Wikipedia:Reference desk/Archives/Science/2009 May 25
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May 25
[edit]Casino Royal Poisoning Scene
[edit]In Casino Royal, 007 is poisoned by digitalis and develops V-TACH. That would not occur, as digitalis SLOWS the heart rate. Why don't the movie producers take a few minutes to verify the medical scenes in their movies?
P.S. the poison was probably modeled off atropine, as victims of atropine poisoning exhibit the same symptoms as in the movie.
Pilotbaxter007 (talk) 00:11, 25 May 2009 (UTC)
- Interesting. Our page on ventricular tachycardia in popular culture does assert that this was a mistake in the movie. However, that statement is incorrect as far as I know, so I checked the source and found it much less reliable than our usual standard. Here is a reliable source, and here is another, to show that digitalis at high levels can cause ventricular tachycardia. So, I will correct our page. --Scray (talk) 02:05, 25 May 2009 (UTC)
- For those still interested, our article on adverse effects of digoxin does (correctly) list ventricular tachycardia. --Scray (talk) 02:10, 25 May 2009 (UTC)
- A movie where the hero saves the world with a lucky draw to an inside straight is probably not one with a whole lot of reality checks. -- Tcncv (talk) 06:39, 25 May 2009 (UTC)
- No, see, Bond was so skilled that he got great cards! Ghh. That whole poker thing was the low point of an otherwise fine movie. Could you perhaps explain this "tell" thing one more time? It's such a complex concept! -- Captain Disdain (talk) 11:53, 25 May 2009 (UTC)
Virginity -- Celibacy
[edit]If a person is virgin for life... I mean, (i.e. a Catholic priest)... are there risks of diseases, or something like that? --190.50.95.157 (talk) 00:18, 25 May 2009 (UTC)
- Are you asking whether someone can get an STD without having sex? The answer is yes—some are spread through alternative means (e.g. HIV in blood transfusions) that may or may not be very likely, but can occur. Are you asking if being celibate by itself will give you diseases? No. --98.217.14.211 (talk) 00:33, 25 May 2009 (UTC)
Exactly, I ask if celibate itself could give you any disease. --190.50.95.157 (talk) 00:37, 25 May 2009 (UTC)
- No, it won't.--98.217.14.211 (talk) 02:01, 25 May 2009 (UTC)
- I have read (I can't remember where) that because males do not stop making sperm, that a persons testicles could become overful causing a very painful, but if treated harmless, disease.Drew Smith What I've done 04:27, 25 May 2009 (UTC)
- Doesn't regular ejaculation decreases the risk of Prostate cancer? But then there are ways around that one... --antilivedT | C | G 05:41, 25 May 2009 (UTC)
- (EC - twice) On the other hand (no pun intended!) I've heard that ejaculating too often has been linked as a possible cause for prostate cancer. --KageTora - (영호 (影虎)) (talk) 07:38, 25 May 2009 (UTC)
- That's just ridiculous. The idea that all of the sperm just stay alive indefinitely and keep swimming around in the testicles is silly to begin with; no other cells in our body manage to keep from dying, so why would sperm be exempt from this? The body will reabsorb any excess semen. It's not a problem. -- Captain Disdain (talk) 08:56, 25 May 2009 (UTC)
- This is persistent myth, e.g. for the cause of nocturnal emissions. I'm not going to boldly assert that people who never ejaculate have no long-term health differences from those who do so regularly; for all I know it may affect hormone production, with consequent auxiliary effects. But I may assert that there have been no serious experiments one way or the other. Dcoetzee 06:54, 26 May 2009 (UTC)
- But that does not imply that not having regular ejaculations causes prostate cancer. Sperm that is not ejaculated is reabsorbed into the body. The idea of huge testicles indicating complete celibacy is a nice idea but untrue. There are cases of enlarged testicles [1](work safe) but the causes are well documented. 86.4.190.83 (talk) 07:36, 25 May 2009 (UTC)
- See Prostate_cancer#Ejaculation_frequency for more information. AndrewWTaylor (talk) 16:40, 26 May 2009 (UTC)
- Nuns and other women who never give birth are more prone to breast cancer, per [2]. It seems to be the giving birth rather than the sexual intercourse that makes the difference. This was documented back in 1713 and confirmed since. Edison (talk) 18:36, 26 May 2009 (UTC)
Strange aircraft wing
[edit]I've recently seem some very strange aircraft, and this article (http://englishrussia.com/?p=2331) says it has huge advantages compared to more classical designs. Obviously, it should have it's flaws, because else nearly every aircraft would be designed lika that. Does anyone have any ideas about this? Besides, it's strange that it has no article here, as Elliptical wing means something completely different. --131.188.3.21 (talk) 09:57, 25 May 2009 (UTC)
- My guess is that this would behave much like a biplane and have the same advantages and disadvatages. Aircraft were originally built as biplanes mainly for structural reasons - a single canvas wing is very difficult to tension - but once aluminium started to be used strong monoplane wings could be built. A biplane has greater lift than a similar sized monoplane but it is not twice as much because the vortex of the two wings tend to cancel in the space in-between the wings. Monoplanes are therefore more efficient in terms of lift per unit area of wing. This elliptical design gets a good separation between the top and bottom aerofoil surfaces so the negative effects may be somewhat lessened. Like a biplane, it is likely to have good manoeuvarability and short takeoff and landing characteristics, but I have not been invited to fly one, so as I say, I am only guessing. SpinningSpark 10:55, 25 May 2009 (UTC)
- I have no idea whether that's real or not, but this being the internet, the picture could simply be fake. I suspect it is; the design seems pretty senseless, and I can't find a single YouTube video featuring such a plane, at least not with the words "elliptical wing". In fact, even fairly rigorous Googling only reveals those very same pictures all over the net...
