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August 3

Snowing right now

Where in the world is it snowing right now? Barbaricslav (talk) 01:35, 3 August 2011 (UTC)

It's winter in the southern hemisphere so it may well be snowing in the ski resorts in the mountains of Chile, for example, or perhaps in the Snowy Mountains of Australia. Antarctica is likely to have a storm or two. I have known it to snow in some of the northern hemisphere mountains in August -specifically in the Canadian Rockies. Bielle (talk) 01:58, 3 August 2011 (UTC)

Perhaps also Alert, Nunavut:

"Alert has a polar climate. The weather is very cold, and there is snow cover for 10 months of the year on average. The warmest month, July, has an average temperature of 3.3 °C (37.9 °F). Alert is also very dry, averaging only 153.8 mm (6.06 in) of precipitation per year. Most of the precipitation occurs during the months of July, August and September, mostly in the form of snow. On average there is 16.1 mm (0.63 in) of rain which occurs between June and September. Alert sees very little snowfall during the rest of the year. September is usually the month with the heaviest snowfall. February is the coldest month of the year. Snowfall can occur during any month of the year, although there might be about 20 frost free days in an average summer.[7]" Count Iblis (talk) 02:09, 3 August 2011 (UTC)

New Zealand's South Island received a heavy snow dump a week or two ago. Plasmic Physics (talk) 04:36, 3 August 2011 (UTC)

It seems that there is no current snowfall in southern Chile, Australia or New Zealand. According to BBC News there should be light snowfall in Punta Arenas on Friday. But Weather Underground reports ongoing snowfall in several locations on Antarctica: Amundsen-Scott, Base Orcadas, Dumont d'Urville Station, and Vostok Station. 130.188.8.11 (talk) 09:30, 3 August 2011 (UTC)

As someone who does a bit of skiing, I can report that, sadly, although it is snow season here in SE Australia, it was 10 degrees C in the nearby mountains today (approx 50 degrees F). But apparently snow is forecast for Sunday. HiLo48 (talk) 10:31, 3 August 2011 (UTC)

South Africa. [1] ~AH1 ^(discuss!) 14:20, 8 August 2011 (UTC)

hammerhead sharks

can hammerhead bite head on or do they have to turn there heads to one side to stike — Preceding unsigned comment added by Jteuscher (talk • contribs) 01:42, 3 August 2011 (UTC)

Our Hammerhead shark article (which could do with a few more sources I think) suggests that hammerheads are mostly bottom feeders, and states that they may sometimes pin down rays with the 'hammer' to eat them. I'm not entirely convinced by this, but they certainly look better adapted to taking bites out of things underneath than in front. Given that some species have been known to attack humans though, I think it is safe to assume that they are flexible enough to attack in other ways. AndyTheGrump (talk) 02:10, 3 August 2011 (UTC)

For a specific example, see also Great_hammerhead#Feeding mentioning examples where the shark "disables" the prey (stingray) with its first bite, then pins it with its head, and finally "takes the ray in its jaws head-first". This section does cite five references. ---Sluzzelin talk 02:17, 3 August 2011 (UTC)

Torque and power

why the maximum power and torque of an engine specified at different RPM's ?

Torque is essentially force, power is essentially force multiplied by velocity. They are different things. You can have a large torque when the engine is not moving, but the power in that case is zero. Looie496 (talk) 02:44, 3 August 2011 (UTC)

Effect of star Jupiter on Earth

In his series of books beginning with "2001 A Space Odyssey", Arthur Clarke has a race of super advanced aliens cause Jupiter to turn into a star. If such were to happen, would we be likely to see the new Jupiter with the naked eye, and would the light be bright enough to disrupt life on Earth? — Preceding unsigned comment added by GuadalupePeak (talk • contribs) 02:39, 3 August 2011 (UTC)

I guess you didn't read the book. (2010: Odyssey Two, that is.) In the book, he has the aliens turn it into a very dim star, just bright enough to warm up Uupiter's moon Europa. Looie496 (talk) 02:50, 3 August 2011 (UTC)

As far as the visibility is concerned, you can already spot Jupiter with the naked eye during daytime, see here. If Jupiter were to turn into a star, it would be much easier to spot, of course. Count Iblis (talk) 02:56, 3 August 2011 (UTC)

Jupiter's Moons Ganymede and Callisto can also be seen using the naked eye, see here. Count Iblis (talk) 03:13, 3 August 2011 (UTC)

I think we used to have a page on the Lucifer Project which is a conspiracy theory that NASA (or the illuminati or NWO or whatever malevolent power you want to believe in) were going to try to ignite Jupiter.. Looks like the page is gone, but you can still find info about it if you google the term. Vespine (talk) 03:51, 3 August 2011 (UTC)

I think the main concern with this would be whether the new star would be bright enough to damage the retina, like an arc welder. Jupiter is about 1/10 the radius of the Sun, thus 1/100 the area - but it's also 4-6 times further away, making it 1/16 to 1/36 smaller in apparent size than that. But if it had the same color temperature as the sun, that 1/1600 bit of area would be just as bright as the sun itself. In total eclipses even fairly small areas of exposed sun are dangerous - actually much more dangerous than looking at the sun because the iris opens up, not being designed for extreme brightness in an overall dark scene. Especially at night this would be dangerous. Humans might learn to avoid looking at it before going blind (though I think something like that would be harder to learn than you'd think) but certainly nothing else would. These risks would be much reduced if it turned out to be a brown dwarf or something, much cooler on its exposed surface. Wnt (talk) 04:46, 3 August 2011 (UTC)

It's a pretty pointless question, it's like asking: if Jupiter gives off light, how much light would it give. The answer is pretty much up to you. Alternatively, if this lead sinker floats in water, how dense is it. Lead doesn't float in water, so the answer is: it is as dense as you want it to be, although less than water. So, if Jupiter was a star, it is as bright as you want it to b, as long as it is brighter than it's natural reflection. Plasmic Physics (talk) 05:26, 3 August 2011 (UTC)

Not to get too picky, but Jupiter is technically "brighter" than its natural reflection, it emits more energy than it gets from the sun, per the Kelvin–Helmholtz mechanism. What makes Jupiter not a star is that it doesn't undergo nuclear fusion; according to our article on Jupiter, it would need to be 75 times more massive in order to support nuclear fusion. In order to make it a star, Arthur C. Clarke had to invoke his own third law by introducing a little bit of "magic" in the form of the monolith. As Plasmic Physics notes, there is no conceivable way Jupiter could actually be a star, so discussing how it would become one is a purely fictional venture. --Jayron32 05:44, 3 August 2011 (UTC)

Well, in the 2010 film it was shown about the same color temperature as the Sun, and I think then my comments would hold. People would look up in awe and wonder, and end up tapping around with the white cane. Wnt (talk) 16:54, 3 August 2011 (UTC)

Meh. There's no evidence the filmmakers were terribly interested in making a scientifically accurate depiction of such a star anyways. Like anything else in the film, the effect is for dramatic purposes and isn't supposed to be scientifically accurate. I mean, you've completely accepted that a giant magic rectangle is capable of turning Jupiter into a star and yet have a problem with the spectral class of the star so created as represented in the film? If physics already doesn't work as it is supposed to in said film, what's the point of picking and choosing which wrong physics to complain about? The new star doesn't blind the people in the film because film physics works different than real physics. There's almost no point in playing the "how many ways is this film wrong" game unless you want to go all the way, and really what's the point. Films, like nearly all fiction, depend on suspension of disbelief to work; if you're so unwilling to accept such a suspension of disbelief to enjoy the film on its own terms, I don't see where this is a productive line of thought anyways. --Jayron32 18:00, 3 August 2011 (UTC)

Well, you don't neccesarily have to go all the way, as long as you are willing to make exceptions, and not to base an argument on those exceptions, to avoid circular reasoning. Plasmic Physics (talk) 19:31, 3 August 2011 (UTC)

The article was Lucifer Project I change the link supplied by User:Vespine and restored the page for those that want to read it. Graeme Bartlett (talk) 13:15, 4 August 2011 (UTC)

Beyond the standard model and low temperature physics experiments

Hi, is it possible that one could find standard model discrepancies at very low temperatures (like someday 10^{-50} kelvin?) as well as at the very high energies in particle accelarators? Thanks, Rich Peterson24.7.28.186 (talk) 03:54, 3 August 2011 (UTC)

• Like maybe dark energy doesn't "work" except at low temps?24.7.28.186 (talk) 03:56, 3 August 2011 (UTC)

• • The reason why high temperature testing of the Standard Model is done in the first place is generally to try to understand what the universe was like arbitrarily close to the Big Bang. The deal with low-temperature physics is, we have lots of examples around us (i.e. most of the universe is pretty cold) and most of the really exotic stuff happens when particles are energized enough to start to break down. You can get essentially infinitely hot (pre-empting the objections: yeah, I know there are limits here too, but not the same way as at the other end), but you've got a limit to how cold you can get. We've gotten very close to that cold limit, so we've got a pretty good handle on what happens there, but we've come nowhere near recreating the conditions at Big Bang time, which is why that is where the bulk of research is driven. --Jayron32 04:22, 3 August 2011 (UTC)

I feel like the "limit to how cold you can get" is illusion. The universe goes through different regimes of physics according to the log of its age, and the log of its temperature. There may be no limit to how old or how low temperature it can get, and I'm also suspicious that over very long time scales at very low temperatures and very low masses, some new physics could emerge when ours is too hot to be of much importance, just as has happened so many times before in history. Wnt (talk) 04:56, 3 August 2011 (UTC)

Could you please explain to me how one can go a slower speed than "stopped". Because I am not smart enough to understand how one may get colder than absolute zero. --Jayron32 05:35, 3 August 2011 (UTC)

Seconded. --Stephan Schulz (talk) 07:07, 3 August 2011 (UTC)

As I said, a logarithmic scale. People have proposed all sorts of bizarre physics for the first second after the Big Bang. What happens when you look at the interactions of matter at 10^-30 Kelvin over a period of 10^50 years? Maybe we're living now in another one of those periods of strange high-energy physics in the "moment" after the Big Bang, from that perspective? In other words - suppose there's proton decay. Suppose there's electron decay.^[2] Suppose you have a sea of neutrinos and nothing else, whizzing around over unimaginable time spans until they somehow come to rest with respect to one another. Do they start forming chemical-ish interactions? (No, I don't know, but I think it's a fair question) Wnt (talk) 08:09, 3 August 2011 (UTC)

I suppose it's possible, but it may also be outside of the range of human observability. Imagine a world where stuff happens on a timescale where one second of our time is expanded into 1 million years of real time (that's basically the logarithmic scale you are talking about here). Effects on THAT scale may well be unobservable within the limits of our methods to detect them. If humans lived one billion years rather than 70 years, and were able to observe the universe at such a time scale who knows what we may see. But, Wnt, you're delving into the realm of pure speculation; and while we may hold that technology may allow us, in the future, to delve into such realms scientifically, there is no indication that we may now or even within our lifetimes, so there's really no point in making it a big deal, right now. We can only say that, based on our current observations we have no reason to suppose anything terribly interesting happens at such low temperatures. It might, but there is nothing to say that it will. --Jayron32 11:37, 3 August 2011 (UTC)

I recognize this - though I wouldn't rule out that physicists might do a fair job of describing what a particle mediating a neutrino-neutrino bond would look like if there were one. The main reason why I think about this is that so often I have seen "the end of the universe" (and the "beginning of the universe" for that matter) described in such definite terms, when I feel like there is no real evidence that any era of time and temperature is truly the first or the last. Wnt (talk) 13:29, 3 August 2011 (UTC)

Except that the end of the universe may not even be at absolute zero, it could be considerably warmer than that. See Ultimate fate of the universe. While the physics of what might happen at some (currently impossible to achieve) arbitrarily tiny temperature close to absolute zero may be interesting, there is no wide spread agreement that the universe is asymptotically approaching that temperature. It is but one model of the end of the universe, and there's not yet a whole lot of evidence that it is far-and-away the best model. --Jayron32 13:52, 3 August 2011 (UTC)

Also agreed. But an open universe is still the leading contender. I think that any glimmer of evidence in this direction would do much to dispel the pall of fatalism that pervades modern pop physics. If people realize there's even a chance that the universe goes on and on and on, with new kinds of physics at each new time scale, it would fire up their imaginations. Wnt (talk) 16:52, 3 August 2011 (UTC)

Yes, it is possible that one will find that the Standard Model is false by studying physics at very low temperatures. That could happen if quantum mechanics (on which the Stanard Model is based) is not fundamental. If quantum mechanics is only approxmately true, then that would give rise to an effective theory in which decoherence would happen eve if there are no nteractions with the environment. This would then become visible only at extremely low temperatures at which the decoherence rate due to the environment becomes very small. Count Iblis (talk) 14:52, 3 August 2011 (UTC)

Thanks199.33.32.40 (talk) 18:46, 3 August 2011 (UTC)

That of course implies that any human created model of the universe could even be fundemental. I'm not entirely convinced that any model could exist at infinite precision; The Standard Model exists because it works, not because it is (or even should be expected to be) infinitely true under an arbitrarily high level of precision. If the Standard Model is shown to not apply at certain conditions (be it very high or very low temperarures, or any other set of extremes) then science would supplant it with a more precise model which includes the new data and the new paradigm. It wouldn't make the Standard Model substantially more wrong however; the existance of quantum mechanics doesn't make the Newtonian models invalid, for say, calculating ballistic trajectories or figuring out the stresses on bridge supports. Models are always going to be an approximation on reality, and we choose which models we use by the specific application where they work not because they are expected to be right for all applications. It isn't a question of being "fundementally" correct, just in finding the correct paradigm to give you the best solutions for your particular problem... --Jayron32 15:06, 3 August 2011 (UTC)

Getting sulfur from Gypsum.

Gypsum is Calcium Sulfate and has the formula CaSO4·2H2O, which seems to indicate it has a lot of sulfur in it. Let's say I wanted to get pure sulfur out of gypsum, what would I need to do? — Preceding unsigned comment added by 24.72.218.111 (talk) 06:41, 3 August 2011 (UTC)

You could use a strong reducing agent to obtain the sulfur - though the reducing agent would be worth more than the sulfur. Or you could use microorganisms that extract oxygen from the gypsum under anaerobic conditions - I'm not sure if this has been done on a large scale for synthetic purposes, but it happens accidentally with drywall, which can thus emit hydrogen sulfide which can more readily be used to make elemental sulfur.^[3] Google knows no hits for "fermenting gypsum" - somebody ought to fix that. ;) Wnt (talk) 08:04, 3 August 2011 (UTC)

To what temperature in Kelvin or degrees Celsius does Gypsium have to be heated to decompose it into vitriolic aire and calx? Is it easier to reduce vitriolic aire to sulfur? Plasmic Physics (talk) 08:44, 3 August 2011 (UTC)

"Vitriolic aire" is not a common term for me, but as sulfuric acid is called "oil of vitriol" I'll assume that it is SO3. Usually people are interested in doing this reaction the other way, in Flue-gas desulfurization. From a few scraps I just read it sounds like the decomposition of gypsum isn't very pretty, with decomposition starting around 900 C but peaking at 1200-1300 C.^[4][5] Decomposition is into lime (CaO, calx?) and SO3, but at that temperature SO3 is more or less in equilibrium with SO2. At much cooler temperatures, 500-800 C, SO2 (and I assume SO3) can react with carbon to produce elemental sulfur.^[6] Wnt (talk) 13:50, 3 August 2011 (UTC)

Evolution

Apart from Index to Creationist Claims, what other major, long, detailed or comprehensive list of arguments defending evolution or responses to arguments against evolution are there on Internet websites? Is that list the only such list in talk.origins?

