Wikipedia:Reference desk/Archives/Science/2010 January 30

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January 30

itching

Why do we itch ? what is the reason behind itching? Why do we yawn ? i know that it is surly not for taking much air. —Preceding unsigned comment added by Myownid420 (talk • contribs) 04:15, 30 January 2010 (UTC)

One possible reason for itching is parasites, though perhaps you meant scratching? See also yawn --220.101.28.25 (talk) 04:34, 30 January 2010 (UTC)

Yes, itching is to alert us to a potential problem on the skin, such as bugs. I've often felt a mosquito on my skin and swatted it dead before it could inject me with it's bacteria and virus cocktail. While parasites may seem like a minor annoyance to us now, ridding ourselves of them, or at least limiting damage from them, was absolutely essential to life for much of human (and pre-human) history. Thus, there was a strong evolutionary incentive to develop the itch and scratch defense. Of course, the system does sometimes go wrong, and we end up damaging our skin, as in the case of meth addicts. StuRat (talk) 18:16, 30 January 2010 (UTC)

See itch.--Shantavira|^{feed me} 10:01, 30 January 2010 (UTC)

Itching can be caused by diseased skin. --Neptunerover (talk) 16:09, 30 January 2010 (UTC)

According to a certain Buddhist teaching, the pleasure gained from scratching diseased skin is comparable to that which is obtainable in Samsara. I have not heard any direct reference to Samsara actually causing itching, although that alone would not preclude it from being one possible reason behind itching (No one can say there's only one reason, anyway). --Neptunerover (talk) 16:29, 30 January 2010 (UTC)

Samsara [1] would cause itching in people who are sensitive to some of its ingredients. --TammyMoet (talk) 18:15, 30 January 2010 (UTC)

Indeed, that could potentially cause itching, sneezing, and maybe even some vomiting. It all depends on one's sensitivity. ;)--Neptunerover (talk) 09:02, 31 January 2010 (UTC)

good answers but i wanna to ask what changes does occur in effected parts so as to feel us itch?what happens at molecular level? which hormones or anything does trigger itching? —Preceding unsigned comment added by Myownid420 (talk • contribs) 10:33, 31 January 2010 (UTC)

Our itch article mentions opioids and histamine. This paper implicates MRGPRX1 in the peripheral nervous system. This paper implicates gastrin-releasing peptide as a mediator in the spinal cord. --Mark PEA (talk) 11:57, 31 January 2010 (UTC)

Not too long ago the 'Ask the Experts' section of Scientific American dealt with a question like the one you ask, although I don't remember the details or how many months ago it might have been. If I remember slightly right, it had something to do with certain skin cells themselves doing something like raising a false alarm or ? (I can't remember) I believe that article might answer your question though, even if I cannot personally link you to it. --Neptunerover (talk) 12:56, 31 January 2010 (UTC)

That gets into the area of autoimmune/allergic reactions. Some of the problem is at the skin, but I also think the brain has certain thresholds for how many nerves in an area need to report an itch before it takes it seriously. That's why, if you see a bunch of spiders, you suddenly feel itchy. The trigger threshold has just been lowered, and your brain now interprets every stray nerve impulse from the skin as a potential spider crawling on you. (I wonder how many of you will get itchy just from reading this. :-) ). StuRat (talk) 18:37, 31 January 2010 (UTC)

So you're saying it is possible to manipulate the itch trigger threshold of other individuals with words and images? So then when we go to a scary movie, they're manipulating a bunch of different triggers in our minds, like the shiver trigger, which gets her to accept an arm over her shoulders, and then next there's an itch trigger and she goes yuck and pushes your arm off her. It's all a clever plan by the film company to keep us coming back. =)--Neptunerover (talk) 00:20, 1 February 2010 (UTC)

What does Buddhism have to do with this? There are so many possible causes of itching that it is difficult to determine a cause but we are not allowed to provide a diagnosis. However allergies are another common cause but the wide range of allergies is anything from dust to temperature. ~AH1^(TCU) 03:10, 1 February 2010 (UTC)

Buddhist monks wear loose fitting clothing, though I'm not sure if this reduces any itching other than that which might be incurred through the wearing of tight clothing. Sometimes curing itching can be as simple as slipping out of that wool sweater. --Neptunerover (talk) 04:40, 1 February 2010 (UTC)

Saline Faraday cage

Would wrapping an object in two thin layers of plastic with salt water in between act similarly to the traditional metal Faraday cage? Horselover Frost (talk · edits) 04:40, 30 January 2010 (UTC)

The Electrical conductivity article shows the conductivity of copper to be ten million times that of seawater. So your saline bubble would be better than nothing, but very feeble. If it's transparency that you're after, then perhaps one of those transparent metal oxides like tin oxide would be better. --Heron (talk) 09:43, 30 January 2010 (UTC)

The conductivity of those tin oxides is worse even than salty water. But a Faraday cage only needs to be a mesh of wires - not a solid sphere - so it's easy to build one you can see out of if transparency is the problem here. SteveBaker (talk) 19:37, 30 January 2010 (UTC)

Flexibility is the issue, not transparency. Horselover Frost (talk · edits) 21:04, 30 January 2010 (UTC)

A wire mesh would be reasonably flexible. --Tango (talk) 21:16, 30 January 2010 (UTC)

Is the electric field static? If so, then there's no difference between a bad conductor and a good one: the electrical conductivity relates the E-field to the current density and, of course, there is none. The charge distribution inside the liquid cage material would be different from the metal one, as in the latter case the positive ions are fixed in crystal lattices. However, the macroscopic effect onto the E-fields must be the same: the cage has still to be an equipotential surface. In electrodynamics, you'll need to consider both conductivity and inductance, in addition to the usual refraction and reflection depending on the dispersion properties of the material. — Pt _(T) 01:09, 31 January 2010 (UTC)

You will have to consider the skin depth. In salt water is is much bigger, meaning that radio waves will propagate further through salt water. A mm of copper will be equivalent to 3 meters of salt water. (if we believe the figures above. Graeme Bartlett (talk) 11:03, 31 January 2010 (UTC)

touch screen

how the implement the touch screen system on the simple (used button)i-pod. —Preceding unsigned comment added by 117.242.97.71 (talk) 08:45, 30 January 2010 (UTC) if it's possible than send the brife explenation about it also inform that what is needed instead of the indium tin oxide —Preceding unsigned comment added by 117.242.97.63 (talk) 08:49, 30 January 2010 (UTC)

I am not an expert on Apple or iPods, however this section in the Touch screen article might answer your first question, Technologies /Capacitive/ Projected capacitance, at least for the iPhone and iPod Touch. Or specifically iPod click wheel. There is also iPod Classic. If this is wrong please let us know.
The second question, "what is needed instead of the indium tin oxide", needs a bit more detail if you can, please, for a faster answer. --220.101.28.25 (talk) 09:58, 30 January 2010 (UTC)

Adding to above re indium tin oxide quoting the Touch Screen article mentioned. "A capacitive touchscreen panel consists of an insulator such as glass, coated with a transparent conductor such as indium tin oxide", which also has its own article. --220.101.28.25 (talk) 10:15, 30 January 2010 (UTC)

super-simple question about life on other universe

this is a super-simple question, I'd just like to hear your answer explicitly. If we imagine a universe with different physical laws (as is commonly done) then let's imagine intelligent life in that universe, doing mathematics. When exploring the SAME closed axiomatic system (e.g. ZFC), would the life find the SAME theorems are true/provable as we do for the same system? For example, would the life find that in that universe (despite there being different physical laws), there are still infinite primes, and in every other way as well the mathematics corresponds to the mathematics here.