- In any case, even if it was real, your logic is a little iffy: saying that the design must be faulty, because otherwise every aircraft would be designed like that presupposes that people instantly arrive to the best solution. I mean, why didn't the Wright brothers build a stable aircraft right from the beginning instead of the flawed contraption they had? Well... you gotta start somewhere, and if you hit upon a design that works (not that the Wright brothers really did, but anyway), it can remain essentially unchanged for a long time simply because it's good enough. (The M1911 pistol is a great example of this: it's still being used by some armed forces, even though the basic design is over a hundred years old. There are far more advanced sidearms out there, but it's a popular classic.) It can take a long time for a genuine innovation to arrive and really make an impact. -- Captain Disdain (talk) 10:57, 25 May 2009 (UTC)
- Oh, I think the photos are real: at least the ones at the top of the page, the bottom two are obvious fakes. What I don't believe is that it has ever got off the ground, and you would be quite foolhardy to take off in something you had bolted together in your back yard and has a side panel that looks like it's been in a car crash. There are no (unfaked) pictures of it actually in the air, although the engine and prop are clearly working. SpinningSpark 17:30, 25 May 2009 (UTC)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/f/f3/Ba_b747-400_g-bnle_arp.jpg/200px-Ba_b747-400_g-bnle_arp.jpg)
- For a small aircraft that needs high manouverability, I could imagine this thing being interesting. However, it loses the benefits of 'dihedral' (which imparts inherent stability) - it will be hard to fly (although computerized fly by wire controls could fix that). Who knows what construction difficulties and structural strength this design might impart? The claim for high efficiency comes about because with conventional wings the higher pressure air under the wing tends to 'leak' around the wing-tips into the low pressure air that's on top of the wing. That wastes lift and causes tip-vortices which increase drag. This wing has no tips - but the high pressures under the lower section of the ellipse can still move around to the low pressure over the top section - but that's a much larger vortex. But then the high pressure under the top section will push around into the low pressure over the bottom section - creating a counter-vortex. It's really hard to predict the results of these two counter-acting effects. The 747-400 (see picture at right) has little wing-tip fins that attempt to 'dam' that air. I dunno - it's hard to imagine someone like NASA wouldn't already have tried this if it had widespread benefits...they've tried some pretty weird designs in the past so it's not like there is a lack of effort in innovating wing shapes. SteveBaker (talk) 13:26, 25 May 2009 (UTC)
- Although that particular aircraft has no dihedral, there is no essential reason that wings in that format could not be given dihedral so I don't think that dihedral is an essential drawback to the ellipse-wing. Besides which, stability is not always a good thing. Stability and manoeuvarability are exchangeable and are a compromise on all aircraft; for military fighter aircraft manoeuvarability has overriding importance and for this reason, amongst others, stability is often low. Likewise aerobatic aircraft want manoeuvarability over stability. The Cessna 152, for instance, is so stable that you can put it into a stall, let it start dropping like a stone and then let get of all the controls. The aircraft is so stable that it will pick up speed, start flying again and then level out into straight and level flight all by itself (warning: don't try this at home) as if it had an autopilot. On the other hand, it is no fun to fly, equivalent to exchanging a sports car for a minibus. Likewise with the winglets, there is no essential reason they (or some other wingtip device) could not be fitted to an ellipse-wing, although I am unconvinced that there is a need for them. The smooth shape of the ellipse-wing at the "tip" will encourage laminar flow, removing one of the reasons for them. SpinningSpark 15:50, 25 May 2009 (UTC)
derating factor
[edit]What is the power derating factor? —Preceding unsigned comment added by 82.212.71.164 (talk) 11:06, 25 May 2009 (UTC)
- cats?--131.114.72.215 (talk) 11:10, 25 May 2009 (UTC)
- I prefer ferrets myself. SpinningSpark 11:18, 25 May 2009 (UTC)
Steam II
[edit]Occasionally there is a reference to "Steam II" as if there are two phases of steam. However even this rather complicated phase diagram of water, which identifies a grand total of eleven different phases of ice, does not mention steam II. Would it be steam in the supercritical region? SpinningSpark 11:14, 25 May 2009 (UTC)
- Could it be anything to do with this industrial cleaner[3]? Mikenorton (talk) 12:29, 25 May 2009 (UTC)
- No, I'm definitely talking about phases of matter and not the trainers or the locomotive magazine or the make of paint dryer or the make of boiler. An example of its use is in this article. I first saw it on an Open University program, I was not really paying attention to it, but I believe I saw a phase diagram with "Steam II" marked on it. SpinningSpark 12:57, 25 May 2009 (UTC)
- The title of the article that you linked doesn't say quite what it seems to, it's the second part of a two-part article, this is the first [4]. Mikenorton (talk) 13:13, 25 May 2009 (UTC)
- No, I'm definitely talking about phases of matter and not the trainers or the locomotive magazine or the make of paint dryer or the make of boiler. An example of its use is in this article. I first saw it on an Open University program, I was not really paying attention to it, but I believe I saw a phase diagram with "Steam II" marked on it. SpinningSpark 12:57, 25 May 2009 (UTC)
- Doesn't answer your question but according to Ice#Phases there are at least 16 forms of ice of which 15 have been proven, or 17/16 if you count amorphous ice Nil Einne (talk) 13:08, 25 May 2009 (UTC)
- Hmm, that article could do with a phase diagram could it not! SpinningSpark 13:37, 25 May 2009 (UTC)
- I am amazed that there really is an Ice-9. I mean, I'm not, because there's also a thagomizer, but I'm surprised the table doesn't somehow center on Ice-9. Tempshill (talk) 19:53, 25 May 2009 (UTC)
- Hmm, that article could do with a phase diagram could it not! SpinningSpark 13:37, 25 May 2009 (UTC)
- This also doesn't answer your question but there can be at least four different phases in supercooled liquid water.[5]Mikenorton (talk) 13:52, 25 May 2009 (UTC)
Gray hair
[edit]I have asked this question three times before. Each time, there is no answer because the topic is quickly derailed by discussions of artificially colored hair. Therefore, I want to make this clear: I am not in any way interested in any discussion of artificially colored hair.
When hair turns gray, I have always seen a hair that is gray from root to end. My hair is dark brown and my gray hair is actually white. I have no hairs that are brown on the end and white at the root. This makes me wonder... Do hairs turn from natural color to gray? If so, how does the entire hair change color? Do the gray hairs come from a different follicle than the natural colored hair? I'm just wondering why I never see a hair that is brown on one end and white on the other. -- kainaw™ 15:32, 25 May 2009 (UTC)
- From personal experience, I have come across hairs that are coloured near the end and grey/white at the root, but very few. In those hairs there is a short (~1 cm) transition zone of decreased pigmentation rather than an abrupt loss of pigmentation. I suspect the reason that they are hard to find is that there are so many hairs on your head. Those that are in the midst of losing their pigmentation are hidden among the other hairs. They only become noticeable when you get your hair cut, and cut hairs likely would have removed the coloured bit. -- Flyguy649 talk 15:52, 25 May 2009 (UTC)
- I am in agreement with Flyguy649, with the additional note that white hairs are often thinner and more brittle than coloured hairs. It could be that the bi-coloured hairs are more likely to break off and be lost due to the tip being to heavy for the white base. Matt Deres (talk) 15:56, 25 May 2009 (UTC)
- Each individual hair is produced by a single folicle. Each folicle loses its ability to produce color at a different age. So, hair produced by a folicle before the loss is colored, and after the loss the new hair is gray. Therefore, the timr it takes for particular hair to becoem completely gray is the time it takes to grow from root to tip, which in turn depends on the length of the hair. Most hairs are eithr all colored aro all gray because the time is relatively short in comparison to the time span over which all your folicles lose their coloring ability. -Arch dude (talk) 20:59, 25 May 2009 (UTC)
- There was a recent article on sciencedaily.com about grey hair here. The gist is that hair goes white because our bodies naturally produce bleach, and as we age we are less able to remove that bleach. The article also says that hair goes white from the inside out. Quietmarc (talk) 22:03, 25 May 2009 (UTC)
- Dominant guerillas, I think, known as Silverbacks, have their fur turn grey even though they are only 12 years old. So hair turn grey may be by evolutionary 'deign' rather than just a side-effect of age. 89.242.123.98 (talk) 23:54, 25 May 2009 (UTC)
- Each hair follicle does not keep producing hair constantly. Instead, there is a cycle of growth, quiescence, hair loss, and then renewed growth. While I don't have anything to show this is the case, I imagine that the color loss may occur during the quiescent to renewed growth phases. In this way each individual hair shaft is either entirely colored or entirely gray. -- 128.104.112.37 (talk) 00:32, 26 May 2009 (UTC)
- And look at me, I was trying to picture Che Guevara with a nice silver streak running through his mane... --Jayron32.talk.contribs 04:23, 26 May 2009 (UTC)
- It occurs to me that if you can't get a satisfactory answer from reliable sources, it would be a good idea to ask or look into the situation for a traditionalist/adherent Sikh, Rastafarian or someone else who never cuts their hair Nil Einne (talk) 22:00, 26 May 2009 (UTC)
- This report on a joint study by the Universtiy of Bradford and a German uni Mainz might help [[6]]. Couldn't get a hold of the original report.71.236.24.129 (talk) 04:34, 27 May 2009 (UTC)
- As an aside, its probably not a good idea to compare the mechanism of hair colour of other mammals to that of humans. Most mammals have striped hairs - in that there are bands of different colours. For example, of you look at the pelt of a wild mice - that typically looks brown - you will notice that each hair shaft is actually is yellowish at the tip and black nearer the root. The sum of this gives the brown hue to the pelt. This type of hair pattern is called agouti after the eponymous rodent. This is caused by the pulsatile expression of the Agouti signalling peptide around the hair follicle, which switches the production of pigment from black to yellow. ASP is only turned on during the early growth phase of each hair, therefore only the tip of the hair is yellow. By modifying the Agouti gene locus so that that peptide is expressed at different times or in different parts of the body one can get animals of all sorts of hues. The silverback gorilla is likely to use a modified version of this system. However during human evolution, we appear to have lost this signaling system, so we no longer have banded hairs under genetic or hormonal control. In contrast, our hair turns white when the follicular melanocytes die. As others point out above, there may be a few human hairs that "fade to grey" along their length, but the likelihood of finding one is small, due to the timespan it occurs in. Rockpocket 06:19, 27 May 2009 (UTC)
- Totally OT, but an e-pony/mouse would surely be something to behold. 87.81.230.195 (talk) 15:56, 29 May 2009 (UTC)
- Thanks. I want to note that I've already written a lot about ASP in hedgehogs. Hedgehog quills are normally tri-band. Through inbreeding, there are many mutations that cause a lot of variety in the tri-band colorings. However, none have come out blue yet. -- kainaw™ 12:34, 27 May 2009 (UTC)
Racism and science.
