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February 16

Aerial skiing

I have been looking at explanations of how aerial skiers appear to change their rotational motion in mid-air. These describe how orientation can be changed by moving parts of the body separately in sequence, like a self-righting cat, while never actually imparting any overall spin (which would be impossible due to conservation of angular momentum). Yet looking at real footage, it is hard to see that such explanations are correct. For example, see 0:45 to 0:53 here. During the first part of this sequence he has a seemingly clear rotation around his head-to-toe axis, and yet as he comes into the landing this disappears. How is this possible without changing angular momentum? 86.160.221.91 (talk) 01:38, 16 February 2014 (UTC)[reply]

It's very hard for me to fully understand the motion, both because I'm not looking at a full set of slomo options and because I don't know the angle of the photography. But my assumption is that it relies on a basic point that you don't really have angular momentum about two axes at the same time. When he lands, he has a simple head-over-heels angular momentum. When he spins, his body is angled relative to this axis, and he is both spinning head over heels in that other angle, and spinning around his body axis. I assume these vectors add up to the simple head-over-heels vector, even if it's hard for me to understand it visually? Wnt (talk) 05:48, 16 February 2014 (UTC)[reply]

With regard to the video, it appears to me that he could impart a spin to himself aerodynamically, by tucking in one arm while extending the other to serve as a dive brake to increase drag. 67.169.83.209 (talk) 06:56, 16 February 2014 (UTC)[reply]

When skiers launch themselves off the ramp they establish the angular momentum required to rotate about both their head-to-toe axis and one of their lateral axes. After that, they are able to alter the speed of rotation about these axes by altering their moment of inertia about these axes. They do this by retracting and extending their arms, bending their knees etc. Sometimes they move both arms symmetrically, and at other times they retract or extend just one arm. Skiers and divers can position their arms and legs to achieve a significant range of moments of inertia. Theoretically they can display many different maneuvers based on one set of angular momentum vectors (x-axis, y-axis etc.) just by altering their moment of inertia about each axis and this is what makes their performances so inscrutable that they appear to defy the principle of conservation of angular momentum.

A gyroscope can't display a similar variety of different maneuvers because gyroscopes acquire extraordinary stability from their great speed but skiers and divers are turning at speeds much slower than gyroscopes. A gyroscope toppling due to inadequate speed is analogous to the amazing maneuverability of skiers and divers. Dolphin (t) 11:44, 16 February 2014 (UTC)[reply]

Applying Einstein field equations over black hole

Do Einstein field equations also apply on black holes? 182.66.50.164 (talk) 07:51, 16 February 2014 (UTC)[reply]

In fact, what most people describe as a "black hole" is one of several solutions of the Einstein field equations, particularly for the Schwarzschild metric. If the enclosed mass is sufficiently large, there exists a Schwarzschild radius as part of the solution. In the simplest case, that radius defines an event horizon, and that is why people loosely call the region inside that radius a "hole" - things can fall in, but nothing comes out - not even light.

Of course, if you worry about all the confounding details, there are lots of other things to bring up: conservation of angular momentum, electric charge, radiation pressures, quantum-mechanical effects at the edge of the event horizon... leave it to mathematicians to turn a "solution" into a series of more challenging problems!

This is to say nothing of Stephen Hawking's most recent 2014 paper - Weather Forecasting for Black Holes - very probably the one that will be his last contribution to the physics of black holes. I, as a bit of a cynic, read between his lines, and interpreted the paper as a sort of parting volley - "ha ha, physics community! I've mis-led you for forty years, and there is no such thing as a black hole in the first place, the math just doesn't work out!" But, I'm sure you and other readers can read it and make up your own minds... (Incidentally, I downloaded the PDF when it was first published on ArXiV, and read the whole thing on my iPad... I found a typo, and checked the LaTeX source, and the typo is there, too..."7evaporating black hole," an error I can only imagine was due to an improperly formed TeX reference that Professor Hawking's assistive text entry software mistyped... and it must have been a real pain to try to correct that, because no update has been posted for the last few weeks). Nimur (talk) 09:21, 16 February 2014 (UTC)[reply]

Maybe people were too busy soapboxing rather than telling Hawking so he doesn't know? Nil Einne (talk) 13:47, 16 February 2014 (UTC)[reply]

Out of respect, and in the furtherance of whatever may be left in my academic career, I have stopped trying to correct people who have more Ph.D.s than I. Nowadays, I just point out any relevant errors I find, buried among the minor details, and hope that any other interested detail-oriented people will make good judgements. Even I have produced a typo, on rare occasions; but these days most of my publications are in wiki-format and are not widely read by pedantic English-speakers. Nimur (talk) 17:41, 16 February 2014 (UTC) [reply]

So when he says that "inside the event horizon, the metric and matter fields will be classically chaotic", is he saying that the old idea of a singularity in the middle surrounded by a sea of empty space with occasional bits of fast-falling stuff isn't right? In the past I've read that with a galactic black hole you might not even notice when you drop inside the singularity, but here... the inside of a black hole is some kind of ... stuff? Does this mean that when you've dropped far enough in, if somehow you could survive, you'd could see objects flying around, complex matter constructs, somebody who says he's God who wants to talk to Captain Kirk about his warp drive? Also, in that quote when he says "event horizon" he means an approximate event horizon inasmuch as the back traffic is sparse and unpredictable? Oh, yeah, and last but not least -- how close does this push the refined classical view of a black hole to a fuzzball, which is also full of ... stuff? Wnt (talk) 17:47, 16 February 2014 (UTC)[reply]

The below is predicated on clearing up a critical common misunderstanding: stuff falls in to black holes, but it is not correct to say that it can never escape. This effect is called Hawking radiation (in honor of its proponent); and it is responsible for the eventual evaporation of the black hole. So, don't get confused - stuff can and does escape the event horizon - just in a very complex, round-about way.

The energy and length scales of the dynamics inside the event horizon are sufficient to tear fundamental particles apart. The "chaotic" description means that the exact geometries are difficult to predict, and the mathematical explanation is because the disturbances are non-smooth. (That means that no matter how small you zoom in, there is still fluctuation).

The paper essentially says that the radiation emitted from a black hole directly corresponds to the time-reversal of the accretion of mass and energy; but that the internal dynamics make it difficult to correlate any specific ejected photon back to any specific input matter that fell in previously. By analogy to weather forecasting: we know that if a hurricane causes rain to fall, any individual raindrop is full of water molecules that evaporated from some ocean somewhere; but we can not predict the trajectory forward or backward: we can't watch ocean-water evaporate and meaningfully know where it will fall; and we can't catch an individual raindrop and meaningfully know where its constituent water originated. The dynamics inside the hurricane are chaotic but they are not, in principle, any different from the behavior inside the black hole: particles are following complicated dynamic trajectories that are determined by interactions with other particles and mediated via fundamental forces. We can write a geodesic to describe these trajectories, but for chaotic systems, the geodesics are non-smooth. Complexity nothwithstanding, the particles still traverse these trajectories. This is what Hawking means when he says the system is unitary and that it satisfies CPT symmetry. The "apparent event horizon" is simply "the point when the geodesic becomes non-smooth" - and that depends entirely on you, the observer, and the scale length that you can actually resolve. (We do not, categorically, call the edge of a hurricane an "event horizon," simply because we failed to describe the internal dynamics with sufficient precision!)

I should emphasize: we don't know if CPT symmetry must be preserved, at least not any more than we know that energy must be conserved. It is merely a very fundamental way of generalizing the consistency in all other observed phenomena. Another thing we don't know is whether Einstein's field equations actually correspond to a complete description of the real world! To me, it is more reasonable to assume that symmetry is the fundamental principle of our universe. In other words, I believe that conservation of energy and momentum is more fundamental to our universe than some goofy geodesic equation Albert Einstein wrote a hundred years ago - especially now that his equation has been clearly shown to predicts implausible behavior - a fact known to physicists since the 1970s! When Hawking referenced his own 1976 paper, he is essentially saying the same thing: his original statement about black holes is, if nothing else, an indictment of the flaws in general relativity. But everyone else was so excited about the incredible science-fiction applications of the "black hole" that they just kept running with it! Nimur (talk) 20:51, 16 February 2014 (UTC)[reply]

Often chaos isn't all that ... chaotic. For example, two of Saturn's moons apparently have orbital chaos^[1] yet they continue going around and around, and all the physical phenomena involved are continuous. Chaos can be a mere folding and stretching of possibilities, a mere "x modulo epsilon / epsilon" calculation. But the way you describe it, it sounds as if the innards of the event horizon are a place abruptly different from the outside, with Planck scale variations in gravity. Now I'm in absolutely no position to say, but Hawking objected to firewalls saying (which I don't really understand) that "if the firewall were located at the event horizon, the position of the event horizon is not locally determined but is a function of the future of the spacetime." Would the same objection apply to this? Could the chaos be something more mundane (like particles quantum tunneling out of the singularity, though I assume that isn't right)? Wnt (talk) 03:48, 17 February 2014 (UTC)[reply]

For convenience, here is Black Holes: Complementarity or Firewalls?, the paper Hawking cites. It explains the conundrum: three statements cannot simultaneously be true. Among them, "information originates near the event horizon," corresponds to energy that originates near the "edge" and escapes by quantum-mechanical processes. Again, the developments put forth by these scientists don't prove what happens: all they show are what cannot happen, by demonstrating that certain theoretical constructions yield a contradiction. (And to your question about "chaos" - these guys formulate the black hole of mass M as a quantized system that transforms input matter into Hawking radiation via an intermediate system transform, whose entropy - number of available states - is exponential in M, the mass of a black hole. Try tuning a monte carlo simulation to search a problem space that large - it's a little bit worse than an n-body problem like the dynamics of planet-moon orbits!) Nimur (talk) 05:30, 17 February 2014 (UTC)[reply]

I suppose what's throwing me off is that at the highest level, it would apparently resolve the paradox to say that "Hawking radiation is not in a pure state", or "the infalling observer encounters something unusual at the horizon". In Hawking's paper he is saying that the radiation is not in a pure state, but like the weather, but in your interpretation above (in the unlikely event I haven't misunderstood), you seem to be saying that the infalling observer encounters some kind of meat-grinder at some point before hitting the singularity. It still seems like more solutions than necessary. I should not pretend to understand the evolution of the internal quantum state at this point; I don't understand how it predicts what being inside the hole would be like. Wnt (talk) 13:28, 17 February 2014 (UTC)[reply]

Frank Wilczek apparently said of Hawking's latest paper "I think the kind thing to do is to pass this over in silence." That's harsh, but it's a fact that most of Hawking's colleagues haven't paid much attention to his work for decades now. I have nothing against him, but he's not the genius that laypeople imagine him to be, and I think there's no sense in citing any of his recent papers here. The firewall paper did start a debate, which is still unresolved as far as I know, but Hawking isn't a major participant in it. -- BenRG (talk) 06:01, 18 February 2014 (UTC)[reply]

How strong of a handicap is playing chess blindfolded for a chessmaster?

Obviously for a computer it doesn't matter what format they receive the moves, a millionth of a second later they can translate that to their internal data structure representing the board. But for a chess player (grandmaster), how strong of a handicap is it when they play blind? (No board in sight, just told moves algebreically). I mean in quite specific terms, like ELO rating. Any information? --89.132.116.141 (talk) 13:18, 16 February 2014 (UTC)[reply]

It sounds to me like this is the sort of thing which would vary wildly from one grandmaster to the next, as well as how much the attention the grandmaster gives to Blindfold chess. I also wonder if there is enough information to come up with a meaningful figure, for example the now defunct but apparently highest profile blindfold chess tournament is Amber chess tournament which wasn't just blindfold chess but also rapid chess. Nil Einne (talk) 13:44, 16 February 2014 (UTC)[reply]

Most players at the grandmaster level are so good at mentally visualizing the chessboard that having an actual chessboard in front of them means little. It only starts to be important when you get to multiple simultaneous chess games, which impose a load on memory. Looie496 (talk) 14:53, 16 February 2014 (UTC)[reply]

Looie, you've just stated something extremely firmly. Do you have any evidence? I would consider a 200 point drop in ratings to be totally normal if the GM doesn't actually have a board in front of them but has to visualize it. You're saying there is no effect. So, can't you show this with some refernece? Thanks. 212.96.61.236 (talk) 16:36, 16 February 2014 (UTC)[reply]

There are blindfold ratings here: [2]: the OP might like to correlate these with the FIDE ratings of the individuals.--Phil Holmes (talk) 16:48, 16 February 2014 (UTC)[reply]

But if you know anything about how Elo rankings work, you've got a big conundrum: rating calculation depends on measured relative performance among a crowd of others... so, who is wearing the blindfold? Are you suggesting that one person wearing a blindfold has to be compare - not only to opponents who aren't blindfolded - but also compared to other games, where neither competitor wore a blindfold? It is actually not clear whether that comparison is meaningful. Elo style ratings only make sense when there's symmetry between all n members of the sample population so that the performance in any specific game can be compared against other games with other players. Bear in mind that the rating result for the blindfold-game depends on the rating of the un-blindfolded opponent also - and his current rating depends on whether he played previous games against blindfolded or unblindfolded opponents. Nimur (talk) 20:06, 16 February 2014 (UTC)[reply]

I'm actually OP here. So, I actually meant, blindfolded versus a non-blindfolded opponent!!! I was curious how much the blindfold changes pertformance on an absolute scale, i.e. if you are blinded on one game without any other changes (opponent isn't blinded) how much does that make your rating drop? Assume for people like Kasparov, Vishy, or Carlsen 212.96.61.236 (talk) 21:09, 16 February 2014 (UTC)[reply]

Then, the Elo rating system isn't what you want, because it's categorically a relative - not an absolute - scale!