Don't tell me I'm being naive or failing to understand the difference between math and science: YOU'RE being disingenuous for failing to answer my simple yes or no question. It's a simple question. It's not a false dichotomy. Please just answer either,

“ yes, different physical laws, but if they support life, the life would find the same things true when exploring the same given axiomatic math - e.g. the life would find there are infinite primes, pi is about 3.14159..., and everything else we find in standard math, etc" ”

or you can answer

“ no, different physical laws for the universe might include different epistemology. We have no way of knowing that they will find the same theorems true/provable/etc even when exploring the same given closed math system ”

it's such a simple question. Just answer it honestly and directly for me please: will math and logic be the same. thanks! 84.153.213.154 (talk) 10:02, 30 January 2010 (UTC)

Tweaking constants is different from altering the working of logic, I think. (I don't know what altering logic would mean.) That is to say, "yes". 213.122.17.205 (talk) 12:39, 30 January 2010 (UTC)

In the future, please give us a chance to answer your question before assuming that we won't do so properly. Physics is separate from logic. We can easily conceive of different physical constants and even altogether different physical laws, but I certainly can't conceive of what it would mean to change logic. Since I can't conceive it, I can't say it is impossible, but the usual changes people discuss (what would happen if space was 4D? What would happen if the speed of light was 30mph? etc.) wouldn't have any affect on logic. They would, however, affect which axioms mathematicians would choose (and get funding!) to study. --Tango (talk) 12:58, 30 January 2010 (UTC)

sorry, does that mean "yes" or "no"? It seems, if I'm parsing your sentence correctly, that you're saying "since I can't conceive of the 'no' alternative, I can't say 'no' is impossible"? But wouldn't "I can't conceive of it" mean that it's absurd, and not a possibility? Surely if it were possible, you could conceive of it? 84.153.213.154 (talk) 13:19, 30 January 2010 (UTC)

It means "maybe". As I said, the kind of changes people usually talk about, which involve changing physical constants, wouldn't have any impact on logic (so the same axioms would give the same theorems). That doesn't mean that there aren't other changes possible (for an appropriate definition of "possible") that would affect logic. I am flattered that you think I am capable of conceiving everything possible, but I am not sufficiently arrogant to assume that. --Tango (talk) 14:24, 30 January 2010 (UTC)

I was going to answer the question but the OP needs to learn some manners —Preceding unsigned comment added by 94.171.225.236 (talk) 13:13, 30 January 2010 (UTC)

I'm sorry about my manner of posing the question here, but as you can see even despite my explicit request not to, Tango still felt the need to answer "physics is separate from logic" (I had said: "Don't tell me I'm being naive or failing to understand the difference between math and science") -- I literally meant that I understand physics and math are separate, please don't tell me that, try to understand what my actual question is instead. So, if I came off as rude, it is because I knew what the "knee-jerk" response is -- and I've gotten in dozens of times -- and tried to make clear that it isn't what I was looking for. If the honest answer to the question I am looking to have answered is "I don't know", you can say so. You don't have to pretend it's not a real question, or just ignore it, or come up with some other excuse not to answer it. 84.153.213.154 (talk) 13:19, 30 January 2010 (UTC)

In imaginary, hypothetical universes, anything can be anything - black is east, up is white. So, the original question is malformed. You're asking us if something hypothetical is possible. Really, you should be asking us what consequences there would be, given some hypothetical set of conditions. Unfortunately, we can't do that, because you haven't established exactly what conditions would be preserved in your hypothetical universe, and what would be different. Nimur (talk) 14:13, 30 January 2010 (UTC)

People are right to complain about your lack of manners. You cannot both ask a question AND tell people what the appropriate answer is at the same time. Dauto (talk) 15:03, 30 January 2010 (UTC)

Feel free to modify the question on my behalf so it is more clear. It's not that I want to tell people how to answer my question: it's that I want to make sure that it is clear that I am not conflating mathematics and physics. Thus the reason for my heavy-handed additions is only to make clear what my question is, since every time I ask it, I get an answer to a question that isn't mine. Thanks for any improvements you can make to the tone of my question while retaining its clarity. 84.153.213.154 (talk) 15:23, 30 January 2010 (UTC)

If I'm reading this right, you're asking someone to be polite for you? Vimescarrot (talk) 15:56, 30 January 2010 (UTC)

Even in this universe, with these physical laws, we've come up with different types of logic, and weird geometries. Any sort of logic or math is essentially a human construction (maybe we could generalize that to an intelligent construction), even if it was initially created to attempt to mirror reality. So perhaps the classical logic in this other universe would be different, and they might develop different systems of mathematics than we have. However, if this other intelligence did create a system that has the same structure as our numbering system, and the logic of proof was the same, then of course the same things would be true in it. Buddy431 (talk) 16:19, 30 January 2010 (UTC)

In this system, base 10 comes naturally to our intelligence because it's a base 10 star system. 9 planets and the Sun. Pluto's 'status' as a planet comes not into question considering that the Sun is 10, and counting down through the planets, Pluto is down around zero, and so the whole status as a planet thing is quite understandable yet irrelevant to our base 10 system. --Neptunerover (talk) 18:01, 30 January 2010 (UTC)

Please tell me you are joking... --Tango (talk) 18:04, 30 January 2010 (UTC)

How would I know? I've never checked any other stellar systems to see if the intelligence there uses a number base system coinciding with their number of planets plus stars, fingers, toes, or whatever else. Who knows? --Neptunerover (talk) 18:33, 30 January 2010 (UTC)

Please read correlation-causation fallacy. You can pick any arbitrary constant and say that "caused" the base numbering system, but you need some evidence to back it up (and SteveBaker below has shown the evidence against this hypothesis). In fact you mentioned another constant in your post, number of digits on both hands. You could also say that its the average weight (in lbs) of a 1 month old baby, average height (in cm) of a 4-year old, upper length of a chloroplast (in μm), ad infinitum. --Mark PEA (talk) 20:53, 30 January 2010 (UTC)

By George, I think you're right! Causation is strongly correlated with coincidence. --Neptunerover (talk) 21:44, 30 January 2010 (UTC)

NeptuneRover - that's incredibly stupid even by your standards. Humans learned to count when we only knew about the Earth, the Moon, Mercury, Venus, the Sun, Mars, Jupiter and Saturn. That's 8 - except that they wouldn't have counted the Earth because nobody knew it was a planet - so more likely seven. The other planets and moons require a telescope to see them and we're 100% sure that counting was discovered before lens-making. But even then - the planets mostly look very different from the sun and moon because you can't really tell there is a disk there with the naked eye - they were assumed to be stars that "wandered" rather than traversing the sky in nice circles. So why would they include the sun and moon, the wandering stars (but not the stationary ones), not include the occasional comet and also include this big seemingly flat thing that we happen to be standing on! There is no way that counting the planets (either with or without Pluto) determined our counting system...it's utterly obvious that it's the number of fingers that did that. Please don't answer questions by guessing or imposing your own (exceedingly weird) cosmologies. SteveBaker (talk) 19:25, 30 January 2010 (UTC)

Pardon me, sorry no, I'm afraid you misunderstood me there. I wasn't at all making a claim about causation. I mean, for instance, nobody knew Neptune was blue like an ocean prior to it's being named after a god of the sea, but that's not going to keep me from pointing it out as a coincidence. As far as what the coincidence means, if anything beyond nothing, who knows? Beyond the fact that such coincidences occur in vast numbers... Vast. --Neptunerover (talk) 22:35, 30 January 2010 (UTC)

Firstly, you said "base 10 comes naturally to our intelligence because it's a base 10 star system" - which is certainly a claim about causation. Anyway - what about Eris - that makes 11 and what about Makemake and Sedna doesn't that make it 13? So it's not even a coincidence - it's a contrivance of your own making added here just so you have something to say...it's like "OMFG! Both the 2009 Audi S6 Sedan AND the 2009 BMW M5 Sedan have 10 cylinders and we count up to ten. Coincidences are everywhere!" SteveBaker (talk) 23:05, 30 January 2010 (UTC)

