. I object to the phrase "is actually contracted", but I'll re-read Ladder_paradox#Bar_and_ring_paradox. If size really changes, then a sphere would fit through an oval ring at speed. Dbfirs 17:30, 9 January 2011 (UTC)

As measured in an inertial frame of reference, an object is measured to be shorter along the object's direction of travel, and unchanged in size in the other two spatial dimensions. E.g., an object that's measured to be a sphere in its own rest frame will when moving be measured to be an ellipsoid. Objects are not measured to have been rotated at all (unless you count a Lorentz boost as a kind of 4-dimensional rotation); they are purely measured as being compressed along the direction of travel.

As seen by a hypothetical insanely high-speed camera, this same compression along the direction of travel is also seen, but there in addition appears to be a kind of distortion, which is different from a rotation. For example, a sphere directly in front of the camera but moving perpendicular to the camera's axis will appear to have been compressed in the direction of travel, i.e., the object's image will have an outline that's an ellipse rather than a circle, and the sphere will also appear to be distorted such that a dot on the part of the sphere closest to the camera will appear to be further in the direction of travel than where the center of the elliptical outline is. But the image will appear somewhat different from the image of a sphere that's been rotated and then compressed. Parts of the object around the object's outline will show less apparent rotation before compression than will that dot that's closest to the camera.

As another example, a sphere directly in front of the camera that's moving directly toward the camera will be seen as having a circular outline, but any picture on the sphere will be distorted such that the picture is stretched out from the center toward the outline. But the part of the sphere that's closest to the camera will appear in the center of the image, so the distortion again is different from a rotation. Red Act (talk) 18:24, 9 January 2011 (UTC)

Thanks for the expert view. I think I was confusing measuring with seeing, and I realised soon after I suggested it that the rod through a ring explanation doesn't extend to 3-D. I've modified my answer above in view of Red Act's and Henning Makholm's expertise, so that it doesn't mislead the OP. I still think that a sphere will still "look" spherical, and this seems to be confirmed by Terrell rotation, but I agree that "seeing from a distance" is not "observing". Experiments on high-speed particles seem to confirm that the reduction in size (and consequent increase in density and charge concentration) are "real" in a fundamental way for measurements taken by the observer in a different inertial frame. Dbfirs 21:21, 9 January 2011 (UTC)

I need to look into Terrell rotation more, which I probably won't have time to do today, but at first glance it looks like I was wrong about a photo of a moving sphere having an elliptical outline. However, from the last paragraph before the References section of this paper, it looks like I was right about the distortion involved not really being equivalent to the sphere having been rotated. I have put strike-throughs in my post above, to eliminate the part about the sphere appearing compressed in a photo. Red Act (talk) 23:55, 9 January 2011 (UTC)

The effect is that of an exact rotation in the limit where the object you look at spans only a small angle of your vision, so what we see becomes an orthographic projection. If you can see the object with the unaided eye, expect some additional distortion, but if you need to use a telescope, it will look very nearly like a rotation -- at least geometrically (color and illumination are of course subject to Doppler effect that Terrell/Penrose say nothing about).

The explanation I find most intuitive takes off from the two snapshots Baez describes. They are taken at the same time and place; one of them by us and another by a hypothetical observer who has the same velocity as the object we're photographing. The mathematics of the pixel mapping (which Baez glosses over) works out to this fact: any sufficiently small area of one of the spherical snapshot is geometrically similar to the corresponding area on the other, but may be smaller or larger. This means that the image of the moving object we see will have exactly the same shape as the one the comoving photographer could take. This immediately implies that we cannot see any contraction (because surely the comoving photographer will not see one), but we may see the moving object as it looks from a somewhat different direction that we would expect -- because that is the direction in which the comoving photographer sees it.

For a simple example, suppose a fast spaceship is moving north and we photograph it exactly at the moment where we see it being due east of us. Our photograph will look exactly like the comoving photographer's image, but how is that? At the time we take the picture, the spaceship will already have moved quite a bit north of our latitude, and since the comoving photographer is here now, it means that he is really south of the spaceship. In our reference frame he trails it by up to the perpendicular distance between us and the spaceship's path, but in the photographer's own frame he can be arbitrarily far behind the spaceship, because the distance we measure is Lorentz contracted. So what his photograph (and ours!) will show is the spaceship seen obliquely from behind. The amount of apparent rotation approaches 90° when the spaceship approaches the speed of light, and will be smaller when we're observing it in directions that are not perpendicular to its velocity.

The point of the last paragraph of Baez's description seems to be about how the interaction between objects that move at different velocities (say, railway car and the track) look, and how we can deduce that something is awry by looking at how the image we see evolves in time. That is true as far as it goes, but does not contradict the illusion of rotation in instantaneous snapshots. (And as long as we observe only a single object and it is far enough away to appear like an orthogonal projection, radial movement would be invisible to us anyway, so it will be visually consistent to assume it is moving (very quickly!) in the direction its apparent rotation indicates). –Henning Makholm (talk) 01:04, 10 January 2011 (UTC)

Microwave oven flavor transfer

If someone heats up a spicy dish of food in a Microwave oven, and seconds after it is removed a cup of water is placed inside, (let's assume for the purposes of making tea or other hot beverage), could the water in the cup possibly obtain any of the characteristics of the flavors of the food previously heated? Could the water take on the smell or taste of the food? 10draftsdeep (talk) 16:42, 7 January 2011 (UTC)

Absolutely. Heating increases the rate of evaporation of any substance; so the microwave, after heating food, will likely have a non-trivial amount of smellable and/or tastable compounds in the air. The water that follows your burrito into the microwave can certainly collect some of these compounds. --Jayron32 16:50, 7 January 2011 (UTC)

(Edit Conflict) This seems to me, as a frequent microwave user, entirely possible and indeed likely, though not due to any mysterious properties of microwave ovens as such.

When one heats food in a microwave oven it becomes filled with water vapour laden with the odours of the food, some of which (depending on the efficiency of its ventilation system) both remains in the oven's air and is deposited as condensation on its inside walls. If one immediately afterwards places and heats a cup of water in that oven, it is quite likely that enough of that 'flavoured' vapour, both from the air and revaporised from the walls, will mix into the water so as to leave a detectable taint. I must confess I haven't experienced this, but only because I usually boil a kettle for my (often concurrent) tea or coffee (though I sometimes reheat an undrunk, cold cup in the microwave). On the rare occasions when I heat a meal's second course (a steamed pudding, say) in the same microwave, I usually try first to disperse/remove (by mopping condensation) as much as possible of the previous course's 'residue' precisely so as to prevent such taste taints. 87.81.230.195 (talk) 17:07, 7 January 2011 (UTC)

It's critical to dispel the myth that evaporation produces 100.0% pure steam. Even in professional grade distillation apparatuses, the evaporation process can create a vapor that may contain evaporated residues, or even solid particulate matter, from any compound that was dissolved in the water. I'm surprised we don't have a vapor transport article; it's a redirect to a related article. Nimur (talk) 19:57, 7 January 2011 (UTC)

It also bears reminding people that if you can smell it, it is in the air. If it is in the air, it can come back out again. --Jayron32 20:25, 7 January 2011 (UTC)

Definition of life

I was reading the "life" page on wikipedia. and the first definition of life seemed a little confusing:"systems that tend to respond to changes in their environment, and inside themselves, in such a way as to promote their own continuation." because every closed system containing chemical substances that are in a chemical equilibrium respond to the changes the same way (acording to Le chatelier principle) I know that life is not a closed system. but is this definition correct? can we say that such behaviors in living organisms is because of the chemical equilibriums in them? — Preceding unsigned comment added by Sina-chemo (talk • contribs) 20:06, 7 January 2011 (UTC)

You aren't alone in being confused. Defining life is a very fuzzy thing. It actually isn't that easy to do. For every actual written definition of life I have ever seen, there exists some obviously non-living thing which can be shown to meet it. It becomes especially tricky to define life when it comes to looking at the border cases, such as viruses and prions. --Jayron32 20:23, 7 January 2011 (UTC)

Keep in mind that in the Life article, it says: "Since there is no unequivocal definition of life, the current understanding is descriptive, where life is a characteristic of organisms that exhibit all or most of the following phenomena:..." Each of the phenomena can describe something non-living, it's the collection of phenomena that is used to define life. -- JSBillings 20:42, 7 January 2011 (UTC)

Also, the spectrum of definition ranges from mainstream biology, where the definition is a lot easier ("koala = alive, rock = not alive"); to extremophile biology (where the definition is much more complicated and requires detailed analysis of biochemistry); to the borderlines of current scientific knowledge (SETI and artificial intelligence both make efforts to scientifically define "life", sometimes coming up with something that could include astrophysical phenomena, sophisticated machinery, computer software, and so on); and at some point, we go off the deep end into fringe science and eventually "religion." (If they exist, is a "God" alive? And ghosts? Pseudoscientists actually suffer seriously from a lack of definition - which lends to the enormous gaping holes in their thought-process). Within any particular realm, the community will develop an operational definition. Most mainstream biologists use a few chemical indicators and particularly rely on the concept of tropic response, which can be more concretely defined (see the list at the bottom of our article). Nimur (talk) 21:17, 7 January 2011 (UTC)

Stuart Kauffman has written about abiogenesis via auto catalytic sets of chemical species. In short, properties similar to homeostasis can be exhibited by non-living things, and he argues that non-life can transition to life in this manner (See his book "At home in the universe" for an accessible pop-sci account). However, contrary to your example, chemical systems that look similar to life are generally not equilibrium systems, but far from equilibrium Dissipative systems. Essentially, pumping energy into the system allows the formation of stable, persistent structure. In this light, my personal favorite edge case for life is the Great Red Spot. Lastly, "obviously living" organisms, such as amoebae, lizards or humans, considered chemically/thermodynamically are far-from-equilibrium, not close to equilibrium as you suggest. SemanticMantis (talk) 21:26, 7 January 2011 (UTC)

More directly to your question, Le_Chatelier_principle explains that a new equilibrium can be reached after conditions are altered. But there is a change from the old equilibrium to the new one. The only thing that persists is the notion of equilibrium, and notions can't be alive (when ideas some similar properties in common with life , we call them memes). Because the original equilibrium A disappears and a new one B is formed with different properties, no state or aspect of the system has responded to the changed conditions in a manner that preserves itself. Whatever the (modern) definition of you choose, including the one quoted in our article on life, a closed system at equilibrium will not satisfy it. SemanticMantis (talk) 23:01, 7 January 2011 (UTC)

Gould on transitional fossils

Hi guys. I have a question about evolution. Creationists seem to think that, due to political pressure, in the early 80s the late Stephen Jay Gould reversed himself on whether good examples of transitional fossils exist. Examples:

http://creation.com/punctuated-equilibrium-come-of-age

http://www.discovery.org/a/7271

I should be candid: I suspect that they have a point. I cannot see how Gould’s earlier statements to the effect that “transitions between major groups are characteristically abrupt” [14] can be reconciled with later claims that “transitional forms are generally lacking at the species level, but they are abundant between larger groups.”[15] If Gould reversed himself on the status of transitional forms, the perennial charge that creationists “quote mined” his views seems a little silly.

What I’m asking is if anyone knows some scientific context that I’m missing here. Does “major groups” mean the same thing in both quotes? Before c~1980, did Gould ever clearly say that transitional forms or fossils exist, or cite some specific examples? I glanced through Gould’s papers from 1972 and 1977 but I’m afraid that they’re a bit too far over my head for me to be certain of their meaning.

I’m not a creationist and I’m not asking anyone to “argue me out” of creationism.