[edit]Why is racism a scientifically wrong belief? The article on racism doesn't explain it clearly enough. Thanks in advance, ― Ann ( user | talk ) 15:49, 25 May 2009 (UTC)
- Because there are no scientifically reliable methods of discriminating races from each other. The methods that can be used (such as using haplo-groups) often have little to do with the conventional races at all. Also, you would need to specify which brand of racism you want to talk about. Most racism has nothing to do with rational thinking in any case. Since science attempts to be rational, the two have little to say to one another. Matt Deres (talk) 16:03, 25 May 2009 (UTC)
- (edit conflict) There is no scientific evidence that can't be explained by differences in culture. It also hasn't been proven that the cause is differences in culture rather than being of different intelligence, so it isn't so much scientifically wrong as just not scientific. If there is a difference, it's not that big, so anything more than mild racism is scientifically debunked. It should be noted that if there is a small difference in the intelligence of different races, that doesn't mean that it's in the direction a lot of people seem to think it is. Also, even if there was a difference, it couldn't easily be said which was better. For example, there is a clear difference in how men and women think, but there's no agreement as to who is more intelligent. — DanielLC 16:10, 25 May 2009 (UTC)
- It's also of note that any racial differences are probabilistic over the aggregate of a population. So what you're saying is, "in a given population (defined in some sort of useful way), the average IQ is X." But that doesn't tell you anything about individuals within the population, which is how racism is always practically expressed—you don't get the job not because you don't have the ability, but because you are a member of a population that on the aggregate has different abilities than others. You can illustrate how silly this is by doing the reverse (boosterism)—imagine being asked if someone is a good basketball player on the basis of their race alone. The idea is completely silly—any individual member of a race could be a good or bad basketball player, even if on the whole for a variety of reasons some races might on average produce better basketball players than others.
- The definition of "race" is itself scientifically problematic—there are no "pure races" and never have been. The most rigorous scientific definitions are still very probabilistic—people who live in a given area have a certain higher percentage of having certain combinations of genes than people who come from other areas. In reality there is a graduate spectrum of relatedness among the human species.
- Lastly, the question can never be is "racism" scientific—racism is a form of social judgment that sits on top of questions of racial difference. Are there racial differences? Obviously some (on average)—some of which are easy to measure (skin tone variations) some of which are hard (intelligence, which is hard to measure even under ideal circumstances). Whether one thinks that justifies discrimination is an entirely non-scientific question (it is a philosophical or political question). --140.247.241.193 (talk) 19:42, 25 May 2009 (UTC)
- One of the problems is the meaning of the word itself. Scientifically, racism means the view that people from different origins have different characteristics besides their look. So, saying that someone from African descent and with dark skin tolerates a hot climate and sunburn better than a Caucasian, and the later tolerates cold and a lack of sunbathing better - which is obviously true - would still be considered racism? The problem with this is that the word "racism" means today just "something very evil" and nearly nothing else, and actually used to discredit some other party even if they didn't mean to discriminate people based only on "racial" descendence. I think this discussion would more likely fit the humanities desk, as the world racism has mostly propagandistic uses. Besides, with this current usage, no one even dares to study or write about racial differences, and writing "racism is scientifically wrong just because it's wrong" is a must, if you do not want to be labeled as someone very evil.
- Of course, racism in it's current usage is wrong, as the behavioral differences seen in statistics are caused by cultural, educational or other social heritage, and not by biological makeup.
- The interesting, and sad thing is, that forcefully denying the above mentioned behavioral differences (and calling everyone a racist who mentions them) actually leads to increase racism, rather than solve the problem. Of course, saying that these behavioral differences are cause by the genetic profile of that specific group is equally wrong. I prefer referring as racism only to this last example, and not how most politicians tend to use it. --131.188.3.20 (talk) 20:46, 25 May 2009 (UTC)
The original poster may be interested in the overlong article Race (classification of human beings). It discusses the history of the concept, and four current ways that it's used as a classification, objections to all of them, etc. Tempshill (talk) 23:27, 25 May 2009 (UTC)
- Racism is like claiming that within a species, there are breeds that are better at some activity than other breeds. Aren't all horses equally able to run a race or pull a plow? Aren't all dogs equally able to track, pull a sleigh or herd ruminants? Don't all pigeons have the same homing ability? Edison (talk) 00:47, 26 May 2009 (UTC)
- Was the answer to those questions supposed to be no? A Chihuahua can't pull a sleigh nearly as well as a Great Dane. In any case, that's not very scientific. You have to actually check, you can't just say what it should be. — DanielLC 05:11, 26 May 2009 (UTC)
- Racism might be more like assuming that dogs of some particular color are more likely to bite you than others. But Temple Grandin, animal scientist, claims that the selective breeding which led to chickens which lay white eggs has left the hens more prone to stress. White lab rats have behavioral differences from wild rats of various fur colors. Minor physical or coloration differences between subgroups of an animal species may correlate to varying extents with behavioral differences. I have heard intelligent and well educated people assert that there simply cannot be any differences in intelligence, aptitudes or physical abilities between races, on the same principle that there should not be discrimination between different races. Edison (talk) 18:30, 26 May 2009 (UTC)
- Yes, clearly there are the possibilities of differences on average between population groups, and anyone who disagrees with that on the face of it is probably doing so for primarily political reasons. But dogs are a very poor comparison—dog breeds are very carefully developed exercises in inbreeding over tens of thousands of generations with relatively small population sizes for specific characteristics that often are at the expense of others. There is nothing comparable in humans, and the differences between human races are really quite slight when compared to differences between dog breeds. (Temple Grandin is careful to point out that what she says about domesticated breeds does not apply to human races, if I recall.) --140.247.251.62 (talk) 18:49, 26 May 2009 (UTC)
- Racism might be more like assuming that dogs of some particular color are more likely to bite you than others. But Temple Grandin, animal scientist, claims that the selective breeding which led to chickens which lay white eggs has left the hens more prone to stress. White lab rats have behavioral differences from wild rats of various fur colors. Minor physical or coloration differences between subgroups of an animal species may correlate to varying extents with behavioral differences. I have heard intelligent and well educated people assert that there simply cannot be any differences in intelligence, aptitudes or physical abilities between races, on the same principle that there should not be discrimination between different races. Edison (talk) 18:30, 26 May 2009 (UTC)
- Was the answer to those questions supposed to be no? A Chihuahua can't pull a sleigh nearly as well as a Great Dane. In any case, that's not very scientific. You have to actually check, you can't just say what it should be. — DanielLC 05:11, 26 May 2009 (UTC)
- Racism is like claiming that within a species, there are breeds that are better at some activity than other breeds. Aren't all horses equally able to run a race or pull a plow? Aren't all dogs equally able to track, pull a sleigh or herd ruminants? Don't all pigeons have the same homing ability? Edison (talk) 00:47, 26 May 2009 (UTC)
- There are two entirely separate things going on here. It is entirely scientific to say that there are races - and that they are different in many ways. We know (for example) that people of African descent are more prone to sickle-cell anaemia...it's a fact - there is no point in denying it. There are LOTS of differences between people of different races. It's scientifically valid (but not entirely politically correct) investigate those differences.