I am asking this because there is a list of responses to Index to Creationists claims in Creationwiki. — Preceding unsigned comment added by 110.174.63.234 (talk) 08:34, 3 August 2011 (UTC)

There is no need for a list since the validity of scientific theories is not decided by a list contest. Dauto (talk) 14:29, 3 August 2011 (UTC)

That really doesn't answer the poster's question at all. I can think of plenty of reasons why a list would be useful, besides a "list contest". —Akrabbim^talk 14:50, 3 August 2011 (UTC)

Don't know if you'll think it counts but there are several YouTube channels with lots of evolution videos that give evidence for evolution and also rebut creationist claims. I can't search YouTube at work but the main one I can think of off the top of my head is thunderf00t, if you find his channel you should be able to go through related videos from there. His most recent videos have him debating banana man, I recommend you don't start with those videos since his debating is not nearly as polished as his self produced videos. Vespine (talk) 22:27, 3 August 2011 (UTC)

EM waves traveling through a vacuum

What's the physical difference between a volume of space in a vacuum with no EM wave propagating through it and another volume of space in a vacuum with an EM wave propagating through it? 20.137.18.50 (talk) 18:18, 3 August 2011 (UTC)

The physical difference is that one has an EM wave propagating through it and the other does not. Sorry, but that is a physical difference, and there's no simpler way of stating it. I could say that one of them contains photons and the other doesn't, but that really isn't any simpler. Looie496 (talk) 18:24, 3 August 2011 (UTC)

"I could say that one of them contains photons and the other doesn't, but that really isn't any simpler." If that's true, then the presence or absence of wave/particles is something I can begin to get my head around. 20.137.18.50 (talk) 18:27, 3 August 2011 (UTC)

It may be easier to take your thinking back one step, classification wise, to understand how EM radiation works. Think of EM radiation as a physical thing itself. That thing can be modeled as or observed as a wave, or it can be modeled as, or observed as, a particle, depending on which context you want to work with it. It's kinda like asking "am I a father or am I a son". I am actually both, but it depends on what context (in relation to my own father, or in relation to my own child) you are asking the question. Likewise, "electromagnetic radiation" is a thing like me. Asking whether or not EM is a wave or a particle depends purely on the context of the question. Just as I am both a father and a son at the same time, and I can say that without contradiction, you should also be able to accept that EM is both a wave and a particle at the same time. When you ask "what is the difference between the a vacuum with EM radiation and one without", the simple answer, as Looie496 stated, is the radiation itself. --Jayron32 18:37, 3 August 2011 (UTC)

And from the experimental point of view, the presence of a EM wave can be detected with, for instance, an antenna. Associated with the wave there are oscillating electric and magnetic fields (That's what's waving) which influence the behavior of the electrons in the antenna creating a measurable signal. Dauto (talk) 18:43, 3 August 2011 (UTC)

However you want to slice it: electric fields, and magnetic fields, are fundamental properties of the universe. They exist. We can measure their values. We can write equations that precisely model their observed behaviors. You can choose a variety of different approaches to write accurate equations that work well for particular scenarios.

(Classical electrodynamics): If you want to model the universe as a coordinate-space, you must define a vector-field for the electric (E) and magnetic (B) fields. An electromagnetic wave exists when this vector-field takes on certain specific values, and can propagate. We explicitly define those values by solving the wave equation for Maxwell's equations, which define the relationship between the position and value of E- and B- fields.

(Relativistic electrodynamics): Special relativity explains the coordinate-transform that relates electric field and magnetic field. Using the mathematical framework provided by relativity, it becomes trivial to translate your coordinates into a different frame; physically, this means that magnetic field and electric field represent the same phenomenon. For example, one observer at one position at some instant may see a static magnetic field; while relatively-moving observer (moving at a specific velocity) may see no magnetic field, and a time-varying electric-field. These observations are equivalent and consistent with a coordinate transform. Maxwell's equations, which work in classical situations, work equally well for relativistic treatments.

(Quantum electrodynamics): If you want to model the universe using particles, you must specify the position and value of the photons, which is equivalent to defining the wavefields as above. If you consider incredibly small time- and length- scales, or very high energies, you must consider other fundamental interactions, in addition to electric and magnetic interactions.

(Electroweak unification): Furthermore, electric field and magnetic field are special cases of electroweak interaction, observed at low energy scales. Electroweak unification is the rigorous mathematical formulation that explains how electric field, magnetic field, and the weak interaction can all be represented in a single equation.

Whether you want to model this universe by representing it with quantized state (including inherent uncertainties in those quantized states); or if you prefer to model it as a set of continuous fields for all coordinate-points; or as a lorentz-contracted, general-relativity-compensated space-time coordinate system; it is just this simple: electric field, and magnetic field, are fundamental properties of the universe, along with the value of mass and charge, and a few other physical quantities. We take their existence in the equations as axioms, because that matches our observations of the universe. Despite their apparent mathematical simplicity, the equations we use to define field or particle interactions are based entirely on experiment. Nimur (talk) 19:05, 3 August 2011 (UTC)

Gravitational waves and frame of reference

I was just reading the article on gravitational waves, and from what I gathered, any moving object produces gravitational waves, like a boat on a lake. Would this mean that there is an absolute frame of reference? --Melab±1 ☎ 19:38, 3 August 2011 (UTC)

Never mind, I saw the part talking about acceleration. But, does anyone still care to comment? --Melab±1 ☎ 19:38, 3 August 2011 (UTC)

You said "any object", but I suspect that all massless particles should be excluded from this list, so make that "any object with mass". StuRat (talk) 20:15, 3 August 2011 (UTC)

Your suspicions are unfounded. Massless particles also contribute to gravity, since they do carry energy. Beware that only the rest mass of a massless particle is zero. Dauto (talk) 20:47, 3 August 2011 (UTC)

Well, I'll comment on the original question. My understanding is that gravitational waves are thought to transform in the same way as light waves -- a way that does not yield an absolute frame of reference. Looie496 (talk) 15:42, 4 August 2011 (UTC)

Destroying the Popemobile

Could the Popemobile be destroyed by an anti-tank weapon? Whoop whoop pull up ^{Bitching Betty | Averted crashes} 19:54, 3 August 2011 (UTC)

Simply glancing at both articles that you linked make it clear that the Popemobile has bullet-proof glass around the Pope's seat and anti-tank weapons easily cut through bullet-proof glass. -- kainaw™ 19:58, 3 August 2011 (UTC)

If the Popemobile was impervious to anti-tank weapons, wouldn't they make tanks out of the same material? AndyTheGrump (talk) 20:52, 3 August 2011 (UTC)

I thought maybe the Popemobile had something besides bulletproof glass protecting the Pope. Whoop whoop pull up ^{Bitching Betty | Averted crashes} 21:50, 3 August 2011 (UTC)

"Sir, It's impervious to our anti-tank weapons!" "Then it's time to break out the big guns. Prepare the anti-popemobile weapons." APL (talk) 22:03, 3 August 2011 (UTC)

Many of the Popemobiles don't even have glass. They are completely open. Did you even attempt to scan the article? -- kainaw™ 15:04, 4 August 2011 (UTC)

Yes hes also protected by God . No weapon forged against his Holy Father shall prosper! (Isaiah 54:17) FeydHuxtable (talk) 15:58, 4 August 2011 (UTC)

[[Except for all of those Popes who were, in the end, assassinated. --Mr.98 (talk) 16:17, 4 August 2011 (UTC)

No. There are several Popemobiles so one anti-tank weapon would be insufficient. Also permission to do the experiment might be refused. Cuddlyable3 (talk) 22:20, 3 August 2011 (UTC)

Answering Kainaw: It says that Popemobiles have been required to have bulletproof glass ever since the Pope John Paul II assassination attempt. Answering FeydHuxtable: Listen to Mr.98. Answring Cuddlyable3: There may be several Popemobiles, but there is only one Pope. All an assassin would have to do is figure out which one is carrying the Pope and then fire off his anti-tank round. Whoop whoop pull up ^{Bitching Betty | Averted crashes} 19:37, 4 August 2011 (UTC)

You didn't mention popeicide. Sometimes there has been more than one pope and if that should happen again, your idea could serve as a drastic method of pope-culling. Cuddlyable3 (talk) 13:00, 6 August 2011 (UTC)

the moon should have an atmosphere

because take ONE lonely molecule of whatever "air" you want...as it wonders around the moon, it would rather go inside (due to the moons gravity however small) than wander off, and once it is around the surface, that small gravity will always be enough to make it go 'Id rather stick around here" than just wander off again, as though the moons gravity was literally 0. so by this reasoning, either there is no moon, its mass is really 0, mass does not correlate with gravity, or the moon actually does have an atmosphere contrary to popular opinion. is this? p.s. excuse lithuanian. — Preceding unsigned comment added by 84.0.197.58 (talk) 22:07, 3 August 2011 (UTC)

Does the article Atmosphere of the Moon answer your questions? --Jayron32 22:13, 3 August 2011 (UTC)

I'm sorry, but that article seems to be gobbledegook to me, and more a coverup than anything else. It's very short, for one thing, and introduces a word word "sputtering' for how sunlight supposedly pushes off the atmosphere from the moon, and also 'outgassing' and 'meteorites' all to push the atmosphere off of the moon. Sunlight obviously has a negligible ability to move anything, as opposed to enough gravity for the astro-men to make just tall bounds, but fall back to the moon. Think about it: the astro-men jumped and fell back down, but we are to assume that sun somehow with light alone makes the atmosphere careen off? Also outgassing is likewise ridiculous suppogestion - it might explain why some things from INSIDE the moon go volcanoing off outside the moon, but that does not explain why atmosphere already hanging around would not fall in, just like astro-men. The only reasonable explanation from reading that article (which does not address any of my specific questions posed above) is that it is a cover-up, invented after a fact, perhaps to match imagery or prevously published astro conjecture. There is nothing in the article which makes sense to me, and the whole thing is fishing. Can you address my points in this paragraph, if I am after all mistaken (which is not without unprecdent). Also with micrometeorites, what is the article suggestion: that for every molecule of gas, a micro-meteorite comes at just the right trajectory to careen off with it like two billiard balls? Or, what is the mechanism supposabled?--84.0.197.58 (talk) 22:23, 3 August 2011 (UTC)

You have misunderstood the article that Jayron32 referred you to; it actually explains how the Moon does have a thin but lingering atmosphere. The article Sputtering explains what that word means. Congratulations on your mastery of English as a Lithuanian apparently located near Budapest, and on exposing yet another of Wikipedia's cunning coverups. Cuddlyable3 (talk) 22:46, 3 August 2011 (UTC)

Despite your disbelief solar radiation and solar wind do exert enough pressure to remove most of the moon's atmosphere. Why on earth would anybody want to cover up the existence of a lunar atmosphere?

(WP:EC)As I understand it, you're technically correct; there are a few gas molecules hanging around. See Atmosphere_of_the_Moon, which describes how this 'atmosphere' is so low-density as to be negligible, for all but the most pedantic or specifically detailed purposes. SemanticMantis (talk) 22:16, 3 August 2011 (UTC)

Atmospheric escape has better detail than Atmosphere of the moon, for some reason. Comet Tuttle (talk) 22:34, 3 August 2011 (UTC)

The language desk will be green with envy of "suppogestion". Wanderer57 (talk) 00:59, 4 August 2011 (UTC)

Acutally the reason why earth enjoys such a healthy and thick atmosphere is due to the Magnetosphere, without it the sun would blow most of our atmosphere away too, which is precisely what happened on Mars and is the reason why Mars only has a thin atmosphere. Secondly, comparing astraunaughts to gas molecules is pretty silly. Astraunaughts are huge and slow and gas molecules are tiny and fast, they only need a tiny push in just the right direction to send them flying. Vespine (talk) 01:21, 4 August 2011 (UTC)

I think OP asks a valid, interesting and intelligent question, and the ones who "answered" him perform the usual wp bizzo of setting up a straw man, and bashing that, or just ignoring the question. There are gas molecules that come in from outer space, and ones that are radiated from within the moon. Is it not the case, OP wants to know, that ALL of these molecules will be bound permanently to the moon, and so the atomosphere can only grow, and never be diminished?

I think the answer is that as the sun warms the gas, some of the gas molecules will be bounced up high and come near to the escape gravity zone. There, if they hit again in the right direction, they will leave orbit and escape the moon. The more molecules there are, the more likely it is that such collisions will occur, and the more gas molecules will leave the moon. That means that as the atmosphere is depleted, the gas becomes colder and less active. That it turn means that there will always be a thin gas around such bodies, but the less massive they are, the more likely it is that gas will escape the planet. There is probably some mathematical correlation whereby we could predict how thin the atmosphere of a planet would be, if we know how massive it is. Myles325a (talk) 07:31, 4 August 2011 (UTC)

Nobody is bashing strawmen here. we gave him a straight answer and he disdained it as being ridiculous. There's nothing we can do if someone refuses to read an article with an open mind. By your answer it seems to me that you should read Atmospheric escape as well to get a more thorough understanding of that subject. Dauto (talk) 14:18, 4 August 2011 (UTC)

This is a fair question, not answered in the article, and the language gibes are uncalled for. Now let's get started. From a quick Web search:

Lunar escape velocity = 2.4 km/s

Mars escape velocity = 5 km/s

Venus escape velocity = 10 km/s

Earth escape velocity = 11 km/s

Jupiter escape velocity = 60 km/s

As we see, that's a difference, but not nearly so qualitative a difference as there is between the atmospheres of these planets. Atmospheric escape explains that Mars and Venus have both lost a fair amount of atmosphere due to their lower mass. Specifically it explains (Atmospheric_escape#Thermal_escape_mechanisms that escape happens because some individual molecules of air reach escape velocity, at the level in the atmosphere where the mean free path is comparable to the scale height. That last bit means the bigger a planet's atmosphere, the higher a platform the air has to jump from in order to reach orbit; but even on Earth that isn't really much of a difference. For Jupiter and Saturn it probably matters! But the key here is that there's someplace where you're looking at the Maxwell distribution and asking how many individual air molecules, just because of their temperature, can make the jump all the way out beyond the planet's gravitational pull, never to return.

Now if you think the article about the lunar atmosphere is gobbledygook, you're not going to like that article on the Maxwell distribution, but reading through it carefully it looks like the drop-off for high velocities is proportional to e^(-v^2), which provides a pretty sharp cutoff. (I've tried before to make mathematical articles clearer to the reader, but their incomprehensibility is pretty strongly defended, and I'm not good enough with the topic to accomplish much) Note that the difference between Earth and the Moon is comparable to the difference between Jupiter and Earth - as a result Jupiter swims in a vast sea of hydrogen, whereas the Earth is stripped of hydrogen and helium, and the Moon is stripped of everything. (Temperature also has to do with this, but I think it would only affect velocity according to its square root, which isn't that huge of a difference) Though I suspect that if there were enough xenon it could hold onto that - I see some forum postings and such agreeing but didn't pursue a good source. Wnt (talk) 17:17, 5 August 2011 (UTC)

The Moon has no significant atmosphere because it is blown away by the solar wind the wind is strong enough to take away gas, but not dense objects like rocks or people. The atmosphere of the moon is thinner, and might be said to 'come and go'. High solar flare activity blows it away, ice from comets, asteroids and stones that impact replenish it. The earth has an atmosphere because of the magnetosphere as per Vespine's description. The magnetosphere is generated by the heat in the iron center of the earth, which has been molten since earths creation. Once the core of earth goes cold, the magnetosphere will disappear and the atmosphere will follow. Mars is like an older version of earth, it's core has gone cold, the atmosphere is thinning out. All of these bodies have their atmospheres topped up slightly by ice (comets and so forth) from time to time. Deep space planets can hold their atmospheres without a magnetic force field because the solar wind is not as strong, eventually, the solar wind comes to a halt along with it's booty at the heliopause far far away. Penyulap _talk 12:59, 6 August 2011 (UTC)

See lunar water. ~AH1 ^(discuss!) 14:14, 8 August 2011 (UTC)

August 4

Spotting nocturnal animals at night

So, I recently put up a bird feeder in my yard. It is on ~7 foot pole with a birdhouse/feeder on top in which I put sunflower seeds. The birds love it. But during the night, something eats all the seeds. I put a squirrel guard on the pole, and have personally witnessed (during the day) that it does a good job of keeping squirrels out of ther feeder. So I'm a bit stumped as to what is eating all my birdseed overnight. I had previously heard that there was a certain color light (red, green, blue?) that nocturnal animals can't register, and will approach feeders even though it is illuminated. I would like to know what color light this is so I can put one in my yard. I really just want to sit on my porch and spot the culprit, and not have deal with expensive infrared lights, or motion-cameras. Any assistance would be appreciated. Quinn ^{❀ BEAUTIFUL DAY} 00:30, 4 August 2011 (UTC)

I should say that I already have an exterior light fixture in the yard, with a regular old "white" light, so I'm hoping I can just change the bulb to a different color. Quinn ^{❀ BEAUTIFUL DAY} 00:32, 4 August 2011 (UTC)

I'm pretty sure it's red. Have you just tried to 'catch them in the act'? I have exactly the same thing happen at my place and it's possums they aren't timid at all, they'll walk on our deck even when the lights are on and we're out there too with guests over. It won't be possums where you are, but maybe whatever it is isn't as shy as you think. Vespine (talk) 01:08, 4 August 2011 (UTC)

Not sure where you think I am, exactly, because possums are pretty common in central Mississippi. Regardless, I don't think it's possums for the very reason you stated; whatever it is, it is very sneaky...won't come out when I have the lights on. I wonder if it could it be some sort of bug (insect) eating the seeds? Quinn ^{❀ BEAUTIFUL DAY} 01:23, 4 August 2011 (UTC)

Aah, so you call them possums too, they're technically opossums, we have possums in Australia. Vespine (talk) 03:29, 4 August 2011 (UTC)

A bat? The Northern flying squirrel? Are you sure it isn't just the birds getting up earlier than you? AndyTheGrump (talk) 01:29, 4 August 2011 (UTC)

I'd vote for a bat, too, although they mostly eat insects, but I imagine some might go for bird seed. Just in case it is something on foot, perhaps a raccoon, I suggest spreading some sand at the base of the pole so you can look for tracks the next morning. StuRat (talk) 02:14, 4 August 2011 (UTC)

Chupacabra. Either that or the Southern flying squirrel. Chances are 50/50. μηδείς (talk) 02:04, 4 August 2011 (UTC)

Ooops, yes, wrong squirrel species. :( AndyTheGrump (talk) 02:08, 4 August 2011 (UTC)

A good little mystery. Is the pole smooth metal or climbable? How far from the pole is the nearest tree? Birds can gobble seeds vwery quickly. You have probably thought of all this.