However, for my education, I would appreciate if anyone can point out something that I’ve missed.173.13.48.54 (talk) 20:07, 7 January 2011 (UTC)

I think that the above statements are, like most arguements out of the creationist camps, based on overanalyzing a tiny amount of data while ignoring the abundance of the rest of the data. I don't see the statements as contradictory at all. He says "transitions are abrupt" in the first one, but "transitional forms" in the second one, without defining how long is "abrupt". Transitions can be abrupt, but not so abrupt as to leave zero evidence. Also, science and scientists DO change their opinions about things over time. This is how science works. Perhaps Gould's earlier theories on punctuated equilibrium became more refined over time as new evidence became availible. That isn't a contradiction; its a refinement of the existing theory. I'm not sure which interpretation of Gould's statements is correct, but there are two alternate interpretations to the creationist one. Furthermore, you could just say "Come on, its two sentances made from a man who published enough works to fill a small library. Taking two statements, out of context, and attempting to "prove" that Gould somehow based his scientific pronouncements on "political pressure" rather than sound science is complete and utter bullshit. --Jayron32 20:16, 7 January 2011 (UTC)

Furthermore, it also represents a fundemental flaw in the creationist strategy. Rather than reading Gould with an open mind, and lacking any preconceived notions, and then try to work out what he means and if it makes sense, the "contradiction" claim starts from the premise that Gould MUST be wrong, and if we dig hard enough we can find evidence to support that. And THIS evidence was the best they could come up with to verify their preconceived conclusions. That should tell you something. That doesn't mean that everything Gould ever published or ever had to say about evolution should turn out to be 100% correct. That isn't how science works either. Gould may have been wrong on some of his stuff. That doesn't mean that everything about evolution is just "made up" or "completely wrong". --Jayron32 20:20, 7 January 2011 (UTC)

I think Jayron's point about punctuated equilibrium is probably the germane one. Gould was the primary promoter of PE as an explanation for the gaps within the fossil record; my understanding of the situation is that most other evolutionary theorists didn't so much disagree with it as think he and Eldredge were putting more emphasis on it than they should (and, of course, many people simply thought it was a rewording of various other hypotheses - as our article goes into in some detail). As he became more and more the public figure in the case against creationism, I imagine Gould found himself in an uncomfortable position: any weakening of his support for PE would be used as fodder by the creationists to say that he was admitting that his understanding of evolution was wrong. It's tough enough to admit that you've mis-stated something or changed your opinion on something you used to promote, but it becomes extremely sticky when you know beforehand that your relatively minor change in evaluation will get turned into something completely other by professional liars. I've read a good bit of Gould's stuff (though it's been a while) and it's my impression (WP:OR alert) that, as evidence and support began to shift away from PE into a more gradualist view, Gould's popular writing at least began focusing on slightly different topics (the relationship of science to religion, his Full House book, etc.), perhaps as a way of avoiding (or at least downplaying) the issue. Matt Deres (talk) 20:35, 7 January 2011 (UTC)

I will note that the first quote doesn't include anything like its full context; even ignoring the rest of the document, it is illuminating to read the entire sentence from which the fragment was extracted. "All paleontologists know that the fossil record contains precious little in the way of intermediate forms; transitions between major groups are characteristically abrupt."

Note that he does not state that transitional forms are unheard of or nonexistent in the fossil record, only that they are rare. This would be exactly what is predicted under punctuated equilibrium. Pulling some plausible-sounding numbers out of thin air, let's suppose that 0.1% of fossils are the remains of transitional forms; that's just one out of every thousand fossils, certainly qualifying as "precious little". On the other hand, if paleontologists have collected and fully characterized a million different sets of fossilized remains, you'd still expect to find a full thousand transitional forms in the collection: "abundant" in terms of absolute number.

One could make a similar set of statements about diamonds. They're certainly quite rare; odds are that if you pick up a random rock, it won't turn out to be a diamond. Nevertheless, they're abundant — thousands are traded every day in New York and Amsterdam, and you can see dozens of examples in most jewellery stores. TenOfAllTrades(talk) 21:21, 7 January 2011 (UTC)

Yeah, but diamonds exist because God put them there. Checkmate, atheists!. TomorrowTime (talk) 23:35, 7 January 2011 (UTC)

It would be an interesting undergraduate research paper to try and ferret out the change in Gould's thinking. I think calling it "reversing" and impugning it as somehow meaning he is unreliable is clearly wrong. We stress different aspects of our arguments to different audiences, because we assume different things about what they know and how they will interpret our work. To other specialists, we emphasize the novelty of our own small tweaks (e.g. Gould arguing for PE as a preferred model over gradualism, all within the framework of Darwinian evolution); to a broader public, we try to make sure that our in-discipline arguments don't detract from larger understandings (e.g. Gould emphasizing that PE does not mean that there aren't transitional forms, or that Darwinism is wrong). These two statements of Gould's are not incompatible if you take the purpose of their broader context into account, but I think it's clear that in the later articles, Gould is really trying to debunk any notion that PE opposes Darwinism. I wouldn't call that a reversal, so much as, er, an evolution in his expression. I doubt his underlying opinions changed too much. But it would be interesting to actually track this down historically. --Mr.98 (talk) 01:10, 8 January 2011 (UTC)

One thing to bear in mind is that the form of a species may not be free to vary as much as the underlying genetics - two recognizable forms may exist that are functional, but the intermediates between them fail badly. This is best seen in a spatial distribution - hybrid zones - you can have a butterfly which mimics one group of species, or another very different group of species, but those intermediates get eaten, so they take up only a rather small band of territory - and outside the bands, the two forms don't get more and more extreme as you move away. This is maintained actively by selection, and presumably also by genetic mechanisms that tend to stabilize certain phenotypes (heat shock proteins are known for that). The same could happen over the course of time, with selection forcing a species first to resemble one standard appearance and then a different one. Wnt (talk) 06:46, 8 January 2011 (UTC)

The practice employed by the creationist websites is called quote mining, fyi. That article even has a section on Gould. --superioridad ^(discusión) 21:14, 9 January 2011 (UTC)

January 8

Gravity/Conciousness

It has been suggested that the incredible weakness of gravity compared with the other forces is because gravity is the only force which mainly resides in the other dimensions postulated by string theory.Is it conceivable that thought/afterlife/conciousness act similarly as gravity waves, like thought waves, have yet to be detected.

John Cowell.00:28, 8 January 2011 (UTC)= —Preceding unsigned comment added by 118.208.93.193 (talk)

Certainly it's conceivable: you've just conceived it. Whether it has any merit as a scientific theory is another matter. I am not aware of any evidence that thought, whatever it might be, has any properties in common with any of the fundamental forces of nature or the waves that mediate them. --ColinFine (talk) 00:54, 8 January 2011 (UTC)

Roger Penrose believes that there is an important relationship between consciousness and quantum gravity. The idea strikes me as kind of silly, but it has received a certain amount of attention, or perhaps notoriety is a better word. Looie496 (talk) 01:04, 8 January 2011 (UTC)

Yes, but Penrose does not claim that he has actual evidence for that hunch. (His metaphysical ideas are controversial, whereas his actual science is acknowledged by everyone to be solid -- and he seems to be perfectly aware of and candid about which is which). –Henning Makholm (talk) 03:00, 8 January 2011 (UTC)

It strikes me that the burden of proof is that on those who would claim that consciousness is anything more than something materialistic. The brain seems to be a fairly modular thing — there's a strict movement "upwards towards consciousness" (metaphorically, of course) moving from less-to-more complicated brains (lizards, dogs, dolphins, chimps, humans, etc.). This strongly seems to suggest that consciousness is "simply" a very complicated function of a very complicated set of neural wirings. Why one would want to introduce extra dimensions into the equation (other than the desire to not simply be a blot of matter, doomed for a finite amount of time) seems, from a scientific standpoint, fairly unclear. It doesn't mean it isn't possible. But does a lizard have the same physical hardware that you are postulating? Does a dog? Does a housefly? Does an amoeba? Does a virus? And if not, why would humans have it, and no others? Where does it start, and where would it stop? It just doesn't really seem, a priori, to be a very compelling theory, at least to me. It seems far more likely that what we call consciousness is just a measure of specialized computational organs/circuits/what-have-you within the forebrain brain. Circuits we do not at all fully understand, to be sure, but I think we're starting to get close to a general model of things, and it doesn't include anything like you're suggesting. --Mr.98 (talk) 03:43, 8 January 2011 (UTC)

I'm reading the question as discussing gravity just as an initial example of something the OP has heard may also exist "in other dimensions" according to "string theory".

The actual question is then: could consciousness exist in other spatial dimensions, and if so could our sense of consciousness in this 3-space be in some meaningful way "connected" to corresponding consciousnesses in other sets of spatial dimensions?

If I'm interpreting that correctly, then I'd have to say "maybe". I don't know enough about strings and Mbranes and whatever else to know whether in the various theories about them, it is possible for an elementary particle in our 3-space to be a manifestation of a multidimensional vibration that also manifests as "corresponding" elementary particles in other N-spaces. If so, then perhaps the particles making up our brains are mapped onto various other "brains" (including whatever higher-than-3-dimensional corresponding structures might be called). Maybe the complexity of how those vibrations/string/particles are organized in each of those other spaces also produces a consciousness that corresponds to our consciousness in this world.

That would be kind of spooky, wouldn't it be? :) I don't have an answer as to how likely anything like that might be, though – and, remember, "string theory" is still all just a mathematical framework with no empirical support whatsoever or any likelihood of there being any anytime soon, either, afaik. So even if this kind of thing were supported by theory, there would still be little reason to believe it is anything like that in Reality. WikiDao ☯ 04:38, 8 January 2011 (UTC)

The OP may be interested in Leibniz's Monad theory. Like Penrose, Leibniz had some interesting thoughts regarding consciousness and physics. Also like Penrose, Leibniz's scientific contributions are well respected. In the Monadology he hints that perception and consciousness may be tied to the fundamental units of matter. Or something. I don't think many people subscribe to theory of Monads these days. SemanticMantis (talk) 05:50, 8 January 2011 (UTC)

It seems to me that the fact that consciousness evolved is a pretty strong argument against the idea that it harnesses any sort of subtle as-of-yet unknown physics. Much of modern physics could have been very useful to biological entities (e.g. lasers, radio waves, ...) but organisms "naturally" using such physics completely failed to evolve anywhere in the biosphere. Why should consciousness be an exception? 83.134.178.145 (talk) 10:13, 8 January 2011 (UTC)

Still, there is something for science to explain here which, so far, it has not been able to do. There is no workable scientific description of the phenomenon of self-awareness. Everybody is aware of this because one is directly experiencing it - the division of the world between me and not-me and the sensation of being inside looking out on the rest of the universe. We believe that everyone else has this sensation only because we have it ourselves: there is no objective test to detect or measure it. If I claim my computer is self-aware there is no test to prove me wrong. If I claim that my mother is not self-aware, what test could be administered to falsify the claim? One can ask the subject if they are self-aware, but to any question I could, at least in principle, program my computer to give the same answer as given by my mother. Someone famous said this was the last great unanswered question of science. Given that we cannot even detect it, it is a little premature to ask how many dimensions it exists in. SpinningSpark 15:14, 8 January 2011 (UTC)

Presumably your mother could pass a mirror test. While by no means air-tight, many professionals would use this as evidence for self-awareness. SemanticMantis (talk) 15:46, 8 January 2011 (UTC)

She probably could, but then so could my computer with the help of a clever programmer so a positive result would not be determinant. Failure to pass the test likewise does not prove beyond doubt lack of consciousness. SpinningSpark 16:18, 8 January 2011 (UTC)

I suspect that most cognitive scientists would see this partially as a problem of definition. We treat consciousness and self-awareness as a "I know it when I see it" sort of affair. We have a very hard time articulating what we think it means in measurable terms. I suspect what we see as one phenomena is really a bundle of things running on different "circuits" in the brain. I still find, though, that there is little to make one think that a non-materialist, non-emergent solution makes any sense. The brain is one complicated piece of hardware — that's true even of far more "lesser" brains than human ones. It strikes me as essentially premature and illogical to assume that we should begin by appealing to things outside of the brain to understand it. There's plenty there that we still need to understand before we conclude that a wholly biological �answer is insufficient.