- HOWEVER, what is entirely UN-scientific is to discriminate between individuals on the basis of race. The variations between individuals of one race are generally far greater than the differences between races - so to pick one individual and to treat him/her differently because of the color of his/her skin is entirely illogical and unscientific.
- SteveBaker (talk) 01:32, 26 May 2009 (UTC)
- Actually, I think that is inaccurate. First, of course, we are all "People of African descent". But secondly, people with a a long ancestry from malaria-prone areas are more prone to sickle-cell anemia. Many Africans are, but then, many are not. By lumping them all together, you are artificially creating a "race" that, quite by accident, shares this property, while the actual cause only applies to a sub-population. "Races" are social constructs with fairly limited predictive power about the non-obvious criteria - in Brazil, for example, your income and life style influence your perceived skin colour... --Stephan Schulz (talk) 07:26, 26 May 2009 (UTC)
- Actually for the malaria thing, it's more complicated then that, see thalassemia Nil Einne (talk) 21:53, 26 May 2009 (UTC)
- I'm surprised this hasn't already come up but I think this is highly relevant to the discussion race and genetics. A key part IMHO "The 0.1% genetic difference that differentiates any two random humans is still the subject of much debate. The discovery that only 8% of this difference separates the major races led some scientists to proclaim that race is biologically meaningless. They argue that since genetic distance increases in a continuous manner any threshold or definitions would be arbitrary. Any two neighboring villages or towns will show some genetic differentiation from each other and thus could be defined as a race. Thus any attempt to classify races would be imposing an artificial discontinuity on what is otherwise a naturally occurring continuous phenomenon.". While not everyone agrees "However, other scientists disagree by claiming that the assertion that race is biologically meaningless is politically motivated and that genetic differences are significant. Neil Risch states that numerous studies over past decades have documented biological differences among the races with regard to susceptibility and natural history of a chronic disease. Effectively Neil Risch is attempting to redefine "race" for human populations to represent that small proportion of variation that is known to vary between continental populations." I don't think it is fair, or logical to dismiss all scientists who argue that race is biologically meaningless as just letting their political beliefs get in the way. I would say that both sides are likely influenced by their political beliefs but regardless, it doesn't mean there aren't valid scientific reasons to argue both ways about whether race is a meangingful scientific concept. This doesn't mean people dispute that certain genes are more strongly associated with certain groups if you choose to define such a group in some way Nil Einne (talk) 21:53, 26 May 2009 (UTC)
- Actually, I think that is inaccurate. First, of course, we are all "People of African descent". But secondly, people with a a long ancestry from malaria-prone areas are more prone to sickle-cell anemia. Many Africans are, but then, many are not. By lumping them all together, you are artificially creating a "race" that, quite by accident, shares this property, while the actual cause only applies to a sub-population. "Races" are social constructs with fairly limited predictive power about the non-obvious criteria - in Brazil, for example, your income and life style influence your perceived skin colour... --Stephan Schulz (talk) 07:26, 26 May 2009 (UTC)
- This is a pretty complicated question. One might reasonably say that, given no other evidence about two people other than their races, you may prefer one over another for a certain job or task, since race conveys limited statistical information about a person. Irrational decisions arise in situations where the statistical information supplied by race is given disproportionate emphasis over the direct information supplied by examining the individual; or over information about the individual that could be easily obtained. Irrational decisions also arise in cases where the statistical information supposed to arise from race has no basis in experiment, or those experiments are procedurally faulty (as in the case of most scientific racism). To give a ludicrous example, young males tend to break bones more often young females; therefore, given a random young male, you'd be more likely to conclude that their leg is broken than when given a random young female. On the other hand, a much better way of determining this is to actually examine their leg. Dcoetzee 06:39, 26 May 2009 (UTC)
casimir effect pressure anomalies
[edit]Hello
Alot of talk about zero point or vacuum energy has been passed around lately and its been used to explain everything from telepathy to gravity. Loads of it is complete hocum some is not. I was wondering if you guys could help clear something up for me. I recently read an article that proposes that changes in the state of this vacuum energy either on its own or to cause upsets in air pressure etc could mave objects. Is this possible if not yet proven and what is the view of the general scientific community on this idea. I read it was considered as a means for space propulsion. Note I am not talking about psychic connections, healing, living universe etc, just wether the changes in the vacuum could conceivably move objects.
Thanks. —Preceding unsigned comment added by 79.68.254.143 (talk) 16:01, 25 May 2009 (UTC)
- Do you have a link to the article? Generally speaking it's deeply unclear what ought to count as "vacuum" in modern physics. If there are vacuum disturbances that can exert forces on objects then we're likely to decide to give them some other name than "vacuum", making the vacuum inert by definition. That's pretty much what the known particles and forces are, fluctuations of the vacuum that we've decided to call by different names. Note this includes the Casimir force, which is no more or less an effect of vacuum fluctuations than anything else. -- BenRG (talk) 19:02, 25 May 2009 (UTC)
The article was on the new scientist and suggested a vacuum energy sail, ill try find a link. Think it suggested a polerization of the vacuum so one side vibrates more and thus exerts more pressure on one side, thus moving it. Like the casimir effect except instead of pushing the two mirrors together only pushing one side.
thanks —Preceding unsigned comment added by 79.68.254.143 (talk) 21:08, 25 May 2009 (UTC)
- I haven't had a chance to dig up this particular New Scientist article yet, but I would urge its readers to be particularly cautious when new inventions which (apparently) violate conservation of momentum laws appear. The most recent major screwup – of which I am aware, at least – was in 2006, when they published a very credulous cover story on the EmDrive. TenOfAllTrades(talk) 12:52, 26 May 2009 (UTC)
Here a link to what I think is the article. http://www.quantumfields.com/slow-lane.gif its an image. tell me what you think? —Preceding unsigned comment added by 79.68.254.143 (talk) 14:26, 26 May 2009 (UTC)
- Thanks for the link. This doesn't look like reactionless propulsion, it looks like a very roundabout description of a photon drive, i.e. a rocket that emits light for propulsion. In other words, it's a Rube Goldberg flashlight. The whole vacuum-fluctuation angle doesn't make it a better source of photons. For that matter I could probably figure out a way of attributing the operation of an ordinary battery-powered flashlight to vacuum fluctuations. That New Scientist reported on this doesn't mean anything. I think it was once a good physics magazine, but it's pretty cringeworthy these days. They seem to have no knowledgeable physicists on staff and a lot of their articles are basically press releases for kooks. This looks like it's in that category. -- BenRG (talk) 21:20, 26 May 2009 (UTC)
- I agree with that. I wouldn't recomend the New Scientist to anybody that actually wants to learn anything about real science. Scientific American is still a better choice of science-to-the-public magazine than any other I've seen. Dauto (talk) 15:17, 27 May 2009 (UTC)
the color of protons/nutrons
[edit]There are so many different elements and many of them are different colors. Though they are all made of the same things protons nutrons and electrons? How can somthing made from the same things have so many different colors? how can a material be a different collor just because it has a dirrerent amount of nutrons electonrs or protons? So if we could look at a seperat nutron of sepret proton what color would it be? --76.236.178.7 (talk) 16:27, 25 May 2009 (UTC)
- Your understanding of colour seems to be wrong. I'm not an expert in the area, but the A-level chemistry explanation is that photons from a light source (e.g. the sun) are absorbed by the electrons of an object, which causes excitation of the electrons, so the jump up to a higher "energy state". When the electron falls back to its ground state, an electromagnetic wave is emitted. In chemicals that we see as coloured, this wave is in the "visible light" area of the EM spectrum (between ultraviolet and infrared). Protons and neutrons individually won't have a colour, I believe. --Mark PEA (talk) 16:55, 25 May 2009 (UTC)
- ...so many different elements..., actually, most elements are metals, and most of those are some shade of grey/white (with the exception of gold and copper) not many different colours. Or did you mean chemicals rather than element? SpinningSpark 17:10, 25 May 2009 (UTC)
- Mark's explanation is a pretty good one - in the case of 'diffuse' reflection (which gives objects their color) - the light is absorbed - kicking an electron up to a new energy level - and re-radiated at a different frequency when the electron gives up that energy. But shiney surfaces use a much more complicated mechanism - requiring 'quantum electrodynamics' to explain how they reflect light (typically without changing it's color). It's a complicated matter - and it's WAY more complicated when you stray from pure elements to chemical compounds where the interaction of lots of different atoms causes the phenomenon of color.