As for color of light, in our neck of the woods they sell strobe lights for the purpose of discouraging wildlife from coming near. The idea is to place the light where the animal cannot approach without looking at it. If something is climbing your pole, a downward-pointing strobe on the pole might have an effect. Wanderer57 (talk) 02:17, 4 August 2011 (UTC)

BTW, how do you know it's not birds eating the seeds ? You said they are eaten at night, but are you always up right at dawn ? The proverbial "early bird" might very well be the "culprit". StuRat (talk) 02:22, 4 August 2011 (UTC)

Could be birds, I suppose. If so, that's fine. That's what the feeder is for. But I'll get up at night and check it, and one minute the feeder is full...an hour later it's completely empty. And it holds a lot of seed. Getting kind of expensive, really. I should clarify, I don't simply want to identify it...I want to figure out the best way to catch it in the act so I can "get rid of it" if you catch my drift. Quinn ^{❀ BEAUTIFUL DAY} 02:48, 4 August 2011 (UTC)

So, in a nutshell, my question is: Is there a good way to observe wildlife at night? And again, a FLIR camera is a bit out of my price range. Quinn ^{❀ BEAUTIFUL DAY} 02:53, 4 August 2011 (UTC)

At my house (southeastern Canada), raccoons empty out bird feeders regularly, and these are feeders that hold 4 kilos (+/-10 pounds) of sunflower seeds when full. Unlike your predators, though, 'coons are not afraid of lights, even if I turn the lights on as they are feeding. Only opening a door they can see will get them to amble off, and they return minutes after I go back indoors. We finally had to electrify a plate at the base of the pole. 'Coons are smart and they test it every month or so. (For those of you reading this from the U.K. or other European points, don't panic; the shock is very mild from North American voltages.) Bielle (talk) 03:17, 4 August 2011 (UTC)

Maybe the creature eating it couldn't care less whether it is day or night. Therefore empty it out before dark, if possible. Then try to observe it unobtrusively from a distance at frequent intervals during the day. If it is a nocturnal creature it may make an exception and come out during the day, if it has become habituated to finding food at your feeder. Bus stop (talk) 03:28, 4 August 2011 (UTC)

That might work. Though come to think of it, you could simply take the feeder indoors at night, and leave the whatever-it-is to find food elsewhere. After all, I don't suppose it realises it is a bird-feeder. It found a source of food, so it eats it. If you do succeed in whacking it over the head with a baseball bat or something, another one is likely to discover the source of food later (unless you have exterminated the last surviving 'whatever'), so killing it doesn't solve the problem. AndyTheGrump (talk) 03:39, 4 August 2011 (UTC)

I have had the experience with raccoons as Bielle, if there's food they are quite willing to come into lit areas. Is this a tube-style feeder or more of a platform feeder? It could simply be that crows or other larger birds gobbling it up. I once came home to find that a bear had figured out how to open my iron silo feeder, which is metal and cannot be opened while hung up on its hook. The bear appeared to have swatted it down and knocked it around until the lid came off. Now I hang it up where bears can't reach. Beeblebrox (talk) 04:06, 4 August 2011 (UTC)

Beeblebrox, if you have bears, then you shouldn't have bird feeders. If you manage to keep them out, then they will still be in your yard, hungry, and angry, which is a very bad combo. StuRat (talk) 05:28, 4 August 2011 (UTC)

For the record, I think Racoons would eat you if you fell asleep outdoors at night. They aren't particularly aggressive or vicious, just an annoying combination of smart and persistant and not giving a shit. My dad went for YEARS trying to devise novel systems to keep the racoons out of our trashcans, and every year the racoons would figure it out. If we could somehow convince racoons to put on snazzy suits and wear sunglasses, they'd make perfect superspies. If the OP lives in an area with racoons, I'd vote for that as the likely culprit. Where I grew up, racoons weren't spooked by anything. We'd stand on our back steps at night and try to scare them off by throwing sand and rocks at them. They'd just look at us like we were crazy and go back to looting our trashcans. --Jayron32 05:52, 4 August 2011 (UTC)

Um, the problem is the strange desire that only those observed taking advantage of charity deserve it. The feeder's motivation is far from selfless. Next he'll want commercial endorsements and signed releases. Charity is charity, and commercialism commercialism. μηδείς (talk) 05:29, 4 August 2011 (UTC)

• @StuRat: Don't worry, I am well aware of bear danger (now). I've moved since that incident, at my new place the feeder is 20+ feet off the ground and the neighborhood bear has never even tried to get at it. We don't put seed in it in the spring when they are super-hungry and tend to come to town and get into people's garbage or dog food. Beeblebrox (talk) 18:48, 4 August 2011 (UTC)

Good job, Beebles. Whoop whoop pull up ^{Bitching Betty | Averted crashes} 11:51, 5 August 2011 (UTC)

OP again: Doubt anyone is still paying attention to this, but in case you're interested, it turned out to be squirrels. It is a platform feeder on a 7 ft. pole, and even though I have an squirrel guard (an upside down metal cone beneath the feeder), which seemed to keep them out during the day, I caught a couple of squirrels raiding it just before day break. One squirrel would put its hind legs on the pole, and reach up and grab the rim of the cone. The other squirrel would get on it's back, and reach up and rake all of the seed off the platform onto the ground. Then they'd feed. This amazes me for 3 reasons:

• It's pretty ingenious what they are doing.
• It requires cooperation, in which the one that could reach the feeder rakes the seeds on the ground for both of them, when it could just as well have jumped from the other squirrels back onto the feeder and had it all to himself.
• The don't do this during the day when I know they're watching. When I'm on my porch watching the feeder, the squirrels remain on the ground, and act like they can't get around the squirrel guard.

Anyway, I've decided to just put a cupfull of seed in at a time, and figure that the squirrels are just a fact of life. Thanks for the suggestions. Quinn ^{❀ BEAUTIFUL DAY} 01:10, 5 August 2011 (UTC)

Not just "a" fact of life. The fact of life. μηδείς (talk) 01:44, 5 August 2011 (UTC)

@Quinn: That's actually pretty awesome. Nature can be amazing quite often. Thanks for sharing! --Jayron32 03:10, 5 August 2011 (UTC)

Now I'm concerned that you've unintentionally created a lab for the development of super-intelligent squirrels who will soon rise and enslave the human race. :-) StuRat (talk) 03:46, 9 August 2011 (UTC)

Response to Creationwiki

What is talk.origins's response to Creationwiki's refutations of Index to Creationist Claims? What are its people's response? — Preceding unsigned comment added by 110.174.63.234 (talk) 02:12, 4 August 2011 (UTC)

This is the Wikipedia science reference desk. Is this a question about a science-based matter? AndyTheGrump (talk) 02:16, 4 August 2011 (UTC)

Well, I think this is a science-based matter. But I don't see the need for more responses -- if there are some, will there need to be a response to the response to the response to each talk.origins item, which is itself a response to a creationist claim? At some point one just has to rest one's case. Looie496 (talk) 02:59, 4 August 2011 (UTC)

This is a science matter but it isn't really something for RD/S. If you want talk.origins responses, look in the web archives and some usenet archives of talk.origins like Google Groups. This should be relatively easy. If you can't find any, this likely means none exists. You are welcome to start a thread on talk.origins, observing appropriate netiquette (both general usenet netiquette and the specific netiquette of that group), if you really want responses but consider what Looie497 has said before you get your hopes up. Note even if anyone here posts to talk.origins, they shouldn't be giving a response like they would on talk.origins. Bear in mind talk.origins is just a usenet group, and the talk.origins archive is primarily someone's archive of selected posts to the usenet group. There is no such thing as an 'official' talk.origins response and if anyone did want to response, it would ultimately only be the response of that person. 06:42, 4 August 2011 (UTC)

Edit: As I expected, a quick search easily found a response to creationwiki on the archive site here, basically saying what Looie496 said. There is also some mention of creationwiki in this discussion [7] although I don't know if it's something in their rebuttal to the index. Bear in mind the archive has had minimal updating since 2006.

On the other hand, many discussions on the actual usenet group show up in a simple search [8] (safe search off), some of them may relate to the rebuttal to the index.

Nil Einne (talk) 06:55, 4 August 2011 (UTC)

It may be worth mentioning that the talk.* hierarchy was created especially to house discussions that tend to go back and forth forever with nobody ever changing their minds. Along with talk.origins there's talk.abortion, talk.politics.mideast, etc. These groups have existed for decades, and every possible argument and counterargument has probably appeared there already; it's just a matter of finding it. -- BenRG (talk) 07:57, 4 August 2011 (UTC)

ABO/Rh retype

i got my medical check-up result,and was curious about the medical terminology.ABO :O — Preceding unsigned comment added by 173.2.212.31 (talk) 05:32, 4 August 2011 (UTC)

See blood type. StuRat (talk) 05:46, 4 August 2011 (UTC)

International space station

Do the space stations have the ability to transform electricity through any equipments to the earth? provide the answers as quickly as posible to my email if any — Preceding unsigned comment added by Ebysebastian (talk • contribs) 06:56, 4 August 2011 (UTC)

The ISS, and previous stations (Skylab, Mir, and the Salyuts) only generate a small amount of power, enough for their own use. People have suggested giant space power stations which beam power down to the earth - see space-based solar power. -- Finlay McWalter ☻ Talk 09:13, 4 August 2011 (UTC)

Agreed, they don't have the ability to transfer electricity to the earth. (Well, maybe a tiny amount, if they charged a battery there which returned to Earth with the Shuttle.) StuRat (talk) 22:05, 5 August 2011 (UTC)

humans on other planets

actually universe is huge...we born on earth .which is in milkyway galaxy and our star sun..how about the evidence of the aliens or living creatures on other galaxies ? they too have huge stars and some dwarf galaxies too...is there any evidence or any reports those things? — Preceding unsigned comment added by Pebel vsrk (talk • contribs) 09:05, 4 August 2011 (UTC)

No evidence yet - see SETI. You need to clarify whether you specifically mean "humans" or "any intelligent life form". Humans are definitely unique to Earth. Roger (talk) 09:25, 4 August 2011 (UTC)

You know that how? --Trovatore (talk) 09:49, 4 August 2011 (UTC)

From the Australian Bureau of Statistics, "Our best estimates indicate that roughly 100% of all people live here." HiLo48 (talk) 10:25, 4 August 2011 (UTC)

Doesn't seem to be in the ref given. Anyway you haven't indicated how they would know.

If the physical universe has infinitely many galaxies, which it well may, and if there is a fixed positive probability of humans in any given galaxy, then by analogy to the infinite monkey theorem there is a probability of 1 (which is not the same as certainty — see almost surely) that there are humans in some other galaxy. Of course the "fixed positive probability" bit is a bit of a materialist assumption; it is not a given that "human" is definable in terms of configuration of matter. --Trovatore (talk) 20:45, 4 August 2011 (UTC)

Using the same argument, there must be a planet with intelligent pink flying pigs, or anything else you can imagine, and one identical to Earth except that this question was never asked! Seriously, though, I would remove the positive requirement on Trovatore's probability and get an answer of zero, but that is just my opinion. Estimates are just not valid from our slight knowledge of the origin of life because they "beg the question", and the universe might still turn out to be finite but unbounded. Dbfirs 07:35, 5 August 2011 (UTC)

The universe could turn out to be finite, but it might not. As I understand it the evidence is pretty balanced at the moment. That is, the confidence interval for the curvature includes the value zero — the simplest models for nonpositive curvature are infinite, for positive curvature, finite. There are compact models with negative curvature but in my admittedly non-expert opinion they come across as forced (they're things like a solid dodecahedron with opposite faces identified).

Curious why you think the probability per galaxy should be zero? Remember that you have to get exactly zero (or at least, for any positive ε, only finitely many galaxies where the probability is greater than ε) to avoid the conclusion that it will almost surely happen somewhere if the universe is infinite. Just saying the probability is not greater than one in $10^{10^{1000000000000000000000000000}}$ isn't good enough. --Trovatore (talk) 08:39, 5 August 2011 (UTC)

Yes, I deliberately chose zero because of my opinion on the origin of life (but this is not the place to argue over opinion). The question also arises as to whether the theoretical existence of something (planets, intelligent life, pink flying pigs) at an infinite distance constitutes existence as we know it. I rather liked Andy's comment regarding the Drake Equation in an answer below. Dbfirs 12:02, 5 August 2011 (UTC)

See also our article on extraterrestrial life.--Shantavira|^{feed me} 09:29, 4 August 2011 (UTC)

The only origin I can think of that would have a probability of exactly zero is some sort of deliberate creation, where the creator declined to do it elsewhere. I actually do believe in God, so I won't rule that out; I'm just curious whether that is in fact what you meant. It's a little hard to understand why God would have made such a big universe to put people in only one tiny corner of it, though.