Incidentally, the computer answer doesn't disprove the original test. The only reason the computer can do it is because a self-aware being made it be able to do so. So there is self-awareness in that system — it comes from the fact that a self-aware being said, "hey, here's how we fool this test." What would be more interesting is if a computer system that was not programmed to do that specifically somehow developed that ability. That would be more akin to the biological analog. ---Mr.98 (talk) 16:52, 8 January 2011 (UTC)

Brain

Will putting things in your brain kill you? And what do FFI prions taste like? —Preceding unsigned comment added by 203.96.12.131 (talk) 04:13, 8 January 2011 (UTC)

(1) Not necessarily, but it will void your warranty. (2) Chicken. –Henning Makholm (talk) 04:38, 8 January 2011 (UTC)

(1) ... as a side note, despite many attempts, I have never been able to contact customer service; so I suspect the warranty is ineffectual anyway --Senra (Talk) 18:14, 8 January 2011 (UTC)

Depends. A brain surgeon could probably put something in there without doing too much damage. This is occasionally done. Microchips and such. See Neural implant.

If you're just talking about shoving something in there, then sure, there's a serious danger. But even so, some people survive it. See Phineas Gage!

Finally, I doubt you'd ever get enough prions together in one place to actually be able to taste them. APL (talk) 05:01, 8 January 2011 (UTC)

Putting in a couple of working neurons might help some people. Prions taste of nothing but they smell of troll. Caesar's Daddy (talk) 07:42, 8 January 2011 (UTC)

Reading Wikipedia puts thoughts in my brain. It hasn't killed me yet. Gandalf61 (talk) 07:56, 8 January 2011 (UTC)

At the risk of giving medical advice, please don't put physical objects into your brain. It's much more likely than not to harm you, and even small brain lesions can in fact lead to death depending on their location. Prions don't likely have any discernible flavor. 71.198.176.22 (talk) 16:30, 8 January 2011 (UTC)

It's very easy to put something in the brain without killing someone: see lobotomy. That being said, it's fairly difficult to put something in the brain without appreciably damaging it, and probably requires a medical degree to do so on a regular basis (it literally is brain surgery, after all). Buddy431 (talk) 22:50, 8 January 2011 (UTC)

Motor

First motor invented or generator invented becoz I heared the motor was the first am I right? — Preceding unsigned comment added by Kanniyappan (talk • contribs) 11:14, 8 January 2011 (UTC)

Yes. Dynamo says "The first electric generator was invented by Michael Faraday in 1831". It then apparently contradicts itself by mentioning Jedlik's dynamo, 1827. Electric_motor#History_and_development says Faraday invented a mercury motor (which does no useful work) in 1821. I don't know if he was the first to make such a thing, and technically every motor can be used in reverse as a generator, but pushing the wire around in circles in an attempt to generate current sounds difficult, so assuming nobody made any higher-tech motor before Jedlik's dynamo, the motor came first. 213.122.7.185 (talk) 14:53, 8 January 2011 (UTC)

A partisan advocate of Jedlik introduced many dubious claims based on sources in Hungarian. 19th century histories of motors and generators (in English) only credited Jedlik with some dynamo improvements much, much later than the claims in the Wikipedia articles about Jedlik, motors, and dynamos. We need someone able to read Hungarian to clarify what the sources actually say. Edison (talk) 20:30, 8 January 2011 (UTC)

If you consider a steam engine to be a motor, then they go all the way back to Hero's engine. StuRat (talk) 14:55, 8 January 2011 (UTC)

Cosmology

I recently heard of an idea: an explosion so massive, that it sends shockwaves through space-time. At subluminal speeds, an observer should be able to see a wave front of Lorentz and time contraction, followed by dilation of both kinds. Is this a plausible idea? --Plasmic Physics (talk) 11:37, 8 January 2011 (UTC)

Not exactly, but gravitational waves come close. The largest difference from your description is that gravitational waves are supposed to propagate at lightspeed, and that they cannot (as a matter of GR mathemathics) be exactly spherically symmetric, so they wouldn't be generated by a symmetric explosion however massive. –Henning Makholm (talk) 12:51, 8 January 2011 (UTC)

What should create notable gravitational waves, what should the intensity be proportional to? --Plasmic Physics (talk) 22:24, 8 January 2011 (UTC)

Faking carbon/radioactive decay

This is a bit of a complicated question relating to carbon dating and radiometric dating.

Carbon dating is useful for finding the age of relatively recent fossils. The carbon-14 begins to decay, and around 5700 years or so, it's half replaced with nitrogen-14. Every 5700 years (the "half-life" of carbon-14), half the remainder decays. We can measure around how old the fossil is by comparing the amount of carbon-14 to nitrogen-14.

What I was curious about is, would someone be actually able to change the amount of either carbon-14 or nitrogen-14 in the fossil? Is such a process possible?

Of course, carbon dating only works to about 100,000 years ago. For older fossils or actual rocks, you use radiometric dating (as I think it's called). Let's say this mineral is full of uranium-235. After about 700 million years, it's half replaced with lead-207. So 700mya is the half-life of uranium-235. After another 700mya, another half of the uranium-235 has been replaced with the lead-207, and so on. Would it be possible to remove or add bits of either the uranium-235 or the lead-207, like I suggested with the carbon-14 and nitrogen-14?

Please note, I'm not suggesting to actually fake fossils and minerals in this way. That would be bad...but is it possible? Crimsonraptor | (Contact me) Dumpster dive if you must 15:00, 8 January 2011 (UTC)

All forms of radiometric dating (of which carbon-14 and uranium series dating are two of several examples) are subject to errors from contamination, sediment mixing in fossils, and other sources of incidental, accidental, and systematic errors. That is why most radiochemists prefer to date from as many sources of information as possible to cross-check. Intentional contamination seems fairly difficult to me, however. If you're a paleontologist who wanted to pass off a fossil as older or younger than its radiometric age, you might be able to guess about which part of the fossil to contaminate, but I'm not sure how good such a guess could be, or whether such tampering wouldn't be obvious or at least make the radiochemist sample from a different part of the fossil. Other less sophisticated forms of scientific fraud (misreporting measurements, for example) are much more common. 71.198.176.22 (talk) 15:48, 8 January 2011 (UTC)

You would need to replace a portion of the fossil with something of a different age. If you knew in advance the exact location where the sample would be taken, this could be done (although making it look right would be tricky). Otherwise, you might have to replace the entire fossil. StuRat (talk) 15:51, 8 January 2011 (UTC)

OK, so you'd have to change the actual material itself, not the stuff in the material? Crimsonraptor | (Contact me) Dumpster dive if you must 15:55, 8 January 2011 (UTC)

Yes, because the fossil and surrounding material has to be removed as a sample and pulverized to extract the daughter isotopes of interest. The sort of tampering you're contemplating here might very well be more difficult than fabricating an entire fossil from scratch (which has happened at least a few times in the history of scientific frauds. In the art world this kind of deception would be much easier, because owners of valuable art can restrict chemists from sampling all but certain portions of the work in order to prevent it from being disturbed in a detectable fashion. That allows forgers more leeway.) 71.198.176.22 (talk) 16:19, 8 January 2011 (UTC)

Most radiometric dating methods would not be able to date the fossil directly anyway. The sequence of rocks containing the fossils can be dated by working out the age of lavas or ash layers interbedded with the sedimentary rock e.g.[16]. It would be simpler just to claim a fossil find from the wrong part of the sequence, but no-one would accept that unless other examples were forthcoming. Mikenorton (talk) 16:01, 8 January 2011 (UTC)

There also is a strong difference between ¹⁴C-dating and most other dating methods. ¹⁴C dates organic material. It depends on the fact that ¹⁴C is created at a (fairly) fixed rate in the atmosphere, and hence is at a fairly constant level in the atmosphere. Living things are in good equilibrium with the atmosphere. In other words, we know reasonably well what percentage of carbon in living things is ¹⁴C. Once something dies, it essentially stops exchanging carbon with the environment. ¹⁴C decays. The daughter element, ¹⁴N, typically escapes. We determine the age of the object by looking how the ¹²C/¹⁴C ratio has changed (by decay of ¹⁴C), without ever looking at the daughter element. Other radiometric techniques work differently. If you look at e.g. K–Ar dating, we do not know the initial amount of ⁴⁰K. We do know, however, that the daughter element, ⁴⁰Ar, is a gas, and will escape from molten magma, but not from crystallised rock. So we start with an unknown amount of ⁴⁰K and zero ⁴⁰Ar. For dating, we assume that all ⁴⁰Ar we find is the result of the decay of ⁴⁰K, and we can hence determine the age (of the solidification event) from the ratio of ⁴⁰Ar to ⁴⁰K. The nice thing about this is that we can repeat the experiment with different samples with different initial ⁴⁰K. If the samples are the same age, and not contaminated somehow, they will all have different absolute amounts of ⁴⁰Ar an ⁴⁰K, but all the same ratio of them. In a diagram, the different samples all fall onto the same straight line. This property allows us to detect contamination and problems, or, in the other case, to strongly confirm the dates.--Stephan Schulz (talk) 23:56, 8 January 2011 (UTC)

It seems to me that it ought to be possible, although I don't know anything specific. It seems to me that by subjecting the material to a flux of photons or other subatomic particles with the right properties, it would be possible to make the ¹⁴C decay more rapidly than it would otherwise. This is definitely possible with uranium 235 -- it's the principle underlying nuclear energy generation. It would, however, very likely leave behind substantial evidence of the manipulation. Looie496 (talk) 18:52, 9 January 2011 (UTC)

Dedendum circles

"dedendum circle diameter must be less than base circle diameter then the part of profile is not involute towards lower side of base circle." is this statement right for interference of involute profiles.are not the dedendum circles same as base circle.please help. —Preceding unsigned comment added by 59.93.129.167 (talk) 15:59, 8 January 2011 (UTC)

Can you clarify your question? Our article List_of_gear_nomenclature may help you out. It only explicitly defines dedendum angle, though the graphic for addendum shows a dedendum radius. The base circle radius is not the same as the dedendum radius. The article seems to indicate that the base circle radius plus the dedendum radius would give the pitch circle, but I may be misinterpreting. SemanticMantis (talk) 16:56, 8 January 2011 (UTC)

SnCl2-Sn(OH)Cl vs. SbCl3-SbOCl conversion

At what pH do these conversions take place? I have a solution with a pH of 1.5 and there is a white precipitate that must be either of these. --Chemicalinterest (talk) 18:33, 8 January 2011 (UTC)

The exact pH will depend on the chloride concentration. pH 1.5 seems quite acid for either one, unless you're right out of chloride in the solution, but the antimony will come out before the tin does, that's for sure. Physchim62 (talk) 02:28, 9 January 2011 (UTC)

Regardless of the pH, this is what I got. --98.221.179.18 (talk) 13:00, 9 January 2011 (UTC)

Dioxin in Germany

How and why did the Polychlorinated_dibenzodioxins contaminated food in Germany recently? Quest09 (talk) 19:13, 8 January 2011 (UTC)

A news article says "tainted fatty acids" used to make animal feed are suspected. Edison (talk) 20:26, 8 January 2011 (UTC)

yes, but why would someone taint animal feed with dioxin? If you feed hormones to a cow or chicken you make it fatter, but there is no advantage in mixing dioxin on purpose. So, why did it happen, where did it come from? Quest09 (talk) 20:40, 8 January 2011 (UTC)