- Things as small as electrons, neutrons and protons are far too small to reflect light. A 'wave' of visible light is between about 400 and 700 nanometers - an atom of (say) carbon is around 70 picometers - that's around 10,000 times smaller than the wavelength of light. That's why you can't see individual atoms in a normal microscope. Protons, neutrons and electrons don't have a 'size' at all - they are just infinitely small dots. So when you get into the physics of how light is reflected or refracted, absorbed or radiated, it all gets very complicated. It's wrong to think of things as small as atoms as having a 'color'. SteveBaker (talk) 01:21, 26 May 2009 (UTC)
- Of course, not to confuse the living shit out of the OP, but while protons, neutrons, and electrons do not have a color, quarks do. Well, not really, but they have a property which is not a color, but we call"color" just to confuse the living shit out of people. See Quantum chromodynamics for more living-shit-level confusion of quark color... --Jayron32.talk.contribs 00:54, 27 May 2009 (UTC)
- I was wondering whether someone would muddy the waters by saying that! SteveBaker (talk) 17:23, 27 May 2009 (UTC)
- Of course, not to confuse the living shit out of the OP, but while protons, neutrons, and electrons do not have a color, quarks do. Well, not really, but they have a property which is not a color, but we call"color" just to confuse the living shit out of people. See Quantum chromodynamics for more living-shit-level confusion of quark color... --Jayron32.talk.contribs 00:54, 27 May 2009 (UTC)
Snakes
[edit]are there any BLIND EYED snakes in Missouri —Preceding unsigned comment added by Donnafounie (talk • contribs) 16:29, 25 May 2009 (UTC)
- They are sometimes found in caves. Are there caves in Missouri with snakes which have over generations lost the use of their eyes? Edison (talk) 00:43, 26 May 2009 (UTC)
Spider eyes
[edit]Is it possible to visually calculate what the world looks like to a spider, when seen through 8/6 eyes? --81.77.122.172 (talk) 17:03, 25 May 2009 (UTC)
- The question is not so much the number of eyes but the way the brain puts the information together. I think it's going to be hard to make sense of that through human understandings of such things (one big coherent image is sort of what we are used to—imagining it as eight different images is probably not actually how the spider sees it and says more about our understanding of vision than theirs). --140.247.241.193 (talk) 19:58, 25 May 2009 (UTC)
- Yeah - it's really not possible to know. For example - human eyes have a blind spot in each eye - literally, a place in the middle of the retina where you are totally blind. Are you aware of this spot? No! In fact you have to go to considerable trickery to fool yourself into actually noticing it! Are you aware of the continuous vibration of the eyeball that's used to improve spatial resolution...do you notice that? No! Are you aware of not being completely unable to see color in your peripheral vision? Nope? I thought not! Our brains are very good indeed at hiding the deficiencies of the system from our conscious minds. I assume the spider's brain is doing something similar - but perhaps it isn't - we really have no way to know from simply looking at the geometry of the spiders' ocular geometry. Hence we have no clue how the world looks to it. SteveBaker (talk) 01:07, 26 May 2009 (UTC)
- Is it even possible for the human mind to comprehend what a 3D view constructed from eight separate images (making a huge assumption here in suggesting that this is how a spider's visual system actually works) would look like? I guess that a computer might be able to knock one out (in the same way as you can get them to draw multidimensional shapes that make your head hurt if you try to visualise them as meatspace objects)...
- I'd really love to know how the infra-red sensitivity of some snake species ties in with the other senses. --Kurt Shaped Box (talk) 02:47, 26 May 2009 (UTC)
- Can you give a citation for no color sensitivity in peripheral vision? 4.242.147.133 (talk) 03:19, 26 May 2009 (UTC)
- See cone cells. It's not so much "no sensitivity" as "gradually less towards the periphery." Dcoetzee 06:49, 26 May 2009 (UTC)
- Can you give a citation for no color sensitivity in peripheral vision? 4.242.147.133 (talk) 03:19, 26 May 2009 (UTC)
- (1) On the poor color sensitivity in human peripheral vision - it is true, and well known. AFAIR, it is related both to the low number of cone receptors in the peripheral retina and to how the ganglion cells in the peripheral retina are "wired". Actually, it is also very easy to test. Pick up one color pencil from a set, without looking, and hold it in the outstretched hand at eye level, starting as far back as your hand would go. Now move it very slowly forward. At some stage you will be able to see the pencil out of the corner of your eye. Now ask yourself what color it is. You'll be surprized... (2) On the spider vision - we can not possibly imagine what spider "sees" as it possesses a brain architecture very different from ours. However, if we imagine that all the processing that occurs in the retina and beyond is similar in spider and in human (which is not true), then having additional eyes is not much different from having a rear view mirror in a car, or having several graphic application windows opened at once on your computer monitor. My point is, simply having more eyes is not the main difference between the spider and a human :). Spider visual system is truly unique and truly exquisite, especially in Salticidae, Lycosidae, and some other active hunters. Unfortunately, it is far less well studied than rodent, cat, or primate visual system. Still, googling for "spider vision" returns plenty of fascinating stuff. --Dr Dima (talk) 07:17, 26 May 2009 (UTC)
- The cone cells detect color but the rod cells only detect overall brightness. However, the rods are faster and more sensitive to subtle brightness changes. As cone cell says - the number of cones drops off around the periphery of the retina. Hence, color sensitivity drops to essentially zero at the edges of your field of view...it's like watching a black and white television. The evolutionary reason for this is that you need to be acutely aware of things happening in your peripheral vision where a predator might be sneaking up on you - so you need cells that are fast, responsive to motion and to the subtle brightness changes that come about when a shadow is cast nearby or something. We probably evolved color perception mostly for detecting whether fruit is ripe or not - but for that you can look directly at the fruit and get it in the center of your visual field where color perception works best. But unless you try experiments such as Dr Dima (above) suggests, you're totally unaware of the fact because your brain 'censors' that kind of annoying detail. The color you think you're seeing around the edges of your visual field is guessed or remembered from the last time you looked in that direction. That's why in Dr Dima's experiment, you need to pick a colored pencil at random - and WITHOUT LOOKING AT IT - move it into your peripheral vision. Since your brain can neither guess nor remember the pencil's color - it gives up trying to fool you and you see it in shades of grey. The 'censorship' is so good that User:4.242.147.133 demands documentary proof of something he/she has been looking out for an entire lifetime and never noticed! Is that cool or what?!