As for infinite distances, there are no infinite distances involved in the scenario I'm talking about. The universe itself would be infinite, but the distance between any two points would be finite. So even if the existence of something infinitely far away would not constitute "existence as we know it", whatever that means, that doesn't change anything. If you meant that existence just so far away that we can never find out about it is not existence, well, that seems dangerously close to the rather discredited notion of logical positivism. --Trovatore (talk) 19:13, 5 August 2011 (UTC)

Yes, that's my reason for believing the zero probability, but I did say that it was only my opinion, not something I would try to prove. On the topology of possible universes, you are no doubt more knowledgeable than I, but I struggle to imagine an infinite universe in which all distances are finite, unless you are thinking of a Multiverse. Perhaps the universe is stranger than I can imagine? Dbfirs 19:49, 5 August 2011 (UTC)

Simplify — think of the real line. The real line itself is infinite, but the distance between any two points on it is finite. --Trovatore (talk) 19:51, 5 August 2011 (UTC)

Yes, sorry, my brain obviously wasn't functioning properly when I wrote the above. Your simplification occurred to me, and I (metaphorically) kicked myself before I read your reply. I should have compared the question of other intelligent life with the well-known question "Are there seven consecutive sevens in the decimal expansion on pi?" since we know the infinite structure of the straight line and mathematical 3- or 4-D space (-time), but we don't know the infinite "pattern" of pi. Dbfirs 06:43, 6 August 2011 (UTC)

... continued to explain my thinking ... The distance of the seventh consecutive seven in the decimal expansion of pi from the decimal point (using a metric of one unit per decimal place) could well be infinite -- no-one knows. By analogy, the distance from us to the nearest planet with pink flying elephants (or pigs or whatever you imagine) could well be infinite -- no-one knows. It all depends on whether an infinite universe is truly random, and that, currently, is a matter of faith, not science. Dbfirs 21:52, 6 August 2011 (UTC)

Evidence: Wow! did someone reply to our call? Cuddlyable3 (talk) 12:12, 4 August 2011 (UTC)

Before anyone jumps on to analyzing the atmospheric dynamics of hypothetical planetary systems in the reception-zone of the positive and negative feedhorns of the "Wow!" signal, how about the far simpler analysis of the PSRR of the signal processing circuit? How about the bit error rate of the digital computer that processed it? How about a root locus stability analysis of the analog and digital signal filters? How about intermodulation introducing an out-of-band signal into the spectrum under study? Four spurious samples of low-resolution data, with a duration lasting less than one minute, which have never been reproduced, do not constitute evidence of anything. I have never actually seen the circuits for the Big Ear; but I have spent a good amount of time in the formal and informal study of radio signal processing; and I see interesting bursts of noise every day. In all cases, if I care to investigate the noise, it invariably comes down to one of these benign factors; in other words, the "extraterrestrial signal" is "terrestrial noise." Very often, radio-noise is due to distant lightning strikes; or your neighbor opening their refrigerator door, causing the compressor to turn on, surging a few amps through the shared AC power transformer. The magnitude of these electromagnetic signals is much larger than any signal ever received from Outer Space - and they are noise. If you're lucky, you might be able to pick up extraterrestrial noise. At that stage, you can analyze its properties, compare it to known physics, and usually, you can say "hey, neat! My goofy radio contraption successfully detected ... radio signals from a stray electron in the high atmosphere that got a little hotter than usual because of direct sunlight." And you can publish your results in Science or Nature. Or something. But, to conclude extraterrestrial intelligence from four spurious samples defies any sort of procedural study of the signal. The Wow! signal is noise. This conclusion is obvious. Thorough understanding of radio physics, or at least an elementary primer in basic signal processing, is a prerequisite to legitimate radio-SETI. It is incredibly frustrating when legitimate scientific analysis takes a back-seat to populist sensationalism. Such silly and unfounded claims discredit the entire SETI effort. Or, to rephrase: if you don't know what noise looks like, how can you claim to know what a signal looks like? Nimur (talk) 18:19, 4 August 2011 (UTC)

Nimur you misrepresent the analysis by Dr. Jerry R. Ehman Ph.D. as having "concluded extraterrestrial intelligence from four spurious samples" that you declare are obviously noise. Please read his report to understand better. You are wrong about the received signal duration. Proper evaluation of the Wow! signal involves estimating the probability of a terrestrial source or conceivable combination of sources causing an emission on a frequency that is globally protected for radio astronomy and which, during its detection, matched the scanning lobe shape of a receiving horn that I understood to be calibrated against point sources in space that are not in dispute. You parade a select few signal-to-noise limitations as though they are relevant to faulty design of circuits for the Big Ear that you have not seen! Some extraordinary evidence is needed to back your claims that 1) serious radio astronomy is pursued oblivious to lightning and refrigerator power surges, and 2) you know things about signal processing that were not common knowledge to Ehrman and co-workers at Ohio State University Radio Observatory. Here is where you will find them now and here is more background information. Reading your post gives the impression that you are trying to discredit actual SETI work. Cuddlyable3 (talk) 17:59, 5 August 2011 (UTC)

The report linked above was never subjected to peer review. There is no shortage of academic, industrial, and professional journals that would be happy to publish meritorious, high-quality scientific results related to experimental radioscience. That's all I have to say about this subject. Nimur (talk) 20:08, 5 August 2011 (UTC)

Yes Nimur, professional journals such as Astronomical Journal, Vol. 72, p. 793, Observations of Planetary Nebulae at λ3.75 cm., Author: Ehman, J. R. I believe you have nothing to say about Ehman's work or qualifications. Cuddlyable3 (talk) 21:30, 5 August 2011 (UTC)

Two points: (1) the article you have just linked makes no mention of the Wow! signal; (2) ... because its publication date is 10 years prior to the reported Wow! signal. Did you even read it? It was a brief paragraph about radio observations. I too have authored brief paragraphs about radio observations in peer-reviewed journals; that fact does not mean everything I say about space-aliens is true. The fact that a scientist may have previously presented solid work in a journal does not mean that all his future work is infallible. I did not say anything about Ehman's work or qualifications. I made a very specific statement: this report, which you linked earlier, was not subject to peer review. I don't really feel like your argument is going anywhere; but, you may choose to believe whatever you like. If you want to believe that the Big Ear report and the Wow! signal represent good science, you are entitled to your opinion. Nimur (talk) 23:57, 5 August 2011 (UTC)

Nimur, you complained about Ehman's work in terms of "goofy radio contraption", "populist sensationalism" and "silly and unfounded claims". Some explanation of how a scientist able to present solid work in a peer reviewed professional journal has allegedly decayed so much so fast is called for. What are you saying, if anything, about space-aliens? I indented your post as a reply to mine and hope you don't mind. Cuddlyable3 (talk) 13:49, 6 August 2011 (UTC)

So you argument is... the fact that his work a decade previous was peer reviewed makes up for the fact that the work in question was not? If that's the case, I have some shares in a cold fusion plant I'd like to sell you... and maybe a little intelligent design as well! (As well as some N-rays, if you're feeling flush...) --Mr.98 (talk) 02:41, 7 August 2011 (UTC)

Nimur, somewhere occluded by your mockery you have asserted three - 3 - times that Dr. Ehrman's work report is not peer reviewed and therefore (?) does not represent what you call good science. After defining a question the scientific method starts with observation of data and proceeds to formulating a falsifiable hypothesis. You may find Peirce's explanation of Abductive reasoning enlightening. The SETI activities that you find so discredited has a defined question and is in the data collection phase. It has not yet produced a falsifiable hypothesis for an obvious reason: the present lack of cooperative aliens. When and if these things are in place you may see peer reviewed articles. For now, investigations proceed by the work of many well qualified (but under-funded) workers while you just present your superior thoughts here. Your latest mocking comparisons with cold fusion fraud etc. are offensive. Cuddlyable3 (talk) 10:32, 7 August 2011 (UTC)

There is as of yet no really compelling evidence. As to the likelihood of estimating the probability of anyone being "out there" to receive and reply to a signal, you might check out the Drake equation, which at least helps to clarify exactly what would go into such an estimation of probability. Personally I am pretty pessimistic about the idea of useful two-way communication between Earthlings and anyone else, unless special relativity is very, very, very incorrect or the quantum world grants some kind of work-around. --Mr.98 (talk) 14:22, 4 August 2011 (UTC)

World War II US Submarine Equipment

I would like to know what companies made periscopes and TDC's for US submarines of WW II, please 24.89.36.162 (talk) 11:09, 4 August 2011 (UTC)

On page 280 of U.S. Submarines Through 1945: An Illustrated Design History by Norman Friedman, it states that "C&R" (Convoy and Routing?) called for bids for 10 periscopes to its 1929 specifications in January 1930. It goes on to say that "all three manufacturers bid." This appears to refer to Kollmorgen, Barr and Stroud and Nedinsco (Nederlandsche Instrumentim Compagnie), a subsidiary of Zeiss. Kollmorgen won the bid. Unfortunately, that's as far as Google Books would let me see. This periscope manual published just after World War II lists five manufacturers: the three I've already mentioned, Keuffel and Esser and Bausch & Lomb. According to this Undersea Warfare magazine article, Kollmorgen was also "the dominant U.S. periscope manufacturer" of World War I. Hope that helps. Does TDC stand for Torpedo Data Computer? Clarityfiend (talk) 21:07, 4 August 2011 (UTC)

Temperature inside an atomic nucleus, & what if it were cooled

Hi, I've heard that a sample of rhodium was recently cooled to 10^(-10)Kelvin, just above absolute zero. That being true, isn't it also true that the temperature inside each of the many nuclei in the sample was higher? Would it be possible someday to cool the nuclei as well, slowing the internal motions inside each nucleus? Thanks, Rich Peterson24.7.28.186 (talk) 11:59, 4 August 2011 (UTC)

Temperature is a property of the bulk material. You really start to get into problems if you try to define temperature for an individual molecule or atom. Furthermore, absolute zero only defines zero molecular motion, not zero energy, so there will still be, for example, exchanges of gluons and mesons inside of the nucleus which are holding it together, and those interactions will occur even at fractional kelvin temperatures as low as you note. --Jayron32 12:35, 4 August 2011 (UTC)

• So I've heard(about absolut zero and zero point motion). What's your point?-Rich Peterson199.33.32.40 (talk) 00:34, 5 August 2011 (UTC)

I'm not sure what you mean that absolute zero ... defines zero molecular motion. Surely molecules as well have zero-point motion; it's just smaller than it is for smaller particles. This is a good place to remind everyone that temperature, in general, is not about kinetic energy. --Trovatore (talk) 20:58, 4 August 2011 (UTC)

The nuclei of stable isotopes are already in their ground state and cannot be cooled any further. Unstable nuclei release excess energy when they decay which happens spontaneously. The concept of temperature doesn't really make sense for such a small system. Dauto (talk) 14:26, 4 August 2011 (UTC)

• the thermo article here seems to say that ten fermions is enough. Wouldn't a rhodium nucleus have about 100 fermions?--How do we know a stable nucleus can't be cooled? Are you saying that in principle it can't be cooled further(except, when an alpha particle once in a while tunnels out, say), or that so far it has never been observed or method devised? Thanks.199.33.32.40 (talk) 00:34, 5 August 2011 (UTC)

It can't be cooled because there are no accessible states with lower energy so no energy can be removed from the nucleus. The number of particles here is not important. What's really important is the distance between energy levels which is of the order of 1 MeV. That means that excited states only become accessible at temperatures around 10 billion Kelvin (Give or take an order of magnitude). At energies much lower than that the nucleus effectively behaves as a single particle with no internal structure. Dauto (talk) 02:59, 5 August 2011 (UTC)

Maybe the OP is thinking of a Bose–Einstein condensate. Roger (talk) 14:36, 4 August 2011 (UTC)

What makes you think that could be the case? There is nothing about that in the question. Dauto (talk) 15:41, 4 August 2011 (UTC)

Hmmm, do nuclear isomers represent a "temperature" of sorts? Wnt (talk) 18:17, 5 August 2011 (UTC)

In principle I suppose they could, if you had enough excited states available that the behavior of the system started to become stochastic. But it doesn't make any sense that I can see to say, for example, that technetium 99m has a "higher nuclear temperature" than techetium 99, because it's just a single step from one to the other. There is no identifiable equilibrium around, and without some notion of (at least approximate) equilibrium, thermodynamics makes no sense. --Trovatore (talk) 19:47, 5 August 2011 (UTC)

Well, what about if we(if we could)heated up a stable isotope of uranium into a million degree plasma and observed a .1% decrease in halflife? Wouldn't that mean tunnelling out of the nucleus was becoming more probable, hence indicating a higher temperature inside?RichPeterson199.33.32.40 (talk) 22:07, 5 August 2011 (UTC)

Green birds in Greater London

I was startled by the sight of a flock of about 20-30 birds whizzing past my window yesterday. They were all bright green. I'm no bird expert (hoping someone here is) but they put me in mind of parakeets, but I only got a fleeting glimpse, so can't ofer much more description. Any good ideas what they might have been? (Surely not parakeets?) --Dweller (talk) 12:48, 4 August 2011 (UTC)

Probably parakeets. Grandiose (me, talk, contribs) 12:51, 4 August 2011 (UTC)

Rose-ringed Parakeets (aka Ringnecked Parakeets), perhaps? There are several self-sustaining populations of feral parrots in the UK... --Kurt Shaped Box (talk) 13:04, 4 August 2011 (UTC)

That's unbelievable... thank you, it could well be. If you can point me to any photos of a bird (or flock) in flight, that'd be great. --Dweller (talk) 13:10, 4 August 2011 (UTC)

Is File:Psittacula krameri -Whitefield, Bangalore, India -flying-8.jpg of any use to you? Take a look at Alexandrine Parakeet too - it's a similar-looking (but larger), closely-related species that is also sometimes found as a feral bird, though less often. --Kurt Shaped Box (talk) 13:17, 4 August 2011 (UTC)

Ah. Now I'm not so sure. While I only got a fleeting look at the disappearing flock, I don't recall their tail feathers being so fan-like. I thought their shape in flight might, repeat might have been more swallow-like...? --Dweller (talk) 13:50, 4 August 2011 (UTC)

Okay... How about the Monk Parakeet - in flight: File:Myiopsitta monachus -Florida -two flying-8b.jpg, though I suppose that you would have noticed the grey colouration? I believe that there are some in the UK. TBH, I couldn't tell you what they look like when moving - I've only ever seen this parrot in photos. Have you checked out these species on YouTube, btw - I suspect that there will be HQ video of all of them in flight (probably pets flying around someone's front room), and there may even be vids of the specific flock of feral birds that you saw... --Kurt Shaped Box (talk) 15:22, 4 August 2011 (UTC)

I think they must have been parakeets, especially now you've convinced me there's considerable variety in tail feather appearance between varieties. Yes, I'll check out Youtube. How extraordinary. Never seen them before. --Dweller (talk) 15:27, 4 August 2011 (UTC)

Yes they're parakeets. I see them almost every day now. 82.43.90.27 (talk) 14:17, 4 August 2011 (UTC)

They have certainly been there since the 1960s. I recall as a child being told that they escaped from a pet shop on the Goldhawk Road. There was also a flock of Budgerigars but they don't survive cold winters so well.Elen of the Roads (talk) 15:34, 4 August 2011 (UTC)

Yup, Rose-ringed Parakeets. There is a large population from the west London suburbs (see Kingston parakeets), all the way up the Thames valley. A common sight, though they often draw attention more by their noisy calls. If you saw a flock of thirty, I'd suspect that they were roosting nearby. AndyTheGrump (talk) 15:44, 4 August 2011 (UTC)

Also hawks and owls hate Budgerigars for being tame, its a bit harder for them to catch Paras.