(And they're both German automobiles! Will the coincidences never end?) Again you misunderstand about the 'causation' implied by my statement. I'm saying because it's a base 10 system, that comes naturally to the intelligence of this system. One doesn't cause the other, they only coincide. In this system, base 10 is a factor as basic as gravity, and life here has adapted to it. I don't want to argue here. --Neptunerover (talk) 23:36, 30 January 2010 (UTC)

Please - stop with this nonsense. "In this system, base 10 is a factor as basic as gravity, and life here has adapted to it." - no it's not! Octupi have 8 arms, not 10 - there aren't 10 planets, there are 8 or 13 or about 20 depending on how you count them. 10 is no more "basic" than a bunch of other numbers. I routinely do arithmetic in base 2, 3, 4, 8 and 16 - and on occasion 36 and 50. The human brain is just as capable of doing that as working in base 10. Also, there have been entire civilisations of humans who based their number systems on base 6 and 60. Your position is quite indefensible. Oh - and your "just so" story about Neptune is wrong too. The planet was not named until several years after it's discovery. People had measured the size of the disk of the planet before it was named - so it's color would have been well known by then. If you aren't prepared to defend your statements here (preferably with references) then don't post them. We really aren't interested in you posting your crazy pseudo-science here at the reference desk. SteveBaker (talk) 23:55, 30 January 2010 (UTC)

I don't want to argue. You do. I don't. Coincidentally, that's really weird that you mentioned octopi, since that's just like that Chuck Norris movie. Maybe there's a deeper meaning to everything after all. --Neptunerover (talk) 09:18, 31 January 2010 (UTC)

The preferred plural of "octopus" is "octopuses". --Tango (talk) 10:04, 31 January 2010 (UTC)

Yeah, well that may be preferred, but I heard the best one was "Octopods". --Neptunerover (talk) 12:33, 31 January 2010 (UTC)

Close - you mean "octopodes". That is what it would be if we were speaking Ancient Greek, but we're not, we're speaking English. English only uses certain foreign plurals with loanwords, everything else gets a normal English plural, and "odes" isn't one of the ones we use. --Tango (talk) 13:00, 31 January 2010 (UTC)

Hey right, that's what I heard! --Neptunerover (talk) 19:34, 31 January 2010 (UTC)

I believe, original poster, that you are caught up in too many concepts about laws and constrictions about the world. In your head, you appear to have reified so-called physical laws. They are just helpful approximations. It's easy to forget that, when those approximations are often so accurate and so useful. There never was and never will be a physical law per se. Vranak (talk) 18:20, 30 January 2010 (UTC)

Obviously the underlying truth in mathematics would be the same everywhere - but it's very likely that their math would be hard for us to recognize. For example:

• We say that the area of a circle is A = pi.r². We use the radius-squared to calculate the area with a constant factor of around 3.14159 that we call 'pi'. But in a different culture, it's possible that people might more routinely think about the areas of things and more often calculate the radius given the area - so they'd have r = wi.A^-2 - where 'wi' is short for 'wibble' and this is a fundamental constant which would show up all over their mathematics. Of course the value of 'wi' is approximately 0.318309 - which is 1/pi. They might even have come up with r = (wi.A)^-2 with 'wi' being roughly equal to 0.10132. The resulting contortions of our standard equations to keep them looking nice and simple with 'wi' instead of 'pi' would result in some different-looking equations.
• They might also choose to change the value of their units to make some constants equal to 1.0 so that they'd disappear from their equations altogether. If they chose their units of time and distance such that the speed of light were 1.0 then E=m.c² would become E=m and if they figured that out much sooner than we did in their scientific history then perhaps the whole idea that mass and energy are different would never exist for them.
• Another possibility is that their counting system might be different. We use digits that go from 0..9 (if we're working in base 10) - it's more than likely they'd be using some other counting base - which is a trivial matter to sort out. But there are other quite different choices: There is something to be said for using digits that mean -5 to +4. If I use small digits to mean 'negative', then you'd count in base 10 like this: 1, 2, 3, 4, 15, 14, 13, 12, 11, 10, 11, 12, 13, 14, 25... and then later: 44, 155, 154. There are actually some arithmetic simplifications that come from counting that way. You could imagine some weird setup where they preferred to keep everything in the log domain - so instead of doing simple counting with integers, they always used logarithms of numbers. IMHO, that's really unlikely - but using negative-valued digits actually makes a lot more sense than the way we do it. If you think that's unlikely - consider the Romans. Roman numerals are really a completely different way of representing numbers and would be a perfectly valid way to do arithmetic if it were not so horrible to deal with!
• Yet another weirdness could come about from their choice of what things are 'base units' and what are 'derived'. We have mass, length and time that we consider to be base units - but those are not the only choices. You can build an entirely self-consistent math and physics from choosing your base units to be something like speed, density and gravitational attraction. (Do I have that right? I think I do. Someone correct me please!)
• Most of our mathematics started out with geometry and arithmetic with things like set theory and topology coming much later. But if the aliens started out thinking about topology and set theory first and only got into arithmetic and geometry much, much later, then they would have discovered things in a very different order than we did and have a completely different take on how things tick. Beings that thought about math so differently might be spectacularly difficult to communicate with.

But none of those things make the fundamental knowledge any different - they would just serve to make their equations really hard to compare with our own. Any halfway decent mathematician could unravel them in short order - and then it would be childs play to write computer programs to translate their math and physics into forms that we'd recognize and vice-versa. SteveBaker (talk) 19:03, 30 January 2010 (UTC)

For more information about Steve's weird number system with negative digits, see balanced ternary (that's the base 3 version, but it's the same principle). I can't help with the base units thing because I have no idea what "gravitation attraction" means in this context... --Tango (talk) 19:30, 30 January 2010 (UTC)

Yes - I've come across balanced ternary - it's used in some telecoms applications. The nice thing about the scheme I described above is that if you're adding up a long column of numbers, you can just cross out matching pairs of (for example) 4's and 4's before you start adding. If the numbers are fairly random then in a long column, they tend to cancel out and you end up with very little actual addition and carry-one stuff to do in your head. Negative numbers are also easier to deal with because you don't need a '-' symbol, negative numbers just happen to start with one of the negative digits. Doing things like -7+3 in our system is painful - but 13+3 is easy 3+3=14 the 1 and the 1 cancel so the answer is 4 (or -4 in our notation). Subtraction in this scheme entails changing all of the big digits into little ones and then doing addition - there are no special rules for that...but there is a problem with 5 because there is no positive 5 digit - only a negative 5. This is why this system is most tempting to use it with odd-numbered bases. If you're doing (say) base 9 - then you don't need the ugliness of the '5' digit that has to be either positive or negative and which messes up the 'cancelling out' method of adding long tables of numbers because you end up with a bunch of left-over 5's that you have to tally up at the end. With a zero and 1,2,3,4,-4,-3,-2,-1, it's simpler to do base-9 arithmetic than base 10. SteveBaker (talk) 20:11, 30 January 2010 (UTC)

As a point of interest, Roman numerals are indeed horrible for doing written arithmetic in the algorism style, but are very well suited to arithmetic using an abacus. The Romans had handy little pocket abacuses, and you can perform quite sophisticated arithmetic using grooves in sand and pebbles. I thoroughly recommend a little research and experiment on the topic to anyone interested in history or maths. 86.180.52.43 (talk) 19:30, 30 January 2010 (UTC)

Steve, you might want to double check your calculations after the first bullet. Dauto (talk) 19:44, 30 January 2010 (UTC)

Yes - I did...sorry. SteveBaker (talk) 22:57, 30 January 2010 (UTC)

OP, one statement of yours needs to be strongly challenged: Surely if it were possible, you could conceive of it?. That assumes that all humans have the same imaginative capacity (er, no, 1000 times no), and that all humans know exactly what is possible and what is not (er, again, no; we're not pre-programmed robots; and we're not God). -- Jack of Oz ... speak! ... 23:42, 30 January 2010 (UTC)

Well, no, it was directed at me, so really it just assumes that I am perfect. That is an understandable mistake! ;) --Tango (talk) 10:06, 31 January 2010 (UTC)

Wow, what's with all the random spontaneous assumptions of psycholinguistics? This post is becoming chaos. Therefore, a healthy dose of oneness is required. ~AH1^(TCU) 02:55, 1 February 2010 (UTC)

why are winter winds so strong?

