Wikipedia:Reference desk/Archives/Science/2013 May 23

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May 23

Bodies of water silting up

Do we have an article that discusses the phenomenon of water becoming land as it silts up? I'm thinking of a pond that gradually fills with soil (I'm writing an article about a cemetery whose sexton intentionally did that to a pond, since mowing a little extra grass was cheaper than keeping a pond), or of an estuary that gradually becomes floodplain; I checked Wigtown, where the latter happened, but I found nothing relevant. Siltation (to which silting redirects) is related, but it really doesn't care about much other than silt pollution; I was hoping for something more closely related to the process of filling in a watered area, but can't find anything. Nyttend (talk) 02:28, 23 May 2013 (UTC)

I believe this is called Deposition (geology). The Wikipedia article only covers coastal deposition in any detail, but I got to that article from River delta, which is basically what you're talking about, river deltas form by a natural silting process that you're talking about. Deliberately filling in bodies of water is called "landfill" (different definition from the place where you bring your trash) and the Wikipedia article that covers it is called Land reclamation. --Jayron32 03:22, 23 May 2013 (UTC)

Actually, the succession of plants in such areas may have more to do with the transition from open water to dry land than does siltation per se. You may find the article Hydrosere of interest. Deor (talk) 12:40, 23 May 2013 (UTC)

Validity of the ideal gas law

For what temperatures and pressures is the ideal gas law a valid approximation? — Preceding unsigned comment added by 130.56.81.186 (talk) 04:31, 23 May 2013 (UTC)

What did your teacher say when she taught you this in Chemistry class a few days ago? -Jayron32 04:36, 23 May 2013 (UTC)

The various gas laws, such as Boyle's law, Charles's law and the ideal gas law, were discovered over a century ago by scientists whose experimental equipment was very rudimentary by modern standards. These scientists were only able to investigate the behavior of gases at pressures close to atmospheric pressure, and temperatures close to those found on the Earth's surface. These gas laws are valid at around one atmosphere (low pressure) and typical terrestrial temperatures. At very high pressures and very low temperatures, gases begin to behave a bit like liquids so the various gas laws become increasingly inaccurate. Dolphin (t) 06:28, 23 May 2013 (UTC)

Actually, it is quite wrong to say the approximation works around atmospheric pressure and is les good far from it. What is important, for the ideal gas laws to be a good approximation, is to be sufficiently well away from the vapour saturation line (a curved line from the high triple point to the liquid/vapour critical point, plotted on a graph of temperature vs internal energy - a line where to the left of it the substance is a mixture of liquid and gas, and to the right of it is purely a gas). The critical point of any substance is where the specific heat of the substance as a gas becomes infinite. The triple point is the temperature and pressure at which liquid, solid, and vapour phases co-exist. Plotted on a graph of temperature vs internal energy, the triple point is a straight line, stretching from the Low Triple Point (min internal energy) to the High Triple point (max internal energy). Lines of constant pressure can be plotted on a temperature vs internal energy graph as contours. These contour lines are straight diagonal lines well the the right of the vapour saturation line, and increasingly curve towards the horizontal as they approach the vapour saturation line, abruptly changing to the horizontal just at the VSat line near the triple point, transitioning to a gradual curve that is horizontal at the critical point. Where the constant pressure lines are straight diagonals is where the substance behaves as an ideal gas.

For water, the critical point is 647.1 K and 22.064 MPa, and the High Triple point is 273.16 K, 611.7 Pa, and 54.01 MJ/kmol, and water (steam) will not behave as an ideal gas at atmospheric pressure. For oxygen, critical point is at 154.58 K & 5.043 MPa; High Triple Point is at 53.36 K, 146 Pa & 7.315 MJ/kmol. Other substances have very different triple and critical points, at higher and lower temperatures, and higher and lower pressures. A few gasses follow the gas laws pretty good at ordinary temperatures and pressures, many do not. The NIST-JANAF Thermochemical Tables, published as Monograph 9 by the Journal of Physical and Chemical Reference Data, gives full details in tables for a hundreds of common substances. Any good university library will have it.

