Wikipedia:Reference desk/Archives/Science/2010 January 9

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January 9

Instruments to track plate motions

Is GPS and satellites the only tool they use to track plate motions. I though GPS only does things perfectly accurate if the signal connection is good, to see things this far in blue ocean which things looks almost black, GPS will do more of a sketchy job. Do satellites do a perfect or a lusy job in low signal light block place? Is the tracking of plate motionperfectly accurates. Because all books I have all cites things differently.--69.226.34.161 (talk) 00:11, 9 January 2010 (UTC)

Nothing is perfect. Are you asking about Plate tectonics?

Also, GPS satellites work well both in the light and the dark, but they don't do well if the receiver is covered by a forest canopy. --Jc3s5h (talk) 00:17, 9 January 2010 (UTC)

I think that the OP is asking about tracking oceanic plates, where a sensor would be miles underwater (in the dark bit of the ocean). Indeed, GPS doesn't work down there. I'm sure geologists place markers on the seabed, but as there isn't a general deep-water positioning system, they'll have to revisit those with a surveying ship periodically and determine their position individually (with reference to the ship, and from there they can express that position in a general system like the GPS datum). -- Finlay McWalter • Talk 00:24, 9 January 2010 (UTC)

Ummm, if you want to know how an oceanic plate is moving, then you just track the islands. Dragons flight (talk) 04:05, 9 January 2010 (UTC)

Also the rate and direction of spreading at mid ocean ridges can be derived by using the magnetic reversal records contained within the ocean floor, which gives a pretty good idea of how the plates on either side have been moving over time. Continents are actually the hard ones, in some ways. Eve Hall (talk) 15:31, 9 January 2010 (UTC)

At a first approximation, tectonic plates are perfectly rigid, islands fixedly attached to them, and plates move only normally to the geoid. But if we're doing real science we can't rely on those assumptions, and need to actually measure the intraplate flexion (which this paper puts at up to 2mm/yr). The utility of island measurements is confounded also by the clustering of islands along the margins of oceanic plates, the least representative and least stable locus on the plate. -- Finlay McWalter • Talk 15:59, 9 January 2010 (UTC)

Talking about placing a yellow ball point object into the ocean. Then they have to use something so they will memorize where the ball point object was and years later they have to know where the object is traveling. This might be the best way to do a experiment, but I wonder if they can they can cause error bars.--69.226.34.161 (talk) 00:42, 9 January 2010 (UTC)

Laser ranging can also be used to identify precise locations. Graeme Bartlett (talk) 04:50, 9 January 2010 (UTC)

Also, when scientists measured the average ocean surface height after smoothing for waves and inter-annual changes, they found that sea levels were lower in places that were above oceanic trenches. Other movements such as isostatic rebound from climatic changes (even [[global warming) as well as large earthquakes, oceanic landslides and volcanic eruptions may have slight effects on the movement of crustal plates. ~AH1^(TCU) 18:31, 9 January 2010 (UTC)

Very Long Baseline Interferometry is often used track global tectonic plate motions. this has a little more information than the article. Noodle snacks (talk) 08:23, 10 January 2010 (UTC)

putting Pluto back to planet status

Some rumors when I surf on internet said about putting Pluto back to being a planet. Have they plan to put Eris into being a 10th planet, since Eris is a bit bigger than Pluto What about Makemake will they ever qualify it as a planet?--69.226.34.161 (talk) 00:37, 9 January 2010 (UTC)

Planet status is arbitrary nonsense. Don't let they determine it for you if you disagree. Personally, I don't even consider Jupiter a planet. I find its immense size, strength of pull, and unavoidable presence more aptly described by the term mother-in-law. 61.189.63.173 (talk) 00:52, 9 January 2010 (UTC)

The IAU didn't get around to formally defining "planet" until 2006; see IAU definition of planet. Dwarf planet#Current members lists the five objects in our solar system currently considered to be "dwarf planets", including Pluto, Eris, and Makemake. Comet Tuttle (talk) 00:57, 9 January 2010 (UTC)

And the most likely time for them to reverse the 2006 decision would have been at the next general assembly in 2009, and the issue doesn't even appear on the agenda [1]. I don't think the IAU is going to change their minds about Pluto. --Tango (talk) 01:01, 9 January 2010 (UTC)

The thing to keep in mind is that the word planet does not belong to the IAU. Pluto is not an IAU planet. It's still a planet simpliciter. --Trovatore (talk) 01:04, 9 January 2010 (UTC)

Right, the IAU only regulated the technical usage of the terminology. As with any use of technical words, a term can have different meanings between being used technically and just colloquially (for example, bug). —Akrabbim^talk 01:13, 9 January 2010 (UTC)