There's been a wild flock of wild parakeets at Englefield Green for over ten years now but recently the population seems to have exploded for some reason. Was at a barbee over at Egham on Friday, there were litteraly hundreds of them flying over the garden, some came within 10 feet of us. We were like Whoa!!! So spectacular... If you want to photo them Runnymede Park is a happy hunting ground. FeydHuxtable (talk) 15:58, 4 August 2011 (UTC)

Just to prove the point about how common they are, I've just had two fly past my window (SW London suburbs), squawking loudly... AndyTheGrump (talk) 18:06, 4 August 2011 (UTC)

I can only assume nothing eats them. London clearly needs the return of the Red Kite, successfully reintroduced into Northamptonshire about 10 years ago. Elen of the Roads (talk) 20:23, 4 August 2011 (UTC)

I suspect that a Kite would prefer easier targets. The parakeets gregarious nature will make preying on them difficult, and they are agile fliers - and Kites generally prefer to scavenge anyway. One might be tempted to introduce the parakeets natural predator (whatever that is) to control the population, but that is a tactic that has misfired before. I think the ecosystem of south-east England has bigger problems than the parakeets anyway - and ironically, the London suburbs, where our noisy friends have settled, are probably more ecologically diverse than the small remaining areas of 'nature' we have. Then again, for a bird that evolved in the mountain uplands, an ecosystem consisting of tree-filled gulleys between vertical cliffs is probably ideal - we think we live in a man-made environment, but the parakeets may see it differently. AndyTheGrump (talk) 03:42, 5 August 2011 (UTC)

More info on parakeets in London here, here, and here. What I find unbelievable is that there are some people in London who don't know about them... !! Ghmyrtle (talk) 09:13, 5 August 2011 (UTC)

I live in east London, a mile and a bit from the Olympic Park, and had never seen one until a visit to Kensington Gardens last month. It seems they are fastidious in their choice of neighbourhood! Alansplodge (talk) 16:48, 5 August 2011 (UTC)

what effects onbody organs human hanging death

dear sir,

human hanging death ,deadd body organs is it use full for donate or transplent like eye,kidney,lungs .

after death how much time for donate human body organs

thanks & regards shivkumar(india) — Preceding unsigned comment added by 27.97.208.211 (talk) 17:47, 4 August 2011 (UTC)

A better question is what effects DON'T onbody organs human hanging death. --Goodbye Galaxy (talk) 18:33, 4 August 2011 (UTC)

A lot depends on the exact method of hanging used. See Hanging#Medical effects for details. Beeblebrox (talk) 18:53, 4 August 2011 (UTC)

At the very least, it pretty much rules out a neck transplant. ←Baseball Bugs ^{What's up, Doc?} carrots→ 19:17, 4 August 2011 (UTC)

removed OP's email Bazza (talk) 15:09, 5 August 2011 (UTC)

Good question. I'd think that organs in the head, like the eyes, might be damaged by a spike in blood pressure. The jerk at the bottom isn't so severe that I'd expect it to damage the organs of the abdomen. Then the other issue is that you'd need to remove those organs immediately upon death. This contrasts with cases where somebody is brain dead, but the body lives on in a hospital, where the organs don't need to be removed until the recipient is prepped for surgery. So, this might be a rather limiting factor with hangings. StuRat (talk) 22:01, 5 August 2011 (UTC)

Mike the Headless Chicken lived for 18 months. This suggests that a brain-dead hanged body can be kept alive for a while. Do not try this at home. Cuddlyable3 (talk) 13:32, 6 August 2011 (UTC)

Freeview signal, UK

1) Why do some channels have a stronger signal than others? Shouldnt they all be the same? 2) How many Freeview channels could be encoded into one analogue TV channel? 92.24.140.101 (talk) 19:41, 4 August 2011 (UTC)

The answer to 1 is that it still depends how far you are from the television mast, and what the intervening terrain is like. As to 2 - I'll leave that to the engineers among us. --Elen of the Roads (talk) 20:26, 4 August 2011 (UTC)

Almost all UK TV terrestrial TV reception antennas are directional Yagi antennas with reflectors. They have to be pointed at the broadcasting tower. To receive signals from two different towers you'd need two different antennas feeding the same outlet, which is a very rare thing to do. So, for a given receiver, if you're receiving two channels they're still from the same tower. -- Finlay McWalter ☻ Talk 20:42, 4 August 2011 (UTC)

Freeview (that's UK Digital Terrestrial Television broadcast using the DVB-T standard) broadcasts a bunch of channels in one digital stream, at a given frequency. That's called a "multiplex" - this page lists the different multiplexes. So you'd expect to see the same signal strength for BBC1, BBC2, BBC3, BBC-News, and the others in the same miltiplex (because they're all carried on the same stream on the same frequency). A different multiplex, at a different frequency, is going to have somewhat different strength: so ITV1 and Five should be the same as one another, but not necessarily the same as BBC1. Wikipedia has some pretty detailed articles about specific transmitter towers - looking for example at Emley Moor it lists the frequencies at which each multiplex is broadcast; with a bit of digging you should be able to figure out the tower and frequencies that you're receiving. As you can see in the Emley Moor article they don't broadcast all the muxes with the same power. Even if they did, radio signals at different frequencies propagate differently: they interact differently with the atmosphere and with water suspended in it, they diffract over the terrain differently, and interact differently with your general-purpose TV antenna. -- Finlay McWalter ☻ Talk 20:28, 4 August 2011 (UTC)

As to your second question (about how many digital channels one can fit into the space freed by turning off an analog TV channel in analog switchoff) - it depends on how they configure the MPEG compression for a given subchannel - they're currently fitting 7 conventional subchannels onto MUX2, for example. HD channels will typically consume much more bandwidth, and so you'd expect to see fewer on a given MUX. This is much the same arrangement for digital radio (T-DAB); the UK's DAB service has been criticised for having too many channels and so having to reduce the effective bitrate for each stream (see this article). A very informative paper about analog switchoff in Europe is here. -- Finlay McWalter ☻ Talk 21:09, 4 August 2011 (UTC)

Brownian ratchet

Hi, I have a couple of questions about the Brownian ratchet setup, but with ratchet disconnected, leaving just the paddle wheel, free to rotate as it chooses. Assume the paddle wheel is massless and frictionless.

1. Does the paddle wheel do a random walk, so that eventually it will inevitably have rotated by any given amount, just as tossing a coin will inevitably eventually produce any given surplus of heads over tails or vice versa? If so, does this rotation occur at zero energy cost?

2. As the vanes of the paddle increase in size (remember it's massless and frictionless), all other things being equal, do the random movements of the wheel, measured as angular displacement, become larger, smaller, or remain the same?

86.181.170.252 (talk) 19:59, 4 August 2011 (UTC)

1. Yes, and yes.
2. The random movements become smaller because the number of collisions grow proportionally to the area but the surplus collisions in one direction due to random walk only grows proportionally to the square root of the number of collisions becoming statistically less important for larger objects.

Dauto (talk) 20:17, 4 August 2011 (UTC)

Thanks. As regards (2), I can see the surplus grows on average with the square root, but isn't the surplus the only thing that matters? More surplus = greater movement? 86.181.170.252 (talk) 21:13, 4 August 2011 (UTC)

If the paddle wheel is massless, its behavior when a particle hits it doesn't seem to be very well defined. What happens to it and to the particle? Rckrone (talk) 23:22, 4 August 2011 (UTC)

The massless thing was inspired by the article Brownian ratchet, but looking more carefully, I see that actually only the conecting rod is said to be massless. I don't exactly understand why, if the other parts have mass, it's necessary to specify that the rod is massless. But, in any case, if it makes no sense for the paddle mass to be actually zero, then can we just say that it is negligibly small? I guess really I just didn't want the increasing mass of a huge real physical wheel to be taken into account when calculating the scaling behaviour that I was asking about. 86.181.170.252 (talk) 23:41, 4 August 2011 (UTC)

Yeah, after thinking about it I realized that if you just take it to be vanishingly small, the spot on the wheel where the particle hit would get velocity twice the component of the particle's velocity in the angular direction, so it's not really a problem. Anyway, the angular velocity of the paddle wheel after a collision would depend on how far from the axis the particle hit it. If the wheel is bigger, more particles are hitting farther from the axis so the angular speed after each collision would be smaller on average. Rckrone (talk) 23:48, 4 August 2011 (UTC)

So, if k^2 is the vane area, we're first of all saying that average surplus collisions is proportional to k. Then these collisions are evenly distributed over radial distance 0 to some number proportional to k. And this all adds up to a net decrease in average angular motion as k increases? 86.181.170.252 (talk) 00:53, 5 August 2011 (UTC)

If the mass of the paddle wheel is small compared to the particles, its angular velocity doesn't really accumulate. Instead the angular velocity at any given time is completely determined by the last particle to have hit it. That said, the average angular speed depends only on the speed of the particles and the radius at which they hit the paddles. The number of collisions doesn't matter. Rckrone (talk) 01:59, 5 August 2011 (UTC)

No wait, this isn't quite right. The paddle wheel basically gets pushed around bouncing of the particles, but if two particles come pushing it from opposite directions they can pinch the paddle wheel and be deflected in some way. I think the paddle wheel speed will get very high in this situation as it gets reflected back and forth, but I'm not sure what the speed will be after the particles are deflected. I think the moral of the story is that the wheel behaves weirdly if it doesn't have appreciable inertia. Rckrone (talk) 02:10, 5 August 2011 (UTC)

The wheel speed can be calculated using the Equipartition theorem which gives

$\langle E\rangle ={\frac {1}{2}}I\langle \omega ^{2}\rangle ={\frac {1}{2}}k_{B}T$

Where omega is the angular speed. That gives unsurprisingly an infinite speed for a massless wheel. Dauto (talk) 03:11, 5 August 2011 (UTC)

Although the momentary speed might have to be factored in somewhere in the calculations, what I'm ultimately interested in is the overall rate of progress of the wheel. I may have this wrong, but if it's a random walk, then I think there should be a single parameter characterising the "speed" of the walk. To model this we can say that in each very small timestep Δt, the wheel will move c*sqrt(Δt) radians in a random direction, then c is the number I'm interested in (does that sound right?) 86.181.170.252 (talk) 02:34, 5 August 2011 (UTC)

Living liquid

Would it be possible to have a living liquid? Whoop whoop pull up ^{Bitching Betty | Averted crashes} 20:47, 4 August 2011 (UTC)

Do you mean like a Changeling? Dauto (talk) 20:53, 4 August 2011 (UTC)

Or an amoeba? --Jayron32 20:55, 4 August 2011 (UTC)

Yeast frequently exists as a liquid. Those eternal cell lines that the oncologists use are liquids. Amoebae are just liquid in a bag - but then the human body is mostly water. I suppose it depends on how you define 'liquid' in a biological, rather than a physical sense. --Elen of the Roads (talk) 21:17, 4 August 2011 (UTC)

Yeasts (and other laboratory cell lines) exist as cells suspended in a liquid; it is incorrect to describe them as liquids. Cells don't exist as single phases of matter. They contain several distinct solid, liquid, and 'fluid' phases. TenOfAllTrades(talk) 23:31, 4 August 2011 (UTC)

This is a somewhat complicated question to answer. When the molecules suspended in a liquid become too large, it starts to be called a "colloid"; if they're large enough it becomes a "solid" (like plastic). I vaguely remember reading that around the turn of the 20th century much was made of the colloidal nature of life, before thinking about it that way became passe. In somewhat a similar way, a cell is made up of a droplet of liquid surrounded in a membrane which is also liquid (though without more reinforcement from extracellular matrix (more or less a solid) such a cell is quite vulnerable anyway) - but is a vesicle or a liposome a "liquid" in the same sense that a homogenous solution would be considered one? So when asking how to make liquid life... well, it seems like mostly a matter of creative description. If you want to avoid the cell membrane, you might consider a virus; or you could imagine some complex "cell" in which all the biochemical components are covalently linked together so no membrane is needed; but if it's too big it would sediment in a test tube on standing and would that count as a liquid? ... I think the boundary blurs as you look at it. Wnt (talk) 05:18, 5 August 2011 (UTC)

I meant (sort of) a large multicellular organism that is held together only by surface tension and the other forces holding liquids together. Whoop whoop pull up ^{Bitching Betty | Averted crashes} 11:50, 5 August 2011 (UTC)

How about some slime mold? Wouldn't that be a viscous liquid for some species anyway? Googlemeister (talk) 16:21, 5 August 2011 (UTC)

Well, the issue is, what's the difference between a dissolved solid and a wet solid? Especially when it contains a vast range of different compounds? Because proteins crystallize, we know that their interactions are sufficient to make them solid; so in order to exclude forces that hold solids together, the hypothetical lifeform should have no protein-protein interactions - or at least none on a large scale (how large?). Non-Newtonian fluids are confusing enough with just one or two ingredients. Wnt (talk) 16:44, 5 August 2011 (UTC)

Hanging: suicide or execution?

If someone is about to be judicially hanged, but they jump off the platform themselves, is it considered suicide or execution? Whoop whoop pull up ^{Bitching Betty | Averted crashes} 20:50, 4 August 2011 (UTC)

You're thinking of the last man to enter Parliament with honorable intentions? --Trovatore (talk) 20:51, 4 August 2011 (UTC)

In UK law it made no difference - death on the scaffold was always considered to be execution, particularly as the death penalty usually specified what was to be done with the body. In any case, suicide was until recently considered a mortal sin by the Christian church, while the abovementioned Guido Johnson was (possibly still is) hailed as a martyr. --Elen of the Roads (talk) 21:38, 4 August 2011 (UTC)

1) The Catholic Church does not consider Guy Fawkes a martyr, and I'm not sure it ever did. He was executed for trying to kill people, not for his faith. 2) The official position of the Catholic Church on suicide includes "Grave psychological disturbances, anguish, or grave fear of hardship, suffering, or torture can diminish the responsibility of the one committing suicide." [9] I think avoiding being drawn and quartered is a pretty fair 'grave fear' of 'torture', especially given that the torture was intended to imminently kill him anyway. 86.161.210.242 (talk) 12:20, 5 August 2011 (UTC)

Surely a person who jumps away from certain death is no suicide, whether he breaks his neck or not. It makes me wonder, though, whether we would be unpleasantly surprised to find out who is celebrated as a martyr on September 11, 2201... Wnt (talk) 23:23, 5 August 2011 (UTC)

We would be pleasantly surprised just to be alive in 2201. Cuddlyable3 (talk) 13:26, 6 August 2011 (UTC)

At least as far as the long drop method formerly used in the UK is concerned, there was no platform to jump off: the drop was achieved by a large double trapdoor that opened under the victim. Picture here. AndrewWTaylor (talk) 11:29, 5 August 2011 (UTC)

August 5

Question (acetone)

I used Acetone to clean my car windows. The fumes and vapors from the Acetone got so bad that it irritated my eyes and body. What can I do to get rid of the fumes and vapors? Thanks and hope to hear from you soon. Thanks for the answers, is there any more suggestions. — Preceding unsigned comment added by 174.111.55.161 (talk) 01:30, 5 August 2011 (UTC)

If that question still requires an answer, let us know. μηδείς (talk) 01:48, 5 August 2011 (UTC)

Roll down the windows and drive for an hour with the air blasting through the car. You might wish to read our acetone article. Looie496 (talk) 01:50, 5 August 2011 (UTC)

If the vapour saturation is high enough, duck and light a match. Plasmic Physics (talk) 02:02, 5 August 2011 (UTC)

Watch out, some idiot will try that and sue... but seriously, acetone is a small, highly volatile molecule which easily diffuses into the air and blows away. Also, in small amounts acetone is a normal metabolite in the human body - though in diabetics it can build up to acetone breath and become part of a pathology. So as long as you let the car air out enough that you don't smell it (assuming a normal sense of smell) it should not be a hazard at trace levels. Wnt (talk) 05:24, 5 August 2011 (UTC)

Can hardly sue Wikipedia for misinformation, it is a wikia afterall. Plasmic Physics (talk) 08:04, 5 August 2011 (UTC)

No, but they can get a court order to force Wikipedia to reveal your identity, and then they can sue you. --Jayron32 16:16, 5 August 2011 (UTC)

That would be a problem for them, my identity is not contained with Wikipedia. Plasmic Physics (talk) 19:33, 6 August 2011 (UTC)

Is using acetone to clean car windows a good idea? Seems like a great way to ruin the rubber seals and allow leaking later, or to damage the paint on the car. Googlemeister (talk) 12:49, 5 August 2011 (UTC)

Agreed, bad idea. Use the blue window washer solution made for cars. But, now that the deed is done, I suggest rinsing it thoroughly, rolling all the windows down, and letting is sit for a while. StuRat (talk) 21:51, 5 August 2011 (UTC)

Thomisida

White and pink crab spider

. Good morning everybody. This spider is surely a member of the Thomisidae family. But I'd like to know the exact species. I photographed it in July, in my garden, lower St-Lawrence region, Prov. of Quebec, Canada. Dhatier (talk • contribs) 03:21, 5 August 2011 (UTC)

Good morning. That is a very fine photograph. Cuddlyable3 (talk) 12:40, 5 August 2011 (UTC)

WHAT PERCENT OF THE PLANETS IN THE GALAXY HAVE LIFE

i know it is hard to say for sure, so your best guess is fine. also, do most planets with life have aliens (sentient) or just trees and bugs and single cell organisms?--Fran Cranley (talk) 03:42, 5 August 2011 (UTC)

The short answer is that nobody knows. The long answer is to look at the Drake equation, fill in the necessary fields with whatever value you consider appropriate, and then admit that you don't know either. All we know is that this planet has life, and that it took a long time to evolve to its present state - so a modicum of care over the health of the planet might not be misplaced. AndyTheGrump (talk) 03:50, 5 August 2011 (UTC)

From what we have observed, it seems there could be 1,235 planets outside the solar system that we can detect (as of Feb 2011). There are also 8 planets in this solar system. As far as we know only 1 of them has life (but we could be wrong). So if you want to calculate a percentage based exclusively on what we have observed of the Galazy so far, it is 0.0805%. Obvioulsy there is a vast amount of unobseverd planets, so that percentage doesn't mean anything at all. --Lgriot (talk) 11:21, 5 August 2011 (UTC)

We don't know if any of the "observed" extrasolar planets have life ("observed" in quotes because we mostly just deduce their existence indirectly from spectrographic and brightness variations when observing their parent stars). We have found no blindingly obvious signs of life on other planets in the solar system, but we have extremely rarely even looked for signs of life at any of the known or suspected extrasolar planets. Our tools for doing that are wholly inadequate at the moment. Indeed, our inadequate observation equipment very much limits the type of planets we can detect to implausible candidates for life. Life on Earth evolved essentially as soon as the surface cooled down. This suggests that primitive life may be very frequent. On the other hand, complex life seems to have taken ~3 billion years to evolve from single-celled ancestors, and wether Earth has evolved intelligent life yet is debatable ;-). --Stephan Schulz (talk) 11:44, 5 August 2011 (UTC)

Where do we find anyone intelligent enough to debate that? Cuddlyable3 (talk) 12:38, 5 August 2011 (UTC)

I believe life must be far more prevalent than intelligent life. As noted above, life on Earth seemed to start as soon as the proper conditions existed, so I would assume this would also happen elsewhere. However, if there were many planets with advanced technology, then we'd expect to have heard from some by now. Perhaps there's a middle ground, with many planets containing whales and such, which are somewhat intelligent, but either not quite intelligent enough for extra-planetary communication, or simply lacking the hands, tentacles, etc., needed to do so. StuRat (talk) 21:46, 5 August 2011 (UTC)

What I'm a bit scared about is that the reason for the Fermi paradox may well be that technological civilisations destroy their habitat (and thus themselves) before they learn to leave it... --Stephan Schulz (talk) 23:46, 5 August 2011 (UTC)

Simple solution to that: don't try and learn to leave it. We'll live forever, then ;) --KägeTorä - (影虎) (TALK) 14:15, 6 August 2011 (UTC)

Water flowing on Mars???