- So is the spider 'aware' that it has eight eyes? Perhaps...but perhaps not. We really have no way to know what it's visual cortex hides from it's higher brain functions. If you didn't know you had two eyes and had no independent control of your eyelids - it would be pretty hard for you to figure out that you have two of them. Our perception of eyesight isn't two separate pictures - it's one 'fused' image...most of the time. But then think about a chameleon - it's two eyes are steerable in two utterly different directions - does it somehow still see one fused image? If you try to simulate what the chameleon might see by (for example) putting a mirror at 45 degrees in front of one of your eyes and turning it around - you get the impression of two images overlaid on top of each other - not two completely separate pictures. Pilots who fly the Apache helicopter actually have to learn how to see two separate images (like a chameleon presumably does)! That's because the Apache requires you to wear a helmet that has a monocular display that comes from a camera on the front of the aircraft over one eye and straight through, normal vision with the other eye. Normally, the monocule shows an infra-red view that "overlays" your normal vision - but it can be zoomed in and out so the two images don't match anymore - and they still have to be able to fly the helicopter and target weapons at the same time - using one eye for each purpose. Apparently a large fraction of people who try to do this mental trick never manage it and flunk out of Apache-flight-school-101 as a direct result of that.
"You can lead a cow up a flight of stairs but not down a flight of stairs - because of the design of their legs..."
[edit]This seems to be a commonly quoted piece of bar room trivia. Is it in fact true? --81.77.122.172 (talk) 17:06, 25 May 2009 (UTC)
- There is anecdotal evidence (and even videos on youtube) that claim it to be false. There is even a popular book that uses this very question as a title. Most of the people who say that cows can walk down stairs say that the animal has to either be led or otherwise enthused to do it and will not approach a downward set of stairs of its own volition. The same can be said of other animals with similar hind legs such as dogs, horses, donkeys, goats and sheep - all need encouragement or leading but will eventually do it. Nanonic (talk) 17:22, 25 May 2009 (UTC)
Try going up a flight of stairs on all fours, and you'll find it easy. Try going down a flight of stairs on all fours, and you'll be hesitant at the very least. It can be done, but you have to adjust the way you would 'normally' crawl on all fours. Try it and see. --KageTora - (영호 (影虎)) (talk) 21:06, 25 May 2009 (UTC)
- KageTora, That experiment is faulty. Cow knees bend the opposite way from our knees and elbows. Many four-legged creatures are like that, including dogs and cats. APL (talk) 01:00, 26 May 2009 (UTC)
- I believe that those are not knees, but rather the animal's ankles. The knees are usually located way up the thigh. Look at the flamingo, for example, where the ankles are actually midway between the end of the legs and the torso. ~AH1(TCU) 01:03, 26 May 2009 (UTC)
- Fair enough. My point was only that the creature's legs were different than ours, with potentially different capabilities. APL (talk) 01:27, 26 May 2009 (UTC)
- I believe that those are not knees, but rather the animal's ankles. The knees are usually located way up the thigh. Look at the flamingo, for example, where the ankles are actually midway between the end of the legs and the torso. ~AH1(TCU) 01:03, 26 May 2009 (UTC)
- I was actually aware of the difference, but without breaking the OP's legs and arms, there is no practical way to remedy it. In some scientific experiments, you just have to make do with the tools you've got. --KageTora - (영호 (影虎)) (talk) 06:23, 26 May 2009 (UTC)
- The truth is that it's not much fun for cows/horses, but most animals can go down stairs with a bit of coaxing. They much prefer ramps and elevators, however. Some animals, such as mountain goats, are probably even better suited to going down stairs than humans. Dcoetzee 06:28, 26 May 2009 (UTC)
- Even Mountain goats would prefer to approach ledges and stair like structures from the side, hitting the ledge at an angle. The design of human stairs won't allow for that. So if you had sufficiently wide stairs your four legged friends might go down them diagonally. 71.236.24.129 (talk) 03:50, 27 May 2009 (UTC)
Distance That Whale Song Is Audible
[edit]According to our article on Whale song, it says that research by Cornell University showed that whale noises travelled 3,000,000 km. Now, how many times around the planet would that be? Considering it would be almost ten times the distance to the moon, I find this hard to believe (I am not saying the sound would get to the moon, for obvious reasons, I am saying the distance cited is ludicrous). Should this be changed? --KageTora - (영호 (影虎)) (talk) 20:52, 25 May 2009 (UTC)
- You're right, it is clearly nonsense. It was vandalism (here), I've reverted it. It should be 3,000km (at least, that's what it was before that edit, I don't have the source to check it is correct). --Tango (talk) 21:06, 25 May 2009 (UTC)
scientific method and evolution
[edit]In reading the article on the scientific method the following is noted:
"Scientific method refers to bodies of techniques for investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge. To be termed scientific, a method of inquiry must be based on gathering observable, empirical and measurable evidence subject to specific principles of reasoning.[1] A scientific method consists of the collection of data through observation and experimentation, and the formulation and testing of hypotheses.[2]"
So, my question is: to what extent does the science of the Theory of Evolution adhere to the scientific method? If it does not, then in what way is the exploration/investigation of the Theory of Evolution "scientifically" utilized or based? Are there other legitimate "scientific methods" other than the traditional one? —Preceding unsigned comment added by 69.77.185.91 (talk) 21:04, 25 May 2009 (UTC)
- The scientific method is rather difficult to define. It is applied very differently in different fields. Evolution is certainly scientific, though. It is a theory supported by empirical evidence (from the fossil record, analysis of DNA, etc.). Evolutionary biologists hypothesise about how a certain animal or group of animals evolved and then they go out and find more fossils and see if they match the intermediary stages their hypothesis predicts, refine their hypothesis and then go and find some more fossils and repeat ad infinitum. --Tango (talk) 21:11, 25 May 2009 (UTC)
The Scientific method is the practical side of the philosophy of science. It is all about formulating and testing hypotheses. The term "Theory" is used of a hypothesis that is of major importance and that has whthstood many tests. (The term has other meansing, but please do not confuse them.) To be useful, a hypothesis must be "falsifiable." That is, a scientist must be able to us the hypothesis to predict the (initially unknow) outcome of an observation or an experiment. If the outcome is not as predicted by the hypothesis (theory,) then the hypothesis (theory) has been shown to be false. The theory of Evolution has been tested in this manner many, many times,and has not been falsified.This is in stark contrast ot (for example) the "theory" tha God created teh earth in seven days: this is not falsifiable, because this theory postulates an omnipotent God, and an omnipotent God can produce anything that we can obaseve. sucn a "theory" has no predictive power, and is therefore not within the purview of science. -Arch dude (talk) 00:57, 26 May 2009 (UTC)
- There is no great mystery about "The Scientific Method" - you have an idea (a 'hypothesis'), you figure out an experiment that would test that hypothesis. If the experiment comes out right - you publish your hypothesis and your experimental technique and the results you got. Other people try the same experiment - and if they agree that you're right - then you have a theory...otherwise you start again with a new hypothesis. Evolution was a hypothesis since the time of the ancient Greeks - but evidence had not been methodically gathered...so it remained a hypothesis. Darwin found his finches and other unusual groupings of animals and that constitutes experimental evidence. Since then, we have countless cases where we have shown either the results of evolution - or in the case of species with very short generations, we've even been able to show it in the lab. The consequences of evolution show up in the need to continually come up with new antibiotics as bacteria evolve immunity to the ones we've been using successfully for years. We can even show evolution in humans by looking at how junk DNA has accumulated in separated populations of humans. Things like adult lactose tolerance can be shown to have evolved in humans over just the last 5000 years or so. So there is plenty of experimental evidence - gathered independantly by people from widely separated disciplines. Evolution frequently stands up to contrary hypothesis - the commonly stated case of the bacterial flagellum, for example...but these challenges have always been successfully and comprehensively deflected. That makes evolution one of the most solidly based scientific laws we have. SteveBaker (talk) 00:45, 26 May 2009 (UTC)
- Well, its not as law, which is to say that it is not a consise description of a single phenomenon, but rather a theory, which is a comprehensive explanitory framework. The terms "law" and "theory" are frequently misunderstood outside of people who study the philosophy of science.