You might be interested to read about certain computer chess algorithms that seek to determine whether a specific move, set of moves, or board-position is "objectively better," (which is related, but distinct, from making progress towards a win). It is actually quite difficult to define "better" for chess (except for the obvious "win/did-not-win" categories). As such, it is difficult to meaningfully measure the performance of one opponent against one other opponent. You could have the two competitors play a large number of games - some with a blindfolded player, and some without - and compare win statistics. But that couldn't be converted into an equivalent FIDE-style rating at all! Nimur (talk) 05:16, 17 February 2014 (UTC)[reply]

Whatever. I (still OP) think you're splitting hairs. I obviously really mean the following: if I were a carbon copy of Kasparov in every way, what would my ELO rating be? It would be the same as Kasparov's, since I am Kasparov in every way and ELO ratings are relative. Now what if I am a carbon copy of Kasparov in every way except that I am secretly blindfolded in a way that nobody knows - I can't see the boards that I play. Now, if I am rated in STANDARD (not blind) chess competitions, would I still have nearly Kasparov's rating? Or would it be expected to be 100 points lower, or 200 points,e tc. Same for others I have listed. What would the average handicap be? (for these experienced blind players). --91.120.14.30 (talk) 10:05, 17 February 2014 (UTC)[reply]

If there were a way to create a "carbon copy" of Kasparov, then his and every other chess player's rating would be different, because there would be two Kasparovs in the rankings pool. Every time any two players play even one single match, that causes everyone else's Elo rating to change. That's how the scoring system is designed! The ranking was designed by chess nerds, for chess nerds, and it has all the messy mathematical complexities that chess nerds thrive on. I think you want a simple answer, but this is a complex problem!

The best way I can describe chess ratings is to consider the scores of every player as a giant simulated annealing problem. You want to invert for the value for each player, so that you can predict the statistical win-loss ratio of any player against any other player. This is effectively using a statistical approach to determine the inverse of an n-by-n matrix for very large n. You have a bunch of prior matches, with win-loss estimates; and from those sample points, you assign a value to every player; then check whether the matrix of all possible match-ups is close to a best-fit with your data; and then you iterate. What set of scores should you assign to every player that yields a matrix whose elements are most consistent with the statistics of all prior games? There's a large null-space, and the problem is degenerate : you can't possibly have data for all n by n elements.

What happens when you add one person who is a clone? Well, the matrix size increases, but its rank does not; the size of the null space increases, and problem of assigning scores becomes more degenerate! So, no, sorry, you can't just assume that a cloned Kasparov has the same chess rating as his original. That isn't how it works! You have to blindfold your clone and then run him through a lot more games, and everyone's Elo rating changes, including the original guy.

One of the best ways I have proven to myself that FIDE-style chess ratings are mostly junk is by playing a bunch of symmetrical chess engines (identical software!) against each other, and calculating the ratings that emerge. I say again, it's like running a simulated annealing algorithm on a degenerate problem. You get an answer, but it's mostly noise. Now that free and open-source chess software is widely available, and powerful computers are cheap and easy to come by, everyone should try this. It's a bit eye-opening. It made me never want to play chess again. The game is not yet solved, but with computers, it has become way too deterministic to be fun for me; and the ratings are really a lot more bogus than most chess nerds will usually admit. Nimur (talk) 05:55, 18 February 2014 (UTC)[reply]

Thanks for completely ignoring my question. Your point is basically irrelevant, as we can simply imagine that the carbon copy of Kasparov starts playing while the real Kasparov is killed - the pool doesn't change. If even that isn't enough for mathematical reasons, then we can start the carbon copy with Kasparov's current rating, while Kasparov is killed. If that STILL isn't enough, then we can simply copy the Universe into two parallel universes. Universe 1 is the current one (control), Universe 2 is where the (there, real) Kasparov secretly is blinded for every one of his remaining matches, without anyone knowing this. Likewise we can create a separate Experiment universe from the Control experiment, in each Universe a top player is secretly blinded. Question: if we repeat this experiment with a separate universe for each player we are testing, then what is the average change in a given top player's ELO reating between the control universe and the test Universe? (We only consider top players, who are experienced blind players.) Example. If instead of blinding them we made the secret change that in each Control universe there would be a small paperclip that is placed under all of the rest chess boards in every game that the person undergoing the experiment plays, then we would find that every test Universe statistically matches the control Universe. A paperclip secretly placed under the chess board does not affect ELO ratings. So, this is my experimental question, and it concerns an actual real-life effect. How much handicap do experienced blind-chess players experience if they are blinded in a normal match? You can mince it however you want, but it's a straight-forward question. --91.120.14.30 (talk) 11:14, 18 February 2014 (UTC)[reply]

Who would win the Super Bowl if Dallas had to play all its games in snow? It's an easy, straightforward question to ask, but it's a hard question to answer. Nimur (talk) 21:34, 18 February 2014 (UTC)[reply]

Transformer

According to the transformer article, an ideal transformer has no resultant flux in the core. How, then, does the primary induce a voltage in the secondary by virtue of flux linkages and the induction law? This has always puzzled me.--86.168.108.70 (talk) 01:59, 17 February 2014 (UTC)[reply]

I may be misunderstanding something but the transformer article says about ideal transformers: Flux is confined within the magnetic core. Therefore, it is the same flux that links the input and output windings. Is that the same thing as saying "no resultant flux"? Vespine (talk) 02:36, 17 February 2014 (UTC)[reply]

It does say Permeability of the core is infinitely high which implies that net mmf (amp-turns) must be zero, which means that H (magnetic field strength) but not B (magnetic flux density) must be zero. This may be what you were thinking of, and does not introduce the flux linkage problem that you refer to. —Quondum 06:12, 17 February 2014 (UTC)[reply]

Er, B=uH doesnt it? So no H gives no B and hence no dB/dt so no flux lnkages so no sec voltage. So that cant be how a transfprmer works, can it?--86.168.108.70 (talk) 15:32, 17 February 2014 (UTC)[reply]

The implication here is that u is infinite so that B has a value. Graeme Bartlett (talk) 19:59, 17 February 2014 (UTC)[reply]

Yes but from previous assumption of zero H (becuase mmf=0) then B= ∞*0. Work that one out!--86.168.108.70 (talk) 22:02, 17 February 2014 (UTC)[reply]

It is not my interpretation that B is zero, so we still have well-defined nonzero dB/dt, which couples the voltages in the primary and secondary. H is zero, which corresponds the currents in the two windings matching exactly. —Quondum 00:34, 18 February 2014 (UTC)[reply]

If you have a problem with the indeterminate expression, simply think of µ as very very big. That sidesteps the calculation problem while giving you "almost ideal" results. —Quondum 04:22, 18 February 2014 (UTC)[reply]

Yeah. So if u is very very big (ie tends to infinity) and H=0, what is B then? The fact that B is caused by H and H is zero should make it obvious that B is also zero.--86.168.108.70 (talk) 15:40, 18 February 2014 (UTC)[reply]

it is my intention to try to move this discussion onto thr Transformer article talk page. Does anyone object to this? 109.144.132.3 (talk) 01:56, 19 February 2014 (UTC)j[reply]

It would not be appropriate to do so. An article's talk page is for discussing the article content, not for tutorials about its interpretation. You do not appear to have grounds for suggesting changes to the article. —Quondum 04:59, 19 February 2014 (UTC)[reply]

But the above discussion does have a bearing on the articles content: namely that the explanation of operation of a transformer is wrong because it states that induction is the method of energy transfer. There is no induction when the secondary is loaded as flux linkages are miniscule in such a system.--86.168.108.70 (talk) 13:28, 19 February 2014 (UTC)[reply]

February 17

Desert agriculture

In general, is it common for non-cold deserts to be productive farmland if irrigated? With amusement I note locations such as 26°19′N 43°32′E / 26.317°N 43.533°E / 26.317; 43.533, massive areas of center-pivot irrigation in the Saudi Arabian deserts. However, like anywhere else, you have to consider the soil: do most temperate or tropical deserts worldwide have the right nutrients and other factors to permit extensive agriculture when water is added, or is it more common that the soil simply can't be farmed productively? I didn't see anything on the subject in Desert farming or Arid-zone agriculture, let alone in the broader Desert article. Nyttend (talk) 02:46, 17 February 2014 (UTC)[reply]

California's central valley is sometimes described as an irrigated desert - especially now that our state is in severe drought! So, (knowing that our best resource for regional agriculture outreach is at Davis), I went straight to University of California at Davis's soil science webpage. A few clicks on the site brought a wealth of great resources, not the least of which are an easy-to-use interface to California, Arizona, and Nevada statewide soil quality databases. They even have an iPhone app so you can check the soil where-ever you are! The raw data is also available for the lower 48 states, from the United States Department of Agriculture's NCSS database, but that data is harder for me to interpret (untrained as I am in soil science). Point is, they've put together a very high quality set of tools, software, web services, and reports and maps - and they even define terms (like soil water capacity and soil pH, in the context of agricultural soil quality). Nimur (talk) 05:46, 17 February 2014 (UTC)[reply]

Desert soils are commonly high in phosphate and potassium, two key nutrients. They tend to be low in fixed nitrogen, and often have factors that impair plant growth, such as salt, highly alkaline soil, or poor drainage. The upshot is that in most cases it isn't simply a matter of planting things and watering them, but the soils can be made productive if treated correctly. Looie496 (talk) 14:58, 17 February 2014 (UTC)[reply]

A large part of desertification in North Africa, Central Asia, and the Levant was caused by overgrazing by goats and livestock which led to soil erosion. Lebanon was once densely wooded, and Canaan was the land of milk and honey. As Looie mentions, the lack of fixed nitrogen is an issue. There have been projects to use things like mixing in crude oil to stabilize what soils there are so the will hold seedlings and moisture, and to plant crops that fix their own nitrogen. I suspect the low return on agriculture in oil rich oligarchies compared to the ease of just importing food has been the main cause this has not succeeded, but agriculture in Israel should prove a profitable comparison. μηδείς (talk) 17:22, 17 February 2014 (UTC)[reply]

In many of the drier parts of Australia, adding water worked for a while, then massive problems arose because of salinity. Large areas of land are now less useful than they were before water was added. HiLo48 (talk) 23:40, 17 February 2014 (UTC)[reply]

Note that there may well be a difference between true desert (rolling sand dunes and such) and xeric shrubland, which, unlike desert, has more plant life and is probably more useful as cropland once water is added. StuRat (talk) 03:38, 19 February 2014 (UTC)[reply]

Proof of Earth going around Sun (serious)

26% of Americans were unsure and there is a smug backlash from armchair scientists.

However what simple experiments can we do on earth to prove it .

The Faucault Pendulum will show the spin of the earth but not prove that the Earth goes around the Sun.

I am after a simple earth based experiment. — Preceding unsigned comment added by 86.171.59.115 (talk) 11:18, 17 February 2014 (UTC)[reply]

I suspect the answer to this will depend on your definition of 'proof'. For astronomers, the fact that a heliocentric model explains the observed motion of planets in a simpler way than a geocentric one is good enough - especially if one assumes that the motion can be (near enough for most purposes) explained by a Newtonian understanding of gravity - and this needs no experimental apparatus beyond ones own eyes, good 'seeing' (i.e. away from light pollution), the ability to recognise specific planets and stars, and plenty of time to accumulate the data. With a good enough telescope, it should also be possible to observe stellar parallax - and you could do this over six months or so. I can't think of a 'simple earth based experiment' that doesn't involve astronomy though. AndyTheGrump (talk) 11:37, 17 February 2014 (UTC)[reply]

If you want to know how to educate 26% of Americans about any misconception, and you find a way to do it, you should at the very least be appointed as secretary of education, if not elected president. If you encounter one or two people who aren't sure if the Earth orbits the Sun, you will have to clarify exactly what their conception of the solar system is. The experiments needed to resolve their misconception will depend on what misconceptions they hold. Observations of the phases of Venus and Mars with a reasonable telescope could demonstrate those planets orbit the Sun; lots of people, after seeing that, would be willing to make the leap to the conclusion that Earth does too. Jc3s5h (talk) 11:45, 17 February 2014 (UTC)[reply]

Thanks Andy, Stellar Parallax is the best answer I think. The phases of the planets could be described by the Ptolemaic model. — Preceding unsigned comment added by 86.171.59.115 (talk) 12:33, 17 February 2014 (UTC)[reply]

It would be really cool if a high school could manage to tune into a space probe on another planet and (among other things!) measure the change in lightspeed delay as Earth moves in its orbit. Unfortunately, this really seems to be at the high edge of the best amateur radio capabilities [3]. Wnt (talk) 13:40, 17 February 2014 (UTC)[reply]

Looking through a telescope at the moons of Jupiter might help to show the possibility. I am a bit sad that nowadays children never see the workings of an actual motor, don't mix chemicals together and a computer is just a black box. No wonder they have no idea of the need for physical laws as well as the social ones of Facebook and Twitter. Dmcq (talk) 13:50, 17 February 2014 (UTC)[reply]