NASA is saying they see evidence of briny water flowing on present-day Mars, perhaps under the surface. How on, erm, Mars is it possible for water to be liquid when it should freeze or evaporate in the cold and thin atmosphere? Wnt (talk) 05:01, 5 August 2011 (UTC)

The simple answer is that the conditions under the surface must be different enough from those at the surface to circumvent the problem you describe. Dauto (talk) 06:14, 5 August 2011 (UTC)

Do planetary geologists predict higher pressures underground on Mars sufficient for liquid water to exist? -- 203.82.81.40 (talk) 07:39, 5 August 2011 (UTC)

The key is "briny". Pure water would definitely not be in a stable liquid state at the temperatures that they observe at these sites (250 to 300 K). Salt decreases the melting point of water (by up to 70K, they say) and makes it more stable. --Wrongfilter (talk) 11:28, 5 August 2011 (UTC)

I see someone has started a pretty nice article on seasonal flows on warm Martian slopes, which clarifies that even though the water may be only as salty as Earth's oceans, the slopes are 250 to 300 K. I hadn't realized that anywhere on Mars ever got up to such balmy temperatures! But what still confuses me is why it doesn't evaporate instantly. Is there some way that a relatively thin layer of soil could maintain a partial atm of pressure? Wnt (talk) 16:18, 5 August 2011 (UTC)

Yes, that is what I am wondering. From a Terran point of view, the atmosphere of Mars seems rather vacuous (MSL pressure of ~ 0.6% earth atmosphere. Also, where can I read abou the physical properties of brine? Wrongfilter suggests a 70K freezing-point depression, but our brine article gives 21.1 K (delta temp). Can the boiling point be elevated over this at such low pressures? -- 203.82.93.106 (talk) 20:23, 5 August 2011 (UTC)

I recall reading that Mars was at 20 degC when one of the probes landed on it, but I don't recall which probe it was and if that value turned out to be a measurement error or anomaly. Googlemeister (talk) 20:26, 5 August 2011 (UTC)

Per Climate of Mars the orbitally observed range is -143 to +27 C with a mean temperature of -55 C. The upper part of that range would allow liquid water even without solutes, but it would still turn to vapor under the very low pressures present at the surface. Dragons flight (talk) 00:09, 6 August 2011 (UTC)

Some thoughts:

1) Mars may have had a thicker atmosphere in the past. The magnetic field of a planet seem important here, as it deflects the solar wind, which would otherwise blow the atmosphere away. Early Mars likely had a strong magnetic field, like Earth, due to a molten iron core.

2) Modern Mars is rather desert-like, and deserts have extremes of temperatures. So, while the average temperature may be much lower on Mars, those portions in direct sunlight may warm up considerably, with little atmosphere and no oceans to support cooling and redistribution of that heat by convection. StuRat (talk) 21:38, 5 August 2011 (UTC)

Claims of Scientific Evidence Against Evolution

I have heard some people claim that there is scientific evidence against evolution. Is that true? If so, then what they? Are they really scientific evidences against it? — Preceding unsigned comment added by 110.174.63.234 (talk) 08:22, 5 August 2011 (UTC)

No they are not real scientific evidence against it. Real evidence agaisnt it would be for example fossils of rabbits in the precambrian. Nothing like has ever been observed. It is just people making it up, because they don't want to accept the massive biological evidence AND DNA evidence, AND fossil evidence that are all pointing to the same obvious conclusion: Evolution is a fact.--Lgriot (talk) 11:30, 5 August 2011 (UTC)

FYI, we have articles directly relating to Lgriot's claims: Precambrian rabbit & Evolution as theory and fact. — Scientizzle 15:29, 5 August 2011 (UTC)

The Talk.origins website has a taxonomically organised list of claims by creationists. Notice "claims", not "scientific evidence". The list is here. --Stephan Schulz (talk) 11:48, 5 August 2011 (UTC)

Fossil rabbits in the Precambrian layer wouldn't disprove evolution. Even I you could prove they were definitely from that time period, and weren't just some later insertion, it would only disprove our current models of common descent and maybe our current taxonomical theories. To disprove biological evolution itself would require something much more basic, like disproving that traits are physically inherited, or proving that each species can only vary within certain narrow parameters and that they therefore cannot drift more than a certain genetic distance from a somehow hardcoded 'typical' version of the species, or that no mutations ever produce viable offspring. Of course, we have such a wealth of data showing the opposite that you would also have to show how all this data could be wrong, while proving this unlikely scenario. It would have to be a proof on such a basic level, because biological evolution is a mathematical inevitability once you have inherited traits, variation in traits, and variable reproductive success. Even if the inherited traits had no impact on reproductie success, you would have genetic drift which is sufficient to establish new species if populations are isolated. This is, of course, why even many of those pushing for a creationist interpretation start introducing things like 'Intelligent Design' and 'microevolution': because any halfway intelligent person who looks at the evidence can see that evolution simply has to happen, unless our most basic assumptions about inheritability, or even cause and effect, are fundamentally broken. 212.183.128.47 (talk) 12:03, 5 August 2011 (UTC)

it would only disprove [...] maybe our current taxonomical theories. Maybe??? Come on, mamals during the precambrian era!? it would maybe disprove our current taxonomy? It would be earth-shatering. We'd have to review everything end-to-end. I'd personnaly start wondering if something is playing a little game with us. And I'd be very interested in those theories that try to reconcile these rabbits with the taxonomy we now have. That would be a very interesting debate. --Lgriot (talk) 13:29, 5 August 2011 (UTC)

I can't help it: I read too much scifi. Time machine? Aliens? Separate descent of animals up to rabbits on Atlantis, spreading to the rest of the world when it sank? Rabbit-shaped plant roots? Rabbits turn out not to be mammals? Given that any theory has to explain why all the other evidence suggests our current theories as well as explaining the rabbit, I wouldn't like to say with certainty that it would actually suggest our underlying theories of how taxonomy works would necessarily be wrong, since it would be so unlikely anyway that an explanation that looks unlikely now might look more likely in the event. But even if we had to rework all of that from the bottom, it still wouldn't disprove evolution. 86.161.210.242 (talk) 15:23, 5 August 2011 (UTC)

Perhaps rabbits evolved intelligence and made an attempt at paleontology, with some casualties. ;) But seriously, there is a point there that if we can think of excuses for such a gaping hole in the theory, there's some doubt as to the falsifiability of the theory. I don't think this is a problem limited to evolution though - any theory which is extremely fundamental to a science becomes difficult to falsify because there are so many lines of proof favoring it and so many ways to explain away one experimental observation (the Voyager data questioning whether gravity is really inverse square, for example). There may indeed be some risk that a society could be "blinded with science" this way, but I doubt evolution (or gravity) is the example. Wnt (talk) 16:26, 5 August 2011 (UTC)

And, while we are on the subject, "What, if anything, is a rabbit?" [10] AndyTheGrump (talk) 16:36, 5 August 2011 (UTC)

Maybe finding the Precambrian fossils of this rabbit would convince me, or at least convince me to run away... very, very fast. --Modocc (talk) 21:20, 5 August 2011 (UTC)

You mean Pioneer, not Voyager. The Voyagers weren't spin-stabilized, instead achieving attitude control through the frequent firing of thrusters. The resulting unpredictable little accelerations are much too big for it to be possible to determine if the Voyagers have also experienced the Pioneer anomaly. Red Act (talk) 17:35, 5 August 2011 (UTC)

Good catch! No wonder I didn't find the link. ;) Wnt (talk) 18:11, 5 August 2011 (UTC)

The honest answer is, of course there's scientific evidence against evolution. There's scientific evidence both for and against practically any proposition you care to name. The problem is to weigh the evidence, and figure out, on balance, which side does it support more than the other. --Trovatore (talk) 22:35, 5 August 2011 (UTC)

Come on then. Give us the answer to the OP's question. What IS that evidence? I can't think of any. HiLo48 (talk) 22:47, 5 August 2011 (UTC)

I'll answer, but before I do let me clarify that I'm a biologist myself and pretty much totally convinced of the validity of evolution. The strongest evidence against it, in my view, would be cases where biological systems seem to show very sophisticated engineering, in ways whose natural origins we don't yet understand. One very basic example is the genetic code, using triplets of DNA to code for amino acids; a less basic one that particularly strikes me is the modular structure of the cerebellum. Looie496 (talk) 23:28, 5 August 2011 (UTC)

I wasn't even necessarily going that deep. My point is more that evidence comes in chunks of all sizes; sometimes you put together a lot of little pieces of evidence, none of them very strong in themselves, to reach a scientific conclusion. And there are certainly various small pieces of evidence against evolution. For example, whenever we think that species B evolved from species A, but there must have been an intermediate type C, then if evolution is true, it is more likely to find C in the fossil record than if evolution is not true. If, then, we have not found C in the fossil record, then in the sense of Bayesian inference, that is a small, scientific, data point against evolution. It is not convincing in itself, but it is the sort of thing that could be added to a scientific case against evolution, and is therefore evidence. --Trovatore (talk) 23:58, 5 August 2011 (UTC)

Creationists seeking scientific evidence to refute evolution is as absurd as evolutionists seeking scriptural support to deny creationism.Wolfgangus (talk) 09:20, 6 August 2011 (UTC)

Radio frequencies

I recently noticed my local FM station at 107.9 can also be heard at 86.5. Why is this? I know that the Intermediate frequency is 10.7 MHz, and 107.9 - 10.7 -10.7 is 86.5, though I have no idea how this plays into effect. ^Avic_ennasis @ 13:31, 5 Av 5771 / 5 August 2011 (UTC)

If you look at the station's website, you might find that it has a main transmitter and a relay situated somewhere else, in order to get better coverage. Hence, they'll be on separate frequencies.--Aspro (talk) 13:49, 5 August 2011 (UTC)

(ec)Broadcasters want everyone in a large area (say all of Belgium or all of Arkansas) to hear a station. But a single tower broadcasting will not reach the whole territory (for reasons of power use and topography). So they (or usually mast operating companies like Arquiva) built multiple towers (usually on top of hills) to "tile" the whole territory. In order to service people in remote valleys and people with rubbish antennas, these transmitters are a bit overpowered (than they'd need to be if everyone had a big antenna on their roof). So if you live roughly between two towers, you can see both. In #Freeview signal, UK, above, we talk about the same scenario for TV reception. But whereas TV antennas are (kinda) directional, you'd usually receive FM with an omnidirectional antenna, so you can receive signals from both towers on the same radio receiver, without having to do anything to the antenna. To prevent the two towers from interfering with one another, they transmit on different frequencies. For you, between the two, you're getting a reasonably strong signal from both. You've not said what country you live in (and where) which would help us know precisely what's up, but the scheme is much the same the world over. You can search the website of whatever authority controls broadcast in your country (e.g. in the US it's the FCC) and find the locations of all the regional radio and tv broadcast towers (and their boosters), which usually also lists the channel assignment (the frequencies) each station is broadcast on from that tower. Armed with that you can figure out the physical location from which you receive every signal. TL;DR - you're getting signal from different towers. -- Finlay McWalter ☻ Talk 13:50, 5 August 2011 (UTC)

I understand the use of multiple towers/frequencies to reach a larger audience. However, unless I'm mistaken, most FM radios in the US don't go below 87.5, which is why I'm surprised to hear content on 86.5. Also, if it matters, the callsign of the station heard on 86.5 is "Y108", the same as 107.9. If they were intentionally broadcasting on 86.5, wouldn't they have to identify that in some way? ^Avic_ennasis @ 14:04, 5 Av 5771 / 5 August 2011 (UTC)

The original signal at the intermediate frequency (IF) has to be mixed with another frequency to be converted to the carrier frequency. Mixing is kind of like adding and subtracting frequencies, so to get 107.9 MHz from 10.7 MHz, you need to mix it with 97.2 MHz (97.2 + 10.7 = 107.9). However, on the output of the mixer there will also be an identical signal at 97.2 minus 10.7, or 86.5 MHz. There is meant to be some filtering to remove the 86.5 MHz signal, but in this case some energy managed to get through to you, since none of the components are ideal. —Akrabbim^talk 13:55, 5 August 2011 (UTC)

I think your math is a little off. :-) If it helps, the local station is WDSY-FM. ^Avic_ennasis @ 14:04, 5 Av 5771 / 5 August 2011 (UTC)

Thanks, typos corrected (87.5 --> 86.5). —Akrabbim^talk 14:11, 5 August 2011 (UTC)

In that case, it might be a pirate re-transmission. Is this the first time you have noticed it; in other words, could it have just popped up during the summer vacation like so many pirate stations. Just looked up the US frequency allocations and this is for television, non government broadcasts; that finishes at 88mhz with FM radio above that. So, off-hand I cant think of any legitimate reason that it should be there. Also, if you can receive it way-down-there on 'your' radio, it suggest to me there might be a slight chance that you also have your rig wired up to a rotatable array of some sort, in which case you could have a go at DXing its location and reporting it.--Aspro (talk) 15:02, 5 August 2011 (UTC)

Akrabbim is correct and the effect is described at Superheterodyne receiver#Image frequency (fimage). The guesses above about multiple transmitters, pirates and a direction-finding rig are all wrong. Cuddlyable3 (talk) 16:09, 5 August 2011 (UTC)

The "Laotian bird" Nock-ten (2011)

I have posted a question here at the language desk asking for a reliable source explaining the nature of the "Laotian bird" for which this storm is named. Comments there by those who might have a clue would be appreciated. μηδείς (talk) 15:57, 5 August 2011 (UTC)

I don't know. But a source that looks like it actually took a moment to do some translation says it's Laotian for "bird" (rather than a kind of bird).[11] True, most of the world's media says that it's a "Laotian bird", but I have a sinking feeling they're all copying each other and a 2004 Wikipedia article. [12] This becomes increasingly a worry - as Wikipedia becomes the only easy source for looking up certain things, we may end up breathing our own exhaust. Wnt (talk) 17:28, 5 August 2011 (UTC)

Maybe we're looking in the wrong place. Tropical Storm Nock-ten (2011) says it was the Japan Meteorological Agency (JMA) which gave the storm that name. Maybe it would be more reasonable to assume that it's a Japanese word, maybe for a Laotian bird. HiLo48 (talk) 22:39, 5 August 2011 (UTC)