My daughter asked me this the other day and I had no answer, and it's actually a bit counter-intuitive. Since there is less solar radiation in the winter part of the globe, and hence less energy in the atmosphere, why does the wind seem to be stronger? --SB_Johnny | ^talk 12:35, 30 January 2010 (UTC)

"it's hurrying up due to the cold." is what I would tell her. 84.153.213.154 (talk) 12:51, 30 January 2010 (UTC)

Humor aside, why would you intentionally supply unscientific responses to a child's strictly scientific question? That is exactly the sort of diluted, nonsensical answer which discourages scientific approaches to everyday life. As for the original question, first you need to establish the fact that winter winds are stronger - which is verifiable. You can get data on average wind speeds in your region from the National Weather Service, this data table summary seems like a good place to start. The breakdown is regional and seasonal. Next, you can actually analyze the data (either by direct observation, or maybe run it through Excel and create a few basic graphs).

Now that we have some data to back up the claim, we can develop an explanation for the established trend - are the winter months windier, on average? After looking at the data some more, it seems that on average, winter months have about 2 mph stronger winds, across the USA. Keep in mind that this is a very simplistic average, and doesn't take into account things like gusts, duration, etc. More data is available on that here, also from NOAA's climate center. This trend must be related to the way that winds work - wind explains the mechanism that causes air currents to flow. I would have thought that the thermal gradients that cause winds are probably stronger during the summer months, because more incident solar radiation occurs during the day. But heating of air masses depends on more than just incoming solar energy - it varies a lot on your region and proximity to oceans, mountains, and so forth. The thermal gradients that cause wind are apparently actually stronger in winter. I'm actually having a bit of a tough time coming up with a concise, simple explanation - as the OP points out, less incident solar radiation intuitively suggests less total energy - but this is counter to the data. We can always resort to the "chaos theory" explanation of climate - that global-sized convection problems simply don't behave intuitively because they are so strongly coupled. Another way to look at it is that wind is caused by strong thermal gradient, not necessarily by large absolute values of temperature. It's possible that winter's lower insolation levels result in more uneven heating. Presumably, the lower the sun is in the sky, the more shadowed regions there are behind large hills and mountains - this could account for some small-scale uneven heating effects. I doubt this effect alone accounts for the net increase in wind speed during winter. Nimur (talk) 13:23, 30 January 2010 (UTC)

Winter means a higher thermal gradient overall between pole and equator. I believe this is relevant (source: half-remembered talk by climatologist). Algebraist 14:07, 30 January 2010 (UTC)

Is the wind stronger, or just colder? We probably notice a cold wind more than a warm one. You certainly do get strong winds in the summer - hurricanes are typically a summer phenomenon. --Tango (talk) 13:02, 30 January 2010 (UTC)

Yes, the average wind speed is higher during the winter and Algebrist has pointed out the correct reason: Stronger thermal gradient between the equator and the poles. Dauto (talk) 14:56, 30 January 2010 (UTC)

The point about hurricanes and tornadoes is an interesting, one, though. Are average wind speeds still higher in the winter if those type of extreme summer storms are included in the analysis ? If not, perhaps winds are just more evenly distributed in winter. Also note that most of the wind from a hurricane occurs over water, and observations of wind speed over water may not be included in the comparison. StuRat (talk) 18:04, 30 January 2010 (UTC)

Here is the actual answer as I understand it. In each hemisphere there is a transition zone between the polar and temperate regions that almost always contains a band of cyclonic storms that migrate generally from west to east, following what is called the storm track, closely related to the polar jet stream. In the winter (in the northern hemisphere) the storm track shifts to the south. Farther north, in the neighborhood of the Aleutian islands or the north of Scotland, you can get those sorts of howling storms at any time of year. For an explanation of the energy source, see Atmospheric circulation#Ferrel cellLooie496 (talk) 18:58, 30 January 2010 (UTC)

Another factor, in addition to those mentioned, as to why the winds *seem* stronger is the lack of leaves on the trees (if you're in a location where such things happen). The leaves act as a windbreak, tempering the gusts by inducing turbulence. Lose the leaves, and it is much easier for gusts to pass through the trees, making a location which would have been sheltered from the wind in the summer more open. It's why farmers on the plains plant evergreens around their farmhouses - since they don't lose their leaves in the winter, they temper the winds better than deciduous trees. -- 174.21.224.109 (talk) 20:00, 30 January 2010 (UTC)

Also, the recent storms in the northern hemisphere winter may be the result of the "Arctic Dipole": the warming in the Arctic reduces the overall temperature gradient, allowing the jet stream to sink farther south over land due to a strong negative Arctic oscillation, and those storms typically have strong winds, especially when cold arctic air collides with warm tropical air. This is often the cause of tornadoes as well, when in spring in the US and in early summer in eastern Canada different air masses collide. In summer and autumn is when the hurricane season occurs in the Atlantic, because there's more warmer air in the tropics that the storms feed upon. Extratropical cyclones at mid-latitudes clash warm and cold air, and the strongest winds are often located along fronts because that's where the air masses collide. ~AH1^(TCU) 02:48, 1 February 2010 (UTC)

Clouds id

Hello, I have a picture of clouds and i was hoping someone could help id the different kinds pictured. I think the picture was taken around 30000ft --Muhammad(talk) 14:26, 30 January 2010 (UTC)

Those appear to be a mix of cumulus clouds (the puffy 'cotton ball' clouds in the middle of the picture and below) and cirrus clouds (the thready ones at the top). go to cloud and see. --Ludwigs2 15:38, 30 January 2010 (UTC)

So its cirrus in the background, cumulus in the mid-ground. What about the large extensive ones in the foreground? --Muhammad(talk) 15:49, 30 January 2010 (UTC)

Have a look at the The Cloud Appreciation Society website[2]. Alansplodge (talk) 15:55, 30 January 2010 (UTC)

For Wikipedia articles please see Cloud, which has links to articles on all categories of cloud ie Cumulus, Cirrus as mentioned. The foregound clouds may be Stratus or Nimbostratus, seen from on top. --220.101.28.25 (talk) 16:21, 30 January 2010 (UTC)

moles

i am not talking about rodents.why do we have that black spots(that we mostly use as a identifying characteristic) on our body? many a times they are big, many a times small., sometimes just a spot WHY? —Preceding unsigned comment added by Myownid420 (talk • contribs) 16:47, 30 January 2010 (UTC)

This is a pretty big question which covers an awful lot of ground. I recommend our article melanocytic nevus, which is an overview of the types and causes of moles. TenOfAllTrades(talk) 16:59, 30 January 2010 (UTC)

Also you may like to note that moles are not rodents.--Shantavira|^{feed me} 17:10, 30 January 2010 (UTC)

The OP said they were not talking about rodents. They might not want to talk about rodents. --Neptunerover (talk) 17:48, 30 January 2010 (UTC)
Not meaning to assume anything about the OP with my previous comment, but one can never be too careful. Some people are scared of rodents. Ever see or read 1984? One avoids mentioning rats when around Winston Smith. --Neptunerover (talk) 18:55, 30 January 2010 (UTC)

Suffice to say they are not a good indicator of health. I've had moles go away. I can surmise they are the body's way of dealing with an excess or imbalance of something. Vranak (talk) 18:12, 30 January 2010 (UTC)

Since we have access to good, thorough, detailed, heavily referenced articles on Wikipedia – not to mention a wealth of information on the broader internet – the original poster would be well-advised not to rely on (inaccurate) speculation. TenOfAllTrades(talk) 19:11, 30 January 2010 (UTC)