The fact that heliocentrism wasn't generally accepted until he 18th century shows that it isn't that easy to prove. The measurements of solar parallax taken during the Transit of Venus prove it but it's not that easy to convince a skeptic using that sort of proof. Are we talking about people that don't believe it or does that figure include those who are just confused? Richerman (talk) 14:10, 17 February 2014 (UTC)[reply]

It might not be bad to take a step back and double check whether this is a meaningful belief in the first place. After all, if we leave out the rotation, the Earth is pretty much an object at rest in spacetime, with various things moving relative to it, or vice versa, as is the Sun. Sure, if you want to be a stickler about it there's half a part in ten million of solar tide fouling things up, but the Sun is not completely free from tides either. Sure, the other objects in the system revolve essentially around the Sun, with very little contribution from the Earth, but that's not actually the same as saying that the Sun is "the stationary body", it's just saying it's the one with the gravity that pulls things around. I wonder if the 25% are reflecting to some degree thinking like this, which I don't think is ignorant, even if they haven't thought about it much or put it into words. Wnt (talk) 14:47, 17 February 2014 (UTC)[reply]

(ec)If you're setting out to prove this fact to 26 percent of the American public, you would first need to prove to them why it matters. Does the issue of a geocentric vs. heliocentric system have any impact on their daily lives? I suspect the answer would be No. ←Baseball Bugs ^{What's up, Doc?} carrots→ 14:48, 17 February 2014 (UTC)[reply]

Sherlock Holmes expresses a similar view in A Study in Scarlet. “What the deuce is it to me?” he interrupted impatiently; “you say that we go round the sun. If we went round the moon it would not make a pennyworth of difference to me or to my work.” MChesterMC (talk) 15:37, 17 February 2014 (UTC)[reply]

And what's the counter to that argument? ←Baseball Bugs ^{What's up, Doc?} carrots→ 16:20, 17 February 2014 (UTC)[reply]

The counter argument is the accumulation of knowledge for its own sake is what makes us fundamentally human. If you're only concern is survival (and for some it genuinely is, see Maslow's heirarchy of needs), then no, it isn't important. But insofar as being a genuine person and one who wishes to live the human live to the fullest potential, then knowing stuff to know it is enough of a motivation. --Jayron32 16:28, 17 February 2014 (UTC)[reply]

I don't disagree. The question is, how do you convince the 26 percent? ←Baseball Bugs ^{What's up, Doc?} carrots→ 16:58, 17 February 2014 (UTC)[reply]

Set up a society where they have their lower-order needs met, per Maslow. To be fair, more than about 100 or so years ago, that 74% of the population had advanced to the point where they were prepared to be lifelong learners rather than living at a subsistance level is quite an advancement. Before we get to the 100% point, people need to be more secure in their day-to-day life situation, and their basic physical needs should be able to be met. --Jayron32 17:29, 17 February 2014 (UTC)[reply]

I'd say to Holmes (who may not care much about being "fundamentally human") that it's impossible to know that some datum will never be useful; and that understanding any system can improve your repertoire of metaphors, which are an important tool in forming conjectures. —Tamfang (talk) 20:06, 18 February 2014 (UTC)[reply]

I suppose the most obviously direct way to do this is to look at the motion of the other planets. If you look at the path they take across the sky over many months, it's a very bizarre looping pattern. If the Earth was at the center, then the planets would be undergoing some pretty amazing forces to cause them to slow down, stop, reverse direction and so forth. If we believe in Newton's laws of motion, then we'd have to ask where these enormous forces (enough to stop Jupiter in it's path and make it go backwards!) are coming from. When you place the Sun at the center and plot the motion of the planets from it's perspective, then they all go around the sky in nice nearly-circular paths.

This image, for example: http://www.nakedeyeplanets.com/jupiter.htm shows that (from the perspective of Earth) last last year, Jupiter started slowing down - it halved in speed from September to October, halved again by November, stopped dead in the sky in mid-December, then moved BACKWARDS through January and February this year - stopping again in March, and then accelerating away in April and May. If the Earth is not accelerating, then the force required to do that has to come from somewhere...and the amount of energy required is an ungodly amount because Jupiter is by far the heaviest object in the solar system after the sun!

The problem with that is that it requires people who need DIRECT proof to look at where some particular planet is in the sky at the same time every night for maybe a year and carefully plot that against the background of the stars in order to see these reversals. It also requires that they understand Newton's laws of motion - and that they actually believe in them. The people who have trouble believing all of this stuff have trouble understanding that you can't extract energy from magnets to get perpetual motion and that evolution and global warming are "real". If you can't grasp the difference between a force and energy or a velocity and an acceleration - and if you can't pursuade them of the value of careful scientific observation - then you simply can't teach them what they need to know to do the experiment and interpret the results.

These people (in essence) reject the scientific method - and that makes proving anything VERY difficult indeed. If everything is taken on faith, and on the basis of what you simply imagine to be true - then you're going to be wrong about most things most of the time. That's sad - but it's how humanity operated until sometime in the mid-1700's when the power of observation and deduction really took hold. It's unfortunate - but unsurprising - that a percentage of our population still doesn't "get it" - despite their revelry in the results of the scientific method. If the Earth didn't go around the sun, then the laws of physics would have to be completely different in order to accomodate that - and things like television, cell phones and cars wouldn't work the way they do. The people who disbelieve in the scientific method, oddly seem very happy to believe that all of their modern high-tech gadgets work - while simultaneously denying that the very science that produced them is correct. You might argue that despite some engineer's profound lack of understanding about the laws of physics, that this person was none-the-less able to accidentally discover a way to make a cellphone - but the continued success in people making such high-tech gadgets while (in the view of the science-denier) simply stumbling on amazing things like flash memories (which rely on quantum effects) - defies logic.

Science must be VERY close to being 100% correct for such advanced engineering to actually work. If our ideas were 'off' by more than a tiny amount, we'd still be using horses and carts to get around and lighting fires on mountaintops to get rapid long distance communications.

I can't understand that mentality - but it's alarmingly common!

SteveBaker (talk) 15:29, 17 February 2014 (UTC)[reply]

I don't need to know how electronics actually work in order to use a cellphone - I just need to know that it will work, most of the time - and to know where to take it if it stops working. ←Baseball Bugs ^{What's up, Doc?} carrots→ 16:24, 17 February 2014 (UTC)[reply]

You're missing the point. The point is that it's impossible to design and build a cellphone without knowing a heck of a lot of science - and that science has to actually work. Obviously you don't need to understand the science in order to use the thing - but you should (logically) understand that science must represent how the universe works to a fairly decent degree in order for cellphones to exist. If science was so drastically wrong about such critical things as how the gravitational field of the sun pulls the motion of the planets into orbits - then cellphones couldn't possibly work. For example, the GPS system inside a modern phone has to account for the consequences of gravitational fields in general relativity in order to correct the very precise time signals that come from the GPS satellite system. If we misunderstood gravity to the extent that we were wrong about the Earth moving around the Sun rather than vice-versa - then there is really no chance that we could have made a working GPS system using those ideas. SteveBaker (talk) 13:45, 18 February 2014 (UTC)[reply]

No, the point is that not everyone needs to know how something really works, only a relatively small percentage do. As James Burke told us, several decades ago, in the 1800s and earlier, pretty much everyone knew pretty much how to do anything they needed to do. With advancing technology came specialization. And as specialized as we were 30-40 years ago, it's much more so now. You and I are in the 74 percent who believe in science, and could learn the details of how a cellphone works, if we wanted to - but there's no compelling reason to do so other than curiosity. The 26 either lack that curiosity or are focused on day-to-day survival, as Jayron suggests. They may think the heavens orbit the earth, and they may be wrong, but if you're going to prove them wrong you first have to prove to them why it matters more than day-to-day survival. ←Baseball Bugs ^{What's up, Doc?} carrots→ 15:24, 18 February 2014 (UTC)[reply]

I did not read all the preceding replies, but I thought of Urthecast.

—Wavelength (talk) 17:38, 17 February 2014 (UTC)[reply]

Let's try another hack at this. What does it mean to say the Earth goes around the Sun? Basically, it means that a) the Sun is heavier than the Earth, b) the center of mass of the Solar System is closer to the Sun than the Earth, c) all planets revolve in neat ellipses, near circles, with the center of mass at one focus. With some mumble about the three body problem and what happens when you're making an ellipse around a wobbly center of mass, I suppose... no, wait, that isn't even accurate, because moons and Trojans and plutoids and such don't care so much where the solar system's center of mass is. Basically it's chaos over enough time, planets migrating wherever they feel like, rogues slouching toward Bedlam, etc. But the gravity of the Sun winning out in all of it. Now if the 25% said that they think the Sun is a god riding around in a chariot, a hole in the primum mobile or something, I'd be very concerned. If they said they don't think the Sun is very big compared to Earth, or don't know it has gravity, I'd be worried. But I have a feeling if you asked them, they'd have some sense that the Sun is a giant, bright ball that could eat Earths for breakfast, and as long as they know that much, the rest is philosophical and semantic detail. Wnt (talk) 21:59, 17 February 2014 (UTC)[reply]

One is impelled to refer the honourable member to The Second Coming (poem) in the interests of quotation accuracy. Tevildo (talk) 22:27, 17 February 2014 (UTC)[reply]

There are much bigger fish to fry! According to a 2012 Gallup poll, 46% of Americans admit to believing that the earth is no older then 10,000 years!! Vespine (talk) 23:22, 17 February 2014 (UTC)[reply]

For most of that 46%, that's because someone they trust told them that was the case. It's not just a random individual belief. While those doing the telling continue to tell such tales, and the masses continue to trust them, there is little hope. HiLo48 (talk) 23:35, 17 February 2014 (UTC)[reply]

The proof is harder than most people might think. There are several problems. First of all, as Einstein (and Galileo before him) pointed out, all motion is relative. From this point of view, the point of view of one being stationary rather than the other is just that - a point of view. One could also say that none are stationary, but instead use Mach's principle, as Einstein did. The next step is to ask, which is the most convenient Point of view that gives the most accurate predictions to the movements in our solar system. Here is where the crux was originally. The Point of view of a fix earth gave better results than the point of view of a fix sun with planets running in circles around the sun. From an empiricists point of view, Copernicus and Galileo where simply wrong. It was not until many years later that Kepler had the inspiration of making the planets go round in ellipses that the predictions matched the numbers better than the heliocentric model. I believe there may have been small relativistic improvements after that. The points here are : 1 There is not any one model that is more "true". Kepler model is the BEST because it gives better predictions AND is easier to envision. 2. It is not that easy to prove this to a layman, unless he is willing to put a lot of effort into it. I would just show a pretty and colorful movie of the planetary system and say : Isn't that pretty? So the question then becomes: Why have not 1 in 4 people seen this colorful movie, and how can one see to it that everyone does? Do some people in the the US have any objections to it? I would not know, since I do not live in the US. DanielDemaret (talk) 23:56, 17 February 2014 (UTC)[reply]

Today, I started looking at "Heliocentrism" and noted that some of what I wrote about Galileo and Kepler is not in that article. My source for this was an article in Sciam written in the 1980's. My subscription there does not allow me to view Sciam that far back. Until I have found and researched my source, I find some of what I just wrote about Galileo and Kepler in doubt. DanielDemaret (talk) 12:13, 19 February 2014 (UTC)[reply]

If one really needs a simple proof, I suppose one could say "all astronomers believe it". If one wants real proof, it will take more than a simple chat. DanielDemaret (talk) 00:00, 18 February 2014 (UTC)[reply]

If anyone's interested, the 26% figure apparently comes from the National Science Board's Science and Engineering Indicators 2014, table 7-8, and their source is the General Social Survey's EARTHSUN question. -- BenRG (talk) 02:54, 18 February 2014 (UTC)[reply]

This isn't a simple experiment that you can do at home, but the idea is very, very simple. Pulsars are some of the best clocks we have ever discovered: if you watch one you will see a periodic flash of light (X-rays or radio) that has a very stable period. People who do pulsar timing [4] monitor these flashes with a timing precision of nanoseconds over time scales of years. Because the Earth goes around the Sun, you see these flashes up to 16 minutes (light travel time across the Earth's orbit) earlier when the Earth is in the part of its orbit that goes toward that pulsar. That difference is absolutely enormous compared to the nanosecond precision of the pulsar timing experiments! If the Sun went around the Earth while the Earth stayed in place, you shouldn't see this difference. But you do, because the Earth goes around the Sun. --Amble (talk) 19:23, 18 February 2014 (UTC)[reply]

There are other astronomical clocks besides pulsars. Ole Rømer used eclipses of Io to determine that the distance between the Earth and Jupiter changed in a periodic fashion (well, either that or Io speeds up and slows down in a way that is mysteriously correllated with the length of an Earth year) and used this to estimate the speed of light. Presumably you could do the same with other planetary satellites. Of course, this only shows that separations between the Earth and planets/pulsars change in a periodic fashion, not that the Earth actually moves - but if you use multiple astronomical clocks then you can conclude that either the Earth moves or the rest of the Universe moves to and fro in an amazingly sychronised fashion. Then you apply Occam's razor ... Gandalf61 (talk) 17:09, 19 February 2014 (UTC)[reply]