Wickwack 121.221.2.127 (talk) 07:16, 23 May 2013 (UTC)

Will you get the course credit instead of this student for performing his work for him? I don't really need to pass general chemistry again, which is why I directed him to review what his teacher taught him... --Jayron32 12:36, 23 May 2013 (UTC)

It's not entirely clear whether this homework or not. Not a very good question for a home work since it implies the incorrect notion that there is a specific set of temperature and pressure for which the law works (or doesn't work). Wickwack's answer makes that point clear and therefore was an appropriate response. Dauto (talk) 17:28, 25 May 2013 (UTC)

The ideal gas law is, as the name suggest never precisely valid, it is only valid in the limit where the molecules in the gas don't interact any more and where the gas becomes infinitely dilute. These are two independent conditions, the former is quite obvious, the second has to do with quantum effects. Even if you have an ideal gas w.r.t. to the first condition, i.e. a gas consisting of hypothetical moleculs that don't interact with each other at all, you will still have deviations from the ideal gas law due to quantum effects. These deviations only tend to zero in the limit that the density of the gas tends to zero.

In practice, the devations from the ideal gas law due to the interactions of the molecules are seen in the conditions mentioned by Wickwack above. Quantum effects that cause significant deviations from the ideal gas law are seen in practice in extreme high density matter. E.g. certain types of supernova explosions are triggered due to a star having run out of fuel, contracting as a result causing the temperature and density to go up again and then fusion starts again. But the fusion then starts in matter that is so dense that the ideal gas law isn't valid, the pressure does not depend on the temperature anymore. This independence of the pressure on the temperatre causes a supernova explosion. This is because the rate of fusion reactions increases very rapidly if the temperature increases. Then an increase in the rate of fusion reactions would lead to more heat being generated and to even higher temperatures and therefore much higher fusion reaction rates. What stops such a runaway increase in reaction rates in a normal star like the Sun, is the increase in pressure of a region at higher temperatures which causes such a region to expand and become cooler due to performing work. Count Iblis (talk) 13:00, 23 May 2013 (UTC)

Is there any scientific evidence about spirits and their ability to affect the living?

Resolved

I am from Asia, where almost everyone around is very superstitious. What they do all the time is praying for some blessing of the gods rather than relying on themselves. I only trust myself, but there was an event occurred in a nearby village (just hundreds meters away) that troubled me. The story is long but I'll keep it as short as possible.

The villagers noticed that many adults in the village had died rapidly in the last few years. All death were quick (like traffic accident) and sometimes mysterious (had an unknown fever and died). A shaman said that it was a female ghost that did all the tragic (maybe she loved these guys, lol?). The villagers decided to raise big funds (just around $3000, but it was very big in my country) to hire a local monk and 6 famous shamans which came from far away to perform the ritual, in the hope of stopping the tragic. The ritual took place just a few days ago, with the observation of hundreds curious people.

I was not at the event, but according to my mother, their work was to met the ghost, ask her about the reason and to negotiate with her. The ghost did come, and possessed a female local villager. It turned out that the ghost was male, and he claimed that he had lived in that village for 320 years! According to him, the village road was 6 meters wide, with daisies on the 2 sides. But the villagers expanded their houses to "his road", and now the road was only 4 meters wide, causing movement difficulties for "his horses and elephants". He said that he let "his horses kick and his elephants stomp" the villagers to their deaths. He demanded the villagers to break their house wall, and return 2 meters for his road. I thought that the dead can fly, but this one need a wide road to walk. Funny, right?

The ritual to call the deceased to possess a living is performed frequently in my place, mostly for those who died suddenly, to ask them about their wishes. Some do not even need a ritual, they can do it by themselves. The wife of my grandfather's brother, for example, she possessed her son's wife on the 50 and 100 day anniversary of her death (yes, twice).

To this days, I still don't believe these stupid things much after all. Does science ever acknowledge the existence of these entities and their ability to affect the living? Or is there any study or result about this subject? -- Livy (talk) 05:14, 23 May 2013 (UTC)

No. --Jayron32 05:16, 23 May 2013 (UTC)

Science doesn't even understand how we possess our own bodies, never mind somebody else's. Gzuckier (talk) 06:03, 23 May 2013 (UTC)