Speculation? So if I am to understand you, you believe that that moles and overall corporeal health have no conceivable relationship? Vranak (talk) 19:25, 30 January 2010 (UTC)

I can conceive of lots of things — but it would be much more useful if you provided sources and references rather than guesses. TenOfAllTrades(talk) 20:13, 30 January 2010 (UTC)

Well, you know, curiosity killed the cat, and looking around in the broader internet can turn up some serious garbage, with the accuracy thereof being a matter completely beside the point. --Neptunerover (talk) 19:40, 30 January 2010 (UTC)

That comment was completely beside the point. ~AH1^(TCU) 02:27, 1 February 2010 (UTC)

This is the science reference desk. Nobody thought you were talking about rodents. You should have clarified that you weren't referring to the Avagadro constant. — DanielLC 07:16, 1 February 2010 (UTC)

Furnace efficiency vs. exhaust gas temperature

To raise the efficiency of a gas furnace, you want to reduce the heat loss in the exhaust gas. I wonder how much the exhaust gas temperatures differ between an average efficiency furnace and a high efficiency one. Does anyone know what the typical exhaust gas temperatures are for gas furnaces rated at 80%, 90% and 95% AFUE? —Preceding unsigned comment added by 173.49.10.80 (talk) 17:58, 30 January 2010 (UTC)

I don't have a direct answer, but would like to mention that the problem with lowering the temp of the exhaust gasses is that they no longer rise out of the chimney if they're too cold. This problem could possibly be addressed by adding an electric exhaust fan. You could, therefore, get a higher efficiency furnance than is otherwise possible. I don't think this is common practice, though, since the cost of the electricity must be factored in and any failure in the electric fan would make the furnace dangerous to use. StuRat (talk) 20:26, 30 January 2010 (UTC)

High efficiency furnaces do indeed use power ventilation. (And StuRat, not only is this common, it's required for all new installations in the US.) The temperature is low enough that they use 3-4 inch PVC pipe for the exhaust, and you need a drain to collect the water condensate from the exhaust. (The PVC pipe exhaust is much cheaper than building a chimney in new construction.) The boiler I have (average 93%) is programmed to lower the flame if the exhaust ever goes over 215F (and shut off at 240). The exhaust temperature depends on how hot you heat the water running through it, it's about 20 to 40 degrees above it usually. If it's only a little cold, I program the water to run at 100F, going up to 180F when it's -20F outside. Usually it's at 120-140. At 180 degree water it's not very efficient going up to 98.6% at low water temperatures. See a chart here. (Mine actually does better than that chart, but it gives the general idea.) There are many kinds of high efficiency boilers. The best ones are called mod-con. Modulating, condensing. They measure the outside temperature and modulate (vary) the flame to give different water temperatures. The are called condensing because they extract the Enthalpy of condensation of water, condensing the steam in the exhaust back into water (which you need to remove with a drain). Ariel. (talk) 00:37, 31 January 2010 (UTC)

A further complication is that the exhaust gas has moisture in it, and if you cool it down this moisture will condense out. Why is this a problem? Well, for one thing you don't want moisture in a system that was designed for dry gases (it mucks up the flow, as well as potentially corroding things). So what about if you carefully designed it so that water would only condense after it had left the chimney? Well, at least in an industrial context, it's still a problem if clouds of steam are coming out of your chimney because people assume it is smoke polluting the environment. So you have to make sure that the vented exhaust gases are hot enough to keep water from condensing until it has dispersed. With these restrictions in place, it is indeed pretty standard to extract heat from the exhaust gas to use elsewhere. The actual temperature it is practical to use will depend on the conditions at the site (temperature, humidity) and what you're using the heat for. After all, if you're warming something from 102 C, you're not able to cool your gas to or below that. 86.180.52.43 (talk) 00:08, 31 January 2010 (UTC)

Actually all the new boilers in the US do in fact make clouds of steam at the exhaust, and the first time I saw it I thought there was a fire and contacted the owner, and he told me it's normal. Now I have one of those, and so do many people. I believe these boilers are also required in the UK. The design of the boilers is interesting - it's counter flow. The inlet for air is above the exhaust. This helps the water that condenses inside flow downward, since the air is blowing it down. It also means that the coolest exhaust temperatures (the ones at the top, i.e. farthest from the fire) are used to warm up the incoming (cold) air. This helps the energy efficiency by extracting the maximum amount of heat from the exhaust. They are all made of stainless steel or aluminum to avoid corrosion. The condensate is slightly acidic (from the dissolved CO2 and from sulfur in the fuel) and you need to deal with it properly. If you need to pump it you need a pump rated for it. In some jurisdictions you need to neutralize the acid with chunks of limestone or marble in a tube. But usually you can just dump it down a drain and it mixes with other water in the house (but avoid using a metal drain unless the water is diluted). Ariel. (talk) 00:47, 31 January 2010 (UTC)

Wouldn't the corrosive waste water be a problem if there isn't any other water flowing into the pipes ? I picture it sitting for hours in metal pipes until some more water flushes it out. So you'd need all PVC pipes, from the drain to the septic tank/sewer, I'd think. StuRat (talk) 01:48, 31 January 2010 (UTC)

Don't use it with a septic system, I think it would (might) kill the bacteria. Water doesn't just sit in your pipes, it flows out immediately (unless it's installed wrong, and even then any "pool points" would quickly fill up with gunk, and water would flow right over it). Normally you have other water usage in your house. It's only if you have a pipe that never gets any other water that it's a problem. Over years it will corrode and thin the pipe. (At least from what I heard.) Most pipes are also "lined" with oil and gunk and biofilm that protects them. And it's not that corrosive, it takes years to damage a metal pipe. Some installers just drill a hole in the floor of the basement, stick the pipe in there and leave it. (I think that's nuts, but it's done, I guess it just drains into the soil under the house.) Others will make a hole to the outside and let it flow there (but watch that it doesn't freeze and block up). Also, not all places that the same level of sulfur in the gas. I think without sulfur it's really not very corrosive. If your jurisdiction does not allow copper gas pipes (because the sulfur corrodes them), then make sure to use the neutralizer kit. Ariel. (talk) 02:22, 31 January 2010 (UTC)

Actually, water does just sit in properly designed pipes, in the u bends, which are necessary to prevent sewer gases from backing up into the house. Those would be the first places to corrode. I agree with you that dumping water under the foundation is nuts, as it may seep back into the basement, or, over time, carry away soil and undermine the foundation. StuRat (talk) 18:27, 31 January 2010 (UTC)

A man who was a much published heating system expert of the 1950's once told me that even then they could have designed furnaces of higher efficiency that the typical 80%, by simply increasing the heat exchange surface area, but the limiting factor was that exhaust gases must not condense in the chimney. The house I live in switched from a low efficiency coal furnace to a higher efficiency gas furnace in the 1950's, and the exhaust gases condensed in the masonry chimney, causing creosote to seep through the chimney and stain the interior wall of the house. The solution then was to install a stainless steel liner of smaller cross section, which was less porous to the condensate, but which more importantly had a higher exhaust velocity to carry the gases out before they condensed. A later generation higher efficiency furnace requires forced draft to get the exhaust out. Edison (talk) 04:59, 31 January 2010 (UTC)

Clothes Washer and Dryer

Why isn't there one machine that washes and dries clothes? It would be awesome if the same machine could do the dishes as well.... --Reticuli88 (talk) 19:47, 30 January 2010 (UTC)

There might have been one on the Jetsons. --Neptunerover (talk) 19:51, 30 January 2010 (UTC)

There is, sort of. There's a combination device that has a washer on top, then drops the clothes down into a dryer, below, once finished washing. Why not a single machine ? Well, holding water involves rubber seals that tend to fail when heated to dryer temps. I suppose some high temperture silicone seals might hold up, so it is possible, but just not financially viable. I imagine that such a device would cost more than a seperate washer and dryer would. Still, for space-critical situations, like in a cabin on a ship, it might be worth the additional cost. StuRat (talk) 20:18, 30 January 2010 (UTC)