It's the wrong sort of question. There are some issues where the public is confused by conflicting sources of information (e.g. evolution, age of the Earth, global warming) and further clear evidence may convince some people. As far as can tell though, the motion of the Earth around the sun is not one of those issues. There is no cult Earth worshipers advocating their pet theory, etc. Anyone who is interested can easily consult any number of reference works or ask any number of educated people and get the right answer. It's not hard. The fact that some significant number of Americans don't know the right answer is not an error made for lack of evidence, it is rather a symptom of entrenched indifference. They have no interest in how the planets move, and hence they either never learned that the Earth orbits the sun, or more likely they didn't retain the information. It is easy for people like us, most of whom are science wonks to begin with, to bemoan the ignorance of others, but let's be honest, many people just don't care about knowledge that isn't useful to them in their day-to-day lives. If you want a more scientifically literate population, then the only lasting solution is to foster greater scientific curiosity in people (typically young people). That is by no means easy, but as long as people continue to view science as uninteresting or irrelevant to their lives, there is little hope of getting them to pay attention while you explain how we know that the Earth orbits the Sun. Dragons flight (talk) 19:42, 18 February 2014 (UTC)[reply]

@[User:Dragons flight] Thank you for clarifying what I suspected, that most people do not care in the US. It would be interesting if the question was put by country and demographics. I am having trouble imagining that any grown person would not know this simple fact in Sweden where I live. DanielDemaret (talk) 12:22, 19 February 2014 (UTC)[reply]

The explanation of why it is or is not known to all may have nothing to do with different education systems. It is conceivable that it is more connected to something quite different, like for example an official need to inform on the Galileo Affair. DanielDemaret (talk) 12:25, 19 February 2014 (UTC)[reply]

@[User:DanielDemaret] Just testing how this @ thing works ... DanielDemaret (talk) 12:28, 19 February 2014 (UTC)[reply]

Americans don't have a monopoly on ignorance. From geocentric model:

"Morris Berman quotes survey results that show currently some 20% of the U.S. population believe that the sun goes around the Earth (geocentricism) rather than the Earth goes around the sun (heliocentricism), while a further 9% claimed not to know.[43] Polls conducted by Gallup in the 1990s found that 16% of Germans, 18% of Americans and 19% of Britons hold that the Sun revolves around the Earth.[44] A study conducted in 2005 by Jon D. Miller of Northwestern University, an expert in the public understanding of science and technology,[45] found that about 20%, or one in five, of American adults believe that the Sun orbits the Earth.[46] According to 2011 VTSIOM poll, 32% of Russians believe that the Sun orbits the Earth.[47]"

Dragons flight (talk) 16:47, 19 February 2014 (UTC)[reply]

It would be funny, although unlikely, if a follow-up study were to show that the reason those 26% reject it is because they claim that one can choose any frame one wants to be stationary since motion is relative. DanielDemaret (talk) 14:35, 19 February 2014 (UTC)[reply]

A problem with public opinion polls is it's hard to tell if the person answering questions is deliberately giving what the person considers to be false answers, just for amusement. Jc3s5h (talk) 15:09, 19 February 2014 (UTC)[reply]

Of course there is the warped space by gravity that says the earth is traveling a straight line in 4D space (kind of like the walking in one direction on the earth will return you to the origin (2D planar surface warped into 3D). --DHeyward (talk) 03:42, 20 February 2014 (UTC)[reply]

Copying and pasting

My late father left an extensive bibliography of his work. He was a research scientist for the government and has over 200 published papers and chapters in seven books. I want to create a page for him but there is no way that I can type in all of this information. He passed away several years ago and I have dyslexia real bad. This bibliography is written in his own hand and I consider myself to be the owner of it. It consists of a partial list of approximately 60 papers, his education and work background. His name is Roy B Mefferd Jr and if you type this into Google scholar you will see his credibility.

Is there anyway that I can cut and paste this on his page?

Thank you — Preceding unsigned comment added by Greenho (talk • contribs) 14:31, 17 February 2014 (UTC)[reply]

A bibliography of that sort does not belong in a Wikipedia article. At most there should be a selected list of a few important publications. But your first step should be to establish that Dr. Mefferd meets the criteria for a Wikipedia article in the first place -- basically the requirement is that there should be material about him in reputable published sources. See WP:BIO for more information. Looie496 (talk) 14:52, 17 February 2014 (UTC)[reply]

If you don't have a machine-readable list of his work, and you don't want to type in his hand-written bibliography, then I suppose the only alternative is to scan that list into a computer using a document scanner (most cheap printers have this capability) - or if all else fails to take a very well-lit, extremely high-resolution, square-on photo of the pages. However, all of those solutions really require someone else to type it in for you. Doing a copy/paste of the Google Scholar results might be a way to get started - but I see that it has included some work by Roy B Mefferd without "Jr." afterwards - and I don't know whether those are from your father or whoever he is named after...so you'll need to edit that list.

Additionally, I'd strongly warn you that making biography pages of close relatives is a very dubious thing. Wikipedia requires independence in it's editors and being that he is your father means that you are not remotely independent. There is also an issue of Notability guidelines which may not be a problem for your proposed article - but might well prove to mean that this article shouldn't be written at all. So you should go into this understanding that it's quite possible that other editors may take one look at your work and simply delete it. That always seems like a very harsh treatment - but it happens all too often, and those people are usually on the right side of Wikipedia guidelines. When this happens, people like yourself tend to get very upset - both because their work in writing the article is wasted - and because their perception of having a notable/important parent is being trampled. So going into this, you're going to need a thick skin!

Honestly, at this point, you're probably going to have to recruit some other experienced Wikipedia editor to help you. That person will be more experienced at the subtleties of writing a new article - and would perhaps be able to take a more balanced perspective than you'll be able to do.

SteveBaker (talk) 15:03, 17 February 2014 (UTC)[reply]

There was a Roy B Melford (without the junior) (1892-1964) who was a teacher. Were the "non-junior" pubs in his lifetime?Junior, from the 1940 census, was born about 1921. Edison (talk) 01:47, 18 February 2014 (UTC)[reply]

(edit conflict) To start off with, this may not be most suitable for Wikipedia - it sounds more like a Wikimedia Commons or Wikisource item that can be linked from the Wikipedia entry.

The good news is that the single biggest obstacle to getting something like that on the Web is legal. Documents like this start off copyrighted by default and Wiki-whatever isn't free to copy them without permission. If you are willing to grant permission, we're already more than halfway home. (Note however there are all sorts of obnoxious arguments about the copyright of papers that have been revised or formatted with the assistance of a journal; I'd say many, perhaps most academics ignore them, but you could run into mostly theoretical annoyances with those on Wiki sites unless you use a pre-submission version)

After that, it's a question of what form you have it in. If it is literally handwritten manuscripts, the best thing to do is to scan or photo the work. You can use various software to assemble multiple images into PDF or DJVU formats so that you can post them as a single file for everyone's convenience. There is a chance someone at one of the projects will be willing to take your manuscript and scan it in for you - I'm not sure of the details and this isn't the right place to ask really; I'd suggest maybe the village pump on Commons if you need to. But doing it yourself shouldn't be that hard and gives you more say over the quality.

Uploading the work to Commons is easy -- getting it to stay there may be more difficult. Make sure you explain in the text you submit for the file who this person is and why this is important. I also think it is best to plan at least one alternate distribution site in addition to Commons, because there are some ... awful deletionists out there.

Once you've got the scanned text on Commons, people can read it and transcribe it if they wish. At that point I would say that your job is over; you don't have to make it more accessible than that. Someday optical character recognition will be so good and so easy and so well integrated into sites and web browsers that it won't take any effort on your part. However, you can play with that if you wish, or ask people to assist in manually transcribing portions of whatever you have. Wnt (talk) 15:04, 17 February 2014 (UTC)[reply]

A bibliography, as a list of facts in a natural order, is not protected by copyright at all under US law. However, I don't think such a thing belongs in a Wikipedia article, and I am dubious about it being in scope for commons or wikisource either, but editors at those projects can determine that. DES ^(talk) 16:10, 19 February 2014 (UTC)[reply]

Wnt, the question is about a bibliography rather than the published works themselves. benmoore 16:31, 17 February 2014 (UTC)[reply]

That's what the OP wrote, true, but the "extensive" bit got me hoping there was more. If there's just a few pages listing his published work and nothing more, it should be really easy to scan and post as a few images, and what I said still works. Wnt (talk) 20:50, 17 February 2014 (UTC)[reply]

Using Optical character recognition is not the only option. The other way to turn hand-written stuff into text is to use voice recognition software such as Dragon Naturally Speaking. It is surprisingly accurate these days. Richerman (talk) 18:29, 17 February 2014 (UTC)[reply]

Google scholar indicates he was a productive and cited researcher, but I doubt cittions to 1950's publications show up as compared to some current or recent researcher. Director of a research lab and professor at a university suggest that he might satisfy WP:PROF but articles specifically about him seem less common than articles by him. Edison (talk) 02:11, 18 February 2014 (UTC)[reply]

accelerated regions in non-human DNA

do they exist? --Ulisse0 (talk) 15:04, 17 February 2014 (UTC)[reply]

Human accelerated regions are of course only in humans, but there's no reason why any other species should lack them. However, a few of the mechanisms that have led to these regions in humans may not apply to most other species, because the relative likelihood of certain types of mutation and the adaptive 'goals' (if any) of the evolutionary changes may be different. Wnt (talk) 15:09, 17 February 2014 (UTC)[reply]

ok but chimpanzee's dna was sequenced, wasnt it? were accelerated regions found in it? — Preceding unsigned comment added by 82.58.163.74 (talk) 21:39, 17 February 2014 (UTC)[reply]

Fact-Checking Image: Location of PSR J1748-2446ad

I've been looking for an image of PSR J1748-2446ad and thus far haven't found one, but I was able to find an image of the sky in the general area of the pulsar. Making use of the coordinates that are listed in the article, I marked the location of the Pulsar on this image. Is anyone able to verify for me that I did so correctly? I believe I did, but I don't really know for sure if I read everything correctly as I never work with Astronomy images of any sort. Zell Faze (talk) 17:02, 17 February 2014 (UTC)[reply]

I'm going to be bold and add the image to the article in the mean time. Zell Faze (talk) 17:03, 17 February 2014 (UTC)[reply]

It looks like you've used the RA and declination as listed in the infobox, which aren't given to very high precision. In that case, the yellow box you've drawn is much smaller than the precision on its location. The SIMBAD link gives more precise numbers. Sorry if I've misunderstood what you did in making the map; I'm guessing based on what I can see by eye. --Amble (talk) 18:43, 18 February 2014 (UTC)[reply]

If you're going for a rough locator map, there are examples like the nice map in Epsilon Cygni that are used in many articles. --Amble (talk) 18:57, 18 February 2014 (UTC)[reply]

February 18

Can liquids be strained from liquids?

We are all familiar with the fact that you can strain solids from liquids, even very small particles if the strainer mesh is fine enough.

But can you strain liquids from liquids? Like lets say you had a mix of oil and water and lets say the oil molecules will bigger than the water molecules: could you then pass the liquid through a strainer so fine that the water molecules would pass through the strainer but the oil molecules would be separated?

Or does this scenario defy the very property of liquids?--Jerk of Thrones (talk) 04:00, 18 February 2014 (UTC)[reply]

Dialysis tubing? And molecular sieves are similar, but more like a selective sponge than a selective filter (though they can be "wrung out", to continue the analogy). DMacks (talk) 05:07, 18 February 2014 (UTC)[reply]

One can use a Conical plate centrifuge ... to separate two liquid phases from each other by means of an enormously high centrifugal force. ~:71.20.250.51 (talk) 05:58, 18 February 2014 (UTC)[reply]

Parallel plate separators in effect strain oil droplets from water, and are much used in refinery wastewater systems for that very reason. FWiW 67.169.83.209 (talk) 06:03, 18 February 2014 (UTC)[reply]

See also: Centrifugal water–oil separator (however, these are not "strainers"). ~:71.20.250.51 (talk) 06:12, 18 February 2014 (UTC)[reply]

Osmosis is an example of true molecular sieving, though the way it is described sometimes hides this: the effects at this level (thermodynamically driven flows) that tend to obscure the underlying detail. Oil and water is a bad example, because they don't mix at the molecular level, but you can very effectively remove molecules from water by using a semi-permeable membrane (e.g. desalination through reverse osmosis). —Quondum 04:54, 19 February 2014 (UTC)[reply]

Liquid-liquid_extraction? DanielDemaret (talk) 21:38, 19 February 2014 (UTC)[reply]

By a finger

What's the approximate diameter of a typical ring finger of an adult man? of an adult woman? Thanks in advance! 67.169.83.209 (talk) 06:11, 18 February 2014 (UTC)[reply]

I doubt there is such a thing. This might help though - Ring_sizer. 196.214.78.114 (talk) 06:39, 18 February 2014 (UTC)[reply]

(Just to clarify what I said above: depending on where one took a sample to get a "typical" diameter, the results could vary greatly. I would expect a sample in Japan to be way different from one in the US.) 196.214.78.114 (talk) 06:47, 18 February 2014 (UTC)[reply]

Taken from http://www.bluenile.com/find-ring-size "Ring Sizes in the US. Women’s rings typically range from size 3 to 9. The most commonly purchased women’s ring sizes at Blue Nile range from size 5 to 7. Size 6 is the most popular ring size.