I completely agree with Jayron32, but I think more can be said, I think Gzuckier's answer is a flat copout, science does have a lot to say about how we posses our own bodies, for one, we can be fairly certain it involves our physical brain..> Back to the OP, firstly, congratulations for having some skepticism in a place where you are steeped and surrounded in such incredible events. In the west, there has been an old and strong tradition of people who have challenged these ideas and beliefs and examined them very closely. From Harry Houdini to James Randi, they challenge people to demonstrate these abilities under controlled conditions and for the last century, not a single person has been able to give any compelling evidence that their powers or abilities are more then just psychological "tricks" and illusions and a lot of the time just plain fraud almost identical to methods used by stage magicians. Vespine (talk) 06:07, 23 May 2013 (UTC)

No, Gzuckier is right — science has nothing to say, and will never have anything to say, about how "we" possess our bodies. The materialist explanations amount to denying that there is any such thing as "we". Science can tell us a lot about how our brains control our bodies, but that's a different topic altogether. --Trovatore (talk) 06:27, 23 May 2013 (UTC)

No, you have nothing to say about how we possess our bodies. Neither do today's scientists, because nobody understands consciousness in a meaningful way. To claim that nobody who will ever be born in the trillions of years to come will figure it out is pure hubris. If and when somebody eventually understands consciousness, I guarantee that it will be through science (just like every other discovery about the natural world), not religion, mysticism, or making stuff up. --Bowlhover (talk) 09:15, 23 May 2013 (UTC)

The attempted explanations thus far do not fail for some correctable reason, some "oh, well we didn't quite close that last gap" kind of thing. They are category errors. They are attempting to explain the externally observable correlates of consciousness, not consciousness itself. I don't see how science, as it is currently construed at least, can ever get past that hump, even in principle, because science almost by definition limits itself to the externally observable. However, I am willing to concede that there is no really complete definition of science, and it is imaginable in principle that some future intellectual discipline that does not limit itself to the externally observable, but that is nevertheless somehow recognizable as "science", could have something to say. --Trovatore (talk) 17:06, 23 May 2013 (UTC)

Indeed. We're at a state now, where we can isolate muscle tissue and cause it to do mechanical work in vitro. We can put kidney tissue on a filter and make it transport water. We can take out a pancreas and put it in a dish and stimulate it to produce digestive enzymes and/or insulin. Etc. But I'm pretty sure nobody's ever taken out a brain, put it in a dish, and produced consciousness. I'm not a kook; I'm as materialist in this issue as most everybody is these days. I understand that consciousness etc. is somehow emergent from the function of the brain. But we are so far from explaining it, that we can't even see what direction to start off in. We can't even agree how to prove consciousness from communication or otheer behavior which resembles precisely the product of consciousness, if we can't directly see that it's coming from a human. We can't even prove it when it does come from another human, except by induction and generalization from our own internal case, as you point out. Gzuckier (talk) 05:34, 24 May 2013 (UTC)

Well, my position is a bit harder-core than that. I do not think the hard problem of consciousness has a materialist solution at all. --Trovatore (talk) 06:08, 24 May 2013 (UTC)

There is much study of the paranormal. see Paranormal#Skeptical scientific investigation. Many people and organizations who don't believe in spirits and the supernatural have offered substantial prizes to see if anyone can demonstrate, with scientific thoroughness, the existence of these things. See List of prizes for evidence of the paranormal. (None of these prizes has been claimed!) James Randi is a famous person who has exposed various paranormal claims as being nothing but trickery. Dolphin (t) 06:15, 23 May 2013 (UTC)

Yes, there is plenty of evidence that spirits, if they were to exist, cannot interact with us to give rise to the effects that are commonly attributed to them. Basically, it boils down to such effects violating the known laws of physics, and that there is a huge amount of evidence for those laws of physics. This means that if you were to take up the Randi challenge as mentioned by Dolphin and Vespine above and were to prove that a non-trivial effect does exist, it would be similar to proving that somehow Copernicus was wrong and that the Sun does revolve around the Earth. But, of course, just like you can always put the idea that Copernicus is wrong to the test, you can also put the claims of psychics etc. to rigorous tests in the laboratory.