Japanese words don't end in -ck, either by pronunciation or spelling. The -ck spelling convention alone, limited pretty much to English and German, makes the Lao-ness of the word as written suspect. We seem to be dealing with a word reported at several removes from its origin, like the various English transliterations of the Russian name Fyodor or Feodor (spelt Фёдор) which comes from the Greek Θεόδωρος (Theodōros), "Theodore". The best hint I have found so far is that the Thai language wikipedia article for the storm links to the Thai article on kingfishers. μηδείς (talk) 03:37, 6 August 2011 (UTC)

Is this helpful? It suggests that the Thai for "kingfisher" has both the syllables "nok" and "ten" in it. Bielle (talk) 03:45, 6 August 2011 (UTC)

See Lists of tropical cyclone names#International names. Given the way the naming works, there's little doubt it came from Laos. Regional Specialized Meteorological Centre in Japan which is operated by the Japan Meteorological Agency is in charge of the naming but they use the process outlined there/Tropical cyclone naming#Western Pacific/[13]. Lao script gives wiktionary:ນົກ or nōk as meaning bird. That article and Romanization of Lao isn't particularly clear on what, if any specific, romanisation is normally used by the Laotian government but I presume the specific romanisation was submitted by whoever in Laos was in charge of submitting the name. Given the relationship between Thai and the Lao language and the above, it seems likely the meaning is something akin to kingfisher. Nil Einne (talk) 09:58, 6 August 2011 (UTC)

Yes, nok is certainly the word for bird in both Lao and Thai. A kingfisher is nok kraten in Thai (นก กระเต็น)[14] and in Lao they've probably just shortened it (or maybe it was the other way around). Sean.hoyland - talk 10:30, 6 August 2011 (UTC)

Hmmm, that last link gives a script that delivers in Wiktionary, so maybe "นก-เต็น" is the actual word in one or the other language? This seems to be bringing up search hits about the hurricane (e.g. [15]), though often without the hyphen. But searching that in dictionary pulls up นักเต้น (náktên), defined as "dancer". This discussion is a comic (but not so comic) demonstration that - despite some very useful accomplishments - Wikimedia projects still have a serious need for better communication between languages and cultures ... Wnt (talk) 14:17, 6 August 2011 (UTC)

Yes, the Thai press are using นก เต็น (nok ten) as the Thai script transliteration of the Lao ນົກ​ ເຕັນ[16] Sean.hoyland - talk 17:55, 6 August 2011 (UTC)

[From the Language desk] :The Lao spelling appears to be ນົກເຕັນ.[17] This appears to be a name for the kingfisher.[18]. This recent blog post seems to link ນົກເຕັນ with the Common Kingfisher and with the storm (I can't read Lao). Also, if you go to this dictionary, and search for kingfisher in the box marked "Text", you get the entry for ນົກເຕັນ. Unfortunately I don't know how to link to the entry directly.--Cam (talk) 23:55, 6 August 2011 (UTC)

It was Laos who submitted the name to the WMO Typhoon Committee back when the names were devised in the late 1990s assigning it the meaning "bird" HKO, JMA. The Typhoon Committee then selected the JMA to assign the names as it was already their Regional Specialized Meteorological Centre for the region.Jason Rees (talk) 11:07, 7 August 2011 (UTC)

Thanks, all. I have modified Nock-ten (2011) based on the responses and suggest readers check that article- it could use help from the knowledgeable and even lay native angloparlantes. μηδείς (talk) 03:55, 7 August 2011 (UTC)

When in the history of Astronomy could a planet on the far side of the sun be ruled out?

Hello everyone, bit of a conundrum for you. A common speculation in the old sci-fi genre over the years has been a planet orbiting the sun in the same orbital plane as the jolly old Earth but exactly opposite us, so it was always concealed behind the Sun. I was wondering is any of you fine chaps could tell me when such an idea could be definitively proven to be merely a fancy. Not being too up on the old star-gazing routine I'm a bit stumped! I would imagine it could perhaps either been when our understanding of the solar system and our ability to see the effects of a heavenly body's gravitational field on other heavenly bodies was mastered. Alternatively perhaps when those very clever chaps started launching those space probes and the telemetry showed no such place.

Can any of you fine fellows help an old duffer out here? It's a bit hard on the old noggin don't you know. Chin chin! Quintessential British Gentleman (talk) 18:42, 5 August 2011 (UTC)

Yeah, you basically answered it yourself. We'd see such a planet's gravitational effect on other astronomical bodies (Neptune, for example, was expected to exist before we actually observed it...sort of). You might be interested in 2010 TK7, an asteroid that shares Earth's orbit. --Goodbye Galaxy (talk) 19:24, 5 August 2011 (UTC)

Right... but that wasn't your question! Whoops. If I had to guess, I'd say around late 1700s to mid 1800s, but I'm not entirely sure. --Goodbye Galaxy (talk) 19:27, 5 August 2011 (UTC)

If it was a small planet, like Mercury or smaller, it could hide longer then another earth sized planet could, but at some point, the IAU would take away the planet status. Googlemeister (talk) 20:23, 5 August 2011 (UTC)

A so-called counter-Earth would have been known since antiquity, since it would periodically be visible from Earth. First, Earth's orbit is elliptical and not circular, so a planet that was following the same path about the Sun would 'gain' on us when it was close to the Sun, and fall behind when Earth was close to the Sun. (This problem could be avoided if the counter-Earth were in a symmetrical orbit.) The second problem is that the Sun's position is perturbed by the other planets (especially Jupiter) and so wiggles back and forth; depending on where the counter-Earth was in its orbit, it would periodically peek out from behind the displaced Sun.

Leaving aside those issues, a planet of Earth's mass sharing our orbit wouldn't be dynamically stable. (Or, alternatively, our orbit wouldn't be stable.) Small perturbations (caused, for example, by the other planets) would lead to exponentially growing imbalances in the forces on the counter-Earth, relatively rapidly dragging it out from behind the Sun. The mathematics governing Lagrange points (a counter-Earth would be at L₃) showed up in the eighteenth century; presumably a capable astrophysicist of that era would have been able to determine that no stable counter-Earth orbit could exist. TenOfAllTrades(talk) 20:51, 5 August 2011 (UTC)

The point that any sufficiently large "counter-Earth" would be periodically visible, would have followed from the studies of Kepler in the early 17th century, right? 188.117.30.209 (talk) 08:54, 6 August 2011 (UTC)

If it was small enough and dark enough, we might not know about it even now. Of course, as noted previously, something that small can't really be called a planet. However, the definition of a planet includes it clearing it's orbital path of debris, which is difficult to determine if the path was cleared, but presumably mainly by the Earth. StuRat (talk) 21:28, 5 August 2011 (UTC)

Is Wikipedia auditioning for the part of Colonel Blimp? Cuddlyable3 (talk) 21:45, 5 August 2011 (UTC)

Hmmm, it's true that the center of mass of the Sun and Jupiter is outside the Sun. But wouldn't the Earth and Counter-Earth, being bodies orbiting the sun, follow it on its orbit around its center of mass with Jupiter, thus remaining in line with one another and the Sun? Wnt (talk) 22:54, 5 August 2011 (UTC)

Jupiter's period of rotation is much longer than that of Earth, so they wouldn't be synchronized. Rckrone (talk) 03:09, 6 August 2011 (UTC)

I don't think that matters. If the Sun is (a little bit) revolving around Jupiter, then the Earth should be revolving around Jupiter too, as a "moon" of the Sun when looked at this way. Whenever the Sun is on one side of Jupiter (or the barycenter) the Earth is also. Wnt (talk) 14:22, 6 August 2011 (UTC)

Yeah, you're right. Rckrone (talk) 21:37, 6 August 2011 (UTC)

Do you have a source or link for the Jupiter-Sun barycenter claim, Wnt? μηδείς (talk) 03:40, 6 August 2011 (UTC)

See barycenter for one source (NASA).--Shantavira|^{feed me} 07:52, 6 August 2011 (UTC)

Wow. That's great. I am truly impressed by what one learns from wikipedia, as opposed to those moribund rags like Scientific American and National Geographic. Why had I never heard this before? μηδείς (talk) 03:52, 7 August 2011 (UTC)

Thanks everyone for chipping in. I didn't know about that Counter-Earth article, so essentially even before space probes could have seen the area a counter-earth would've either been visually spotted due to the elliptical nature of earth's orbit or it's existence disproven either mathematically or by lack of observable gravitional effects on other planets, and it's likely that the theory was discredited anytime from the 17th century onwards. Thanks chaps, much appreciated. Keep up the good work. Quintessential British Gentleman (talk) 12:21, 6 August 2011 (UTC)

If the planet only "peeked out" a little from behind the Sun occasionally (which seems improbable - it would more likely wander widely), it would only be potentially visible without the aid of modern-ish instruments during total solar eclipses. However its gravitational perturbations on other planets (like those of Neptune on Uranus which led to Neptune's discovery) would have been obvious to astronomers from Newton onwards, as has been said above.

The concept was used for the locale of the Gor series of SF novels by "John Norman", which was subtitled The Chronicles of Counter-Earth. Norman avoided the problem by having the planet be the home of an advanced alien race, the giant-ant-like "Priest-kings", who used their advanced technology to tweak its motion, keeping Gor always exactly opposite Earth and presumably also adjusting the other planets' perturbations. {The poster formerly known as 87.81.230.195} 90.197.66.72 (talk) 17:44, 6 August 2011 (UTC)

move the world

One of the ancient philosophers, maybe Archimedes, stated that with a large enough lever and a place to stand he could move the world. I have my doubts on that. Given known materials, would it be possible to construct a lever capable of moving the earth a distance of 1 cm if we could assume that a 180 lb Archimedes had a place to stand, and a fixed point where he could use his lever, (we should probably assume that he needs to be capable of moving his lever as well)? My guess would be that even if his lever was a Titanium alloy, the lever would need to be so long that poor Archimedes would just have his lever flex on him rather then lifting the earth, but I am only assuming here. Googlemeister (talk) 20:46, 5 August 2011 (UTC)

Agreed, no real-world material would work. Also note that such a lever would be quite massive, so it's gravitational effect on the Earth might well outweigh any use as a lever. StuRat (talk) 21:30, 5 August 2011 (UTC)

(ec)We can't assume what you ask so it's not our problem. Cuddlyable3 (talk) 21:34, 5 August 2011 (UTC)

It should be noted that you don't need a lever to move the world. Any amount of force will do, for example just jumping up and down. Granted it won't move the Earth by 1 cm. But if you're allowed to start not on the Earth ("a place to stand") then you could theoretically shoot yourself at the Earth with enough energy to change it's orbit by 1 cm, or any amount that you like. Rckrone (talk) 22:39, 5 August 2011 (UTC)

According to my rough calculations, if you can find a material workable enough to shape and rigid enough so as not to bend too much, you can nudge the earth over a bit. The trick is to get enough of the material to create a lever with a length something in the range of 100 to 1000 times the diameter of the observable universe. (Less if you weigh more than 200 kilos and are quite strong.)

As noted these are "rough calculations" so please get input from another person at this desk before starting fabrication. CBHA (talk) 23:46, 5 August 2011 (UTC)

A problem here is that like any object, the Earth's doesn't have a precisely defined momentum and position. The uncertainty in the momentum is actually quite large, it's of order sqrt(M k T) with T the temperature at its surface. This means that it becomes a problem to say that a small amount of momentum, say, of order 10 kg m/s added to the Earth actually changed its orbit. The probability that nothing changed at all will be significant. Count Iblis (talk) 00:35, 6 August 2011 (UTC)

He was correct, but would need a lever approximately 5973600000000000000 kms long, according to my (probably wrong) strokes on the calculator, for a push on the lever of about 10kg. It would need to be a thicker lever the closer it gets to earth so it doesn't collapse under the gravitational effects of bodies in the solar system. The hinge required needs to whitstand the force from said gravity, as well as force from the leverage, the faster he wants to move the earth, the stronger the hinge, foundation and lever need to be. Use the ratio of the 1cm : length of lever, which will be the same ratio as the mass of the earth : force applied to lever's end. He weighs 90kg, but he'd need to be in a 1G environment in his 'place to stand' which would clearly need to move if he is to stand. He needs to move through 5973600000000000000 kms for the earth to move 1cm. Anyone want to check/correct the figure ? Penyulap _talk 13:21, 6 August 2011 (UTC)

Archimedes did not specify a distance. His boast was most cromulent. μηδείς (talk) 03:47, 7 August 2011 (UTC)

August 6

I've read that children dislike vegetables because they're bitter?

I don't see it in the vegetable article though. I'm also wondering if cooking vegetables change their bitterness, if any. Thanks. Imagine Reason (talk) 00:14, 6 August 2011 (UTC)

Most vegetables don't have much bitterness. The most widely eaten exception is spinach; chard and other greens are even more bitter. In Asian cuisine bitter melon is commonly used, and it's a lot more bitter. There are many more bitter spices than vegetables. Looie496 (talk) 00:37, 6 August 2011 (UTC)

Possibly relevant: slow acetylator. --Trovatore (talk) 00:44, 6 August 2011 (UTC)

... except it's a redlink; WADHAAOE. I'm shocked. --Trovatore (talk) 00:45, 6 August 2011 (UTC)

There is mention of the concept at Drug metabolism, Pharmacogenetics, N-acetyltransferase 2, Nutritional genomics and a bunch of articles on drugs and other stuff. One of these may be suitable as a redirect target, at least for now. Nil Einne (talk) 11:50, 6 August 2011 (UTC)

Children dislike vegetables because vegetables don't taste as well as sweets, cookies, icecream, cake etc. Count Iblis (talk) 01:06, 6 August 2011 (UTC)

There are other reasons not to like veggies. Some are tough, and cooking can help there. Adding fat, like butter, can also make them "go down easier". Some people also have a genetic tendency to dislike cruciferous vegetables, like broccoli. And, perhaps by bitter you meant "not sweet". In that case, they may like some of the sweeter veggies, like carrots and beets, or adding a sweet salad dressing to the rest. StuRat (talk) 01:08, 6 August 2011 (UTC)

Or just follow Amy Chua's advice. :) .Count Iblis (talk) 01:50, 6 August 2011 (UTC)

I guess you're thinking of supertasters Nil Einne (talk) 11:55, 6 August 2011 (UTC)

Cooking can sweeten onions by caramelizing them, so yes cooking can help sweeten the pot. Still, with kids, sometimes their preferences must be acquired with time, as they get older. For instance, it can be difficult to eat something if one associates it with an illness, pest or an odd sensation. For a while, I would refuse to eat raisins from a box after having found ants in one. Similarly, for a number of years, I would relive being sick whenever I smelled macaroni and cheese. But I eventually realized these aversions were silly and now, like most adults I think, enjoy foods I may have shunned. With any food it helps if its prepared well, especially by a great cook. For instance, care must be taken to not over-cook any veggie into a bland mush (and even uncooked celery or a carrot needs a good dip). Various soups and side dishes are satisfying, but my preference has always been the casseroles my mom made. She mixed veggies such as carrots, beets, spinach, broccoli, and cauliflower with other ingredients such as cheese, chicken, pasta and potatoes. Her rhubarb cobbler is out-of-this world too. --Modocc (talk) 03:25, 6 August 2011 (UTC)

To begin with some subjective opinions, as someone still repulsed by raw onions to this day, I'd say it's not merely a matter of caramelization - maybe it's the breakdown of allicin or related compounds with a strong stench. But as a child I was much more sensitive to such scents - even smelling a bit of it in the tiny bits of onions in commercial spaghetti sauce, where I'd think every last molecule had been decomposed.