You can still call it a planet in a technical sense, just not the IAU sense. They have no authority to regulate technical usage in general. --Trovatore (talk) 01:16, 9 January 2010 (UTC)

It is worth noting though that the major scientific and astronomical journals all require that IAU nomenclature be followed. So, you can do what you want in private (or even in public) but it would be virtually impossible to call Pluto a planet within the peer-reviewed scientific literature. Dragons flight (talk) 01:32, 9 January 2010 (UTC)

"The Sun orbiting object formerly known as ?" Would that pass? --220.101.28.25 (talk) 06:25, 9 January 2010 (UTC)

Besides that, the IAU does have the authority in so much as while people are free to do what they want, most people and most sources choose to follow them, i.e. they have de facto authority, whether Trovatore likes it or not. This of course follows many other areas of science, again whether Trovatore likes it or not. For example Trovatore is free to call element 105 hahnium if he so desires, it doesn't change the fact that most people have chosen to accept the IUPAC name despite the Transfermium Wars and call it dubnium of course. Similarly, Trovatore is free to call Callicebus aureipalatii as Callicebus madidii or if he wants to be controversial Callicebus wallacii (not sure if this would be the correct way to name it after Robert Wallace) or heck Callicebus robertwallaceisanidiot or Callicebus trovatoreissocool, but again it doesn't change the fact most people accept the International Commission on Zoological Nomenclature naming conventions which allow discoverer to choose the scienctific name within reason and following certain conventions which doesn't currently perclude them naming it after someone who won an auction and in this particular case, I doubt anyone would even know what the heck he is referring to. Nil Einne (talk) 06:38, 9 January 2010 (UTC)

In mathematics we get along just fine without any central authority deciding nomenclature. Other sciences should do the same thing. --Trovatore (talk) 06:43, 9 January 2010 (UTC)

Mathematicians also don't run around giving a unique and unintuitive name to every bug and space rock they see. The existence of recognized authorities for resolving naming disputes is highly beneficial to fostering clear communication in the stamp-collecting sciences. Dragons flight (talk) 09:15, 9 January 2010 (UTC)

In maths, we rarely refer to things solely by name unless they have been around long enough that everyone knows what you mean. You wouldn't just refer to a fairly new theorem by name, you would state the result in full. That is more practical in maths than in astronomy or biology (although it's far more practical in chemistry - every element already has a unique identifier, its atomic number). --Tango (talk) 16:37, 9 January 2010 (UTC)

Trovatore, I'm at a loss here trying to understand what's the point you are trying to make. You certainly don't mean to say that a math journal would accept a paper where someone tries to rename someone else's theorem to their own liking. The referees wouldn't accept that would they? Dauto (talk) 17:33, 9 January 2010 (UTC)

I don't know the details of the process, but I doubt the referees would care what the author calls the theorem. It's just a name, it doesn't make any difference to the maths. --Tango (talk) 17:34, 9 January 2010 (UTC)

I'm sure the referee's wouldn't let somebody rename a famous theorem. would they accept if somebody called fermat's last theorem by any other name? Dauto (talk) 19:35, 9 January 2010 (UTC)

Why not? Their job is to make sure the maths is valid, nothing else. With your example, I can certainly imagine people calling it Wiles' Theorem. Plagiarism obviously isn't allowed, but you credit people by referencing their work, not by naming theorems after them (see List of misnamed theorems). --Tango (talk) 19:47, 9 January 2010 (UTC)

The current definition for a dwarf planet is also very arbitrary, and should probably include far more than five members. Why doesn't it include the whole list, for example including Pluto, Eris, Quaoar, Ixion, Sedna, Orcus, Makemake, Haumea, Ceres, Vesta, Pallas, Juno, and even Chiron, not to mention the countless undiscovered planetoids, plutoids, plutinos, Trans-Neptunian objects, Cis-Neptunian objects, Kuiper belt objects (KBOs), detached objects and large, spherical members of the Inner and Outer Oort cloud? When you get to a small enough size, the definition of a dwarf planet tends to overlap with those of traditional asteroids and comets, or when you get far enough from the Sun the objects are too faraway to observe and may even fly off to the gravitational fields of other nearby stars and have too eccentric an orbit to be considered a planet. ~AH1^(TCU) 18:20, 9 January 2010 (UTC)

The definition of a dwarf planet includes the requirement that is be roughly spherical ("in hydrostatic equilibrium"). It is very difficult to know the shape of a distant object. If it is big enough we can be pretty sure it will be spherical, but for smaller objects it is hard to tell. That is why there are so many objects that might be dwarf planets but haven't been official designated as such. That could be considered a flaw in the definition, I suppose... --Tango (talk) 19:00, 9 January 2010 (UTC)