Uri Geller in the 1970s did put himself through some tests, because he knew how he could deceive naive scientists. Randi criticised these tests for being too naive but at the time he was ignored for being a radical sceptic. Randi then proved his point by letting two magicians present themselves as psychics and let them go through the same tests. When it was reveiled later that they were just magicians, Randi's objections were taken serious. One mathematician who was involved in testing Geller who until that point was a strong believer in his abilities then thought that he could just invite Geller back for the same tests, but now he would make sure the spoons would be labelled. However, Geller did not want to be tested anymore :) . Count Iblis (talk) 11:42, 23 May 2013 (UTC)

2 years ago many of my relatives met a shaman for calling the spirit of my mother's sister' husband. He first possessed his own wife (my mother's sister), then switch to the shaman herself. I cannot tell if it was him or the shaman talking us but the shaman knew every people in my family, and even who had attended his funeral! It is incredible... Is there any spirit possession ritual or the like in the West? -- Livy (talk) 06:51, 23 May 2013 (UTC)

Yes, it's called cold reading. Vespine (talk) 06:59, 23 May 2013 (UTC)

See Spiritualism. --TammyMoet (talk) 11:43, 23 May 2013 (UTC)

The shaman could have deceived us, true. But what about the case of the wife of my grandfather's brother? She possessed her own daughter-in-law. The daughter-in-law was very scared and tired after being possessed for the first time on the 50 day anniversary at her mother in law's house, and she vowed not to attend the 100 day anniversary. My mother's sister (the one mentioned above) laughed and told us that she could not avoid the inevitable. For some odd reason, she ended up in the local pagoda where we perform the ritual on that day (after the ritual in the house), and being possessed for the second time. She even hit 2 of her mother-in-low's sons. When we asked her whether she remembered what she had said and done, she told us that she did not know anything, but felt heavily exhausted. I tell myself not to believe, but it is really weird. -- Livy (talk) 15:10, 23 May 2013 (UTC)

In the West, we usually refer to instances of such behaviour as being indicative of a mental disorder, such as Dissociative Identity Disorder. Ockham's Razor tells us "that entities be not multiplied save of necessity", and we find it unnecessary to invoke any other beings apart from ourselves to explain our own behaviour. --TammyMoet (talk) 15:32, 23 May 2013 (UTC)

Certainly the answer here is a clear and unambigious "NO!". Science has zero evidence for ghosts or spirits or whatever.

While it is true that we don't understand every last detail of how human consciousness works - we do know enough to put limits on what it can do. We know, for example, that it resides in the brain - that it's the result of neural interactions - that it's bounded by the regular laws of physics - consciousness doesn't violate the conservation laws or the laws of thermodynamics. The main reason we can't say more about it is that there is no good definition of what the word "consciousness" actually means. If we had a solid definition for that word, we'd have an answer soon afterwards.

To use an analogy: I don't know the location and species of every plant that's growing in my back yard...but that doesn't mean that there can be 10' tall rampaging carnivorous plants out there! Just because you don't know every detail - doesn't mean that you know nothing.

If there really were ghosts or spirits, science would certainly have noticed large, measurable and unexplainable differences in very simple science experiments...and we don't. If all of that existed, surely the ghost of some scientist would have made his presence known by repeatedly disrupting some kind of science experiment in such a way that the experimenter would have no choice but to notice. This has never happened. Some people such as Harry Houdini have promised that if they ever find themselves in the spirit world, then they will communicate an otherwise secret message in order to prove that fact...they never have.

SteveBaker (talk) 16:01, 23 May 2013 (UTC)

The West and the East do have very different cultural perspectives. ☯ Bonkers The Clown \(^_^)/ Nonsensical Babble ☯ 16:04, 23 May 2013 (UTC)

The Eastern ghost isn't the Hollywood-like ghost figure or the one Michael Jackson sings about. ☯ Bonkers The Clown \(^_^)/ Nonsensical Babble ☯ 16:04, 23 May 2013 (UTC)

They certainly do have different cultural perspectives...but that has no relevance here - we're being asked about whether science has evidence...that's way, WAY different from what a bunch of non-scientist have decided might be true based on some cultural hand-me-down from their ancestors. SteveBaker (talk) 19:14, 23 May 2013 (UTC)