It seems unlikely anyone purposely tained the animal feed (i.e. with the intention of adding dioxins) or at least there's no indication I've seen of that being the case. Various sources [17] [18] suggest the fatty acids were intended for industrial (not industrial food!) use only but were mixed with the fatty acids intended for animal feed. Whether this was accidentally or not doesn't seem clear but it's suggested the company knew about the high level of dioxins for a long while [19]. This doesn't explicitly answer why the fatty acids were contaminated but the first source (provided by Edison) says it's not uncommon. Nil Einne (talk) 21:18, 8 January 2011 (UTC)

It may have been like the antifreeze-in-wine incident of the past - it made someone money. The mineral oil was probably a lot cheaper than food-grade oil. 92.15.7.205 (talk) 21:35, 8 January 2011 (UTC)

I am a german. The Dioxin (probably TCDD) came from fat for industrial uses, just produced by heating it up. Nobody intentionally, or even accidentally, put a TCDD crystal in, but fats were heated up, dioxin produced, and the fats were only to be used for industrial purposes (e.g. manufacturing motor oil). But somehow the fat company sold it to a company called Harles&Jentzsch, which produces ready-to-feed food for chicken and pigs. Then Galloanserae ate this food, and because the dioxin is not biodegradable, it landed in amniote eggs, and meat. Reportedly, some private laboratory knew about a too high dioxin value from the 19th of March (!) but Harles&Jentzsch says that they only knew from the 27th of December onwards. — Preceding unsigned comment added by Eu-151 (talk • contribs) 17:40, 9 January 2011 (UTC)

How would fat, made of carbon, hydrogen and oxygen, gain the chlorine needed to make dioxin or PCB just by being "heated up"? I could understand if PCB contaminated oil were used in a heat exchanger, and some of it leaked from its tubing into the fat being heated. That sort of contamination has happened in the past in other countries. Edison (talk) 21:02, 9 January 2011 (UTC)

2D holographic display

In some sci fi media like anime or video games like dead space (video game) they have 2D holographic displays like this http://cdn.themis-media.com/media/global/images/galleries/display/55/55099.jpg is there any specific name for this kind of technology? Is there any real world tech working on this? All the articles on wikipedia just deal with 3D volumetric displays not 2D holograms. ScienceApe (talk) 20:04, 8 January 2011 (UTC)

You mean a 2d image projected out into thin air? I don't know if there is a general name for them. A company named Heliodisplay makes them. (They spray a thin sheet of mist into the air then project onto that.) But they're mostly just gimmick. APL (talk) 21:56, 8 January 2011 (UTC)

January 9

Why does any number muliplied by nine add up to nine?

i.e 13times 9=117. 1+1+7=9 and so on.AM radio frequencies in Australia are all multiples of nine. <e-mail address removed>, 9 January 2011 (UTC) —Preceding unsigned comment added by 118.208.93.193 (talk)

I removed your e-mail address so that you don't get unwelcome attention from spammers - any answer to your query will appear here. Mikenorton (talk) 00:29, 9 January 2011 (UTC)

They add up to nine because they don't add upto 8. See, Numerology, Apophenia, Confirmation bias, and 23 enigma. --Plasmic Physics (talk) 00:55, 9 January 2011 (UTC)

It's to do with us using base 10. If you add the digits of an number, in any base, and end up with base-1, then the original number is divisible by base-1. If you end up with a (multiple of a) factor of base-1, then the number is divisible by that factor. For example

• 123 (= 3 * 41), is 1+2+3 = 6, so 123 is divisible by 3.
• 32_hex (50 in decimal), is 3+2=5. 5 and 3 are the factors of 15 (16-1), so 50 is divisible by 5.

There should be an article on this, as WHAAOE, but I don't know what the phenomena is called. CS Miller (talk) 01:09, 9 January 2011 (UTC)

BTW, you might have been better asking on the maths desk. CS Miller (talk) 01:11, 9 January 2011 (UTC)

See Casting out nines for a related, somewhat more general phenomenon. Buddy431 (talk) 04:22, 9 January 2011 (UTC)

Let me first of all rephrase your question more clearly. "Any (positive integer) number multiplied by nine" gives you a (positive integer) number that is divisible by nine. What you asking is, why do all positive integer numbers divisible by nine have their digits, in base 10 notation, adding up to 9. Well, they don't. For example, 99=11*9, 990=110*9, 9900=1100*9, etc. are all divisible by 9, but the sum of their digits is 18. The correct statement is: "In base 10, any positive integer that is divisible by 9 has its sum-of-digits divisible by nine, as well". In the example I just gave, the number 9900 = 1100*9, the sum of digits 9+9+0+0 = 18 = 2*9. A simple, non-rigorous proof -- I am a physicist, not a mathematician :) -- is as follows. Imagine you have a number [ a_n ... a₁ a₀ ]. For example, if the number is 3456, a₃ = 3, a₂ = 4, a₁ = 5, and a₀ = 6. Incidentally, 3456 = 384*9 and 3+4+5+6 = 18 = 2*9. Since we use base 10, the value of [ a_n ... a₁ a₀ ] is x = 1*a₀ + 10*a₁ + ... + 10ⁿ*a_n. Now, what happens when you divide by 9? Let's divide every term separately. 10*a₁ = (9+1)*a₁ so residue from this term is 1*a₁; the next term 100*a₂ = (99+1)*a₂ so residue of division of that term by 9 is 1*a₂; and so on. When you sum up all the residues you get 1*a₀ + 1*a₁ + ... + 1*a_n. This is the sum of digits of your original number! The sum of residues equals the sum of digits. So, if the sum of digits divides by 9, so does the full residue; that means the original number divides by 9, as well. --Dr Dima (talk) 02:08, 9 January 2011 (UTC)

The digital root is 9 for all positive multiples of 9. Digital root#Congruence formula mentions the generalization to b−1 for base b. PrimeHunter (talk) 02:31, 9 January 2011 (UTC)

Dr Dima in part says the sum of the digits is 18 but as for all whole numbers the digits 1+8 again add to nine.Regardless of how high the number is taken every time the result is added and re-added it wil eventually resolve to 9. I failed maths at school so please be gentle with me.

John Cowell.118.208.9.92 (talk) 03:14, 9 January 2011 (UTC)

Can you clarify your question? As you noted, the sum of the digits of any multiple of nine sum to another multiple of nine, eventually summing to nine if you do it long enough (that is, 4617's digits add to 18, and 18's digits add to 9). This is just as you stated it. — Lomn 04:09, 9 January 2011 (UTC)

Oh, OK, you're referencing this. Dr Dima is being precise about it (in base 10, integer multiple, a formal statement of "might have to repeat to reach 9", etc). — Lomn 04:12, 9 January 2011 (UTC)

See Casting out nines for a more general, related phenomenon. There's an explanation, but it's a bit dense. One thing to note: whenever you add nine to an integer, you always increase the sum of the digits by zero or by 9. Check this to see that it works out. It's intuitively not hard to see why this: if the unit's digit is zero, it becomes a nine, and the rest of the number remains unchanged (for an increase of 9 in the sum). When the last digit is any other number (1-9), the units digit decreases by one, while the Ten's digit increases by one, for a net increase of zero in the sum of the digits. Predictably, the reverse is true in subtracting nine: the sum of the digits either decreases by nine, or remains the same. Buddy431 (talk) 04:18, 9 January 2011 (UTC)

(edit conflict) This is discussed somewhat at our 9 (number) and Digital root articles, and an interesting use of this property is discussed at Casting out nines. It has to do with the fact that in base-10, 9 is the last digit before you have to start reusing digits (ie. the digits "1" and "0" in "10"). WikiDao ☯ 11:21 pm, Today (UTC−5)

This seems like a fairly decisive and understandable answer that deals a fairly decisive blow against reading too much mysticism into such a thing. Does this mean that the digital root of F in Hexadecimal has the same phenomena associated with it? --Mr.98 (talk) 17:30, 9 January 2011 (UTC)

Yes, as I noted above, for base 'n', if the digital root is n-1, then the original number is divisible by n-1. CS Miller (talk) 20:25, 9 January 2011 (UTC)

When and how are 1920s–30s lighthouses lit?

Resolved

 – –Kerαunoςcopia^◁_galaxies 03:04, 9 January 2011 (UTC)

I'm doing research for a painting of the lantern room of a lighthouse. I'm having difficulty finding information on how a lamp is lit and when it is lit. In the "lighthouse technology" section of the lighthouse article, it is mentioned that the Dalén light was used predominantly in the 20th century (up until the 60s), but although I followed through to the sun valve article and its external link, I'm not finding what a Dalén light actually looks like, and where a sun valve would be placed on, or within, the lighthouse. I've also found images of first and second order Fresnel lenses (from our own Commons), but not what they look like from above. Are they open at the top to allow heat to escape? (In this example, it almost looks like the answer is "no"). As a mere matter of curiosity, how "hot" was the actual beam of light—could someone stand on the gallery with their back to the lantern room while the light was rotating? Any recommendations for more information on this particular area of the lighthouse would be welcome! – Kerαunoςcopia^◁_galaxies 01:14, 9 January 2011 (UTC)

It was an acetylene lamp, with the "solar valve" which turned it on and off based on the sun shining on the apparatus. Some results are found at Google book search such as [20] . This appears to be a picture of the Fresnel lens and a lamp from a lighthouse, though it may be a different lamp than the Dalen. It went all around and had a vent in the top, naturally to let the combustion gases out. I did not find info on the lightintensity or heat of the lamp. Edison (talk) 02:25, 9 January 2011 (UTC)

I found this image [21], which is the man himself standing next to what is evidently a fresnel, though the caption says it's his sun valve, so I assume the sun valve is attached somewhere (there may even be a Dalén light in there too if you're lucky). Unfortunately I couldn't say which piece of apparatus is which. 213.122.40.179 (talk) 02:31, 9 January 2011 (UTC)

I jumped to the Swedish Wikipedia article on the lamp, which linked to an AGA site with some pictures. The solar valve had a bunch of rods which could heat up and turn off the gas when the sun sas shining. See [22] (in Swedish. Google Translate is your friend). Edison (talk) 02:45, 9 January 2011 (UTC)

That clarifies the Dalén light perfectly. I was confused because I thought i would actually see it, but the fresnel lens would simply cover it up. A detailed image of the source wouldn't be visible through the lens. Thanks all! – Kerαunoςcopia^◁_galaxies 03:04, 9 January 2011 (UTC)

Time lapse from brain to tongue.

Any thoughts on the time it takes to make speech from the brain formulating the next word?Think Spoonerisms. John Cowell.118.208.9.92 (talk) 01:20, 9 January 2011 (UTC)

It takes perhaps a fifth of a second to voice a known prearranged response when a stimulus is presented, much like pressing a button as a simple reaction time response. If an unknown stimulus letter is presented, the vocal response time is appreciably longer, but still far less than a second. Anecdotally, if one's attention is diverted after an utterance begins, something random and funny may emerge, as if the speech generator were on autopilot and randomly choose a related but unintended word. Certainly the longest time from formulating an utterance to saying it could be many seconds, but the shortest would seem to be a fraction of a second. Mental chronometry researchers have argued for well over a century as to how to determine the time required for internal mental operations, so whether the number you seek is 200 milliseconds or 500 milliseconds or whatever would be open to debate. Edison (talk) 02:10, 9 January 2011 (UTC)

Thinking Spoonerisms maybe I could rephrase in terms of how many words ahead of the tongue is the brain?

Is English spoken more slowly than many other languages e.g.Spanish?