As with most words used in the sciences - we have different meanings from colloquial English. People talk about spiders as insects - and lots of people[2][3] don't think that birds and fish are animals. Almost everyone thinks that mushrooms are plants. People say that a car stops accelerating when you put on the brakes. You cannot regulate colloquial English - it changes over time - "Gay" used to mean "Happy" - it was once impossible for someone to be simultaneously "Cool" and "Hot" - but now, that's actually very possible. However, science needs precise, long-lived definitions for words. If you are writing a learned scientific paper about the genetics of plants - you absolutely don't want anyone assuming that you were including mushrooms in your work. So if you are speaking formally and in a scientific context then spiders aren't insects, birds are animals, mushrooms aren't plants and your car does indeed accelerate when you push on the brakes. Similarly, Pluto isn't a planet. However, a word is just a word. It doesn't mean that Pluto changed in any way - it just means that we took a vague, fuzzy term and made it more definite - and having done that, scientists started calling Pluto something different. Since we need exacting language, it is entirely appropriate that the leading body of some branch of science should issue a firm statement of what a word means in the context of their branch of science. However, in colloquial English, we can call it whatever we want. I bet that when NASA does it's next Pluto fly-by, you'll hear people there saying things like "We'll take a photo of such-and-such as we go behind the planet." - because in an informal context, that kind of sloppyiness is perfectly OK. But when you publish a formal scientific paper - expect the editors and peer-reviewers to complain like hell if you call Pluto a planet in that context. If you dug your heels in and INSISTED that that wording of your paper were not changed, then the odds are very good indeed that your paper would be rejected by the prestigious journals and conferences. But why should you give a damn? It's just a word. SteveBaker (talk) 19:55, 9 January 2010 (UTC)

I give a damn because I don't like organizations that arrogate to themselves the authority to specify how to use language. Language is supposed to evolve. It doesn't get decided by votes. In a scientific context, it gets decided by one contributor establishing a usage, and then others following that contributor, or else not. Doesn't have to be centralized, and shouldn't be.

I don't know that language is "supposed" to do anything, but if anything, language is supposed to communicate. One requirement of that communication is that everyone agree on what a word means. Sometimes - and in some contexts - the easiest way for that to happen is for some central authoritative body to specify a particular meaning. Mitch Ames (talk) 01:38, 10 January 2010 (UTC)

IAU and IUPAC are particularly irritating on this score. IUPAC makes up silly names like ethene that no one has ever used, and took the plainly a-historical route on aluminium, a spelling that was invented not by its discoverer, but by a letter-writer to a journal, based on flawed reasoning. Not of course that any of that would matter if chemists in general chose to spell it that way; it just particularly sticks in my craw that this body decides to specify it that way.

My impression is that chemists in general don't take the IUPAC nomenclature too seriously. I don't think we should, either, at WP. In particular alumin[i]um ought to follow the usual WP:ENGVAR rules, even in chemistry articles.

That's what I think, anyway. I guess the chemists at WP have decided otherwise; not being a chemist, I won't stick my nose in it. But I think it's too bad. --Trovatore (talk) 20:53, 9 January 2010 (UTC)

"And the most likely time for them to reverse the 2006 decision would have been at the next general assembly in 2009, and the issue doesn't even appear on the agenda [16]. I don't think the IAU is going to change their minds about Pluto."

The other possibility is that the IAU simply doesn't care what name is given to what so long as the nomenclature is unambiguous (or at least, not as ambiguous as the word "planet" was prior to 2006).

In what way is that an "other possibility"? It doesn't seem to contradict what I said. --Tango (talk) 22:28, 9 January 2010 (UTC)

The thing you still don't seem to be getting is that chemists do decide and do choose. They decide and choose to follow the IUPAC nomenclature. They decide to follow the contributor, the contributor being a centralised body. The fact that you personally don't like centralised bodies is up to you. No one is saying you have to. But you have no right to demand that others don't follow centralised bodies if they want to whether because of a dislike of centralised bodies, or anything else.

It's not as if the IUPAC and IAU has an army and is threatening to kill anyone who doesn't follow their rules. They are bodies, set up by the scientists involved with processes set up by the scientists involved, and the scientists involved have decided to follow their processes and decisions of bodies they set up. Generally, the reasons scientists set up these bodies is because they decided they had the need for them. Again, it's not like they were set up randomly by some aliens from the sky, and then forced on the innocent scientists by people with large guns but that the scientists themselves choose to set them up because they decided they would be beneficial. Journals and the like, recognising the need for clarity and precision, may choose to follow and enforce their decisions in respect of their journals, but again, no one is forcing them to, and their editorial boards are free to make whatever decisions they wish and surely entilted to. Depending on the context and a variety of factors, lay persons including media may or may not follow their decisions.