Gee, I just googled for "combination washer/dryer" and found a number of them, although they're quite expensive and it's unclear how well they work. Looie496 (talk) 20:31, 30 January 2010 (UTC)

We've had washer/dryer combos before. They work fine, but there is more to go wrong with them so we've found them less reliable and have a straight washer now. --Tango (talk) 21:42, 30 January 2010 (UTC)

I wouldn't be surprised if there already is such a machine (minus the dishing capacity) used in the larger factory laundromats that contract with hotels and hospitals, etc. Big Machines, I'm betting.
Incidentally, the potentially life-threatening implications of such a machine (or a similar machine) were explored by Stephen King in his short story the Mangler, not meaning to scare the OP. :) --Neptunerover (talk) 20:43, 30 January 2010 (UTC)

Actually large factory laundromats, and hotels use Continuous batch washers (AKA tunnel washers, or screw washers) it's basically a long perforated Archimedes screw the slowly moves the clothes from one side to the other passing through the various rinse and soap stages. See [3]. Ariel. (talk) 00:58, 31 January 2010 (UTC)

Washer/Driers are really common in the UK - I've owned lots of them over the years. In the UK, we generally have smaller homes than most Americans and there isn't enough room to have both devices. So they make front-loading machines that can go under a kitchen countertop which combine washer, spin-drier and hot air drier in one unit. They aren't as cheap as two separate units - but when space is at a premium, they are definitely the way to go. You'd think they'd be convenient too because you don't have to pull all of that damp laundry out of the washer and put it into the drier. But sadly, every one of these machines that I've ever seen has about half the capacity when used as a drier compared to what it can wash as a washer. So you still have to stop the machine, take out half of the load, do a drying cycle then swap out that half of the load for the other half...so it ends up being more work than with separate units. Dishwashers are very different beasts though - you need totally different internal racks for supporting fragile china - you wouldn't want to spin them and at the bottom of the dishwasher there is a food disposal gizmo that grinds up and waste food before it gets washed into the drains. Worse still, you wouldn't want the nasty chemical residues from clothes washing getting mixed into the water that's going to wash things you're gonna eat off of. SteveBaker (talk) 22:51, 30 January 2010 (UTC)

Wow, the UK is very futuristic in many ways, much like Japan, only their future styles are very different from one another. --Neptunerover (talk) 23:07, 30 January 2010 (UTC)

Two points. First, when you transfer clothes from the washer to a separate dryer, you leave some water behind -- the washer drum is still moist. A combination unit has to extract that moisture. Second, when you transfer clothes from the washer to a separate dryer, you can start another load in the washer. So for anyone who has more than one load per washday, having separate appliances may take up more space but it saves time (unless the combination appliance is appreciably faster than the separate ones, but then it probably wouldn't do as good a job). --Anonymous, 03:05 UTC, January 31, 2010.

Good points, but note that the type of combo unit I described, where the washing drum drops the wash into a separate drying drum when done, could possibly have a load of wash and drying going simultaneously, if they set it up to do so. But, of course, it would need to have the dry clothes removed before it dropped the 2nd batch of wet ones into the dryer. Perhaps there could be an additional step where it drops clothes from the dryer into a basket, when done. StuRat (talk) 18:20, 31 January 2010 (UTC)

Wronger than wrong

Our article on Wronger than wrong quotes Isaac Asimov who said "When people thought the earth was flat, they were wrong. When people thought the earth was spherical, they were wrong. But if you think that thinking the earth is spherical is just as wrong as thinking the earth is flat, then your view is wronger than both of them put together." Maybe this is going over my head, but what part about the Earth being spherical is wrong? That it's not a perfect sphere? A Quest For Knowledge (talk) 19:54, 30 January 2010 (UTC)

It is an oblate spheroid - basically, it has a fattened midsection because at the equator, forces relating to its rotation cancel out some of the gravitational forces pulling it together. Awickert (talk) 19:57, 30 January 2010 (UTC)

And there are mountains and valleys (the equatorial bulge is bigger, though). --Tango (talk) 20:03, 30 January 2010 (UTC)

An oblate spheroid is a description for the shape of the earth that is less wrong than an sphere. a geoid would be an even less wrong one. Dauto (talk) 21:42, 30 January 2010 (UTC)

That is true over the oceans, but over land the geoid would be just as wrong as the spheroid or worse, because gravity is uncorrelated with topography. Awickert (talk) 07:54, 31 January 2010 (UTC)

Of course, the point of view stated there seems based on Mr. Shermer's perception of what Mr. Asimov meant when he made the statement. Mr. Shermer has a highly advanced skeptical intelligence. There are likely to be other ways of interpreting what the statement means --Neptunerover (talk) 20:19, 30 January 2010 (UTC)

I can't think of one... --Tango (talk) 20:52, 30 January 2010 (UTC)

I believe you. --Neptunerover (talk) 21:34, 30 January 2010 (UTC)

Context should clear this up: here's Asimov's article on the subject in which he states pretty clearly what he means by that statement. http://chem.tufts.edu/AnswersInScience/RelativityofWrong.htm —Preceding unsigned comment added by Wevets (talk • contribs) 21:43, 30 January 2010 (UTC)

Wow, thank you for that link. A great writer. --Neptunerover (talk) 22:44, 30 January 2010 (UTC)

Yes, Asimov's article makes for an interesting read. I updated our article to make Asimov's point more clear. A Quest For Knowledge (talk) 22:47, 30 January 2010 (UTC)

Ah, thanks everyone! A Quest For Knowledge (talk) 22:08, 30 January 2010 (UTC)

The most obvious point here is that the earth isn't a perfect sphere - but a rather more complex shape that doesn't really have a proper mathematical name (the WGS84 description is the nearest approximation to the mean-sea-level shape - ignoring mountains and valleys). Saying that the earth is flat would be a wildly incorrect statement. Saying that it's a sphere is very, very close to the truth. As someone here pointed out a while ago, the earth is closer to being a perfect sphere than is a standard competition billiard ball. (And it's true - I checked - the acceptable engineering tolerances accepted by the rules of billiards allows a ball that is less spherical than the earth to be used in competition). So saying that the earth is spherical isn't true - but it's more true than saying that a billiard ball is spherical! Sadly, saying that it's an oblate spheroid or a geoid or anything else isn't 100% true either. But saying that it's a sphere is certainly a lot less wrong than saying that it's flat. Arguing otherwise degenerates into a matter of the semantics of the word "Truth" and to whether that is a binary state or a continuum - which is a silly argument that gets us nowhere and is best left as something to keep philosophers in full employment.SteveBaker (talk) 22:41, 30 January 2010 (UTC)

Steve, did you read Asimov's article? He's got a great quote: "Nowadays, of course, we are taught that the flat-earth theory is wrong; that it is all wrong, terribly wrong, absolutely. But it isn't. The curvature of the earth is nearly 0 per mile, so that although the flat-earth theory is wrong, it happens to be nearly right. That's why the theory lasted so long." A Quest For Knowledge (talk) 22:50, 30 January 2010 (UTC)

So, from one point of view, it all depends on the observer. That fits. --Neptunerover (talk) 23:09, 30 January 2010 (UTC)

It's not that I didn't read it - I think Asimov was wrong - VERY wrong. An inability to measure the curvature is the least of the problems. For the earth to be flat, it would have to be infinite or have edges - neither of which are remotely close to being true. It's a matter of topology. If the earth was a spheroid 1 meter across or the size of Jupiter, it wouldn't be any closer to being flat. It's not just a matter of the precision of measurement or the degree of approximation. On the real earth - you can move off in some given direction and after going far enough, arrive back where you started. You couldn't do that if it were flat. You couldn't tile the surface of the earth with square tiles - but you could (in principle) do that if it were flat. That's really why there is a significant difference between how "wrong" the flat-earthers are compared to those people who think the world is spherical. The difference between an oblate spheroid earth and a true sphere are tiny (note the billiard ball comparison). But the difference compared to a flat earth is more than a mere measurement difference. Asimov is a great science fiction writer...but when he strays beyond that, I have less respect for what he says. SteveBaker (talk) 01:27, 31 January 2010 (UTC)