John Cowell.118.208.9.92 (talk) 02:40, 9 January 2011 (UTC)

The question can't be answered in any precise way, because the formulation of words is a gradual and distributed process, and "making speech" is an even more gradual process. For a minimal order of magnitude estimate, you could probably take something on the order of 200 milliseconds. Looie496 (talk) 18:45, 9 January 2011 (UTC)

The time to start yelling "Stop!" to the driver when a passenger sees a danger ahead of a car, or to yell "Duck!" when some danger is swinging toward people seems less than 500 milliseconds. On TV, there seem to be far more syllables per minute in excited Spanish discourse than in English, but unclear how many words it breaks down into. Some speakers of US English have a very, very slow and drawling mode of speech. Edison (talk) 20:54, 9 January 2011 (UTC)

electromagnetic waves

How do electromagnetic waves emit? I understand how the elctric and magnetic fields form, but I don't understand how (or why) they move forward. — Preceding unsigned comment added by Sina-chemo (talk • contribs) 09:25, 9 January 2011 (UTC)

It is a disturbance in the field that is moving, rather than the field itself. In much the same way, a disturbance on a water surface causes a wave to propagate outwards from the original disturbance without the whole body of water moving anywhere. Take a look at electromagnetic radiation and come back if you have more questions (the formal mathematical treatment is at the bottom of the article). SpinningSpark 11:46, 9 January 201it (UTC)

it was helpful.but it would be better if ther was an image or anything that can help me understand it better.thanks alot.

The energy applied to the aerial by the transmitter creates a force field around it -so far so good. As the oscillating voltage reduces to zero, some of the field collapses back into the aerial but not fast enough for it all to collapse. What is left of that force field by the time zero potential is reached, becomes detached from the aerial. As the voltage builds up in the other direction the old detached field is repelled and zips off at the speed of light. --Aspro (talk) 15:54, 10 January 2011 (UTC)

circular motion

a stunt car makes horizontal circles of radius 20m along the inside surface (with an angle of elevation of 30 degrees) of a vertical cone. the coefficient of static friction between the tires and the road is 0.25. find the possible range of speeds of the car.

i've arrived at these two eqns: n cos 30 =mg+0.25nsin30 and n cos 60 + 0.25nsin60=v^2/20 cos 20. where n is the normal force. how do i continue? — Preceding unsigned comment added by Invisiblebug590 (talk • contribs) 10:17, 9 January 2011 (UTC)

In your equations, you are considering the case where the friction force is at its maximum and acting down the slope. This will occur when the car is travelling at its maximum possible speed. You also need to resolve perpendicular to the slope (where the friction force has zero component) to get "n" in terms of mg. I read the question to mean that the radius of the circle is 20m (not 20cos20 as in your equation). You have also omitted the mass from your second equation. Dbfirs 12:57, 9 January 2011 (UTC)

For the minimum speed, consider the case when the friction force is at its maximum possible value but acting up the slope. Dbfirs 13:21, 9 January 2011 (UTC)

What did, and will, toilets look like?

I was going to ask this on AOL Answers, but I don't think their users would've been too happy about it, so I asked here instead:

1. What did toilets look like in 1900?
2. What did toilets look like in 1910?
3. What did toilets look like in 1920?
4. What did toilets look like in 1930?
5. What did toilets look like in 1940?
6. What did toilets look like in 1950?
7. What did toilets look like in 1960?
8. What did toilets look like in 1970?
9. What did toilets look like in 1980?
10. What did toilets look like in 1990?
11. What did toilets look like in 2000?
12. What did toilets look like in 2010?
13. What will toilets look like in 2020?
14. What will toilets look like in 2030?
15. What will toilets look like in 2040?
16. What will toilets look like in 2050?
17. What will toilets look like in 2060?
18. What will toilets look like in 2070?
19. What will toilets look like in 2080?
20. What will toilets look like in 2090?
21. What will toilets look like in 2100?
22. What will toilets look like in 2110?

--70.179.178.5 (talk) 12:13, 9 January 2011 (UTC)

I'm not sure that we are happy about 22 almost identical questions either, but from the 1800s up to at least 1960, toilets in the area where I live consisted of a thick board with a round or oval hole smoothly carved, and this was set in stone pillars, usually with a stone front, over a deep pit, usually on sloping ground so that it could be cleaned out occasionally from a lower opening. I don't know whether any of these are still in use, but they were standard when I was young. The variety with two holes side-by-side seemed to fall out of fashion, but my aunt still used one (on her own as far as I know) until about 1970. We can't predict the future, but perhaps the Composting toilet will become more popular as water becomes more scarce during the next hundred years. Dbfirs 12:41, 9 January 2011 (UTC)

Take a look at this search, many of your questions will be answered by these images - plus a few more such as "what does an elephant toilet look like?" SpinningSpark 13:15, 9 January 2011 (UTC)

For your historical toilets, it really depends 1. where you are asking about (India is not the same as, say, England), 2. what income level you are interested in (are you curious about the very poor or the very rich?), and 3. are you looking for the average toilet or the most advanced (though perhaps not used much) toilet? Dividing it up by decade is probably not helpful, because there isn't going to be very rapid change in the design after a point. (If you lift up the top of your current toilet, you can usually see written inside when it was made. A toilet I had in the early 2000s was from the 1960s, and looked like every other toilet I had seen.) Even if we tried to answer, "what does a toilet look like in 2011?", you'd get a wide spread of responses (I have a fairly average toilet, but it looks very different from toilets I have seen in Germany, for example, and certainly is not as high tech as toilets in Japan). And of course we cannot predict the future, much less a century in the future, so those questions are really not going to get useful answers here. --Mr.98 (talk) 15:02, 9 January 2011 (UTC)

Part of the geographical variation in toilets is due to whether the location is urban or rural. In general, urban areas get indoor plumbing available earlier than rural areas, so the switch from outhouses to flush toilets in general historically occurs earlier in urban areas earlier than in rural areas. Red Act (talk) 15:32, 9 January 2011 (UTC)

In a given location the toilets will have a variety of styles in a given year. In US cities in 1910, for instance, the wealthy had flush toilets, but the poor had outhouses. In 1960 in the US many rural homes still had outhouses, but virtually all city dwellers had flush toilets. A farm in 1960 in the US might have a flush toilet in the house and the old privy still there by the barn for convenience when working outside. A 1920 flush toilet might still be in use, and hard to distinguish from one a year old. All the internal parts as well as gaskets to connect the tank to the bowl are still readily available for toilets from the 1920's, so it could still be in use through the indefinite future. A friend has a new toilet which will squirt water to the front or rear area of the user, and will blow warm air to dry the bottom. It has a heated seat as well. Edison (talk) 20:43, 9 January 2011 (UTC)

You can search at Google Book Search for "flush toilet" or the words without quotes, or "water closet" and restrict the books to a decade. Searching for 1891-1900 I found an 1899 toilet and bathroom. The toilet was much like a modern one, with siphon action, but the tank was elevated on the wall for greater pressure. Anecdotally, this kind worked great. Poorer quality toilets of this period just had "rim flushing," in which water from the mains flowed into the bowl around the rim, with less effective flushing down. As for 1910, "Modern Plumbing Illustrated" (1907) provides some illustrations. Low tanks were replacing high wall mounted tanks in new construction. A larger flush pipe made up for the lower pressure. Here is a description of outhouse at US schools in 1910. Edison (talk) 23:27, 9 January 2011 (UTC)

Why does America still use the "flap" type of toilet cistern instead of the better siphon method that's been around for a century or more I expect? 92.15.3.168 (talk) 21:44, 10 January 2011 (UTC)

Why is the Washlet hard to penetrate the bathroom fixture market here in the US?

The spray toilets like the Toto Washlet are fairly common in Japan, but why are they hard to enter the market in America? I thought most decent Americans would want the utmost personal hygiene, so why are they still slow to accept the fabled spray-toilet? --70.179.178.5 (talk) 12:13, 9 January 2011 (UTC)

I note that the design is based on Japanese rears. Are Americans the same shape? Dbfirs 13:01, 9 January 2011 (UTC)

I'm half-Korean, half-white, and those types of fixtures have worked on me wonderfully! I am a proud owner of a BioBidet [[BB-i3000]. --70.179.178.5 (talk) 13:01, 10 January 2011 (UTC)

Maybe because the Americans are not so extravagent? --Tyw7  (☎ Contact me! • Contributions)   Changing the world one edit at a time! 16:34, 9 January 2011 (UTC)

I still see more Mercedes and other nice European imports than bidet-seats. --70.179.178.5 (talk) 13:01, 10 January 2011 (UTC)

Bidets are common in many countries, but I don't think I've ever seen one in the United States. I'm not sure there's a concrete reason there other than, "it's not what we're used to."

We weren't used to cars for a while, until Henry Ford changed that for us. --70.179.178.5 (talk) 13:01, 10 January 2011 (UTC)

I've used them in other countries and, as an American, found them to be extremely odd.

We found cars to be quite odd for a little bit. Horses found them even more odd than we did. --70.179.178.5 (talk) 13:01, 10 January 2011 (UTC)

That's obviously just because I'm not used to it — my toilet experience has, my entire life, been a "dry" one, and adding water to that just feels exceedingly strange.

Attempting to drive a horseless wagon felt exceedingly strange for a time too, and horses thought they were so strange, they'd feel spooked at the sight of a wagon moving without a horse. --70.179.178.5 (talk) 13:01, 10 January 2011 (UTC)

Add to the fact that our restrooms are all designed for a single toilet and you have an infrastructure problem. (Not with the integrated bidets, of course. But with bidets in general.) I'm not sure why you'd think that Americans would "want the utmost in personal hygiene" — hygiene is a very culturally relative thing, and most Americans would probably not recognize the bidet as really adding all that much in terms of hygiene.

We once didn't recognize soap as being all that necessary for our personal health & hygiene either. For a time, we even thought that any doctor who washed their hands of the so-called "spooks" were "quacks." --70.179.178.5 (talk) 13:01, 10 January 2011 (UTC)

My experience is that Americans view the toilet gadgets of the Japanese as an extreme form of using technology to not necessarily useful ends (so to speak) — Americans, from my anecdotal experience, seem to have very little interest in "improving" their toilets, and see the existing models as working pretty well on the whole. --Mr.98 (talk) 17:21, 9 January 2011 (UTC)

Skidmarks still strain and even end relationships; the bidet-seats would save them. The water used from the bidet's enema washes would be far cheaper than laxatives. We once thought having a computer in our own homes was an extreme form of technology. We also thought having a GPS navigation aid in our own vehicles were extreme technologies once. The time must come for Americans to realize how useful it would be. --70.179.178.5 (talk) 13:01, 10 January 2011 (UTC)

Oddly enough, evidently Google has a form of bidets, at least in their women's bathrooms. In this Google YouTube interview with Conan O'Brien, Andy Richter mentions that Conan's assistant is in the bathroom, "front cleansing". (Video time-marked.) – Kerαunoςcopia^◁_galaxies 18:33, 9 January 2011 (UTC)

That's a perk to attract prospective employees, investors, and more business. All other businesses must follow suit if they hope to thrive better, especially in this economy! --70.179.178.5 (talk) 13:01, 10 January 2011 (UTC)

Living in the U.S. and having avoided such features, I think that my gut reaction when looking at this article is that something is going to go wrong - that feces-tainted water is going to spray off in all directions and shoot out and get all over my pants, etc.

The designers of these bidet-seats have considered this in mind, and made adjusting design accommodations to prevent this. --70.179.178.5 (talk) 13:01, 10 January 2011 (UTC)

Plus, I think that the nozzle in a public restroom will get sprayed with feces-tainted water from a previous user, opening a potential route of infection.