- But back to the OP. The most basic understanding of the scientific method is the basic framework of "hypothesis - observation - conclusion" cycle. The basic idea is that an idea is proposed; observations are made which could either confirm or refute the idea, and then determinations are made as to veracity of the original hypothesis. Its not more complicated than that. Its almost a self-evident method of understanding the world around us; indeed though the basics of it were codified by Roger Bacon and Francis Bacon (no relation to each other) and others over the bast few centuries, the basic process has been carried out since people first started getting ideas and testing them out. Even something as simple as "I think my arm is broken. It hurts when I move it this way. Therefore it is probably broken" is basicly using the scientific method.
- The deal with evolution is that it is pretty solidly backed by huge amounts of data; and its not just that people have specifically sought out and shown that evolution works; its that we operate on a day-to-day basis assuming that it does, and absolutly nothing that happens refutes that it does. As Steve has mentioned, concepts such as antibiotic resistance or even such basic ideas as dog breeding show that we work within evolution all the time, and it always works. People seeking to refute evolution mistakenly believe that the entire system is built on a few easily refuted ideas, and that if they somehow could come up with an as-to-yet unanswered question, it would come down like a house of cards. The problem with that is a) not every question which could be answered has even been asked yet and b) the occasional unanswered question that does come up is rather quickly answered once anyone bothers to take the time to answer it. The classic case of the flagellum was basically worked out a decade ago, and it started because some anti-evolution types said "Hey, look, evolution can't explain the flagellum! So it must all be wrong". Then someone said... "Hmmph. never noticed that" then they quickly showed how evolution could neatly explain the flaggelum, which sent the anti-evolution types seeking out some other esoteric idea which could not be explained, which would then be quickly explained. The same cycle continues, and only adds to the data that fully supports the theory. It's not just that its a proven theory, in that people have worked out the experiments to specifically back it up sometime in the past; its that its a working theory which we use all the time, and continues to work well. Are the minutae of evolution being tweaked all the time? Yes they are. There are always things which are being changed regarding our understanding of evolution; things we assumed to be true turn out to be false, but these are mostly the small details (for one example, read this month's Scientific American article on synonymous DNA mutations). The basic concept is perfectly sound and works perfectly well as a theory. --Jayron32.talk.contribs 04:13, 26 May 2009 (UTC)
- Essays about scientific method seem to assume that there is a ready supply of new hypotheses and therefore that the work of scientists is to test which of these hypotheses wins over the others. That hardly considers real situations where only one hypothesis is proposed and open to analysis. While that is the case, the scientist cannot conclude that the single hypothesis is relatively "good" or "bad" since there is no basis for comparison. (S)he finds that it must be (for now) the overiding theory. However there can be scope for alternative hypotheses within the overiding theory, and these are subject to the scientific method. Cuddlyable3 (talk) 09:38, 26 May 2009 (UTC)
- We have done quite a lot of science now, so we have a pretty good idea of how most things work. That means most new hypotheses are just refinements of existing ones. Major paradigm shifts are few and far between. --Tango (talk) 11:04, 26 May 2009 (UTC)
- Essays about scientific method seem to assume that there is a ready supply of new hypotheses and therefore that the work of scientists is to test which of these hypotheses wins over the others. That hardly considers real situations where only one hypothesis is proposed and open to analysis. While that is the case, the scientist cannot conclude that the single hypothesis is relatively "good" or "bad" since there is no basis for comparison. (S)he finds that it must be (for now) the overiding theory. However there can be scope for alternative hypotheses within the overiding theory, and these are subject to the scientific method. Cuddlyable3 (talk) 09:38, 26 May 2009 (UTC)
- Steve, you've been spending too much time with creationists! A law is not a theory that has been proven to a high level of certainty. A law is a simple result, often a simple formula (Ohm's law, Kepler's laws, etc.), that is generally derived empirically. A theory is a framework that attempts to explain why that formula holds and predicts new laws that can be tested. Evolution is a theory, not a law, and will always be a theory. --Tango (talk) 11:04, 26 May 2009 (UTC)
- Of course, it was Stephen J. Gould himself that argued that evolution was both a law and a theory—that the change of species was clearly observable (a law), whereas natural selection is the theory by which it happened (theory). --140.247.251.62 (talk) 17:13, 26 May 2009 (UTC)
- I would disagree. Observing that organisms change gradually over many millennia doesn't allow you to make predictions (at least, not very precise ones). A law needs to have predictive power. Natural selection allows you to make predictions. You know the gradual changes need to have some reproductive benefit so you can work out, for example, what order certain changes are likely to happen in so you can predict what the missing link in the particular evoluntionary sequence would look like (and then you can go fossil hunting and try and test that prediction). --Tango (talk) 17:19, 26 May 2009 (UTC)
- [citation needed] for the claim that Stephen J. Gould has called evolution both a law and a theory. A quick Google on my part doesn't show any evidence of Stephen J. Gould having said that. He has said evolution is both a fact and a theory [7], as does several of our articles (e.g. evolution as theory and fact). This is quite a different thing, because as we have established in this discussion and elsewhere, a 'law' is a poorly defined word in science and is usually avoided in most modern scientific contexts except where it can't be for historic reasons. A good example is Newton's law of universal gravitation which although still called a law, is arguably not entirely correct. The fact of gravitation or evolution though are there even if the theories of them are not entirely correct. And calling them the fact, conveys entirely IMHO the appropriate sense in the modern world without the confusion of calling them by such a poorly defined and poorly used word in science as law. Indeed I've never heard someone call anything in biology a law, it's thankfully IMHO something that never caught on Nil Einne (talk) 21:21, 26 May 2009 (UTC)
- Of course, it was Stephen J. Gould himself that argued that evolution was both a law and a theory—that the change of species was clearly observable (a law), whereas natural selection is the theory by which it happened (theory). --140.247.251.62 (talk) 17:13, 26 May 2009 (UTC)
- Lest we focus too much on the "test a hypothesis" part of science, we should remember that an important part of the "scientific method" is that someone first needs to make an initial observation, and then have enough curiosity to ask "why?" or "how?". Only then can she/he come up with a plausible explanation (hypothesis) and test it using whatever techniques are available and applicable to the question. Much of what we do in science is actually not "hypothesis driven" (see human genome project, for example) but this doesn't mean that it isn't science just because it doesn't directly test a hypothesis. Rather, it is the new "observation" that now generates new hypotheses or enables other hypotheses to be examined in a different light. --- Medical geneticist (talk) 16:49, 26 May 2009 (UTC)
- Absolutely. The scientific method is a cycle, you can start that cycle at any point. --Tango (talk) 17:19, 26 May 2009 (UTC)
- Allow me to clarify that - an individual research project can start at any point. Science as a whole has to start with an observation. Forming a hypothesis with no reason behind it is a good way to waste time, but that reason can come from somebody else's work. --Tango (talk) 17:22, 26 May 2009 (UTC)