But to an ancient Summarian, an Earth that goes on forever or one curves around and returns to the same place after 40,000 km are the same. If your empire is a couple hundred miles across, it doesn't matter if what's beyond is infinite or not. And as Asimov pointed out, it was the curvature that clued people in on Earth's true nature, well before anyone had the means to sail around the world or try to tile the Earth with squares. If you agree with Asimov's basic premise (that believing the Earth is flat is more wrong than believing it's a sphere), I'm not sure what your beef with him is. Buddy431 (talk) 01:56, 31 January 2010 (UTC)

This is my favorite line: They felt it was flat on the basis of sound evidence. It was not just a matter of "That's how it looks," because the earth does not look flat. It looks chaotically bumpy, with hills, valleys, ravines, cliffs, and so on. So, if anyone ever tries to tell you the earth is flat, you tell them, "duh, look around you." --Neptunerover (talk) 23:16, 30 January 2010 (UTC)

Neptunerover: The Earth can't be flat. If it was, there wouldn't be 4 simultaneous days in one Earth day.[4] :) A Quest For Knowledge (talk) 23:28, 30 January 2010 (UTC)

Again with the time cube? Are you kidding me? That stuff is crap! --Neptunerover (talk) 08:40, 31 January 2010 (UTC)

Hahahaha! SteveBaker (talk) 01:27, 31 January 2010 (UTC)

New rule, AQFK: you're not allowed to post while I'm eating. I nearly choked! – ClockworkSoul 08:40, 31 January 2010 (UTC)

I believe the underlying philosophy of this quote goes something like this. Ideas are just ideas. Whether the ideas are factual or inaccurate, they are first and foremost just concepts that guide our perception of the world. So saying the Earth is flat in no way an impediment to sailing the oceans. We may gain a subtler understanding if we consider it as a sphere, but again, it's really just a mental heuristic whose merit lives and dies with how useful it is. So getting too wrapped up in the description of the Earth is wrong. If it's useful it's useful, but in any event the ideas are only meant to guide understanding, not be a rigid container for whatever is out there. Vranak (talk) 12:22, 31 January 2010 (UTC)

Excellent, very insightful; I may borrow some of your expressions. =) --Neptunerover (talk) 12:39, 31 January 2010 (UTC)

I think you've managed to totally miss the point of the last part of the quote! Putting it another way: All models are wrong to some degree. But if you think that gives all models the same truth status, then you have made a bigger error than the erroneous models themselves—some models are truer than others. --Mr.98 (talk) 13:30, 31 January 2010 (UTC)

I actually get the opposite sentiment from the quote. Treating other people's genuine understanding of the shape of the world as wrong is itself wrong. It's preferable to see the other person's point of view than to belligerently insist that only your model is correct. This is where Galileo got into trouble with the Church. Vranak (talk) 16:45, 31 January 2010 (UTC)

Very cool. I may be wrong, but you're wronger than me! No I'm not! Yes you are! (ad infinitum) The wrongest is he who point finger. (such competitions can be very heated) --Neptunerover (talk) 19:56, 31 January 2010 (UTC)

Exactly. Camaraderie is generally more valuable than being 'in the right'. Of course you have to uncompromising about the truth in certain applications, like aerospace engineering and bridge building. Vranak (talk) 16:53, 1 February 2010 (UTC)

This isn't just a pedagogic or philosophical nitpick. I know several geophysicists who run numerical simulations of things (climate, earthquakes, heat flow, and other earth processes). A fundamental assumption of these codes is a rectangular- or cubic- grid. In some cases, the computer simulations are performed in spherical coordinates - but more often than not, the error between a cartesian-grid ("square earth") and polar grid ("circular earth") is so negligible for a particular problem, that it's not even considered. So, even reputable scientists can often use the theoretical approximation of a "flat earth". These sorts of "egregious errors" are clearly counter to modern scientific understanding - and these scientists are by no means unaware that the earth is actually a mostly round object with a particular shape that can be mathematically described or numerically approximated. It's just not worth it. The point is that scientists need to be aware of all the assumptions they are making. The "relativity of wrongness" can be rephrased quantitatively as "the sequence or order in which each assumption breaks down as the problem parameters become more generalized." If a scientist is cognizant of that sequence, he or she knows when to stop trusting the results of a theory or simulation. The same can be said for any of a variety of theoretical simplifications - classical physics, laminar flow, ideal gas law, perfectly elastic collisions, pure substances, etc. Nimur (talk) 19:50, 31 January 2010 (UTC)

Perhaps this entire discussion could be attached on the talk page for wronger than wrong, not for use as any sort of original insight, but as a reference for what the article should consist of in order for all sides in the issue of wrongness to be represented and covered fairly in the article. --Neptunerover (talk) 23:28, 31 January 2010 (UTC)

Eratosthenes calculated that the Earth was round, and found a rather accurate diameter using a stick and the Sun's shadow. But science is always evolving, and paradigms shift. Scientific skepticism is useful for chosing more likely hypotheses, but may actually prevent science from progressing. There are computer models that depict climate and earthquakes, but is there any singular model that puts everything altogether? There are a countless number of interactions and co-interactions, and it is not possible to depict all of them. Climate models, for example, depict a rough smoothing of the averages over time, but what we experience are the extremes. Recently, a negative feedback was identified in water vapor in the lower stratosphere, and after 2000 a tipping point was passed, causing the stratospheric cooling to reduce water vapor content. Warmer water in the Central Eastern Pacific contributed to lower water vapor content and cooler lower stratospheric temperatures for the past decade. I noticed that Talk:Iris hypothesis has a discussion about this. Climate skeptics will use this to try and disprove global warming, but recent developments like this do not falsify the whole theory, because it's certainly possible that while CO2 and other greenhouse gases increase in the lower troposphere, more tipping points will be passed, and the rate of the increase in the intensity of the extremes increases.

Simplicification comes in many forms, for example a lie to children and discredited thought resulting in widespread scientific misconception such as the tongue map. ~AH1^(TCU) 02:12, 1 February 2010 (UTC)

The only paper ever published in a peer-reviewed scientific journal on Intelligent design

The FAQ on the talk page for our article on Intelligent design states "the only article published in a peer-reviewed scientific journal that made a case for intelligent design was quickly withdrawn by the publisher for having circumvented the journal's peer-review standards". Where can I find more information on how this paper was published and the reaction of the scientific community? It seems like it would be an interesting story. A Quest For Knowledge (talk) 20:51, 30 January 2010 (UTC)

If I'm not mistaken, you might be talking about Stephen Meyer's paper "The origin of biological information and the higher taxonomic categories" in Proceedings of the Biological Society of Washington.

A review of the controversy can be found here from the Palaeontological Association: http://www.palass.org/modules.php?name=palaeo&sec=newsletter&page=25

And here from Panda's Thumb: http://pandasthumb.org/archives/2004/08/meyers-hopeless-1.html

Those are not NPOV, but I'm going to leave finding the other side of the story from Intelligent Design Creationists as an exercise to the reader. Wevets (talk) 21:36, 30 January 2010 (UTC)

Wikipedia has an article on the specific issue: Sternberg peer review controversy. 98.228.57.197 (talk) 21:39, 30 January 2010 (UTC)

It really was a ridiculous matter. The journal in question is not one that publishes material like this at all. It normally publishes dry descriptions of newly discovered fossils of animals and plants and discusses where they fit into the established taxonomy...and nothing else. Then one day, the editor of the journal resigns to take up work in the areas supported by this article. That's fair enough - he has the right to do that. But AFTER resigning but BEFORE actually leaving his post with the journal, he causes this article to be published with himself as the sole reviewer and without the consent of any of the other editors in flagrant disregard for the subject area or publication rules of the journal.