Men’s rings typically range from size 8 to 14. The most commonly purchased men’s ring sizes at Blue Nile range from size 8 to 10-½. Size 9 is the most popular ring size." 196.214.78.114 (talk) 07:07, 18 February 2014 (UTC)[reply]

Those are quite a bit bigger than I hoped for (my question actually had to do with whether it's possible, in principle, to cut an improvised wedding ring out of an empty cartridge case ;-) but thanks anyway! 67.169.83.209 (talk) 08:46, 18 February 2014 (UTC)[reply]

Well, a wedding ring doesn't have to be a complete circle. (this one or this one, for example) - and you could (with some degree of skill) cut a spiral out of the cartridge case and then twist the ends to increase the radius and wind up with something like this one. I think it can be done, with a little imagination. SteveBaker (talk) 13:34, 18 February 2014 (UTC)[reply]

Thanks! Yes, my character could cut two spirals out of the case and forge the ends of each one together to form a ring. (How come I hadn't thought of that?) 67.169.83.209 (talk) 06:30, 19 February 2014 (UTC)[reply]

I once knew someone whose wedding ring was knotwork; the rabbi(?) inspected it carefully to confirm that the knot consisted of a single endless strand. —Tamfang (talk) 20:15, 18 February 2014 (UTC)[reply]

A rabbi? Of what denomination? The construction of the ring matters very little in Orthodox Judaism (the material and the absence of a gem do, though), and other denominations are much less likely to care at all about the particulars of a ring... הסרפד (call me Hasirpad) 01:11, 19 February 2014 (UTC)[reply]

Natural convection article

Natural convection contains a "warning" that certain values are wrong. Can someone work out what needs to be done? There is a bit more info at Talk:Natural convection#The values indicated are wrong. Johnuniq (talk) 09:32, 18 February 2014 (UTC)[reply]

Do homeopathy, spiritual healing and other forms of quackery work after all?

See here, I watched the documentary yesterday. It seems to me that if the placebo effect has such a profound effect, then even a drug that would by itself (i.e. disregarding the placebo efffect) would make things mildly worse, could still have a net benefit. One can then ask if in the Middle Ages people really did benefit from bloodletting, even for treating anemia. Count Iblis (talk) 12:23, 18 February 2014 (UTC)[reply]

Clearly the placebo effect would result in some of those treatments producing a modest improvement for some people in some diseases. However, using that to suggest that these things actually "worked" is a bit contrary to modern usage of the word for drugs and other medical interventions. When drugs are tested that turn out to be no more effective than a placebo, we say that they don't work - and they won't get regulatory approval even though some patients might be improved by use of them.

Something like bloodletting for anemia would undoubtedly perform worse than placebo - so even less effective than a sugar pill, but whether it would be more or less effective than doing nothing depends a lot on the size of the placebo effect in anemia treatment. Certainly we could imagine that the mere sight of lost blood might possibly cause the body to kick some metabolic pathway to kick into high gear and thereby improve anemia - but it's far from clear that this would work. The placebo effect is a patchy thing - some aspects of treatment (notably, the treatment of pain) is extremely susceptible to the placebo effect - where as others show no placebo effect whatever.

SteveBaker (talk) 13:58, 18 February 2014 (UTC)[reply]

It is worth remembering that there is more than one kind of placebo – it's not always Treatment X versus Sugar Pill – and the nature of the placebo will very strongly influence its apparent potency. When people perceive a treatment as being more involved, that treatment will have a greater apparent effect. An intravenous injection of neutral saline will be a more potent placebo than a plain white sugar pill. (Even if you're just comparing pills, there are studies which have shown that the color of the sugar pill affects its perceived potency and effects. Simply being told that one sugar pill is more expensive than another can make it more effective; see our article on placebo for refs.) It's possible that moderate bloodletting, in many cases, would perform 'better' than sugar pills – particularly in an age before detailed clinical chemistry and robust quantitive measures of health – simply because it was a visibly more-aggressive intervention. TenOfAllTrades(talk) 21:19, 18 February 2014 (UTC)[reply]

Would you drink a homeopathic beer?Zzubnik (talk) 14:06, 18 February 2014 (UTC)[reply]

In medicine, the question usually asked is not "Does this work at all?" but more often "Does this work better or worse than our current best treatment?" On this test, these faux-medicine treatments don't tend to fare well. For specific info on evidence, whether for mainstream or faith-based medicine, I recommend http://sciencebasedmedicine.org - the bloggers there do a good job. Friday (talk) 14:09, 18 February 2014 (UTC)[reply]

Certainly it can be argued that putting homeopathic treatments on the shelves at WalMart and some pharmacies (yes, they really do that!) is beneficial because the placebo effect is real, the product packaging looks convincingly like a real drug - so some people will take the treatment and get somewhat better. There are many problems with doing that though.

These things are (typically) nothing more than tiny bottles of water or sugar or starch pills. The manufacturer is charging $7 to $20 for that. A much cheaper (and equally effective) placebo could easily be made without resorting to all of the bullshit that is attached to homeopathy. A pack of TicTac mints (which look convincingly like pills) costs about a dollar - so why pay $20 for pills that are infused with ground up duck liver diluted in water to the extent that there isn't one single molecule of duck liver left in each pill? It's all about packaging and labeling and being found in the pharmacy section instead of the candy aisle.
The problem that worries me the most is that some people will be persuaded to take the homeopathic placebo instead of taking a real drug. There are essentially no legal limits (in the US, at least) to what the manufacturers claim for these "treatments" - where "real" drugs have to be carefully labelled with what they do and all of their side-effects. Many people who don't have any clue what the word "HOMEOPATHIC" means on the bottle are going to be impressed that this stuff has no side-effects whatever (it's just water, after all) - and be taken in by all of it's claims of effectiveness - and avoid getting proper treatment as a consequence.
Once in a while, a homeopathic treatment (which has no intentionally active ingredients) has some unforseen side effect from it's supposedly inactive ingredients - as attested by the problems with Zycam - which was claimed to be homeopathic - but included some high concentrations of zinc compounds that caused a bunch of people to permanently lose their sense of smell. The lack of legally mandated testing on these products is a dangerous thing!

But the crucial thing here is that the claim that some medical treatment "works" should be taken to mean "works better than placebo" - because that's the standard to which all treatments are held. By that standard, these quack cures don't work at all.

The tricky part of the debate is the mechanism and the ethics of prescribing placebo in cases where mainstream medicine is either ineffective, or unnecessary. It could certainly be argued that if someone goes to a doctor for a mild, non-chronic headache - then it would be better to prescribe a harmless sugar pill than aspirin or tylanol because the sugar pill eliminates a bunch of risks from side-effects - and will probably help the headache reasonably well.

SteveBaker (talk) 14:42, 18 February 2014 (UTC)[reply]

You seem to believe that homeopathic placebos have no negative (=side) effects because "it's just water, after all". By that argument they wouldn't have positive effects either. Placebo side effects do exist; the wikipedia article is nocebo, but it doesn't seem to be very good. -- BenRG (talk) 23:11, 18 February 2014 (UTC)[reply]

It all depends what you mean by "work". Do certain forms of alternative medicine produce cures? Some may do - physiotherapy, Acuscope treatment for example. Do certain forms of alternative medicine make people feel better? Of course, otherwise people wouldn't use them. So in that sense they can be said to "work". But if all the evidence gathered is inadmissible because it arises from personal experiences and not research (which is expensive and tends to be paid for by drug companies anyway), then there will be no evidence that it works. Speaking personally, I believe that hands-on healing works because I personally have benefited from it. But my testimonial is of no use in the scientific world. --TammyMoet (talk) 15:05, 18 February 2014 (UTC)[reply]

For what it's worth, nearly any common treatment modality, mainstream or faith-based, has been tested in proper scientific studies, usually many many times. So, it's not that we _only_ have anecdotes to go on. Friday (talk) 15:10, 18 February 2014 (UTC)[reply]

I generally hold Tammy's view: there's a difference between believing I benefit from something and objective evidence that it benefits me. If every time I drink some Vitameatavegamin my headache goes away, it would be silly to stop drinking it just because it doesn't work better than placebo in double-blind trials. However (1) I don't have any objective reason for recommending it to someone else; (2) my experience doesn't advance medical knowledge at all; and (3) I'm out the money it took to buy it. In a world where people deceive others for profit, and deceive themselves and others to make sense out of their experiences we need these things to be regulated. OldTimeNESter (talk) 20:48, 18 February 2014 (UTC)[reply]

A portion of the placebo effect is measuring bias. If a doctor believes you've gotten a good treatment, he may be more optimistic when he records your condition. So, on paper it may seem as though you've improved more than you really have.

That aspect of the placebo effect sure doesn't help the patient. 75.69.10.209 (talk) 04:11, 20 February 2014 (UTC)[reply]

Wrong Science (Victorian)

I'm looking for examples of science "facts" from the Victorian era that were later proved wrong, or theories which were widely accepted but totally wrong in the end. Not pseudo-science, but things like the origin of the Sun's energy (which as I recall was believed to be the energy of gravitational collapse) which were widely accepted by educated scholars of the day. I am not sure if this is really a Humanities question, but I am trying here first. Tdjewell (talk) 14:18, 18 February 2014 (UTC)[reply]

Interesting question. You might want to take a look at Category:Obsolete scientific theories.--Shantavira|^{feed me} 14:25, 18 February 2014 (UTC)[reply]

That's awesome! Just the sort of thing I was looking for. Tdjewell (talk) 14:38, 18 February 2014 (UTC)[reply]

By Victorian times, science was starting to get fairly serious - so the number of utterly wrong "mainstream" theories are relatively few. Go back 100 years before that though - and there were some seriously screwed up ideas in the mainstream. SteveBaker (talk) 14:46, 18 February 2014 (UTC)[reply]

The Victorian era was ~60 years long, and saw quite massive changes in scientific understanding. I think the theory of luminiferous aether could be considered an archetype of widely believed (and reasonable) scientific theories nowadays regarded as refuted. The Michelson–Morley experiment seriously wounded it, and Einstein put the final nail into the coffin. --Stephan Schulz (talk) 15:14, 18 February 2014 (UTC)[reply]

A big one that didn't gain mass acceptance until relatively recently is plate tectonics. Some of the Victorian beliefs (which don't really have a concise name) are discussed at Timeline_of_the_development_of_tectonophysics. One bit that caught my eye was that the best estimate for age of the earth was 20-400 million years old in the 1860s, but by 1900 the estimates were in the ~3 billion year range. SemanticMantis (talk) 15:27, 18 February 2014 (UTC)[reply]

When I was in grade school, I recall that many scientists were still pooh-poohing the notion of Pangaea, even though to the casual observer it was obvious that the continents could fit together like puzzle pieces. Science, like religion, can sometimes let dogma get in the way of observable facts. The difference is that scientists usually come around. ←Baseball Bugs ^{What's up, Doc?} carrots→ 15:35, 18 February 2014 (UTC)[reply]

Lamarckism is the idea that acquired characteristics can be passed down, so that a shortnecked mammal who stretches upward to reach a branch might acquire a longer neck, and over generations its descendants might become giraffes. It was a popular theory in the early Victorian era. It had obvious appeal, in that if you worked hard and studied hard then your children would be strong and smart. Phrenology was popular in the early Victorian era: the theory that one could discern someone's mental faculties by feeling of bumps on the skull to determine the underlying brain structure. Until the germ theory of disease was proved by Pasteur, Koch and others in the second half of the 19th century, in the 1870's and 1880's, the Miasma theory was held by many doctors; that outbreaks of disease were caused by bad-smelling vapors blown from swamps or other foul places. It was also the judgement of leading scientists in the 1870's that arc lights were fine for streets or large public building, but the electric light could not be "subdivided" or made small enough to have one in each room of a house, since arc lights were inefficient in small sizes, and incandescent lights burned out too quickly. Then Edison and Swan developed practical incandescent lights by 1880. Edison (talk)

Caloric theory seems to have lasted well into the 19th century. There was also Phlogiston theory, but it appears that that was debunked in the 18th century (in fact Caloric theory partly displaced it). AndrewWTaylor (talk) 16:15, 18 February 2014 (UTC)[reply]

Phlogiston and phrenology are probably the most straightforward examples. A deeper example might be gradualism -- the idea that geological changes are entirely the result of gradual processes that played out over millions of years. Looie496 (talk) 16:18, 18 February 2014 (UTC)[reply]

Pellagra is a skin disease caused by a vitamin deficiency, and was common in the 19th century among populations who lived on corn (maize). Throughout the Victorian period and up until the early 20th century, scientists thought it was caused by a toxin in the corn or perhaps by germs, rather than by a deficiency of niacin. There was a very hard battle in the early 20th century to show that it was not a germ disease, with the medical establishment claiming the dietary experiments were "half-baked" and "fraud," so the incorrect germ or toxin theory of pellegra would have been well established in Victoria;'s lifetime. In Victoria's time, there was the notion that people had a certain "station in life" based on Social status such that a lower class family's child should not aspire to get a good education and enter a learned profession. Social stratification was thought of as heriditary. An attempt to "rise above one's station" was likely to result in failure. A more modern view is that there is a wide and overlapping distribution of intelligence among the offspring of the different social strata, although wealth does lend numerous advantages which work against meritocracy and Achieved status. Edison (talk) 16:23, 18 February 2014 (UTC)[reply]