- If science required observations before it could create hypotheses, much of our current canon of theoretical physics would never have gotten anywhere. (Einstein didn't observe anything when he was re-thinking space and time. Both SR and GR were undertaken primarily for internal theoretical reasons and not in response to specific experiments or observational problems—though in the case of SR it's worth noting there is some historical dispute over whether he paid any attention to experimental data or not. There are many other theories that have started out as purely "what-if?" questions that may or may not be compelling/likely enough to go through actual testing on.) Most scientists and philosophers agree that it really, really, really doesn't matter HOW someone comes to START thinking about something in science. The question is whether you can then confirm it, falsify it, etc. (In the Einstein example, what mattered not is that he was thinking about space and time disconnected from experiment, but that his theories did have testable predictions that could then later be explored.) Trying to put a "method" on to the investigation side of things does not work nor does it matter — what matters is that the follow-up is done correctly. --140.247.251.62 (talk) 18:38, 26 May 2009 (UTC)
- If you trace it back far enough, you get to observations. The "internal theoretical reasons" you mention were issues with previous theories, which had been developed from observations. So someone made an observation, then someone made a theory, Einstein then looked at that theory and found some problems (even though they didn't, at the time, result in testable false predictions) and fixed them. The process started with observations. --Tango (talk) 20:02, 26 May 2009 (UTC)
- If you trace it back far enough, it goes back to theory. Or maybe observations. Or maybe theory. Because in the end, if you trace it "far" enough you end up wherever you want. The fact is, a huge amount of scientific investigation takes place in a purely theoretical realm. Obviously the theoretical and observational feed off of each other—you can't have just one or the other, but giving one of them the ultimate precedence doesn't make much sense either. Science is the interplay of observations and theory, each feeding off of each other, each pushing the other further in its demands (observe this! understand that! repeat!). --98.217.14.211 (talk) 13:05, 29 May 2009 (UTC)
- If you trace it back far enough, you get to observations. The "internal theoretical reasons" you mention were issues with previous theories, which had been developed from observations. So someone made an observation, then someone made a theory, Einstein then looked at that theory and found some problems (even though they didn't, at the time, result in testable false predictions) and fixed them. The process started with observations. --Tango (talk) 20:02, 26 May 2009 (UTC)
- If science required observations before it could create hypotheses, much of our current canon of theoretical physics would never have gotten anywhere. (Einstein didn't observe anything when he was re-thinking space and time. Both SR and GR were undertaken primarily for internal theoretical reasons and not in response to specific experiments or observational problems—though in the case of SR it's worth noting there is some historical dispute over whether he paid any attention to experimental data or not. There are many other theories that have started out as purely "what-if?" questions that may or may not be compelling/likely enough to go through actual testing on.) Most scientists and philosophers agree that it really, really, really doesn't matter HOW someone comes to START thinking about something in science. The question is whether you can then confirm it, falsify it, etc. (In the Einstein example, what mattered not is that he was thinking about space and time disconnected from experiment, but that his theories did have testable predictions that could then later be explored.) Trying to put a "method" on to the investigation side of things does not work nor does it matter — what matters is that the follow-up is done correctly. --140.247.251.62 (talk) 18:38, 26 May 2009 (UTC)
- Allow me to clarify that - an individual research project can start at any point. Science as a whole has to start with an observation. Forming a hypothesis with no reason behind it is a good way to waste time, but that reason can come from somebody else's work. --Tango (talk) 17:22, 26 May 2009 (UTC)
- Absolutely. The scientific method is a cycle, you can start that cycle at any point. --Tango (talk) 17:19, 26 May 2009 (UTC)
- Lest we focus too much on the "test a hypothesis" part of science, we should remember that an important part of the "scientific method" is that someone first needs to make an initial observation, and then have enough curiosity to ask "why?" or "how?". Only then can she/he come up with a plausible explanation (hypothesis) and test it using whatever techniques are available and applicable to the question. Much of what we do in science is actually not "hypothesis driven" (see human genome project, for example) but this doesn't mean that it isn't science just because it doesn't directly test a hypothesis. Rather, it is the new "observation" that now generates new hypotheses or enables other hypotheses to be examined in a different light. --- Medical geneticist (talk) 16:49, 26 May 2009 (UTC)
- For a nice discussion of the difficulty in easily classifying Darwinism under an ideal set of what it means to be scientific, see Karl_Popper#Issue_of_Darwinism. --140.247.251.62 (talk) 17:12, 26 May 2009 (UTC)
- Oh jeez - Karl Popper! He's a philosopher...and a philosopher who works in a school of Economics at that. <sigh> Philosophers are a waste of quarks. SteveBaker (talk) 19:57, 26 May 2009 (UTC)
- Steve, philosophers may be strange, but they also have a certain charm. 65.121.141.34 (talk) 14:29, 27 May 2009 (UTC)
- So you're saying that I should put up with them - I can't put them down? I'll try getting on top of that - but to be honest, they are at the bottom of my list. SteveBaker (talk) 16:53, 27 May 2009 (UTC)
- You guys are so punny. A Quest For Knowledge (talk) 17:07, 27 May 2009 (UTC)
- So you're saying that I should put up with them - I can't put them down? I'll try getting on top of that - but to be honest, they are at the bottom of my list. SteveBaker (talk) 16:53, 27 May 2009 (UTC)
- Steve, philosophers may be strange, but they also have a certain charm. 65.121.141.34 (talk) 14:29, 27 May 2009 (UTC)
- Oh jeez - Karl Popper! He's a philosopher...and a philosopher who works in a school of Economics at that. <sigh> Philosophers are a waste of quarks. SteveBaker (talk) 19:57, 26 May 2009 (UTC)
- Of course, Steve, I'm sure you are aware that much of what anyone calls the "scientific method" is derived from Popper's particular discussions of it (e.g. the whole falsifiability bit). Other than Robert Merton he is probably the number one person that scientists inadvertently parrot when they discuss things like this, having been somewhat indoctrinated to his general approach to things. --98.217.14.211 (talk) 13:03, 29 May 2009 (UTC)
Predicting Rainstorms
[edit]In London today we had a quick rainstorm. I was speaking to someone on the bus who was telling me they always know that it's going to thunder because insects burrow up from beneath the paving slabs on the pavement. I've noticed this is generally true, and when I got off the bus, there were piles of sand all over the place and ants scurrying round, with a lot of flying insects about. Why is this? Can they sense air pressure? Are they worried about being drowned? Is this just anecdotal evidence or is there a scientific basis for this phenomenon? -russ (talk) 21:19, 25 May 2009 (UTC)
- With regard to thunder, there is a possibility that the insects are detecting voltage changes in the earth, which are an indication that lightning is about to strike? Or perhaps they are truly psychic, not unlike Tyrone Slothrop, and are able to predict where the lighting will strike? Actually, our article on Lightning contains a pretty thorough explanation of how it works; and one could easily propose a reasonably hypothesis about how ants are able to predict thunderstorms based on the information there. --Jayron32.talk.contribs 03:52, 26 May 2009 (UTC)
- We assume the insects flying around were swarming ants seeking mates and new nest sites. I have always understood that ants use a simpler method of predicting thunderstorms. It is akin to the method that humans use - increased temperature, increased humidity and a change in atmospheric pressure. The ants I believe are not seeking to save themselves from death by drowning (you won't see this behaviour in autumn or winter)but attempting to use the properties of the thermals generated by thunderstorms to assist their dispersal. Of course the thermals in London at street level are likely to be limited but these creatures are not aware of that and valiantly strive to spread far and wide. Regarding voltage changes in the earth I wonder how all the electrical cabling that threads through London affects the local readings. Richard Avery (talk) 07:36, 26 May 2009 (UTC)