One thing you can do is go watch some good magicians, specifically mentalists. They do many seemingly impossible things. That can explain the shaman, but doesn't explain your relative's experience. For that, I would read about cases like Clever Hans. Another thing thing you have to realize is that your own memory and perception are also be flawed. Things you remember happening, might not have happened precisely how you remember them. Because these events happen under conditions which are not at all controlled, you can not know what other people know or might be doing. When psychics are studied carefully, their subjects can claim something like "the psychic knew my dead uncle's name" and be adamant that this was the case. But if the session was recorded, what you'll find is that the "psychic" might have said something like "I'm getting a name, John or Jason?" subject: "no". Psychic: "actually, maybe Rob, or Bob, Robert? Maybe Rupert" The subject says "yes, I knew a Robert", Psychic: it was someone very close to you, a fatherly figure, someone you looked up to, your grandfather, maybe uncle?" and the subject says "Yes Robert was my uncle!!" and they are amazed at the psychic's ability. After another 30 minutes of talking, all they remember is that the psychic guessed their dead uncle's name was Robert, but they'll completely forget the process that it took to get there. After they will tell their friends that the psychic amazingly guessed their dead uncle's name. Vespine (talk) 23:24, 23 May 2013 (UTC)

Also, you might find Committee for Skeptical Inquiry interesting. Vespine (talk) 23:25, 23 May 2013 (UTC)

It is clear that I have found the answer to my question. There is no scientific evidence about these entities. Although everything happens in my place is very weird and hard to find appropriate answer, but until there is scientific evidence, I will not believe anyone rather than myself. Thanks to you all for your useful information, and hopefully science can give appropriate explanations for these mysterious phenomena someday! -- Livy (talk) 12:19, 24 May 2013 (UTC)

I don't think this is really "resolved" at all. Consider a human brain that contains one or more so-called "conscious minds" and "subconscious minds", even "multiple personalities". What sets the limits of where a personality begins and ends? What rule says that the domain of brain held by something that perceives itself to be "a person" must be held entirely within a single brain, rather than existing, for example, in a network of communication and written folklore held within the people of a village? Why can't a dead person's consciousness be continued, in part, in the brains of living persons who have absorbed some of his way of thinking? When we speak of mind rather than brain, when we speak of sensations of existence rather than neural pathways, the science seems very weak. I would suggest that it is accurate to speak of overall conserved algorithmic features in terms of an atman, which recognizes the continuity of living and dead; and thereby the reality of reconstruction of the departed "individual" whenever we pay attention to attempting to reconstruct key influences of the personality. But this is also very similar to saying that the practice is delusion, a heuristic meant to seek artistic inspiration (well, more like engineering inspiration, but we don't have an article on that) via a ritual which, though not scientifically meaningful, has the potential to inspire the imagination. I'm afraid the methods of science dissolve into philosophical confusion outside its proper domain. Wnt (talk) 07:17, 25 May 2013 (UTC)

My question was "is there any scientific evidence", not "do these entities actually exist". If it were the later, this question would raise controversy and never end. But it is the former, and the answer is clearly "no". :) -- Livy (talk) 01:16, 26 May 2013 (UTC)

Threr some people who hear them, there are people who feel them , and see that they move things, But they ignore you, It's a bit like a computer and humans, the computer does not feel, and people can move things without him , Thanks --81.218.91.170 (talk) 15:01, 27 May 2013 (UTC)

Measuring roughness

Is there a good way of measuring how rough or smoothly varying a surface is? I have data fields specified as T(x,y), and I'd like a way to quantitatively distinguish fields that change gradually as one varies x and y from those that vary rapidly. In both cases the overall change is generally bounded, so there isn't a lot of net change over long distances, but some vary much more over short distances than others. Viewed as an image, you might say some fields are noisy while others are smooth. I'd like to have a good way to quantify these differences. What are some standard techniques / measures that people use to describe the roughness (or noisiness) of a field? Dragons flight (talk) 06:46, 23 May 2013 (UTC)

Roughness of data, and roughness of a physical surface, is commonly measured/expressed as the Root Means Square (RMS) roughness. You take the error from the mean or ideal value for each data point, square it, and calculate the average of all the squares, and take the square root of that. In mechanical engineering, it is called RMS roughness. In statistics and for numerical data generally, it is called the standard deviation. Wickwack 120.145.149.52 (talk) 07:41, 23 May 2013 (UTC)

Wikilink - Surface roughness seems to give a fair bit of maths to help you out. 80.254.147.164 (talk) 08:48, 23 May 2013 (UTC)

An RMS measure that considers only the deviation from the mean is poor indicator of roughness and doesn't really correspond to human perceptions of roughness either. Consider the two diagrams:

  ---
--   ---   --
        ---

 -   -   -
- - - - - - -
   -   -   -

Those examples are identical from an RMS perspective, but one surface would generally be perceived as varying more rapidly than the other. It is cases like that for which I am looking for a natural way of quantifying that the top panel experiences gradual change and the lower panel undergoes rapid change. Dragons flight (talk) 09:36, 23 May 2013 (UTC)

Actually, the RMS deviation or standard deviation value does correspond to the human "feel of it" pretty well, and is usually the most useful mathematically in most applications. However, if what you want is an indication of rate of change, then I suggest that you do a discrete fourier transform over the extent of the surface (in other words, treat the surface as regularly repeating segments, each of size equal to the surface in question. The result will be a a histogram of frequencies, and make the most significant frequency immediately visible. You can then weight the frequencies and calculate an RMS or mean value of them, to taste. This value will reflect both ammplitude and rapidity of change. Wickwack 120.145.149.52 (talk) 10:39, 23 May 2013 (UTC)

A simpler approach is to calculate the slopes (T/x) between data points, weight them according to peak-to-trough amplitude,and take the RMS value of all the weighted slopes. Wickwack 120.145.193.132 (talk) 11:44, 23 May 2013 (UTC)

How you quantify roughness usually depends on why you need to know it, or how you want to use it. So if you tell us more, we might have better suggestions. Other potential choices come from fractal analysis, such as the box-counting dimension, or the Hausdorff dimension. SemanticMantis (talk) 15:53, 23 May 2013 (UTC)

Also, are these continuous functions, or just point sets? For instance, rugosity might be a nice measure for the former, but not defined for the latter. SemanticMantis (talk) 16:10, 23 May 2013 (UTC)

is there a difference between "roughness" and "coarseness"?68.36.148.100 (talk) 02:54, 24 May 2013 (UTC)

Yes - definitely. Roughness is a term applicable when a surface has random or random-like variation. Coarseness is the term to use when the variation is not random but is associated with grain. For example, a polished metal surface that has then been etched with acid typically has random variations in its surface - so we speak of its roughness. A woven cloth may have a rough feel, but its variation is essentially periodic, not random, due to the weave - so we speak of its' coarseness. In metal working, the surface variation may also be periodic, due to the sequential action of a machine tool, or it may be random-like due to the action of hand-operated sanding. However machine sanding or grinding may impose a grainy finish. In these cases it is a matter of judgement whether the terms roughness or coarseness should be used, but both are measured in the same way - the RMS deviation from true. See any good dictionary. Wickwack 121.215.134.76 (talk) 03:13, 24 May 2013 (UTC)

or I could just see your answer. From your answer I wonder why they are not mentioned anywhere in wiki as being so closely related as you say68.36.148.100 (talk) 03:47, 24 May 2013 (UTC)

You shouldn't just trust me, or any contributor on this forum. You should consult a good dictionary. My role is only to point you in the right direction. Wikipedia articles are not perfect. They are not expected to be. Many are good. Some are very very good. Some are rubish. You could register as an editor, get a username, and improve the roughness article by including a comparison with coarseness and graininess, thereby making your contribution to help the World. Most likely the reason it isn't there now is because the volunteer editors didn't think of it. I've chosen not to edit articles. Wickwack 121.215.134.76 (talk) 05:32, 24 May 2013 (UTC)

I have chose not to edit either. But to point the editors in the right direction.165.212.189.187 (talk) 13:17, 24 May 2013 (UTC)

The most convenient and frequently used way to characterize surface roughness is by measuring its Power spectral density function. Ruslik_Zero 19:30, 24 May 2013 (UTC)

You might also want to look into Hurst exponent. Quote from the article: "H is directly related to fractal dimension, D, where 1 < D < 2, such that D = 2 - H. The values of the Hurst exponent vary between 0 and 1, with higher values indicating a smoother trend, less volatility, and less roughness." Dauto (talk) 13:35, 25 May 2013 (UTC)

global warming referred to in article - is this statement up to wiki standards?

page: Stirling Range (Australia)

This contributor throws a climate change reference and state climate change makes short-term gauges unreliable. Is this a fact or an opinion? Is this a credible statement that Wikipedia can stand behind?

I deleted the reference but editors constantly undo my change. The statement is pasted below from the page (last sentence, I put an arrow point to it).