Once the nozzle retracts, it gets sprayed so that all impurities are rinsed off. The water that cleans off the nozzle may be heated, and/or even soaped! --70.179.178.5 (talk) 13:01, 10 January 2011 (UTC)

I should further add that the (citation needed) sentence "In order to determine the anal position, 300 male and female employees of Toto were surveyed during development." really raises a red flag, because there's a lot more variety of body shape and size in the U.S. than in Japan. Wnt (talk) 18:39, 9 January 2011 (UTC)

Toto is an international corporation. Some of the 300 were foreigners, and they must've used all sorts of body shapes. Possibly, some of the employees were also made to bring their children in for tests to make sure it would work for all ages, body shapes and sizes. Japan has sumo wrestlers too, so some of them may have been test subjects as well. --70.179.178.5 (talk) 13:01, 10 January 2011 (UTC)

In my limited experience with Googleplex men's bathrooms, the lobby restroom toilets are indeed Washlets, but the employee toilets are ordinary American models. -- BenRG (talk) 21:50, 9 January 2011 (UTC)

It's to bring new business and employees to the company, so the lobby must do its utmost to bring prospects the best first impressions. --70.179.178.5 (talk) 13:01, 10 January 2011 (UTC)

Some good reasons were given so far. Here's some more:

1) Bidets don't make a good gift, since it's just too "icky". So much for it being the latest new Xmas gift.

Cars were once too "scary," especially to horses. It was still the latest new Xmas gift for some families. --70.179.178.5 (talk) 13:01, 10 January 2011 (UTC)

2) Americans associate dry butts with "clean" and wet butts with "dirty". That perception's not easy to change.

I never once thought that. I knew from first learning about these spray-toilets that the water spraying from the nozzle is clean from the get-go, so it rinses off what life throws our way. (My BioBidet BB-i3000 model also has a liquid soap dispenser for extra good measure.) --70.179.178.5 (talk) 13:01, 10 January 2011 (UTC)

3) "New technology" toilets have a bad reputation in the US, such as low-flow toilets that leave floaters behind. StuRat (talk) 00:32, 10 January 2011 (UTC)

These are seats that can be fitted on most existing toilet bowls. Only the Toto Neorest 600 is a standalone toilet structure. It has options for multiple flow speeds. --70.179.178.5 (talk) 13:01, 10 January 2011 (UTC)

70.179.178.5, please don't break apart other people's posts to you - it makes it very difficult to see who is posting what. Instead, just reply at the end, adding an extra : to the front of your reply to make attributions clear. While I'm sure it's unintentional, your replies read as if you want to start a debate or make a sale. Matt Deres (talk) 14:58, 10 January 2011 (UTC)

Americans are creatures of habit. Bidets are some weird European et al. fixation, like the metric system. (!) PЄTЄRS J VЄСRUМВА ►TALK 15:06, 10 January 2011 (UTC)

Wet-Bulb Temperature vs Dew Point Temperature

Are these two the same? There are articles on both, with subtle references to each other but to me they seem to describe more or less the same thing. What is the difference between these two? 196.210.162.116 (talk) Eon —Preceding undated comment added 12:50, 9 January 2011 (UTC).

I'm no expert on thermodynamics (I am getting all this from just reading our articles) so I might have this wrong but my reading is as follows. To find the thermodynamic dry-bulb temperature the air is cooled by allowing water to evaporate into it until saturation is reached. This process is adiabatic, ie no heat is input or removed from outside the system. To find the dew point the air is again cooled (but not necessarily adiabatically) to saturation but no "extra" moisture is injected into the system. The first conserves heat, the second conserves moisture. The numerical relationship between these is given at psychrometric chart. SpinningSpark 21:06, 9 January 2011 (UTC)

Brilliant explanation, except you said dry-bulb in one spot where I think you meant wet-bulb. Now that you provide both explanations in the same paragraph I can see the difference. I had actually thought that the two are equivalent even given your explanation. But clearly there is a difference, for example if hot air had 0% relative humidity then it would have a dew point of absolute zero but a wet bulb temperature still somewhere above that. Maybe this is a bad example because water would freeze at those low temperatures but the example sets my mind at ease. 196.211.175.2 (talk) 08:24, 10 January 2011 (UTC) Eon

People in coma

Hi. Is there a list of people in coma? How many living notable people are in coma? Does this deserve a list and a category? Regards. emijrp (talk) 13:51, 9 January 2011 (UTC)

The closest I could find is Persistent vegetative state#Notable PVS patients and Category:People with severe brain damage. PrimeHunter (talk) 14:01, 9 January 2011 (UTC)

As our coma article explains, the state that neurologists call coma rarely lasts for more than a few weeks -- is almost always resolves either into brain death or a persistent vegetative state. When the broader literature speaks of somebody being in a coma for years, it almost always refers to what neurologists call a persistent vegetative state. (Sorry for the pedantry.) Looie496 (talk) 18:40, 9 January 2011 (UTC)

So, are there notable people in vegetative state? I guess so, a list would be interesting. Also, a list with the longest coma states, and people who recovered from them. emijrp (talk) 19:20, 9 January 2011 (UTC)

Terry Schiavo springs immediately to mind. --Jayron32 20:57, 9 January 2011 (UTC)

She's not in a coma. Staecker (talk) 03:50, 10 January 2011 (UTC)

She was in a coma, and then in a vegetative state for 15 years (though not currently, of course). Buddy431 (talk) 04:39, 10 January 2011 (UTC)

Ariel Sharon is the only one I know of currently. Buddy431 (talk) 00:47, 10 January 2011 (UTC)

The request seems to be for notable people presently in a persistent vegetative state. I fear it would include a vast number of folks who have shaped our world; writers, scientists, actors, businessmen and soldiers who are now in their 90's and awaiting death, being spoon fed, and having their diapers changed, not knowing who or where they are. We hear about them only when they die. Edison (talk) 06:00, 10 January 2011 (UTC)

Imagine a "List of people who were gaga at the end." Perhaps Roosevelt, Reagan, Churchill, and many more. Edison (talk) 06:04, 10 January 2011 (UTC)

The living people at Persistent vegetative state#Notable PVS patients are Haleigh Poutre, Aruna Shanbaug, Ariel Sharon. PrimeHunter (talk) 18:10, 10 January 2011 (UTC)

Balancing of reciprocating masses

See section 22.3 in above reference on balancing of reciprocating masses .the book mentions that only cos component of primary unbalanced force is balanced by the additional ass B. it really dosent looks so,because the sine components of mass m and mass b are also in opposition to each other . kindly clarify my point ,or please pint out where i am making a mistake. Kndly do help me :in which direction is the secondary unbalanced force acting? —Preceding unsigned comment added by 59.93.128.223 (talk) 14:04, 9 January 2011 (UTC)

The way I read it, the sine component produces an unbalanced force perpendicular to the line of stroke, and this is indeed not balanced by the mass at B, so the best solution is a compromise but I haven't read the article carefully, and I've never met the theory before, so please forgive me if I have misunderstood! Dbfirs 17:16, 9 January 2011 (UTC)

Dissolving gases in liquids

I have a system where a gas is added above a liquid (for example methane above water) over a very wide range of possible partial pressures. I need to predict the concentration of the gas in the liquid at equilibrium. Henry's Law tells me that the concentration will be proportional to the pressure at least for relatively low partial pressures. So, this leads me to two questions, A) what is a good reference for Henry's Law constants (for example, the proportionality constant for methane and water at 25 Celsius), and B) is there a way to predict (or at least lookup) when and how the behavior will diverge from Henry's Law at very high partial pressures? For the purposes of this question, one can assume the gases are chemically inert in the liquid. Dragons flight (talk) 14:28, 9 January 2011 (UTC)

There's certainly no "one-size-fits-all" solution. You can easily calculate Henry's Law constants for a variety of gases from the data at this site, assuming linear solubility over 0–101.3 kPa (a fair assumption for a sparingly soluble gas like methane, a bad assumption for a reactive gas like chlorine). As for extrapolating those constants to higher pressures, well, you do so at your own risk! If the data are important for an application, they need to be measured. Physchim62 (talk) 02:18, 10 January 2011 (UTC)

Mass/Energy

I've watched in a Nova science show that when an object approaches the speed of light, any additional energy that gets put into moving the object changes into mass. (E=mC^2) --Tyw7  (☎ Contact me! • Contributions)   Changing the world one edit at a time! 16:33, 9 January 2011 (UTC)

Yes, that is one way of looking at it, though experts tend to frown on the formula that I learnt in the 1960s: $m={m_{0} \over {\sqrt {1-{\frac {v^{2}}{c^{2}}}}}}\!$ because treating the "extra" like normal mass can lead to error. Another way of looking at the situation is to treat the extra as "super-kinetic energy" (since the ½mv² of normal kinetic energy is the preceding term in the Taylor Expansion), but the preferred modern approach is to talk about momentum where the relativistic momentum is given by :$p={m_{0}v \over {\sqrt {1-{\frac {v^{2}}{c^{2}}}}}}\!$. See Mass in special relativity for details. Dbfirs 17:03, 9 January 2011 (UTC)

Excuse me, what was the question? –Henning Makholm (talk) 17:22, 9 January 2011 (UTC)

I assumed that the OP was asking about the "energy changing into mass" concept, but I agree that there is no question mark. Dbfirs 17:50, 9 January 2011 (UTC)

Car battery

If the positive and negative connectors on a standard 12v car battery were connected with a wire, what would happen? 82.44.55.25 (talk) 18:17, 9 January 2011 (UTC)

The wire would melt and there is a good chance that you would get a fire or explosion. Looie496 (talk) 18:35, 9 January 2011 (UTC)

(edit conflict) See Short circuit#Examples. Karenjc 18:37, 9 January 2011 (UTC)

Do not try this at home. A new fully charged "12 volt" car battery might have an internal resistance of 0.01 ohms, and a short circuit current of 1200 amps. A 1 foot piece of #12 wire (.205 cm diameter) has a resistance of about .002 ohms, so it would not limit the short circuit current much. The contact resistance of the wire to the battery terminals might limit the current more than the resistance of the wire, since the wire end would spark and melt when the connection was made. A #12 wire would heat up red hot and melt, and the battery might explode. A much smaller wire would also melt or vaporize. A battery may have hydrogen gas present above the liquid, which could explode due in a short circuited battery and cause fragments of the battery and the acid to fly around. Edison (talk) 20:34, 9 January 2011 (UTC)

In spite of the risk it is not uncommon for a mechanic to dab lightly the tip of a grounded wire to a battery terminal as a test for voltage. The hot arc at the point of contact melts the lead terminal and the wire tip, hopefully breaking the connection before more damage occurs. It is also possible but not recommended to use a car battery for electric Arc welding where the short-circuit arc is deliberately maintained. Cuddlyable3 (talk) 23:50, 9 January 2011 (UTC)

Many years ago I was working on a Volkswagen Beetle with a 6V battery. I was using a shifting spanner (adjustable wrench) and inadvertently shorted the two terminals with the spanner. Big spark and buzzing noise for the half second until I whipped the spanner way! There was no explosion and the spanner didn't melt. However, it gave me an unpleasant surprise and since then I have been sufficiently careful that it hasn't happened again. Dolphin (t) 02:13, 10 January 2011 (UTC)

A farmer bought a 4-pronged fork and a tractor battery. He tossed them in the trunk (EN. boot) of his car and they bounced around on the bumpy ride home. When he got home he found a cloud of smoke and a 3-pronged fork. Cuddlyable3 (talk) 04:32, 10 January 2011 (UTC)

I never really appreciated electricity, despite sticking my thumb in a 120 volt light socket, until I connected a cliplead incorrectly on a 110 volt DC circuit and saw it light up. Edison (talk) 05:54, 10 January 2011 (UTC)

And that, ladies and gentlemen, is how Edison invented the lightbulb! APL (talk) 21:31, 10 January 2011 (UTC)

Bailey bridge girders

Bailey and similar bridge girders are made of sections that are less than about two or three metres long. What is the mechanism that joins these sections together into a single girder? The bottom of the girder, at least, will be in tension. I have not been able to find any photo or diagram of the joining mechanism. Thanks. 92.15.24.111 (talk) 18:33, 9 January 2011 (UTC)