I don't think anyone here begrudges your right to dislike centralised bodies if you so desire, nor your right to dislike the decisions of centralised bodies or even people following them. What I find almost offensive is you seem to be implying (and forgive me if I'm mistaken) that it's wrong or bad (which is quite a different thing from you personally disliking) for people to choose to follow them because you think they have to share you same distaste for centralised bodies, and may be even see a advantage or prefer such things. In other words, it seems to me that you are the one, not the IAU, or IUPAC or whatever who is being the far worse dictator since you are demanding that others ignore things you don't like even though they surely have the right to choose to follow them, whereas no one is doing that of you and instead we're saying you're free to do what you want, as we are free to do what we want be that following centralised bodies or whatever.

Again, perhaps I'm misreading what your saying, in which case I'm sorry, but at the very least it seems to me you're trying to convince everyone that their decision to follow a centralised body is clearly inferior to your decision not to, and while you are entitled to think so, this isn't the place for you to try to convince people of such things and it can also easily be seen as offensive. Note that while I clearly don't agree with your dislike, I accept and respect your right to that dislike and am not saying it's inferior just different and not something I agree with.

Personally I'm happy that when I say a distance is 1 metre, people know what I mean, even if that decision was made by a centralised body. In fact, I think it's much better then going thorough a period when everyone has their own definition for one metre. I'm also glad that when I talk about a yottametre, people know what I mean and we didn't go through a period when people were referring to a twentyfourametra, verylargametre or thousaeightametre simply to please your dislike of centralised bodies. I accept that you would prefer the later, that is your right, won't you accept that many people including many scientists prefer former, and that is their right no matter how much you may dislike it?

Nil Einne (talk) 23:54, 9 January 2010 (UTC)

Actually, part of my point is that chemists don't follow the IUPAC nomenclature. If they really did, to be sure, they would have the right to. But in fact, American chemists study aluminum, and British chemists study sulphur, in the face of the official pronouncements.

That being the case, I don't think WP should adhere to this artificially promulgated standard. It's an ENGVAR question and we have a working modus operandi for that. But as I say, I'm not a chemist and I'll leave it to them. That doesn't mean I won't state my arguments and preferences.

Similarly, I hope that the IAU attempt to redefine planet will ultimately fail. I also hope that the whole undertaking of defining words by official actions of such bodies will fall into disrepute. I will say why, and try to persuade. In doing so I am not compelling anyone; could not if I wanted to. --Trovatore (talk) 00:27, 10 January 2010 (UTC)

We seem to have forgotten that what the IAU did was to establish, for the first time, a definition of "planet", from which everything else flows. It would be extraordinary to think that such a body did not already have such a definition; but that was indeed the case. Belatedly, they rectified that astounding lack. Had such a definition been in place when Pluto was discovered, it would never have been called a "planet", and people certainly wouldn't have been getting their knickers in a twist about it 80 years later. Celestial bodies are not animate beings; they do not have feelings, and they do not get offended that we ever referred to a particular one as a "planet" and then later changed our mind. Why humans, particularly from within the scientific community, would want to hang on to a mis-classification in the face of a clearly established set of rules for determining what are planets and what are not, escapes me. I didn't think they were that romantic by nature. -- Jack of Oz ... speak! ... 00:16, 10 January 2010 (UTC)

If that definition had been in place, no. If the other candidate (the one I thought was better; "hydrostatic equilibrium" rather than "clearing the neighborhood") had been in place, then yes. But why did there need to be such a definition? That was never clear to me at all. --Trovatore (talk) 00:32, 10 January 2010 (UTC)

Slight correction: the choice was between just hydrostatic equilibrium or hydrostatic equilibrium and clearing the neighbourhood - it wasn't one or the other. A definition of "planet" was required because large numbers of objects were being found in the outer solar system that were borderline (based on the vague definition that had arisen over time) there was a lot of dispute over which side of the border they should be on. The only way to clear up that dispute was to come up with a definite definition. If that definition was going to be at all scientific, it would either have to include dozens of planets (probably hundreds, if we count ones that haven't been discovered yet) or not include Pluto. The astronomical community, voting at the IAU General Assembly in 2006 voted for the latter. You could argue that there isn't actually a need to classify astronomical objects and the word "planet" should have just been deprecated (in technical usage), but humans like to classify things and astronomers are no different. --Tango (talk) 00:45, 10 January 2010 (UTC)

I don't see why anything had to be deprecated. One could instead accept the fact that some authors would refer to, say, Eris as a planet, and some wouldn't. Why is that a problem?