I don't see how anyone could possibly consider that reasonable - no matter what the field of enquiry. It was a breach of the journals' publishing guidelines, it was a clear conflict of interest for the editor, it was a drastic change of direction for the subject matter of the journal undertaken by someone who had already resigned their position and who was merely acting as a 'caretaker' until a replacement editor could be recruited. It's hard to imagine a less appropriate way to get an article into a Journal...maybe if you forced them to print it at gunpoint or something?!? Anyway, the entire (remaining) staff of the journal has since repudiated the publication on grounds that it's publication peer-review rules were ignored. So to proclaim the status of that journal as backing up the claims of the article (which is what you mean when you claim that peer-reviewed publication actually means something) is really a lie.

Furthermore, the article did not actually make any claims either for or against ID - it was purely a "review article" - a not uncommon scientific practice of collecting together a lot of references on a particular subject and summarizing them in an article for the convenience of the readership. The article didn't present any direct evidence either for or against ID - it merely pointed out that a lot of (not-peer-reviewed) material had been published - and as such, I suppose, it was true.

So the bottom-line truth here is "Someone dishonestly published a not-peer-reviewed paper in a journal from an unrelated field that merely summarized existing not-peer-reviewed writings - and it was later repudiated by the journal." Great. Score one point for ID...or something. It speaks more for the dishonesty of the ID community that they uphold this as proof of the legitimacy of their field than it benefits them. In the end, getting a paper published only means something if the scientific community in general accept the status of the journal in which it was printed. Because the journal clearly repudiated the article - scientists are not going to be even slightly impressed by the fact of its pubication...and that's what matters for an idea to be taken seriously. SteveBaker (talk) 22:28, 30 January 2010 (UTC)

Question re: Magnetic pole switch

Since the Earth is due for a pole switch any time now, what are the likely effects it will have on computing equipment? Will every hard drive across the world get wiped? Should I backup my files on cd rom? —Preceding unsigned comment added by 82.43.89.14 (talk) 23:01, 30 January 2010 (UTC)

One thing up front... "any time now" is only true on geological time scales, if it is true at all (and as the article makes clear, it is not exactly clear that it is going to happen at all). So we're talking about maybe tomorrow, maybe another million years from now, maybe even more. So I'm not sure you need to worry about this as a short-term backup problem. You probably should back up important files on CD-ROM, in general, because the odds of your hard drive having a catastrophic collapse in the next year or two is much, much higher. The odds of every backup hard drive you have failing at the same time is probably higher than this pole shift happening in your lifetime.

A second thing. Let's imagine that this does happen tomorrow and it destroys, for some reason, all magnetic-based media. Whether your e-mail has been backed up is probably the least of your, or anyone else's, problems. There is really no way for your to plan for such a contingency and expect it to matter much. At least, not other than general pandemonium planning (potable water supplies, etc.).

I don't know what the effects would actually likely be, though, so maybe someone else can clear up on that. --Mr.98 (talk) 23:48, 30 January 2010 (UTC)

Direct effects will be zero. The earths magnetic field is so weak you would not notice. It will do nothing whatsoever to hard disks, floppies, etc. However, it might be weak, but it's also large. Indirect effect, specifically from solar wind could become a huge problem. It could induce voltage surges in powerlines that might burn up anything connected to them, or it might simply trip some breakers (this happened once before in canada on August 10, 1996). I don't think that radiation would be a problem, but I'm not sure. Radio transmission would almost certainly be hard if not impossible during (but not after) the switch. Please note, that all this is not from the magnetic field, but from solar wind, which the field is not blocking for us. Ariel. (talk) 00:14, 31 January 2010 (UTC)

Original poster: You realise the article you linked to, Cataclysmic pole shift hypothesis, refers to a change in the axis of rotation, and has nothing to do with Geomagnetic reversal...right? Vimescarrot (talk) 00:28, 31 January 2010 (UTC)

Note that the pole switch linked in the question is not simply a magnetic polarity reversal, but rather the Cataclysmic pole shift hypothesis, which is the extremely "fringe" idea that the Earth's axis of rotation sometimes changes cataclysmically. If something like that happened, the effects would be devastating on many levels. But it isn't going to happen. Even relating to a magnetic polarity reversal, though, my understanding is that the Earth's magnetic field protects us against cosmic radiation, so the collapse that would occur during the reversal might not be so innocuous even though the field itself is pretty weak. Looie496 (talk) 00:29, 31 January 2010 (UTC)

No Ozone layer or Van allen belt effects? Thought pole switch as supposed to be real BAD?? re radiation getting throught to Earths' surface? --220.101.28.25 (talk) 00:45, 31 January 2010 (UTC)

It could be bad, but it can't be too bad - it has happened many times before without any serious effects. We will still have an atmosphere to block radiation, so it will only be a small increase in radiations levels at the ground. --Tango (talk) 11:38, 31 January 2010 (UTC)

Also, I don't believe that the magnetic polarity reversal happens instantly, but over thousands of years. The first signs would be pockets of magnetic instability and reversal, and we do seem to have had some of those. The pockets would move around and slowly grow until eventually more area had the reverse polarity than the normal polarity. Of course, during this period the overall magnetic field is quite weak, allowing the solar wind to wreak havoc on the Earth. StuRat (talk) 01:24, 31 January 2010 (UTC)

The prediction that we are "due for one" is based on the average time between shifts in the past. But these aren't by any means regularly timed events - sometimes the planet goes for millions more years without one happening and other times they come in rapid succession. So it's not like there is a clock ticking down towards zero - then KAPOW!! It's more like you shuffle a deck of cards, draw one - if it's the six of diamonds, KAPOW!! If it's not, you reshuffle the cards and try again. The mechanism is complicated but the fact that we haven't had one for a long time doesn't appear to affect the probability that we'll have one today. I don't think hard drives are affected - the earth's magnetic field is really weak and the disk drives in your laptop don't go wrong if you pick it up and turn it upside-down...which (in effect) reverses the magnetic field from the perspective of your hard drive. SteveBaker (talk) 01:40, 31 January 2010 (UTC)

The biggest problems in terms of magnetism that I know of would be with navigation (both with animals and for humans), though I suppose humans are probably smart enough to see the SE on the compass and head North-West. Falconus^{p t c} 02:42, 31 January 2010 (UTC)

Or just use GPS. --Tango (talk) 11:38, 31 January 2010 (UTC)

Maybe not. The effects of the (temporary) disruption of our protection from charged particles streaming from the sun are hard to predict. It's very possible that such radiation would wipe the memories in our satellites and/or disrupt the radio waves they emit for our GPS receivers to pick up - or (worse still) disrupt radio commands controlling the satellites - resulting in yet more chaos. SteveBaker (talk) 16:30, 31 January 2010 (UTC)

Thank you User:Ariel. for the relevant and helpful answer. —Preceding unsigned comment added by 82.43.89.14 (talk) 11:22, 31 January 2010 (UTC)

Any cataclysmic effects are unlikely, but an extreme solar flare could suddenly put nearly half of all North Americans out of power. In addition, holes have been discovered in the Earth's magnetic "shield". If such a scenario as a strong solar flare directed at Earth does occur, then long power shortages are likely, making the 2003 blackout pale in comparison. [5][6]. ~AH1^(TCU) 01:14, 1 February 2010 (UTC)

The concise answer, I believe (I am not an expert) is that what we have to be worried about is not a reversed magnetic field, it's the time *between* when the poles are normal and when they are properly reversed. While the field is unstable, solar flares can barrage us with catastrophic magnetism. Of course as others have pointed out, you probably should be equally worried about the world-ending ice age that is coming 'any time now', the world-ending volcanic eruption in North America that is coming 'any time now', or the world-ending asteroid that is coming 'any time now... --Jmeden2000 (talk) 16:21, 1 February 2010 (UTC)