Most Bailey bridges are assembled and installed in a matter of days by a small crew. Common hand tools are utilized. All connections are pinned, bolted or clamped. No welding is necessary.[23]. The joins on the bottom girder row can be seen in this picture here and here and here is a diagram. Cuddlyable3 (talk) 23:36, 9 January 2011 (UTC)

The 8 15/16" long x 1 27/32" diameter panel pins[24] (which fit into matching holes in each panel) bear the tension between each section[25] and are themselves secured by much smaller safety pins. 71.198.176.22 (talk) 15:40, 10 January 2011 (UTC)

Unfortunately there is no close-up diagram or photo which shows you how the panels lock together, particularly at their base where they will be in tension. The lower locking mechanism is described somewhere as a "knuckle joint" but the only details I have been able to find about a knuckle joint is this: http://www.ejsong.com/mdme/modules/7759G_Mechanical_Design/knuckle_joint/Knuckle_joint.html 92.15.3.168 (talk) 21:00, 10 January 2011 (UTC)

Rotary mechanical toothbrush

Would the rotary mechanical toothbrush shown here http://blog.modernmechanix.com/2006/06/27/hand-cranked-toothbrush/ be good for your teeth according to modern dentistry? It appears that it may be quicker to use and encourage going up and down rather than side to side. Thanks 92.15.24.111 (talk) 18:39, 9 January 2011 (UTC)

I'm no dentist, but it strikes me that the apparatus there would be very hard to use to get all of your teeth cleaned sufficiently. You'd have to turn it at some very odd angles to get the ones in the back done well. In general I suspect the rotational angle of a modern electric toothbrush would be much more superior to the simple vertical axis of the one shown. But again, this is just a conjecture on my part. --Mr.98 (talk) 21:19, 9 January 2011 (UTC)

Genealogy

Hi all! I'm not sure if this belongs here or somewhere or else, but here goes. I think I may have found a long-lost cousin, but I'm not sure. She shares my maternal grandmother's maiden name. Apparently, this girl's mother's aunt's sister may be my grandma's sister. What is this girl's relation to me? I checked the cousin article, but I'm still not sure. Thanks for the help! --68.101.253.196 (talk) 20:19, 9 January 2011 (UTC)

This all depends on whether the girl's mother's aunt was a blood relative of the girl. It might have been the aunt's husband who was the blood relative, in which case you are not related at all, you just have relatives in common. The sharing of the maiden name doesn't make any difference here unless the girl's mother and grandmother retained their maiden names on marriage (or were unmarried). Assuming that the aunt was not an aunt by marriage, and that there are no half-sister relationships, and that the aunt's sister is also an aunt, it seems possible that you could be second cousins because the aunt's sister could have been your grandmother or another sister in the same family, but you would probably not have explained the situation in such a complex way if this had been the case. If your mother and the girl's mother had been first cousins (their mothers being sisters), then they would probably have known this (though I actually know two first cousins who don't know each other). We need to construct a family tree with names to be sure, but a public forum is perhaps not the best place to do this. Dbfirs 20:48, 9 January 2011 (UTC)

If I understand your discription right, then your grandmother is their great-grandmother, this would make the relative your first niece once removed. --Plasmic Physics (talk) 20:55, 9 January 2011 (UTC)

... but a "mother's aunt's sister" isn't a "great grandmother" -- or have I mis-read the confusing relationship? Dbfirs 21:57, 9 January 2011 (UTC)

Sorry, I was confused a bit. I correct myself, the relative would be a second niece, not a first niece once removed. By the sound of it, the aunt, sister and grandmother are all siblings, your mother and the other mother would be cousins. You and ayour second cousin should share a set of great-grandparents. --Plasmic Physics (talk) 22:21, 9 January 2011 (UTC)

I've never met the idea of "second niece" before. It seems to imply different generations. Dbfirs 22:46, 9 January 2011 (UTC)

Replace "niece" with "cousin", wrong use of word. --Plasmic Physics (talk) 00:18, 10 January 2011 (UTC)

Sugar Chirality.

Is it possible to change the chirality of sugar? If so;

• Would it still taste sweet?
• Would it be absorbed by the body and still be fattening?
• If not, could it be used as a dietary aid?

John Cowell.118.208.9.92 (talk) 22:26, 9 January 2011 (UTC)

The article on L-Glucose answers most of your questions. Dbfirs 22:53, 9 January 2011 (UTC)

Tooth Decay/Heat

Since evolution would not have anticipated heating food and drink,have any comparative studies been done on tooth decay of wild primates and other related animals to that of humans?

John Cowell.118.208.9.92 (talk) 23:13, 9 January 2011 (UTC)

Don't know about studies, but, since the teeth cool down to body temperature rapidly, the only risk is if the temperature change is so extreme that it actually cracks a tooth, due to uneven thermal expansion. StuRat (talk) 23:30, 9 January 2011 (UTC)

If you are heating and cooling your teeth so drasticly that they crack, you're probably setting your face on fire anyways, so I doubt that your cracked teeth are your most pressing concern. --Jayron32 01:00, 10 January 2011 (UTC)

Actually not so this says it can happen after 3000 cycles. Especially if you drink hot tea then have ice cream. Then there is Jearl Walker who put liquid nitrogen in his mouth (section 4.7) and cracked some teeth. (He's a fun read.) Ariel. (talk) 01:08, 10 January 2011 (UTC)

Well there ya go. So a) Don't immediately follow hot tea with ice cream 3000 times in rapid succession, and b) don't gargle with liquid nitrogen, and you should be pretty safe from thermal cracking of your teeth. --Jayron32 01:27, 10 January 2011 (UTC)

gasp! medical advice?!? On the reference desk!?! 71.198.176.22 (talk) 14:50, 10 January 2011 (UTC)

Shame. If he had used liquid Oxygen, he would have been cleaning his teeth at the same time. Googlemeister (talk) 17:19, 10 January 2011 (UTC)

For the record, our article on Homo ergaster says that species may have been the first to master fire; they lived around 2 million years ago and evolutionary pressure would have had some impact in the time between then and now. Comet Tuttle (talk) 19:33, 10 January 2011 (UTC)

January 10

Single Photon/Electron emision.

Articles showing the wave/particle duality of electrons and maybe photons demonstrate aiming individual particles at slits with a resultant interference pattern.However they never explain how single particles are produced and aimed(especially a photon which I assume cannot be magnetically influenced). John Cowell. 118.208.9.92 (talk) 00:59, 10 January 2011 (UTC)

Double-slit_experiment#Quantum_version_of_experiment has a description of such an experiment with single (Fock state) photons and has a few references. You could, presumably, follow the references for more details. --Jayron32 01:04, 10 January 2011 (UTC)

Thanks for reference,(though the maths was beyond me) ,the articles did not explain how to produce,aim and fire the particles from an engineering standpoint. John Cowell. 01:36, 10 January 2011 (UTC) —Preceding unsigned comment added by 118.208.9.92 (talk)

Presumably this: [26] reference (from the article) would be at that level of detail. If not, it itself would have references you could follow to earlier descriptions of such methods. --Jayron32 01:56, 10 January 2011 (UTC)

Laser and polarization filter

All the photons in a laser are entangled together, right? Does that mean that if one of the photons passes through a polarization filter, the rest will as well? In other words, do they always either let all or none of the light through? — DanielLC 03:17, 10 January 2011 (UTC)

No, all the photons in a laser are not entangled. And if you had a beam of entangled photons, just because one went through a polarization filer does not mean all of them do. And finally if you did send all the photons in a beam of entangled photons through a polarization filter it does not mean all or none - quite the opposite, some will go through, some won't, and some will end up in sort of a partial state of going though and not going though. But in total, half will end up going through and half won't. Additionally a polarization filter is (one) method of creating entangled photons in the first place. Ariel. (talk) 09:20, 10 January 2011 (UTC)

Some kinds of lasers do produce linearly polarized light, but semiconductor lasers and gas lasers without polarizing Brewster windows do not. 71.198.176.22 (talk) 15:20, 10 January 2011 (UTC)

Zero Transit Time

In days of yore we were told that atoms had a nucleus with electrons "orbiting" at a relatively large distance away.In an airforce avionics lecture we were taught that electrons changed orbit/energy levels/shells/fuzzy balls/etc emitting or gaining energy depending on circumstance and this involved travelling a very small but finite distance in zero time.I feel a warpdrive coming on! John Cowell.04:10, 10 January 2011 (UTC) —Preceding unsigned comment added by 118.208.9.92 (talk)

They were wrong. The evolution of a quantum system, such as an electron, can be calculated with the Schrödinger equation. It is not instantaneous. — DanielLC 04:15, 10 January 2011 (UTC)

They were not entirely wrong. See de Broglie wave. *gets popcorn* 71.198.176.22 (talk) 15:14, 10 January 2011 (UTC)

I've not seen anywhere that de Broglie waves aren't limited by the same physical laws as the objects that are associated with them? --Jayron32 16:53, 10 January 2011 (UTC)

An electron occupying an atomic orbital is in a de Broglie wave more properly associated with a probability distribution than a point, even considered as a solution to the Schroedinger equation. Therefore it can be said to be occupying disjoint space simultaneously whereas a more point-like nucleus can not, until several orders of magnitude smaller distances are considered. 71.198.176.22 (talk) 17:28, 10 January 2011 (UTC)

Yeah, but that doesn't mean the electron "jumps" magically between different points instantly; it just means that a single electron is "smeared out" over a certain volume of space; it is partially and simultaneously in multiple locations. --Jayron32 19:29, 10 January 2011 (UTC)

Motor oil leakage in cold weather

I bought my car knowing that it had some problems; among these is a slow oil leak. I've been advised that a repair job might be difficult (no clue where the leak is, for example) and that it's not at all necessary, so I take care of the situation by checking the oil regularly and adding more when necessary. As we've descended into the North American winter, I've noticed that the oil level changes less between times that I check it, even though I don't think to check it as frequently. Is there any chance that the cold weather reduces the rate at which the oil leaks? Please note that the rate at which I was losing oil before, while not great, was far faster than could be accounted for by the oil that I wipe off the dipstick when I check it. Nyttend (talk) 04:20, 10 January 2011 (UTC)

Motor oil (see article) may increase Viscosity at low temperature, especially if it is not fresh, which could explain the slower leak. Your real problem is to locate the leak so is a web page that can help[27]. Warning: Are you sure it is only motor oil leaking? A leak of brake or transmission fluid is a serious fault that needs immediate attention. Cuddlyable3 (talk) 04:54, 10 January 2011 (UTC)

With modern multigrade motor oils the viscosity shouldn't change that much. Maybe one of the rubber seals is stiffer? Or the cold is causing parts to shrink a bit tightening the gap? Or it could simply be self-sealing (i.e. gunk is blocking the hole) - you won't know till summer. Ariel. (talk) 05:49, 10 January 2011 (UTC)

Does the skull grow at the Sutures?