Well, it could be an issue when you need a theory of planets in general, I suppose. But astronomers are not really the right people to be talking about such a theory; it's the domain of planetary scientists. It's hard for me to imagine that planetary scientists could have much good to say about the IAU definition. Whether a ball of rock clears its neighborhood (or for that matter, whether it orbits another ball of rock) has little to do with its properties as a ball of rock.

Of course that does open another can of worms. Why is Jupiter a planet, but Ganymede not? The Earth certainly has more in common with Ganymede. In my opinion, if we were really starting from scratch, the ones to kick out of the club would be the gas giants; it's only by historical accident that they were ever grouped with the rocky planets, which are the ones that ought to keep the name planet if the divorce occurred. --Trovatore (talk) 06:05, 10 January 2010 (UTC)

If different people used different definitions they would have to explain what definition they were using every time they used it. That defeats the object of having a word at all. --Tango (talk) 17:16, 10 January 2010 (UTC)

Oh, come on, Tango, don't get silly. If what you say is true, why stop at planet? Surely we need uniform agreement on the meaning of all words, or else their entire purpose is defeated. --Trovatore (talk) 21:00, 10 January 2010 (UTC)

Yes, that is true. The level of precision needed is obviously less in less technical communication, though. --Tango (talk) 21:12, 10 January 2010 (UTC)

I consider that an inaccessible cardinal must be uncountable; some authors don't. I consider zero to be a natural number; some authors don't. I consider finite sets to be countable; some use countable to mean what I call countably infinite (and for that matter, I sometimes use it that way too; depends on context). These things cause minor annoyances from time to time. They absolutely do not "defeat the object of having a word at all". --Trovatore (talk) 21:37, 10 January 2010 (UTC)

Ok, so maybe it doesn't defeat the whole object, but it does reduce the object. You wouldn't use any of those words is a formal paper without defining them, would you? In maths, we can usually give precise definitions very easily, that isn't the case in astronomy. --Tango (talk) 16:43, 11 January 2010 (UTC)

What? Of course I would use them without defining them. I'd look pretty silly defining natural number in a formal paper. If there were a genuine risk of misunderstanding, I might make a parenthetical remark about the naturals including zero, but most of the time there's either no such risk, or else it doesn't matter how the reader interprets it.

I think it would be the same for planet. No one has produced a plausible scenario where failure to define the word planet would cause genuine confusion. --Trovatore (talk) 19:26, 11 January 2010 (UTC)

One instance I can think of where confusion over the classification of an astronomical object would cause confusion is naming it. There are different rules for how different objects are named. If you can't agree on the classification of an object then you won't be able to agree on its name, and then it will be difficult to talk about it (you would have to say "the object with orbital parameters X, Y and Z" or similar). --Tango (talk) 19:48, 11 January 2010 (UTC)

Yeah, those rules are nonsense too. You have to name it after something in La Morte D'Artur!! Why??? Anyway there's no real distinction between where the names for, say, Pluto and Saturn come from. --Trovatore (talk) 20:23, 11 January 2010 (UTC)

"But officer! Who gave the National Institute of Standards and Technology the right to tell me how fast a mile per hour is?" APL (talk) 21:32, 10 January 2010 (UTC)

Unknown animals

I made this section once before, but no one answered before it was in the archives. What kind of owl is in File:Screech owl.jpg? I know it is a screech-owl (Megascops). --The High Fin Sperm Whale (Talk • Contribs) 02:39, 9 January 2010 (UTC)

The information with the picture says it was taken at "Seattle Zoo". If this means Woodland Park Zoo, Seattle, that Zoo's website [4] currently identifies their (only) Screech Owl [5] as a (one-winged) Western Screech Owl (Otus kennicoti). Obviously several assumptions here (identity of zoo, recency of photo, currency and accuracy of website) may be in error. 87.81.230.195 (talk) 07:00, 9 January 2010 (UTC)

Well, I know the zoo it was at has an aquarium built in too. And you could see Mount Rainier from it, as you can see in this shot. But it does look somewhat like a Western Screech Owl (Otus kennicoti). It wasn't missing a wing, but it was blind in one eye. --The High Fin Sperm Whale (Talk • Contribs) 23:36, 9 January 2010 (UTC)

exploding halo planets

Let's say hypothetically there was a dense halo of packed soil rotating around a sun, like a "band planet." Let's say it's radius was equal to the distance from the Earth to the sun, so gravity and whatnot is the same. Let's say it was concave so that water and stuff didn't run off into space. Let's also say that it had an atmosphere and everything.