However, it is believed that rainfall on the peaks near Bluff Knoll may be as high as 1100 millimetres (43 inches), a hypothesis supported by the existence of distinctly moist-climate pockets of vegetation in some high valleys. Because no rain gauges have ever been placed on the high peaks ' ----> (climate change since the late 1960s makes short-term gauges unreliable anyway) we cannot be sure of this.'

Thank you!

montana2021 — Preceding unsigned comment added by Montana2021 (talk • contribs) 15:03, 23 May 2013 (UTC)

That is obviously a "non-obvious" fact - and it needs a solid reference - especially if other editors find it controversial enough to want to remove it. So, you need to find a document, acceptable to WP:REF that says essentially just that. If you can, then the other editors should back down and allow that statement to stand...if you can't, then they are quite justified in removing it. SteveBaker (talk) 15:20, 23 May 2013 (UTC)

Thanks for your help! I feel helpless in seeing the hyper-political climate change believers polluting so many wiki articles. — Preceding unsigned comment added by Montana2021 (talk • contribs) 15:36, 23 May 2013 (UTC)

I think you might do well to read our articles on climate change, and on global warming - they aren't the same thing. As for your suggestion that "hyper-political climate change believers [are] polluting so many wiki articles", we base articles on published reliable sources, not our own beliefs - and since the overwhelming consensus amongst scientists within the relevant fields is that anthropogenic global warming is a real phenomenon: in consequence, where relevant, and where properly cited, our articles may reflect this. AndyTheGrump (talk) 17:13, 23 May 2013 (UTC)

Indeed. The exceedingly well referenced fact of climate change isn't even the issue here - it's the question of whether that makes short-term rain gauges unreliable (reference needed) and whether that has any relevance whatever to the lack of good information about rainfall on these peaks (reference needed). I can't see why that would be so it's not obvious and it's certainly a fact that's likely to be disputed (I'm disputing it!) - so it needs a reference or we should delete it. SteveBaker (talk) 19:11, 23 May 2013 (UTC)

Why do East Asians, particularly Chinese people, dominate at table tennis?

As usual, in the 2013 World Table Tennis Championships the Chinese did very well. Only a few other East Asian countries offered some competition. Participation from Western countries is dominated by Chinese immigrants. Is there a biological reason why East Asians, particularly the Chinese are better at this game than people from other countries? Count Iblis (talk) 16:21, 23 May 2013 (UTC)

Is there a biological reason why the Chinese seem to produce few good cricketers? AndyTheGrump (talk) 16:29, 23 May 2013 (UTC)

I see no reason to suspect a biological reason. Table tennis is popular in China and they have a lot of players. Some of them are bound to get good, and some of them take the sport to other countries. The cost and space requirement of a sport can be a big factor in how widespread it is. Most Chinese are poor by Western standards and table tennis is cheap. Tennis is more expensive, requires more space, and China has few good players. PrimeHunter (talk) 16:42, 23 May 2013 (UTC)

It's almost entirely likely to be cultural. People from different cultures enjoy different foods, make and listen to different music, and enjoy different leisure activities. Those differences are indeed what makes them different cultures in the first place! It doesn't prevent people from other cultures from participating in those activities, but broadly speaking, since you find less people from other cultures participating, you find less people from other cultures participating at the highest level. This has nothing to do with any genetic superiority of an entire race, ethnicity, or culture group and more to do with the arbitrary (but still real) differences between cultures. --Jayron32 17:54, 23 May 2013 (UTC)

Ping-pong diplomacy is a nice read, and there are several documentaries floating around the web about municipal table tennis tables being erected in China. Per Jayron, I think it's cultural, and nothing to do with the biology of people from Asia. The same could be said of badminton. The Rambling Man (talk) 18:05, 23 May 2013 (UTC)

The Mayor of London, Boris Johnson gave a rather splendid speech to the British team at the Beijing Olympics, stating that other while nations saw the dining table as an opportune place for a good meal, the British saw it as an opportunity to invent a new sport, originally called "Wiff-waff".[1] Sadly, we don't seem to be terribly good at it. Alansplodge (talk) 22:42, 23 May 2013 (UTC)

The British are evidently neither cunning nor short enough. μηδείς (talk) 00:58, 24 May 2013 (UTC)

Ha, so there actually is a biological reason why the British don't do well in this sport! Count Iblis (talk) 17:39, 25 May 2013 (UTC)