A regular bone grows from the ends, which eventually fuse. What about the skull? Does it grow from the Sutures? Ariel. (talk) 06:27, 10 January 2011 (UTC)

The flat bones of the skull and face form via intramembranous ossification which is distinct from endochondral ossification (the typical way that long bones grow via the growth plate). This is also discussed briefly in Bone#Formation. The bottom line is that the sutures are where the skull bones fuse together but not where the growth originates. --- Medical geneticist (talk) 11:23, 10 January 2011 (UTC)

electricity through eco friendly means

dear sir,
i have an idea of to produce electricity by using mechanical energy that is produced when a cycle wheel rotates so what are the apparatus to be used and the design and the important thing is that it should be a low cost model —Preceding unsigned comment added by 117.204.69.78 (talk) 09:05, 10 January 2011 (UTC)

I think you mean a generator. But the hard part (meaning the expensive part) is not producing electricity, the hard part is producing the mechanical energy. How are you going to make the mechanical energy? Ariel. (talk) 09:09, 10 January 2011 (UTC)

If you mean a bicycle wheel, I think technically it's an AC magneto, but they're always called dynamos, at least in the UK. They are available quite cheaply, but they don't produce a lot of electricity. See bicycle lighting.--Shantavira|^{feed me} 10:07, 10 January 2011 (UTC)

THe big problem with them is that your lights go out when you stop pedalling. Not terribly safe on a country road. Alansplodge (talk) 13:18, 10 January 2011 (UTC)

There was a TV programme in the UK a year ago in which a team of cyclists tried to power an ordinary house by this method. Their success was limited. Dbfirs 13:26, 10 January 2011 (UTC)

It should be noted that this is only as eco-friendly as your diet and lifestyle. Using beasts of burden (human beings, in this case) is not a very efficient or a priori eco-friendly way to utilize mechanical energy. --Mr.98 (talk) 14:10, 10 January 2011 (UTC)

http://mae.ucdavis.edu/~biosport/jkm/ped_desk.htm 71.198.176.22 (talk) 14:46, 10 January 2011 (UTC)

Engineering

how can we make rotation of fan reverse? — Preceding unsigned comment added by Hk wk (talk • contribs) 11:22, 10 January 2011 (UTC)

An electric fan? If so, reverse polarity of the power source. -- kainaw™ 14:05, 10 January 2011 (UTC)

Or simply turn it round to face in the opposite direction. Whether reversing the polarity at the power source will work depends on the design.--Shantavira|^{feed me} 14:12, 10 January 2011 (UTC)

It depends on the kind of motor it has. You'll probably have to open it and change wiring. A D/C fan can be reversed by changing the polarity. A/C fans are more complicated and it depends on the exact type. Ariel. (talk) 20:21, 10 January 2011 (UTC)

Hiding gold in ink

In the Mr. Monk Gets Married episode of the popular television series, the secret hoard of gold is found to be in the ink of a prospector's journals. Monk says that the prospector had melted down the gold and mixed in black ink, and that "any amateur chemist could do it". Now, I have my doubts - I would expect the ink to evaporate explosively on coming into contact with the molten gold (at over 1000°C). So - is there a way in which an amateur chemist could have hidden his gold in ink? DuncanHill (talk) 11:59, 10 January 2011 (UTC)

Gold paint can be made with powdered gold. I'm not sure of the technical difference between paint and ink, but it could take several volumes of writing to use up one ounce of ink, so I can't see how this would be practical way to conceal any appreciable quantity of gold.--Shantavira|^{feed me} 13:01, 10 January 2011 (UTC)

He did write a lot of journals. I should have mentioned that the ink needs to look like ink and not like gold, as the purpose was concealement. DuncanHill (talk) 13:07, 10 January 2011 (UTC)

I haven't tried this, but it might work with finely powdered gold and high-carbon ink because the gold powder would tend to sink under the layer of carbon. This would not be a very practical method because the concentration would need to be low to conceal the gold. If Monk the prospector had the facility for melting gold, then casting it into an everyday object and painting it to match would be a better option, though care would need to be taken that the object could not be "lifted" (in either sense). Dbfirs 13:21, 10 January 2011 (UTC)

Monk found the gold, it was the prospector who hid it. DuncanHill (talk) 13:25, 10 January 2011 (UTC)

Sorry, I should have read your post more carefully. How did Monk find it? Dbfirs 13:29, 10 January 2011 (UTC)

He had a clue! The prospector had let it be known that his gold could be found in his journals, so everyone assumed you had to read the journals, which Monk started to do. However, they were full of inconsequential ramblings, and eventually Monk realised that the volumes were very heavy, and he realised that the gold was literally in the journals. DuncanHill (talk) 13:32, 10 January 2011 (UTC)

Gold(III) chloride is a green liquid that can be mixed with ink. What one need to avoid however, is anything which will cause the gold to precipitate out as metal. Also, it is a salt and will corrode your nib. --Aspro (talk) 13:48, 10 January 2011 (UTC)

The journals were discernibly heavy? Think of how little ink goes onto a page compared to the weight of the page. Even if the ink was ten times heavier (gold instead of carbon), would you be able to notice the difference between a journal and a journal with writing on? APL (talk) 21:27, 10 January 2011 (UTC)

Why did Alorica close its office in Manhattan, KS?

I tried Googling for it; no straight answers. Also, I called the WORLD HEADQUARTERS of it in Chino, and the lady who answered didn't know either. Does anyone know? Is there a supergoogle they can use to figure out why Alorica closed its doors in Manhattan? Thanks. --70.179.178.5 (talk) 12:22, 10 January 2011 (UTC)

If I get homeless but still have my Dell Inspiron 1720 laptop, how do I make money online with little/no overhead?

My laptop has been all paid off. It was manufactured in Fall 2007 so thanks to the rapidly-depreciating nature of these devices, hardly anyone should think it's worth stealing. (I'd still use a Kensington lock on it.)

So let's say I find a 24-hour coffee shop to camp out in, since I probably might not have much of a choice. I may still have my debit card that I have now, so I could still get started somehow.

However, I might not have all that much money in the first place, so on this laptop, how do I get started on a very-low overhead online business, in order to get back on my feet and earn a living again? What ideas do you have in regards to that? (Ebay's out of the question; with much of my possessions already gone, there isn't much to sell on there. I need to be able to make money without physically possessing much.) --70.179.178.5 (talk) 12:29, 10 January 2011 (UTC)

I can't really help because I had the same idea when I was living on an income below the poverty line, but I didn't find any good money-making schemes. My reason for replying is just to warn you to beware because most of the "money-making schemes" are really just scams designed to defraud you either by asking for money up-front or by paying ridiculously low rates of pay. I hope you have more success than I did, and I hope you don't end up homeless. Is there no ordinary work available in Compton? Dbfirs 12:43, 10 January 2011 (UTC)

What he said. If there were straightforward and reliable ways to make an adequate living from a coffeeshop using only a laptop and their wireless internet connection, I suspect you'd see a lot more people doing so. Unless you can actually come up with a solid business plan for yourself and you have some particularly desirable (valuable!) skills that you will be able to market and use effectively over the Internet, then you're probably better off just getting a job working at the coffee shop. TenOfAllTrades(talk) 13:58, 10 January 2011 (UTC)

Proof-reading, translation, website design, marketing consultancy, but you have to have the necessary skills. Either use your existing contacts to drum up business or sign up with agencies. Itsmejudith (talk) 14:34, 10 January 2011 (UTC)

If you have to ask, then I really doubt if you have the entrepreneurial qualities to exploit the opportunities out there. For instance; you dismiss Ebay -why? You might not have stuff but you do have time on your hands and other people are always throwing away stuff and may even be willing to pay you to take it away, which you can then sell on Ebay. Via Ebay you can advertise your website (you do have a web site don't you) on which you can also advertise other peoples products and get another income stream (but this will be usually peanuts)(that said, the local cat-house might offer good rates of several dollars a click if you can show you are attracting lots of local traffic to your site). You can also use it to advertise your own personal services which you can do because of all that time on your hands. With time on your hands you can travel out and about -take a compact camera with you which can also record video. Keep an eye out for trouble and sell the footage to news channels. Even local papers might of a few dollars for a good action photo. Bank robberies in progress etc., you can syndicate world wide for bigger bucks. Upload to the studio immediately from the scene of the crime. If your out every day you will see these opportunities. Also, for every 20 local businesses you ask. about two will be willing to have a sort video advert posted on Youtube (taken with you camera – with your personal testimony voice-over that it is the kebab shop in Compton or whatever ). Again place links to your website (and their's of course) etc., etc. You have to work as hard at it, as any other job. Plan for being told NO! 25-30 times a day. The few that say 'yes' will more than make up for those that say no. Do lots of small cheap jobs and those bigger ones will just come along by themselves unexpectedly. Don't forget to put money aside for paying taxes.--Aspro (talk) 14:37, 10 January 2011 (UTC)

"Compton"? Two people mentioned Compton. The IP geolocates in Manhattan, Kansas. Keep an eye on Craigslist for your area. 71.198.176.22 (talk) 16:07, 10 January 2011 (UTC)

You can Turk. Its generally small amounts of money, but if you have time and select jobs wisely, you can make a reasonable amount of cash doing it. --Jayron32 16:09, 10 January 2011 (UTC)

But do not accept any jobs that offer payment for writing WP articles.--Aspro (talk) 16:25, 10 January 2011 (UTC)

A lot of web money-making opportunities are not simple things that you can turn on like a switch. For instance some blogs and webcomics are profitable, but only after years of slowly gaining a readership and a following. They're essentially creative businesses that have to be slowly built up from absolute zero. APL (talk) 17:49, 10 January 2011 (UTC)

I think the safest choice is to put all your energy into getting a normal job working 8 hours a day, and once you have landed that and thus secured the means of survival, in your spare time use the laptop to learn a computer-based marketable skill like web design or computer programming or database programming or 3D modeling or the like. Do whatever you can to network with like-minded professionals. After a year or two of such training, depending on how far you progress, you may have enough experience to build a decent portfolio and apply for jobs in a more lucrative field, thus beginning a career. Comet Tuttle (talk) 19:20, 10 January 2011 (UTC)

Agreed. Tech job stuff is high risk (and no benefits) even in better economies, and when one has resources to fall back upon. The best "no skills required" jobs I've seen lately are working at Whole Foods, which has excellent benefits plans and huge discounts on food. But really anything is better than trying to make money from your laptop when you have no home. --Mr.98 (talk) 19:46, 10 January 2011 (UTC)

Cheapest source of ethanol for sterlisation

A while ago, I asked where is the cheapest place for ethanol (for sterilisation) in the UK and it now seems to me that we already have a reasonably-priced source, compared to alternatives that I've checked. The cost is £6.60 for 2.5 L analytical grade (100%), or £2.64/L. How much do you pay per litre at your laboratory? ----Seans Potato Business 15:40, 10 January 2011 (UTC)

Linearization

Hi! I have to linearize a hyperbolic graph. Data: x:1,2,3,4,5,6,7,8 y:8,1;4,7;3,1;2,0;1,4;1,0;0,7;0,5. I've already squared x bu got a hyperbola again. Please help. — Preceding unsigned comment added by Atacamadesert12 (talk • contribs) 18:02, 10 January 2011 (UTC)

Have you tried taking the inverse or the inverse square or the inverse cube of the data? --Jayron32 19:25, 10 January 2011 (UTC)

frost on windows of vehicles

why does frost form on my cars windshield when parked outside my carport, but none when parked inside? —Preceding unsigned comment added by 72.45.79.233 (talk) 19:37, 10 January 2011 (UTC)

It is dew from the air that sort of "rains" down on it. In a carport there is little air, and so, little dew. Ariel. (talk) 20:20, 10 January 2011 (UTC)

Frost may also form without any intermediate liquid form; it may form via deposition. But broadly speaking, the relative humidity still controls when and where frost will form. --Jayron32 20:33, 10 January 2011 (UTC)

Those responses are correct but they leave out an important factor. A solid object exposed to the sky on a clear night will lose a lot of heat by radiating to space -- the result is that things like cars can become a lot colder than the surrounding air. If there is a cover over the object, it radiates heat back, greatly reducing this effect. Even a cloud cover will considerably reduce radiative heat loss. Looie496 (talk) 20:59, 10 January 2011 (UTC)

MnCl2 formation

Why doesn't the reaction of various manganese salts such as manganese dioxide or manganese carbonate with hydrochloric acid not make a light pink solution? The user here had the same result. --Chemicalinterest (talk) 20:40, 10 January 2011 (UTC)