Forgive me, but wasn't this a Star Trek TNG episode, Darmok and Jalad at Pellagra? μηδείς (talk) 05:05, 19 February 2014 (UTC)[reply]

A slightly more obscure example may be Prout's hypothesis, which held that all chemical elements were built out of hydrogen. It was almost correct, and was a perfectly logical conclusion built upon what was available data at the time. --Jayron32 16:52, 18 February 2014 (UTC)[reply]

(Aside point) How come Rutherford's model is in the category of obselete science? Is it because the idea doesn't really take into account wave particle duality? I didn't know it was considered obselete! 80.254.147.164 (talk) 17:23, 18 February 2014 (UTC)[reply]

Old scientific theories seldom truly die, they just get .. reinterpreted. Lamarckism becomes epigenetics, the heat of solar collapse is an important step in star formation, Prout's hypothesis becomes proton and neutron theory, luminous aether yields to spacetime. Of course, statements that things are impossible fare much more poorly. Wnt (talk) 19:28, 18 February 2014 (UTC)[reply]

Nonsense, Wnt. Lamarckism was discredited over a century before what is now called epigenetics was formulated. There was no such evolution, just the reuse of a word coined in 1942, the better part of a century after Darwin disproved Lamarck. μηδείς (talk) 22:10, 18 February 2014 (UTC)[reply]

It's definitely not that clear-cut. To begin with, Darwin himself expounded the concept of Gemmule (pangenesis) (which has some things in common with miRNA) which is a method of inheritance of acquired characteristics which is typically what people mean by Lamarckism. (Really, there wasn't much to Lamarckism per se, it was just some vagueish speculation, and you can definitely say Darwin improved it!) But the point is, things dismissed as Lamarckism, such as Lysenkoism (which was really Michurinism, as Lysenko himself called it) cited experiments which in the past decade have actually been confirmed to some degree. Michurin's philosophically inconvenient practice of graft hybridization did in fact produce valuable strains in his day. Of course, at the same time, one can say that Lamarckism was definitively defeated in that organisms aren't trying to enact some cosmic imperative to become more complicated - epigenetic mechanisms are still evolved mechanisms to deal with changing environments in the evolutionary short term (a few generations). Wnt (talk) 04:05, 19 February 2014 (UTC)[reply]

I suppose what I want is for you to be more clear as to the mechanism you are claiming, since DNA methylation, while "acquired" is an acquired state of DNA, just as mutations are acquired, not an acquired trait, and not in any way comparable to acquiring dark skin from one's parents' tan, or a long neck from one's parents' stretching theirs. μηδείς (talk) 05:00, 19 February 2014 (UTC)[reply]

What I suppose you're missing is that CpG dinucleotides are severely depleted in the human genome. They do not occur at the rate one would expect by chance, given the numbers of C's and G's. This is because methylcytosine converts to thymidine in a transition mutation. I think this still has not been explored enough, doubtless in part because it's a rare event that is not that easy to investigate. But the point is, CpG islands are important for gene activity, and the transition from CpG to mCpG occurs within the organism's lifetime in response to circulating factors that include hormones and small RNAs, which affect both the target organ and (potentially) germ lineages. These methylation events occur in association with a wide variety of histone modifications, and some of these events are heritable to the next generation. When the methylcytosine finally mutates, the result may be a permanent heritable reduction in a gene's activity. Potentially there may also be an increased rate of changes in function (if in coding sequence, for example) or localization of the gene. So the body sort of has a way to say "look, this gene isn't working out for me; I'm turning it down for now, but feel free to fiddle around with it". That's getting really close to the original concept of Lamarckism.

Now to be sure, giraffes are a lousy example, chosen to show Lamarckism can't explain everything. Obviously a giraffe can't stretch its neck period - the whole purpose of vertebrae (one purpose) is to accept compressive force as the muscles twiddle the neck this way and that. Now, if you wanted to look at the behavioral propensity of a giraffe to lift up its front legs for a moment, or the rate at which it repairs damaged collagen in its tendons, who knows, you might find something. But of course, as we know, proper Darwinian evolution does occur, and when selecting out an extreme from the preexisting variation it actually occurs pretty quickly, so there's no particular need to construct a story of giraffe evolution based on acquired inheritance. The two mechanisms both exist, and simple selection seems to be by far the most common in long-term directed change. (perhaps excluding Cope's rule? Also, socially important change between a few human generations may be another matter)

Lastly I should point out a phenotypic trait is a measurement - it can be the result of one gene, many genes, partly environmental, epigenetic, etc. Stature for example. A genetic trait is essentially a subset - an observation of a gene. Sometimes a gene is observed coarsely, by measuring something about the product protein (A, B, O blood type), sometimes more precisely (specific alleles of the blood type locus, some of which have weak activity that can lead to reactions against "same type" donors). It really isn't precise until it gets down to the single nucleotide polymorphism level. Traits like that say a lot about genes, inheritance, population biology, not so much about whether someone will get cancer. I'm not sure why you think I misused these terms. Wnt (talk) 20:35, 19 February 2014 (UTC)[reply]

More directly, the Rutherford model did not give any structure to the electron cloud, and thus was unable to explain large parts of the behaviour of atoms, from chemical bonding to spectral lines. Similarly, it did not recognise that the nucleus is made up of neutrons and protons. It's not strictly "wrong" (at least in general terms), but it's been superseded by the Bohr model, and then later more complex quantum mechanical models. It's obsolete in the same sense in which a Tin Lizzy is obsolete as a car, or HMS Victory is obsolete as a battleship. --Stephan Schulz (talk) 19:37, 18 February 2014 (UTC)[reply]

Medieval dome construction method

I saw a PBS TV show on the construction methods of the dome for the Florence Cathedral. They mentioned that it wouldn't have been practical to build a wooden frame beneath the dome, to hold it in place until completed, due to the volume it would need to fill. They then described how it was likely constructed without a frame.

But I had an idea for another way it could have been constructed (I'm not saying it was, just that it could have). Beneath the dome, on the floor, they could build a horizontal wheel. On that wheel they could construct a wooden arch form (not a dome), up to the height they wanted for the dome. They could then build a masonry arch above the wooden arch. This would become the first part of the dome. Once set, they would then lower the wooden arch form slightly (pull out some shims), rotate it, raise it back up, then build the next masonry arch above that. Repeat this process until the dome is completed.

So:

1) Is this method practical ?

2) Was this method ever used ?

3) Is there a name for this method ?

StuRat (talk) 21:04, 18 February 2014 (UTC)[reply]

My guesses for 1,2,3 are all "I don't think so". That dome is a cloister vault. Unlike the diagram at that article, the one in Florence has an octagonal cross section. So, your hypothetical arch form would have to change shape if you wanted to use it outside of the 4 special directions. Florence_Cathedral#Dome has a lot of detail, and mentions a whole system of chains that was used to reduce hoop stress in the absence of buttresses. My point is, the chain thing wouldn't really work if you tried to build one arch or "rib" of the cloister at a time. Also, it is not clear to me that the 8-radial-part "skeleton" dome would be structurally stable enough to hold together while you were spending decades filling in the gaps (let alone the first single arch!). Our article dome doesn't give much of the statics involved, but arch has some force diagrams. One "key" issue is that the whole assembly isn't really viable until the whole thing is complete, including the keystone. This is especially true in roman arches and spherical domes, but it still an issue in e.g. gothic arches and cloister vaults. SemanticMantis (talk) 21:38, 18 February 2014 (UTC)[reply]

I think you misunderstood me. I don't mean to use my method to create that particular style of dome, but rather a uniform dome, perhaps still made of bricks, thicker on the sides and thinner at the top. I just happened to be watching that show when I thought of it.

As far as it not being viable until complete, that's normally true of a dome or arch, yes. That's why I would wait until one section (arch) was set before moving on. That section should then stand on it's own. StuRat (talk) 23:49, 18 February 2014 (UTC)[reply]

Ok, let's focus on spherical domes. I still don't think it will very well for cathedral scales, but it would probably be fine for say, a domed garage or something. Here's an important point: a circular arch made of masonry is not very strong or stable. I mean here simple arch on its own, not embedded in a larger masonry structure. You can put a bigger circular arch into a thicker wall than a thinner one, and you can put a bigger arch into a thin wall than you can build on its own. There are all sorts of buckling/up/out forces that get directed into the mass of the wall. Consider that you can't even build a simple circular arch out of dry stone (with no wall around it). Even if all the stones are perfectly cut and fitted, their own weight will cause the arch to buckle and collapse (usually upward and outward at the ~10 and 2 o'clock directions is where the failure starts). You can build a circular arch with well-cut stone and mortar or some other adhesive at the joints. Many standard statics textbooks discuss this issue, but I don't have any specific recommendations. If your plan were to work at all, I think it would do best for a catenary dome. At least a catenary arch can support itself without side reinforcement, so you'd have a little more stability while you're filling in the other arches. But don't take my word for it. This stuff is tricky. Modern architects will use very rigorous physics engines and CAD programs to predict forces. Part of the genius of Filippo_Brunelleschi is that he was able to successfully do this stuff at all, without our modern understanding of force distribution via accurate predictive models. I guess I was a little unclear whether you were proposing this as a construction technique of the Renaissance, the modern day, or some other period. I guessed not modern, because we just don't build things like that anymore. Stone and labor are too expensive, and steel and glass and modern scaffolding can make any kind of dome you want. SemanticMantis (talk) 17:38, 19 February 2014 (UTC)[reply]

Interesting comment about the dry stone. It does make me wonder... if you had the right kind (shape) of fine sand, and a 3D printer like apparatus rigged to carefully select and deposit individual grains according to very precise measurement with computer controlled finesse ... could you make a dome out of only dry sand, so that when you tapped on it with your finger it would fall down and pour freely through an hourglass? Wnt (talk) 21:35, 19 February 2014 (UTC)[reply]

Yes, Brunelleschi apparently made a scale model beforehand, although that was a circular dome, not octagonal, but it did use the same herringbone brick pattern used on the final construction, which apparently is what allowed it to support it's own weight during construction. StuRat (talk) 18:35, 19 February 2014 (UTC)[reply]

Also, building a giant "turntable" that is almost perfectly level, moves freely, anchors well, and can support a significant portion of a cathedral's weight seems...challenging, to say the least :) SemanticMantis (talk) 21:42, 18 February 2014 (UTC)[reply]

One arch of the dome seems like a rather small portion of the total weight of the cathedral, to me. And, based on the arch shape, much of the weight should be supported by the sides, even during construction. The wooden form would just be for the excess weight, and perhaps also provide a work platform. StuRat (talk) 23:49, 18 February 2014 (UTC)[reply]

February 19

Can bats transfer "sound maps" to each other?

This applies to biology, specifically bat echolocation. I have not been able to find any info on whether bats can sing "sound maps" - collections of sounds from echolocation that come together to form one big image - to each other, like what happened in Silverwing[5]. It seems logical, since they are simply repeating what they heard from their clicks, although it may not be possible. Does anyone have any information on that? 173.50.125.12 (talk) 01:02, 19 February 2014 (UTC)[reply]

Since most of the preprocessing of sound into neural representation will no doubt occur at a very low level, it is unlikely that a bat will directly perceive all the details of a "sequence of clicks". A second challenge is the adaptation of the vocalization system to accurately repeat a waveform: it is not just sequence of clicks, but a complicated waveform consisting of millions of overlapping reflections of each click. You might be able to mimic someone singing, but imagine trying to accurately reproduce a soundscape of running water, wind and cackling geese using your voice. A further problem is that the crucial three-dimensional component (relative phase and amplitude to the two ears) would be impossible to reproduce with a single vocalization. I expect that bats would develop speech before they develop the ability to "project" an image in this way. —Quondum 04:42, 19 February 2014 (UTC)[reply]

Brilliantly said, Quondam. μηδείς (talk) 04:53, 19 February 2014 (UTC)[reply]

Thanks, though of course I have to admit that I've assumed that what was intended by the OP was that another bat would directly perceive the image. But then, a more manageable, slowed down representation (the few milliseconds of the collected reflection of a click stretched into say seconds or minutes, perhaps only incorporating simplified features of interest) would be more properly considered to be speech, ignoring all the other issues, wouldn't it? Actually, the relationship between echolocation and the vocalization of dolphins and other cetaceans used for communication would probably be an interesting area of study, even though my observations would still apply. —Quondum 05:17, 19 February 2014 (UTC)[reply]

Would there also be problem in positional referencing of a particular sound-scape. Even with voice-expressed locations a mid-air position could be difficult to describe. Richard Avery (talk) 11:08, 19 February 2014 (UTC)[reply]

This strikes me as somewhat analogous to seismic exploration and processing in the oil and gas industry where the objective is to generate a model of the subsurface using reflection seismology. Acquiring and processing the data is a lengthy, complicated and expensive process, both financially and in terms of computing resources. For a bat it's cheap and fast. The final products that represent the 3D model of the subsurface (including positioning information), are very many orders of magnitude smaller than the data recorded. They are described using standard formats so they can be transferred between parties. So, I guess, in principal, a bat could evolve the equivalent of a SEG Y standard to organize the post-processed model and sing that. It's probably the equivalent of someone reciting the first few tens of thousands of digits of Pi. Sean.hoyland - talk 11:36, 19 February 2014 (UTC)[reply]

Merlin Donald discusses in Origins of the Modern Mind and A Mind So Rare (at the same link) the uniqueness of the phonemes of speech in that we represent them to others in the same way we perceive them. This is a highly complex skill which we execute, even then, imperfectly, and which seems to have required some exaptations unique to our lineage. First we made and perceived hand gestures, then we adapted the same mechanism to make and understand a limited set of oral gestures, i.e., phonemes.