Now let's say there were numerous explosions in one arc of the band, causing the destruction of a large amount of the band, leaving what was left only part of a band. Would the remaining part continue to rotate around the sun, and would it still maintain atmosphere? 169.231.9.45 (talk) 03:25, 9 January 2010 (UTC)

I would say that if the band (or Halo or Ring) was stable in one piece, it would now be very unstable. The piece could continue to orbit the sun, except if it was spinning fast enough in the first place to reach solar 'escape velocity'. Unless it was big enough for gravity to have an effect (seems unlikely) it would lose it's atmosphere. This type of 'band' is the subject of the Ringworld series of Sci Fi novels by Larry Niven. He covers these sorts of issues (and IMHO it's a good read). It's in Halo the video game too!

I'm not a rocket scientist so my answers are just based on general science knowledge, if I'm way off some nice editor (who is a rocket scientist Hi Nimur! ) will likely correct me. :) --220.101.28.25 (talk) 03:56, 9 January 2010 (UTC)

The closest sci-fi 'world' to this is Larry Niven's lesser known books: "The Smoke Ring" and it's sequel "The Integral Trees". The math to make these worlds work is complex and requires some really contrived set of circumstances to make them stable. Good books though...better than RingWorld, IMHO. SteveBaker (talk) 04:49, 9 January 2010 (UTC)

(edit conflict)
Having re-read your query & thought about this a bit more, I notice you don't specify how big the 'remaining part' is. If it was say half the entire band I believe it would have no stability and be likely to break up into many smaller segments, or even into rubble and dust. According to Ringworld it, hypothetically, "..rotates, providing an artificial gravity that is 99.2% as strong as Earth's gravity through the action of centrifugal force" at 770 miles/second. As one piece it may be a stable structue, but break it, imagine an aircraft propeller wih a broken blade. Dangerously unstable & Ringworld is made of a mythical material called scrith that is far stronger than "packed soil" or any know substance!
A 'small' piece thrown away from the broken band may survive intact, but would be likely to have a very elliptical orbit.
Thank you SteveBaker, I'll look those books up.--220.101.28.25 (talk) 05:07, 9 January 2010 (UTC)

I'm on a ski holiday in Truckee, California and I have limited internet access, but I can't leave a good question unanswered... In truth, band planets would probably be impossible if they were intended to be built as a solid material. The closest thing would be a planetary ring system - but those rings are made of individual particles whose orbits resonate with each other and with the planet they surround. When large chunks break off, they form shepherd moons, and through the magic of resonance, the ring re-equilibrates to a steady-state, lowest energy configuration. Any particles that begin to shear off, out of the ring system, get pushed back in by gravitational and tidal interactions to their original positions. Now, if your hypothetical band planet were not made of individual granules, but was actually a "solid" contiguous layer, then there would be a whole host of other problems. Such a configuration would be highly unlikely because it is both unstable and is not in the lowest energy configuration; it places huge hoop stress and other deforming shears and strains. Solving out the orbit equations quantitatively, we can calculate what stresses these would be - and invariably, it would require material properties that do not exist, in order to prevent being broken up (take a look at Roche limit). So to answer the OP's question, the band would already be broken up into individual particles; it could never sustain itself as a single contiguous piece of material ringing the sun, (despite the numerous instances in science fiction). Nimur (talk) 13:32, 9 January 2010 (UTC)

I think if the band was rotating at orbital velocity for its distance from the sun, and that distance was outside the Roche limit (which the Earth's orbit is), then it would be fine (over short time scales, anyway). To have gravity holding in air and water as the OP seems to want, though, would require having it rotating far faster. If you have Earth-like gravity, then it is basically the same as having a simple single-span bridge spanning 10¹²m - no realistic material is strong enough not to collapse under its own weight in those circumstances. --Tango (talk) 16:47, 9 January 2010 (UTC)

If the "halo planet" is solid material and the same mass as the Earth, you might end up with a band so narrow and thin that it probably would not support its own structure under the tidal forces it would create from its own rotation around the sun, and an atmosphere under such circumstances would be difficult to imagine because any single stretch of the "halo" or "band" would probably not have enough mass to hold on to air. Also, without an actual core, the "planet" would lack a magnetosphere, and the incoming solar wind would likely fry any atmosphere, water or life that was on it. ~AH1^(TCU) 18:06, 9 January 2010 (UTC)

The lack of gravity from mass is why you need to spin it really fast. If it is really narrow and thin and an almost perfect circle then there wouldn't be any tidal forces, although it would be in unstable equilibrium. --Tango (talk) 18:19, 9 January 2010 (UTC)

hybrid wind water turbine

atleast how much of energy can we approximately generate from a hybrid wind water turbine? —Preceding unsigned comment added by 121.52.146.85 (talk) 03:44, 9 January 2010 (UTC)