But my reaction to almonds was much, much weirder. As a child I was incredibly sensitive to a terrible, oily smell in them - something like a cigarette which to merely touch it for a moment left a reek on my fingers that took soap and hot water and scrubbing to clean off. But when I was around 15 the scent became much less pronounced, so much so that within a year or two I could actually eat a few experimentally. Within a few years after that, the scent became so weak that they became an acceptable snack, and after a decade or two the scent was truly undetectable. I'm thinking that there must be odorant receptors which are activated by promoters that shut off in adulthood. Wnt (talk) 05:01, 6 August 2011 (UTC)

But the next question is "Why ?". What evolutionary path would lead to almonds being objectionable to some children, but not to adults ? Are they actually harmful to some children, perhaps due to the cyanides present in small quantities ? Maybe those chemical stunt some growth process at low levels ? StuRat (talk) 05:21, 6 August 2011 (UTC)

I wonder if diversity in food preferences actually represents an evolution of the scientific method. If some people in a tribe eat a food and others don't, people might recognize that the food is responsible... Wnt (talk) 13:43, 6 August 2011 (UTC)

Children are know to try a lot of things, and hence are at higher risk from dangerous foodstuff. Adults will have learned to be more discriminating. Also, once you're past 25, you're supposed to have done your bit for the propagation of the species, of course, so evolution wouldn't give a hoot if you jumped off a cliff ;-). --Stephan Schulz (talk) 08:50, 6 August 2011 (UTC)

If you jumped off a cliff at 25, your 5 children would starve. :(

You should be 45 at least before you jump off a cliff I think. Rckrone (talk) 22:24, 6 August 2011 (UTC)

You should be well past 70, and have walked your children through all the stages of parenting, long before you consider tetherless bungee jumping. μηδείς (talk) 03:42, 7 August 2011 (UTC)

We do have an article, perhaps not that useful, on Selective eating disorder Nil Einne (talk) 11:52, 6 August 2011 (UTC)

Humans have evolved as Omnivores and thrive on a balanced diet of plants and animals. However catching animals is harder than picking plants because plants don't run away. To compensate for the difference and favour a balanced diet, instinct gives a greater pleasure reward from eating animal products than vegetables. Cuddlyable3 (talk) 13:16, 6 August 2011 (UTC)

Vegetables are not bitter, unless you are not cooking them properly or are a supertaster. I had no problems eating vegetables when I was a kid. I understand that in the US almost everything has sugar added to it: perhaps you are describing the rare taste of something sugar-free. Update: when years ago I used to take sugar with my tea, then tea without sugar would taste unpleasant, "bitter". But after very gradually over years reducing the sugar in my tea to nothing, sugarless tea does not taste bitter at all, but nice. Now I much prefer sugarless tea. 92.28.252.178 (talk) 15:36, 6 August 2011 (UTC)

Alkaloid toxins are generally bitter. And it certainly doesn't help a poisonous plant to taste good and be eaten up before it kills you. μηδείς (talk) 03:42, 7 August 2011 (UTC)

I'm surprised that no other old fart has yet responded with something along the lines of "The kids of today have too much choice. When I was young we ate what was put in front of us or went without." It was certainly true in my case, and I suspect for most of human history for most people. Having a choice of foods at every meal, and in between meals, is the unnatural thing here. Maybe we should get deeper into this issue of actually having this choice. It would have been rare in the past, and maybe there was a point to our preferences when it occured. HiLo48 (talk) 03:49, 7 August 2011 (UTC)

cosmic strings

what are cosmic strings? — Preceding unsigned comment added by 175.110.242.217 (talk) 02:46, 6 August 2011 (UTC)

They are topological defects of space-time. As you can see stated on the first line of the article cosmic strings. Hair whorls are familiar examples of a topological defects. Dauto (talk) 03:16, 6 August 2011 (UTC)

pretzel making

What are the byproducts after baking of submerging pretzel dough in sodium hydroxide (or potassium hydroxide) to produce a glaze? --DeeperQA (talk) 10:45, 6 August 2011 (UTC)

Water. See Neutralization (chemistry). Plasmic Physics (talk) 12:18, 6 August 2011 (UTC)

The above may be true for lye as a reagent, but it would also be good to consider its role as a catalyst. It should be clear from the formation of the crust that there's been substantial chemical change in the dough, but I didn't find much of interest on NCBI (only PMID 14733520, which is more about what the lye prevents by neutralizing acid). And nothing on Google. But there's a lot of information out there - there are probably specialized food resources that I don't know about. Wnt (talk) 14:37, 6 August 2011 (UTC)

The Maillard reaction, one of the reactions involved in the browning process, is affected by pH (enhanced under alkaline conditions). I assume other related reactions are affected as well (not sure which other specific ones are accelerated or slowed). DMacks (talk) 16:35, 6 August 2011 (UTC)

Caramelization is also affected by pH (and also enhanced under alkaline conditions)--I just added that content (with ref:) to its article. DMacks (talk) 17:48, 6 August 2011 (UTC)

space/time, energy/matter

Is it safe to say that space/time is the only place energy/matter is located? --DeeperQA (talk) 10:50, 6 August 2011 (UTC)

Yes. Plasmic Physics (talk) 12:15, 6 August 2011 (UTC)

gravity

Is there any time or place where gravity does not or did not or will not exist? --DeeperQA (talk) 10:52, 6 August 2011 (UTC)

Depends what you mean by "exist". Does zero gravity answer your question?--Shantavira|^{feed me} 11:08, 6 August 2011 (UTC)

No, gravity fields extend indefinitely into space-time, like electric and magnetic fields. Plasmic Physics (talk) 12:21, 6 August 2011 (UTC)

Yes, see Lagrangian point. Cuddlyable3 (talk) 13:05, 6 August 2011 (UTC)

Isn't there plenty of gravity at Lagrangian points, but just pulling in the right way to keep in orbital sync? 81.159.105.227 (talk) 13:34, 6 August 2011 (UTC)

Yes, you are right. Dauto (talk) 14:35, 6 August 2011 (UTC)

Yes. If there was no gravity, the object would fly off into deep space. Objects at L-points are still in orbit around the primary and any orbit needs gravity to close it. --Tango (talk) 21:36, 6 August 2011 (UTC)

No, gravity is still active at a langranian point, it is just a metastable position. Plasmic Physics (talk) 19:26, 6 August 2011 (UTC)

Power outages

Hi. Could recent power outages in the local area been caused by solar geomagnetic storms that hit the Earth? Do those typically cause outages lasting on the order of 1 minute? Is it usually possible to trace or identify the source or otherwise an exact cause of a local outage? Thanks. ~AH1 ^(discuss!) 12:28, 6 August 2011 (UTC)

I doubt it. The geomagnetic induced currents are not that large that they would directly cause problems. You would need circuits of huge areas to get large induced currents. What can happen is that such currents cause tranformer cores to get magnetized, and then the power transmission from the powerplant to the grid becomes less efficient. It is this dissipatated power originating from the powerplant that can destroy transformers. Count Iblis (talk) 17:00, 6 August 2011 (UTC)

What do you mean by "recent"? Our article on geomagnetic storms affirms that they can indeed cause outages, and there was speculation that the storm that struck yesterday/today might be strong enough to have effects, but a quick scan of news doesn't show any specific reports. Looie496 (talk) 20:28, 6 August 2011 (UTC)

distinction between coordinate covalent bond and covalent bond

why does the distinction between coordinate covalent bond and covalent bond vanishes after bond formation in NH4+ H3O+ and CH3NH3+? — Preceding unsigned comment added by 175.110.242.217 (talk) 16:48, 6 August 2011 (UTC)

The "coordinate" part of the Coordinate covalent bond name simply refers to where the electrons of the bond came from before the bond exited. Once the bond forms, there is no longer any evidence of this aspect of the bond. You can point to a bond in a drawing and say "this one's electrons came from that atom", but that is not a property of the molecule itself in real life. The electrons are not individual particles that are specifically part of a one specific bond in the molecule. DMacks (talk) 17:08, 6 August 2011 (UTC)

Indeed, electrons have no memory about where they came from. More importantly the same "bond" could be "formed" in different ways, and get the same result. Describing a bond as a "coordinate covalent" bond really just implies that the bond formed via a Lewis acid-base reaction whereby the bond is formed as a 2-electron filled orbital in one atom merges with an empty orbital in another atom to form a new filled bonding orbital and unfilled antibonding orbital. The other method of bond formation occurs when two 1-electron half-filled orbitals form the bonding/antibonding pair of molecular orbitals. Once the result is done, however, the bonds behave the same whether they formed via the former method or the latter. --Jayron32 17:50, 6 August 2011 (UTC)

How much (embedded) energy is needed to build different kind of power plants?

How much (embedded) energy is needed to build different kind of power plants? And with embedded energy, I mean the energy used by machines of different kinds: electrical sources, fossil fuels as well as renewable sources, etc. And with machines I mean the machines involved in the creation of the power plant, that is: transportation of components to the place, the production elsewhere of different components needed for the construction, and perhaps also the extraction of the raw material needed for the production of components. So, I would like to know how much energy that is needed to build, for example a nuclear plant or a wind turbine, and then I also wonder how long time it would take for the different kinds of power plants to create (transform) the same amount of energy as it took to construct the plant? I know that this is a hard thing to answer, but it would be very interesting if someone could make at least some simple calculations on it. //moralist 19:32, 6 August 2011 (UTC)

At the risk of angering many energy "activists" - there is absolutely no meaningful way to define "embedded energy" without incurring a wild goose chase of infinite recursion. It is for this reason that reliable sources, such as the United States Department of Energy and the Energy Information Administration, make essentially no reference to this parameter. You can verify this for yourself using your favorite web search utility or by perusing the websites of such organizations. I highly recommend reading their reports, incliding the EIA's short- and long-term energy outlooks, to gain perspective into this issue. This is not to say that embedded energy doesn't "exist" - of course energy is used to build new energy production facilities; it's just that quantifying that energy is more a game of politics than of science. You may find similarities between embedded energy and the energy returned on energy invested - another similar economic parameter typically applied to fossil fuel extraction. Nimur (talk) 20:48, 6 August 2011 (UTC)

Here is a good article: "How can we compare or add up our energy consumption?" This article explores the difficulties of adding different types of energy used in different scenarios, and presents the methods used by the United States for statistical purposes. Nimur (talk) 20:58, 6 August 2011 (UTC)

From reading that article it seems trivially easy. Its only "difficult" because they don't use metric. 92.28.249.101 (talk) 23:13, 6 August 2011 (UTC)

Here are some more resources for you to read: Energy Efficiency, which outlines a statistic called the "Primary Energy Conversion Factor" and is based on real data, and Interactions in the National Energy Modeling System, which expresses market and economic interactions with various primary energy conversion factors via a sophisticated computer model. Nimur (talk) 21:16, 6 August 2011 (UTC)

Well, actually, in a free market where all real costs, including those of insurance, waste disposal, and other hidden variables are rationally assigned--rather than assuming "someone" will clean it up, you can make such calculations as best is possible. The problem is incurred when free markets in immediate costs are mixed with the assumption that someone else, usually the tax payer, will deal with the costs of things like long term toxic waste disposal, birds killed by noisy windmills, dam collapse, or poorly designed and managed nuclear plants in quake zones and tsunami shadows. There is no such thing as absolute knowledge. But if you disabuse private investors of the notion that the state will clean up in the case of emergency and require rational preparation to address all costs, the free market will price in such costs for you. Sorry if that provides no specific answer in any concrete case. μηδείς (talk) 03:21, 7 August 2011 (UTC)

There is this technical resource, George Reisman's Austrian economics-treatise Capitalism, available for pdf format download at capitalism.net and for hardcover purchase at Amazon. μηδείς (talk) 03:35, 7 August 2011 (UTC)

To paraphrase what I said the last time this came up: the free market won't insure against large uncertain future expenses because it's too risky. Insurance companies want certainty like everyone else, and they do that by insuring against frequent, small (at the scale of the insurance company) losses. This limitation of the market has nothing to do with whether it's a good idea to build nuclear plants or not. It probably is a good idea, since coal and petroleum are much worse, and nothing else can supply the modern world's energy needs. When there's something that needs to be done but the free market won't do it, governments step in; that's what they're for. I know there are people who believe that the market does everything perfectly and governments should be abolished, but those people are wrong, just like the people who think that homeopathy works, etc. This is the science desk. -- BenRG (talk) 04:30, 7 August 2011 (UTC)

MOX UK

The UK is closing a MOX plant that's only a few years old and cost over a billion to build because there has been insufficient demand for its product, particularly after the Japanese tsunami.

But why is there is talk of building another MOX plant on the same site as the closed/bulldozed one that will cost six billion?

I understand that this is a way to get rid of a large plutonium stockpile, but would it not be cheaper to design future UK nuclear reactors to use the specification of MOX fuel that the 'old' plant produced? 92.28.249.101 (talk) 23:09, 6 August 2011 (UTC)

I take it (from this article) that the closing plant is at Sellafield. As for why... I'm not informed enough on the issues to be totally sure, but it does look an awful lot like a boondoggle. It doesn't look like experts think there is really a market for a new MOX plant. As for why you wouldn't just make reactors that could take old MOX fuel, the issue is likely that the new generation of reactors have inherently different fuel requirements. Reactor fuel requirements are often quite specific if the reactor is meant to be profitable — the margins of profit are not huge. With research reactors (because profit is not a big issue) you can often re-engineer them to take different types of fuel (e.g. changing a HEU reactor to a LEU one) but that usually changes the power output quite a bit and requires extensive design changes. So it's not an easy change. As to why they didn't design it in the first place, the tautological answer is probably "because it wasn't a good idea to do so, probably for economic reasons," but that's not a very interesting explanation.

Anyway, it is a very good question, and it seems a lot of experts and citizens are rightfully asking. The official answer given ("Don't worry, there will be a market! Plus: jobs!") is not very compelling on the face of it. It's really, really unclear right now what the future of the nuclear industry is. For awhile it looked like there would be a "Renaissance" (Nuclear renaissance) in nuclear power, but after Fukushima it is a lot more problematic. --Mr.98 (talk) 00:19, 7 August 2011 (UTC)

The Guardian article linked to above says that the government's talk of building another MOX plant was just a red-herring so that the plutonium stockpile would not be recorded as a massive liability (rather than an asset) on the government balance sheet. Why cannot politicians be honest for a change - we're not in Italy. I hope the putonium can be used up for power generation rather than being a dangerous stockpile for many centuries. 92.24.133.68 (talk) 12:55, 7 August 2011 (UTC)

August 7

Reactive Oxygen Metabolites vs Reactive Oxygen Species

Is there a difference between 'Reactive Oxygen Metabolites' and 'Reactive Oxygen Species'?

Do people actually sleeps like this?

See image on this link. [19]

Is this real or is it a joke? Ohanian (talk) 10:26, 7 August 2011 (UTC)

It might well be a joke (tempting to wake her up...) but it could be real. After all, fairly often I use a position with one foot up in the air balanced against a knee in a tetrahedron. As anyone who's had a stiff neck should know, sleep paralysis seems to involve actively maintaining muscular tension, not just flopping lifelessly. Wnt (talk) 11:37, 7 August 2011 (UTC)

I can state with absolute factual knowledge.. It's not a joke. When I was a child I quite often slept in exactly that position. I can't say why, my body just automatically sought that position for comfort.190.56.115.12 (talk) 14:32, 7 August 2011 (UTC)

I can also confirm it's not a joke. My daughter often sleeps in this position, and so did her grandmother as a child. But the habit appears to have jumped a generation. Hans Adler 15:10, 7 August 2011 (UTC)

CHOCK

What is the back emf produced across the electrical ballast at the time when the supply to the tube light is OFF.vsnkumar (talk) 11:02, 7 August 2011 (UTC)

Welcome to the Wikipedia Reference Desk. Your question appears to be a homework question. I apologize if this is a misinterpretation, but it is our policy here not to do people's homework for them, but to merely aid them in doing it themselves. Letting someone else do your homework does not help you learn nearly as much as doing it yourself. Please attempt to solve the problem or answer the question yourself first. If you need help with a specific part of your homework, feel free to tell us where you are stuck and ask for help. If you need help grasping the concept of a problem, by all means let us know.

To calculate the back-emf in an inductor, you need to to know the voltage across the inductor, its inductance, and the resistance of any discharge path. CS Miller (talk) 12:00, 7 August 2011 (UTC)

Chicken lays eggs with double yolks

I have 6 chickens and one of the chickens lays a large egg which has two yolks each time she lays. My question is: If I were to have a rooster around and her eggs were fertile, would there be any possibility that two chicks would come from her egg(twins)? I'm new at raising chickens. — Preceding unsigned comment added by User:TerrDA (talk • contribs)

== Speed of light why cant we travel faster than the speed of light?why does laws of physics prevent us?