There are birds that exhibit mimicry, but in nature these are more displays like gorilla chest-pounding or peacock strutting than the communication of ideas. In nature these displays are not symbols that can be applied to conveigh arbitrary meanings (but see Alex the Parrot). Our own abilities are very limited. There are some very skilled voice artists short video like Michael Winslow. But most humans don't represent complex audio portraits, just one to a few dozen phonemes and clicks and raspberries and so forth. We can describe running water, wind, and cackling geese--but symbolically and conceptually, not by producing the sounds themselves.

Of note is the recent discovery that dolphins each have a unique personal signature call which they make to announce their presence, and which other dolphins reproduce in order to summon them. Dolphins are the only animals besides humans to have and use names. What else might they be doing behind our backs? μηδείς (talk) 17:29, 19 February 2014 (UTC)[reply]

It strikes me that this would be like trying to use a single speaker to recreate surround sound, but where instead of trying to imitate five or seven speakers (plus subwoofer), you'd have to recreate thousands. No one speaker, no matter how good, is going to give even our poor ears the feeling of being within an orchestra. You might be able to mimic Michael Jackson's singing voice, but you're just never going to be able to mimic him standing six feet to your left and a guitarist on your right. Matt Deres (talk) 17:47, 19 February 2014 (UTC)[reply]

Unifying general relativity and quantum mechanics

What is stopping us from unifying general relativity and quantum mechanics? Concepts of Physics (talk) 06:27, 19 February 2014 (UTC)[reply]

A lack of practical utility? The fact that the few physicists talented enough to address such theoretical physics problems are diverted towards more alluring technical and theoretical challenges? The immense reductive changes in the available funding and career opportunities in pure physics research? The closure and/or realignment of major physics research institutions in the United States? The inherent difficulty of the problem? Reptoid conspiracy to deny knowledge of interstellar travel to pure humanoids? What kind of answer are you looking for? Nimur (talk) 06:56, 19 February 2014 (UTC)[reply]

I have heard somewhere that there are two equations; one from GR (Einstein field equation) and the other from QM (I don't know the name of that equation). And physicists are trying to combine those two equations into a sigle equation to formulate a single unified theory. If I am right, then what is stopping us from combining those two equations? Is the discovery of graviton also essential to formulate a single unified theory? Concepts of Physics (talk) 07:20, 19 February 2014 (UTC)[reply]

GR is a classical physics theory. To make it compatible with QM it must be quanitized. There are precedents for this - for example, classical electromagnetism was successfully quantized in the twentieth century, resulting in the theory of quantum electrodynamics. This involved a process called renormalization. However, when physicists try to quantize GR in the most obvious and straightforward way, this process of renormalization fails. So physicists are investigating other approaches to creating a quantized version of GR, also known as quantum gravity. Two of these approaches are string theory and loop quantum gravity. Both approaches are, so far, almost entirely hypothetical, and the question of which approach is "better" or more likely to succeed is very controversial. Both approaches predict the existence of gravitons, although I think gravitons are more fundamental in string theory than in LQG. If gravitons (or, alternatively, gravitational waves) could be observed, an investigation of their properties might give support to either string theory or LQG - or might point us towards an entirely different theory of quantum gravity. Gandalf61 (talk) 09:26, 19 February 2014 (UTC)[reply]

The failure of the renormalization process is not that surprising from a purely physical point of view. While it is reasonable to expect that an effective theory that describes Nature at a level far away from the Planck length should be renormalizable (because the non-renormalizable terms should have flowed to zero when renormalizing the unknown theory of everything to the effective theory), there is no reason why an (approximate) theory that describes Nature at its fundamental scale should have this property. Count Iblis (talk) 11:45, 19 February 2014 (UTC)[reply]

Take some ownership, science does not belong to the privileged few, but belongs to everyone. Don't ask "What is stopping us from unifying general relativity and quantum mechanics?" -- what is stopping you? 91.120.14.30 (talk) 18:03, 19 February 2014 (UTC)[reply]

For 99.99% of the population, I would assume the answer includes a lack of knowledge equivalent to a post-graduate physics education. Even among people interested in physics, most will never choose to spend to the time required to reach the forefront of physics research. Dragons flight (talk) 19:52, 19 February 2014 (UTC)[reply]

...and for the other 0.01%, the answer includes a lack of knowledge of how to unify general relativity and quantum mechanics. --Bowlhover (talk) 21:26, 19 February 2014 (UTC)[reply]

I'm not a physicist, but even I know they have no shortage of theoretical models. The main shortage is a shortage of fundamental experiments that they don't know what answer to expect from. Come up with one of those, and you're bound to come up with some groundbreaking theory, whether it is describable as fusing these two or something else. The problem is, coming up with one of those generally seems to involve a request for some exceedingly large amount of money to make absurdly high energy things happen, or to look through an absurdly large telescope to some point absurdly long ago in the past. At least, it's absurd to some people.Wnt (talk) 22:01, 19 February 2014 (UTC)[reply]

Soft water

Where is soft water found?14.192.211.48 (talk) 12:51, 19 February 2014 (UTC)[reply]

https://simple.wikipedia.org/wiki/Soft_water Zzubnik (talk) 14:27, 19 February 2014 (UTC)[reply]

Soft water redirects to Water softening. Interestingly, Hard water#Regional information has information on where softer water can be found. http://water.usgs.gov/owq/hardness-alkalinity.html has maps for the US. http://dwi.defra.gov.uk/consumers/advice-leaflets/hardness_map.pdf map for england and wales. http://www.doeni.gov.uk/niea/water-home/drinking_water/consumer/water_hardness.htm for northern Ireland. In Malaysia (where the IP originates from) try http://kmam.moh.gov.my/ for standards, but it looks like the government hasn't produced any surveys yet. You could try http://scholar.google.com/scholar?q=water+quality+Malaysia for scholarly articles if you are up to it. Richard-of-Earth (talk) 17:30, 19 February 2014 (UTC)[reply]

Papering window with alfoil for heat reflection - inside or outside?

I've moved back in with my Dad for a few months and I'm in the spare room which nobody has lived in before and I'm in Australia in summer and the window faces east and I'm a night owl. The Venetians are useless and by 7.00am the room is about 35 degrees Celcius (there are no trees or anything outside, it's just direct sunlight). Dad found me duct taping newspaper against the window and suggested I use aluminium foil instead. Now, one of the panes is covered by flywire which the duct tape won't stick to, so I put it on the inside of the window instead of the outside. My question is, does that affect how much heat/light it's reflecting? Because I sort of feel like the heat is entering the glass before it hits the alfoil and even though a lot of it probably gets bounced straight back out, there may be at least some element of greenhouse effect going on. 58.161.162.150 (talk) 14:28, 19 February 2014 (UTC)[reply]

It does make sense to put the foil outside, since glass does not transmit energy perfectly, and in particular, probably absorbs (depending on the type of glass) a substantial amount of the energy in the infrared portion of the spectrum. The infrared portion probably accounts for around half the energy in sunlight. The effect of this is to heat the glass, which then warms the air inside and outside through conduction, and the foil would do little to stop that. With the foil on the outside, a large percentage of the energy at all wavelengths would be reflected without heating anything. If you further have flywire between the glass and the foil that would be on the inside, which probably absorbs quite a lot of the energy going through it, this would increase the interior heating, but it is not clear from what you said whether this was how you had it. You could try foil under external flywire if you can get it there; I expect which side of the flywire it is will have little effect. You might even want to smooth the foil to the glass on the outside with some liquid to that it is less susceptible to wind etc., preferably something very dilute and soluble that would dry eventually acting as a weak gum, but would allow later removal through gentle scraping/washing – maybe dilute dishwash liquid? —Quondum 15:16, 19 February 2014 (UTC)[reply]

The aluminum foil might do some good, but I suggest inserting a Styrofoam sheet (cut to the proper dimensions) into the window frame, on the inside, then taping up the gaps along the side and bottom (I'd leave the top untaped, as you need to allow air pressure to equalize during heating and cooling cycles). I've found this makes a major difference. You could also line that whole wall with Styrofoam.

I also have a powerful fan pointed at my sleeping position, with a remote dimmer switch in the bed with me, so I can adjust the fan setting from bed.

Also, if you can set up a sprinkler on a timer to splash water on the outside of that wall, that will make quite a difference too. StuRat (talk) 03:09, 20 February 2014 (UTC)[reply]

Arrhenius and van't Hoff equations

The Arrhenius equation, describing the rate constant, is k=Ae^(-Ea/RT). The van't Hoff equation, describing the equilibrium constant, is K=e^(-deltaG/RT). However, activation energy Ea is also the deltaG between reactants and the activated complex. This leads to my question of whether the two equations are actually related beyond the fact, as the Wikipedia article notes, that Arrhenius based his equation off of van't Hoff's? This seems to suggest to me that the equilibrium constant between reactants and the activated complex is equal to the rate of the overall reaction divided by A? Bramble claw x 15:31, 19 February 2014 (UTC)[reply]

I'm not sure that either scientist used their work as the basis for the other, but yes, you are essentially correct; insofar as the entire set of equilibrium and thermodynamics equations is internally consistent; that is they are all basically different mathematical ways to get at the same physical phenomenon. Remember that the equilibrium constant is the ratio of the forward and reverse rate constants, while the Arrhenius equation is only looking at the forward rate constant. It's fairly simple math to show that since deltaG-forward and deltaG-reverse are the same magnitude and opposite signs, that the forward reaction to the activated complex and the reverse reaction to the same complex should be related, basically the difference between Ea-forward and Ea-reverse should be exactly equal in magnitude to deltaG. Something like:

Ea_forward - Ea_reverse = ΔG_forward

and

k_forward ÷ k_reverse = K

With these two relations, you should be able to substitute into either of the Van't Hoff or Arrhenius equation and get the other. I'm really to tired right now to check my math, but from a logic point of view, it makes fine sense. Sketch a reaction coordinate graph and it's easy enough to prove graphically. --Jayron32 03:04, 20 February 2014 (UTC)[reply]

Humidity weather warning for UK

Is there some service that I can use to alert my mother when outside humidity is low so she can open windows in her house? She has a dehumidifier but I imagine that swapping the air out entirely would be very effective when the conditions are right. Can humidity be accurately forecast? Forecasts would be ideal but notifications with no warning would also be useful. ----Seans Potato Business 20:40, 19 February 2014 (UTC)[reply]

Just buy her one of these. --TammyMoet (talk) 18:45, 19 February 2014 (UTC)[reply]

I have one of these; it shows both indoor and outdoor humidity (also "predicts" weather changes, etc. ) -- When it's nicer outside than inside, I open windows.

(Additional sensor required for outdoor humidity: [6]) ~:71.20.250.51 (talk) 19:17, 19 February 2014 (UTC)[reply]

P.s.: there is a cheaper version. 71.20.250.51 (talk) 19:35, 19 February 2014 (UTC)[reply]

Or, even cheaper (actually, **FREE**!): Use a pine-cone...the branches of the cone open out when it's dry and close up tight when it's humid. These aren't a great way to measure the absolute humidity - but all you care about is whether it's more humid indoors than out. So stick one outside the window and one inside and you'll know whether it's significantly less humid outdoors than in. (SteveBaker) 99.96.179.150 (talk) 19:56, 19 February 2014 (UTC)[reply]

I should have bought this one, (includes additional humidity/temp sensor), cheaper and better than my set-up. :( 71.20.250.51 (talk) 20:32, 19 February 2014 (UTC)[reply]

I've read that those hygrometers are very inaccurate. The UK government meteorological office has an automated weather station at Hawarden Airport (closest station to where my mother lives). I imagine that their instruments are far better than that cheap tat. I've found this webpage which gives me the humidity reported. I don't know how they get that information (I failed to find it on the met office website).