I think you're going to have to refine your question. Are you asking about a windmill used to pump water, which is then used to generate electricity (as proposed here)? Or perhaps you mean a turbine that can be used in either water or wind, like this one. Or do you just mean a windpump used to pump water out of a well? In any case, I imaging that the amount of energy produced depends on a variety of factors, including size of the turbine, and the conditions in which it is used.Buddy431 (talk) 04:34, 9 January 2010 (UTC)

This is the 4th time you (or someone who sounds like you) have asked this: Wikipedia:Reference_desk/Archives/Science/2009_December_20#power_generation_using_hybrid_wind-water_turbine, Wikipedia:Reference_desk/Archives/Science/2009_December_25#Wind_mill_.26_water_turbine, Wikipedia:Reference_desk/Archives/Science/2009_December_30#power_generation_by_hybrid_wind_water_turbine (BTW, I noticed you forgot to post on Jan 4.) Ariel. (talk) 06:19, 10 January 2010 (UTC)

Radon in milwaukee

Hey, its mee again. I have a projec t i need to do, and I need to know: Where are radon test samples sent to be tested in Wisconsin? THX —Preceding unsigned comment added by 76.230.208.196 (talk) 03:46, 9 January 2010 (UTC)

If it's in your water supply - then the Wisconsin Department of National Resources Radium FAQ (http://www.dnr.state.wi.us/org/water/dwg/radium.htm) says that you should contact the Wisconsin State Laboratory of Hygiene (http://www.slh.wisc.edu/) who point you to their testing department (http://www.slh.wisc.edu/ehd/testfee.dot) - who are going to charge you $68 for doing the test. SteveBaker (talk) 04:32, 9 January 2010 (UTC)

That's for radium, not radon. Information about radon testing in Wisconsin is available at http://dhs.wisconsin.gov/dph_beh/RadonProt/ —Bkell (talk) 21:38, 9 January 2010 (UTC)

Dark skies

Is there a name for the effect where the sky gets darker at very high altitudes? Astronaut (talk) 04:58, 9 January 2010 (UTC)

I believe it's called "atmospheric transparency". As there is more air between you and "outer space" when you are closer to sea level, there are more particles which can refract and amplify the effects of any light source, causing "light contamination" which causes the sky to appear brighter. As you go higher in elevation, there are fewer of these particles, as well as far fewer light sources (such as cities) which contribute to the distortion effect of the atmosphere, so the sky becomes more transparent and allows you to see the blackness of space more easily. It's similar to the difference between being at the bottom of a murky lake and being near the surface of the same lake: some of the light still gets through at the bottom of the lake, but the closer you get to the surface of the lake, the more clear the water becomes. ···日本穣^? · 投稿 · Talk to Nihonjoe 06:20, 9 January 2010 (UTC)

See Sky#Sky luminance and colors and Rayleigh scattering#Reason for the blue color of the sky. Dolphin51 (talk) 12:14, 9 January 2010 (UTC)

The electronic structure of anhydrous oxide crystals

A long long time ago, a professor told me there was no such as an O^2- anion (that is, an oxygen anion with a -2 charge) - it would spontaneously decompose into an anion radical with -1 charge and a free electron, and this was reflected in the electron affinity equations. If oxygen doesn't have a second electron affinity, then prolly no other atom would.

So then what does the electronic structure of compounds like zinc oxide, magnesium oxide, calcium oxide, strontium oxide actually look like? The crystal lattices aren't showing me things like electron density. I'm thinking actually magnesium forms a polar covalent donor bond with oxygen, so rather than (for a unit cell) Mg2+ O2-, it's actually Mg+ --- O- . Carbonyl'ish to the extent that maybe Mg=O is a contributing resonance structure? And then the unit cells would "link up" in this dipole fashion to delocalise some of this concentrated charge.

I'm thinking that the further down you move the periodic table, the less strong this polar covalent bond is, and basically the more radical-like the component ions (since it's impossible for oxygen to be a dianion all by itself), so basically why MgO reacts less violently with water than say ... strontium oxide, and why magnesium hydroxide is a weaker base than strontium hydroxide is? John Riemann Soong (talk) 05:16, 9 January 2010 (UTC)

There may be no such thing as gas phase O^2- anions, but I am fairly certain that in a crystal latice, there is such a beast. Else, how could one explain the existance of Sodium oxide. Certainly, MgO 'could' be either monovalent or divalent ions. However, in the case of Na₂O, I can't see an explanation that would explain its crystal structure except O^2-. --Jayron32 04:15, 10 January 2010 (UTC)