I've found the dew point forecast to be more useful for telling me when to open the windows than the humidity, as the dew point tells you when the temperature/humidity combo is good. (If you just rely on humidity, you would mistakenly open the windows when the humidity is low but the temp is hot.) I find a dew point below 59°F (15°C) to be comfortable. StuRat (talk) 03:03, 20 February 2014 (UTC)[reply]

Chemistry book series

Are there any "all the basics" book series on chemistry like there are on physics? Something like Landau's course on theoretical physics or the Feynman lectures. I'm not looking for anything in particular, just something to gawk at in idle time. I realize that in their very fundamentals physics and chemistry are the same. --81.175.238.65 (talk) 18:29, 19 February 2014 (UTC)[reply]

EM energy in Fourier representation

In Quantization of the electromagnetic field it is reported that, taking Fourier coefficients, the quantized fields are:

${\begin{aligned}\mathbf {A} (\mathbf {r} )&=\sum _{\mathbf {k} ,\mu }{\sqrt {\frac {\hbar }{2\omega V\epsilon _{0}}}}\left(\mathbf {e} ^{(\mu )}a^{(\mu )}(\mathbf {k} )e^{i\mathbf {k} \cdot \mathbf {r} }+{\bar {\mathbf {e} }}^{(\mu )}{a^{\dagger }}^{(\mu )}(\mathbf {k} )e^{-i\mathbf {k} \cdot \mathbf {r} }\right)\\\mathbf {E} (\mathbf {r} )&=i\sum _{\mathbf {k} ,\mu }{\sqrt {\frac {\hbar \omega }{2V\epsilon _{0}}}}\left(\mathbf {e} ^{(\mu )}a^{(\mu )}(\mathbf {k} )e^{i\mathbf {k} \cdot \mathbf {r} }-{\bar {\mathbf {e} }}^{(\mu )}{a^{\dagger }}^{(\mu )}(\mathbf {k} )e^{-i\mathbf {k} \cdot \mathbf {r} }\right)\\\mathbf {B} (\mathbf {r} )&=i\sum _{\mathbf {k} ,\mu }{\sqrt {\frac {\hbar }{2\omega V\epsilon _{0}}}}\left((\mathbf {k} \times \mathbf {e} ^{(\mu )})a^{(\mu )}(\mathbf {k} )e^{i\mathbf {k} \cdot \mathbf {r} }-(\mathbf {k} \times {\bar {\mathbf {e} }}^{(\mu )}){a^{\dagger }}^{(\mu )}(\mathbf {k} )e^{-i\mathbf {k} \cdot \mathbf {r} }\right),\\\end{aligned}}$

Than the energy is reported as (taking the square of the fields):

$H={\frac {1}{2}}\epsilon _{0}\iiint _{V}\left(E(\mathbf {r} ,t)^{2}+c^{2}B(\mathbf {r} ,t)^{2}\right)\mathrm {d} ^{3}\mathbf {r} =V\epsilon _{0}\sum _{\mathbf {k} }\sum _{\mu =1,-1}\omega ^{2}{\big (}{\bar {a}}_{\mathbf {k} }^{(\mu )}(t)a_{\mathbf {k} }^{(\mu )}(t)+a_{\mathbf {k} }^{(\mu )}(t){\bar {a}}_{\mathbf {k} }^{(\mu )}(t){\big )}.$

However, when integrating over the volume for finding the energy, I find terms like $a_{\mathbf {k} }^{(\mu )}a_{-\mathbf {k} }^{(\mu )}$ as well, since the integral of $e^{i\mathbf {k} \cdot \mathbf {r} }e^{i\mathbf {-k} \cdot \mathbf {r} }$ does not vanish in the integral. What am I doing wrong? — Preceding unsigned comment added by 87.1.53.150 (talk) 19:11, 19 February 2014 (UTC)[reply]

Don't you get those terms twice, once from E^2 (with positive sign) and once from B^2 (with negative sign) so that they subtract out to zero? --Amble (talk) 19:22, 19 February 2014 (UTC)[reply]

I found the answer! In order for

\mathbf {A}

to be real it should be

{\overline {a(\mathbf {k} )^{(\mu )}}}=a_{(}-\mathbf {k} )^{(\mu )}

. See this. --87.1.53.150 (talk) 22:52, 19 February 2014 (UTC)[reply]

Spiritual practices as alternative medicine

I know that TaiChi and QiGong and Yoga are used as alternative medicine to Western medicine, and I am familiar with TaiChi and QiGong as taking concepts from Daoism, an integral belief system in traditional Chinese culture. I am just wondering if Western spiritual practices, like praying the rosary, would also be considered alternative medicine. The Catholic rosary, in particular, seems to have a very strict structure, where the person in meditation has to recite 10 Hail Marys in each decade while thinking about other stuff. Can a non-Catholic pray the Catholic rosary as meditation, or would that be considered too sacrilegious? 140.254.227.25 (talk) 21:14, 19 February 2014 (UTC)[reply]

It would not be considered sacrilegious. It might be encouraged by some. It might seem puzzling by some if the one praying does not believe in what he/she is praying, but I can not see that any catholic would object. DanielDemaret (talk) 21:29, 19 February 2014 (UTC) I base this personal opinion on two tenets of the Catholic Church. 1) Catholic means approximately "universal": It is open for everyone and one does not need to believe in anything to go to heaven. 2) A basic tenet of the catholic church is that one believes in what one says. So if one were to say the words of a rosary, then I imagine it is assumed that one believes in it while one says it, at least. DanielDemaret (talk) 21:53, 19 February 2014 (UTC)[reply]

The religious aspects are more or less a Humanities question and might get a better answer there. Briefly though, many Protestants hold strictly to a position that the dead, even saints, stay dead until a future resurrection, and so accounts of ghosts, spirits, or even praying to Mary would be seen as superstition, or perhaps historically as some evil deception along the lines of the doppelganger (a demonic apparition which demonstrates its falseness by turning up before the person is dead; or aside from that, see Hamlet). However, from a purely scientific point of view, they might make an interesting control in a neurotheology experiment, because they can say the same things with the same cadence and sentiment but without "true" belief. But I think it's worth considering whether qi, like "health", is a general term without a specific meaning. You could look through every tube, jar, refrigerator and freezer at the National Institutes of Health and not find a single specimen of "health" at any degree of purity. They believe in health ... but it's not really the same as believing in God, or even Mary. It's hard to compare philosophical things... Wnt (talk) 21:54, 19 February 2014 (UTC)[reply]

The difference between Tai Chi/Yoga and prayer is that both Tai Chi and Yoga involve some physical movements that help the physical body in some way, whereas prayer (whether chanting the rosary or just hands together and meditation) does not. Some of the yoga exercises I am familiar with were prescribed to me by a physiotherapist as part of therapy for a slipped disc, for example. However, the complementary therapy known as Reiki is actually a spiritual practice, where healing is a (welcome) by-product of spiritual practice. Make of that what you will. --TammyMoet (talk) 12:46, 20 February 2014 (UTC)[reply]

February 20

Bordeaux colour - looks different in different states?

Hi there, I found that the Bordeaux colour looks in different language versions of Wikipedia (fr, de, ru) different - and it is not just my feeling, because even the RGB (red, green, blue) values of each of them is different:

fr - (128, 0, 0)

de - (128, 0, 50)

ru - (176, 0, 0).

See for example the German page: https://de.wikipedia.org/wiki/Bordeauxrot, where is a small discussion about it already (https://de.wikipedia.org/wiki/Diskussion:Bordeauxrot).

Questions:

1) Is it really so - does Bordeaux look different in each of the states? And if so, isn't it weird? :) (I would expect there could be a consensus at such a cultural issue, especially with respect to the fact that it probably is younger than many other colours, which, maybe, in spite of it don't vary according to the state....

2) Why there's no article about this colour in the English version?

3) What would be the RGB values in English Wikipedia, if there is such a colour in English?

4) Who determinates this values for each / for the mentioned states?

Thank you very much! --Jiří Janíček (talk) 00:03, 20 February 2014 (UTC)[reply]

I removed the extra ":" from the 1) paragraph - they are needed after "hard" line breaks only.

Colors with names like "Bordeaux" are fairly vague. You can't expect an exact RGB value - so it doesn't surprise me that there are different values out there. There might also be a cultural difference - but I don't think you can infer that from the RGB values that have been arbitrarily chosen for Wikipedia articles. Worse still, the perception of that color will depend on the brightness of your display, the amount of ambient room lighting when you look at the screen and so forth.

The question of who determines the RGB values for such colors is also tricky because there are a dozen paint and dye manufacturers who name their colors and thereby try to pin a name onto a particular color.

The most widely accepted sets of colors are those produced by the Pantone company. The names and numbers they choose and the precise colors associated with them are widely accepted around the world - so everyone agrees what EXACT color "Pantone Bordeaux" is - in paint, dye, print and on-screen. If you buy a Pantone-bordeaux paint from one company and a pantone bordeaux cloth from another, you can be reasonably assured of a fairly close match.

"Bordeaux" is Pantone color "PMS 221" which has an "official" RGB value of (147,0,66) - so I suppose, on that measure, the German Wikipedia is closest. But it's far from true to say that the pantone definition is something that we should use as a standard on Wikipedia for a color that's best described as a dark purplish red. There is a wide range of RGB values that most people would describe as "Bordeaux Red"...after all, they are merely referring to the typical color of red wine from the Bordeaux region of France - and I'm quite certain that it's not all the exact same color!

SteveBaker (talk) 02:48, 20 February 2014 (UTC)[reply]

It's mostly a way to avoid names like "dark red", or even "red."

Copyright. These simple names cannot be copyrighted, but neologisms can, just like sufficiently advanced combinations.
Not the same as old "red": There are no more "red" cars not only because of the copyright issues, but also because they used to have "red" paint which was a different tone than today's red-by-a-different-name.
Sophistication means awesomeness: If you can pick among dozens of red tones, would you pick the one that's merely called "red"? Imagine the conversation:

"Nice paint job, what is that tone of red called?" – "It's 'red' ."

Marketing issues. "Bordeaux" beats "PMS221". Even more so since no reddish color gets along with "PMS" too well... - ¡Ouch! (^{hurt me} / _{more pain}) 12:23, 20 February 2014 (UTC)[reply]

This is Pantone Bordeaux. μηδείς (talk) 05:26, 20 February 2014 (UTC)[reply]

As always Wikipedia has an article about this, see Linguistic relativity and the color naming debate. Dmcq (talk) 15:08, 20 February 2014 (UTC)[reply]

psychrometric

I am a chemical engineer,I felt a little bit unsure of the psychrometric chart which can be directed to by the following link http://en.wikipedia.org/wiki/File:PsychrometricChart.SeaLevel.SI.svg when browsing it.my understanding is that the wet bulb temperature curve should be coinciding with dry bulb temperature curve when the air is saturated with water meaning 100% relative humidity,but the chart shows the contrary,i am thankful if any of you can get this clarified. — Preceding unsigned comment added by Landwonder (talk • contribs) 01:14, 20 February 2014 (UTC)[reply]

The chart does show them matching at 100% relative humidity. The angled light blue and vertical green lines meet at the top red curve, which is the 100% relative humidity curve. It is a confusing chart, though, so I can see how you might have misread it. StuRat (talk) 01:41, 20 February 2014 (UTC)[reply]

medicine (how do you classify morphine? )

how do you classify morphine? — Preceding unsigned comment added by 49.147.190.51 (talk) 05:03, 20 February 2014 (UTC)[reply]

I am all for it. μηδείς (talk) 05:17, 20 February 2014 (UTC)[reply]

As an opiate, a narcotic, a controlled substance, etc. ←Baseball Bugs ^{What's up, Doc?} carrots→ 06:37, 20 February 2014 (UTC)[reply]

Medically, it is an analgesic - a painkiller. AndyTheGrump (talk) 15:13, 20 February 2014 (UTC)[reply]

Solar System to scale

Does there exist a picture of the Solar System that has the sizes of the planets (+ Sun) to scale and the distances to scale in the same picture? I have just managed to find a picture with either of those. I know it's a bit silly, but it's doable. Th4n3r (talk) 10:28, 20 February 2014 (UTC)[reply]

A few years ago, I created a 3D model of the universe to scale. When the whole solar system was viewed at one time, the individual planets were less than a pixel in size on the screen. It was a little disappointing! To make it usable I had to scale all the objects up considerably.217.158.236.14 (talk) 10:57, 20 February 2014 (UTC)[reply]

This website shows what you are after - it's not in an image but I'm sure you could convert it somehow. I'm not sure the sizes of the smaller planets will be totally precise - since they are 1 pixel in diameter and the sun is 650 pixels - this isn't becasue this is the difference in scale, just that your monitor can only display as small as 1 pixel. 80.254.147.164 (talk) 12:04, 20 February 2014 (UTC)[reply]

A picture? To scale? You are joking right? Either it is a BIG picture or it is not to scale. There is no way you can have the planets and the sun in a picture to scale. 202.177.218.59 (talk) 14:09, 20 February 2014 (UTC)[reply]

I agree that it's not normally useful to show the solar system to scale, for the reasons listed above. However, this does rather give everyone the impression that the planets are a lot bigger and closer together, relative to the size of the solar system, than they are. A scale model set over a very larger area, like a science museum, might work and help to undo this impression. Of course, you would need large signs to direct you towards each planet's dot, which could perhaps have a magnifying glass or microscope with it so you can see it. StuRat (talk) 15:26, 20 February 2014 (UTC)[reply]

Sweden Solar System is not exactly a picture, but it is to scale. --ColinFine (talk) 15:23, 20 February 2014 (UTC)[reply]

Also not quite a picture, but in Ithaca, NY there is the Sagan Planet Walk which has all planetary bodies and their distances at a 5 million to 1 scale. This should give you an idea of just how massive a perfectly to scale picture would have to be. 8.17.117.40 (talk) 15:35, 20 February 2014 (UTC)[reply]

Biology or sociology

Women feel guilty after having sex (or a least casual sex [7] [8]) Is the reason for that biological or sociological? Sources don't agree so I suposse there is no scientific consensus, am I right?--80.28.202.253 (talk) 10:51, 20 February 2014 (UTC)[reply]

Some women might feel guilty after some types of sex. The reasons are partly sociological, in that they feel they violated a religious or moral code, such as fornication (sex outside of marriage), adultery, or incest. Of those, incest has perhaps the strongest biological reason to be avoided (inbreeding). Fornication and adultery can also spread venereal diseases, so there is some biological reason to avoid those, but the biological advantage of breeding with multiple partners (genetic diversity) may outweigh those. StuRat (talk) 15:18, 20 February 2014 (UTC)[reply]