As far as I remember basic Chemnistry there is indeed such a thing as O^2- in crystal lattices. And at least Riedel/Janiak: Anorganische Chemie, de Gruyter, 2007 states, that there is indeed such a thing as O^2-. (Its very basic literature though)--91.6.26.28 (talk) 10:59, 11 January 2010 (UTC)

Yes, but this O2- anion (on one atom!) seems extremely basic to me... yes, too basic, even if there's no water or any protons around. Electronegative as oxygen may be, it seems that the extra electron is essentially "solvated" in the crystal lattice and not tightly bound to oxygen. Of course, by various degeneracy principles, we can never really tell which electron it is. Is it possible to check the following predictions?

a) The Na-O bond in sodium oxide is longer than strictly ionic chemistry would predict, because Na receives some electron density ... heck, longer than the Na-OH bond in anhydrous sodium hydroxide.

b) Na2O is still a decent reducing agent

c) Na2O2 forms in significant amounts during production because the energy of an O-O bond is in the neighbourhood as the partially covalent nature Na-O bond, and of course a covalent Na-O bond is weak, esp. compared to Mg=O.

d) Na2O in aprotic solvent is a more powerful base than LDA.

e) Anhydrous Na2O has interesting electron delocalisation characteristics ... maybe it's weakly conducting, paramagnetic or an interesting semiconductor additive? John Riemann Soong (talk) 12:00, 11 January 2010 (UTC)

dissolving sodium in water ... a pentuple enthalpy whammy?

• The redox reactions of sodium with hydrogen and oxygen are exothermic, e.g. the formation of H2 or Na2O.
• The combustion of the liberated H2 in oxygen (dissolved or in the air) to form H2O is exothermic.
• The conversion of NaH and Na2O into NaOH and H2O (of varying stochiometric amounts) is exothermic.
• The solvation of NaOH in water -- without any other acid-base reactions occurring, is exothermic. (As well as the re-condensation of the formed water-vapour...)

Then we also have the fact that there's an entropy of solvation contribution involved .... but is this insignificant compared with all this exothermicness?

If the NaOH actually reacts with something, like say, HCl ... then this is a fifth enthalpy contribution. (Say, that makes me curious... what happens when you dissolve sodium in an acyl chloride?? Or even just an aldehyde, ketone or an ester?)

Has anyone ever done a sort of "separated itemised accounting" for all of these contributions...? I'm just curious what the figures are. John Riemann Soong (talk) 05:25, 9 January 2010 (UTC)

I'm not sure if, experimentally, you could break this down into "steps", ala Hess's law. When you drop sodium in water, you get hydrogen gas and sodium hydroxide. You don't ever get isolatable quantities of sodium oxide or sodium hydride, even though there are reaction pathways that may have these as briefly existing intermediates. But yes, any reaction involving sodium is going to be highly exothermic, be it water or really anything. You 'could' do the "itemised accounting" for all of the steps, which would invoke Hess's law; however you'd have to be sure that you're proprose mechanism was the correct one. --Jayron32 04:09, 10 January 2010 (UTC)

Vitamin E

What is the difference in bioavailability between tocopherol acetates (i.e., from the solubility) and natural tocopherols? 99.62.185.39 (talk) 06:29, 9 January 2010 (UTC)

I don't have any empirical or quantitative data, but since it basically makes it more fat-soluble (the alpha-tocopherol is the most-fat soluble), I would expect bioavailability would increase? John Riemann Soong (talk) 07:31, 9 January 2010 (UTC)

The molecular species (alpha, etc.) may affect solubility much less than the anion. I suspect, also without empirical or other data, that the acetate form is less expensive than natural tocopherol oils because it is more stable, with a longer shelf-life, but also with substantially(?) reduced bioavailability. Dual Use (talk) 09:14, 9 January 2010 (UTC)

He's talking about the esters of tocopherols with acetic acid, right? What anions are we talking about? :S AFAIK the phenol should be protonated at physiological pH and the hydrogen-bonding would be more significant than any acid-base chemistry. John Riemann Soong (talk) 09:28, 9 January 2010 (UTC)

Shut eye

1. What's the difference between being asleep and being unconscious?

Being asleep is one of the different ways to be unconscious. It is a form of unconsciousness.

2. Is the one state of mind different compared to the other?

I'm not sure, but I remember there were some related answers from imaging working brains (with positron emission tomography?)

3. Is being asleep laying down different to sleepwalking?

Yes, sleepwalking is an altered form of (very impaired) consciousness, not an unconscious state in the medical sense, although it probably is in the legal sense.

4. Are dreams possible when you're unconscious?

Maybe. There is some evidence that people under anesthesia suffer unpleasant dreams, but most of the time they don't remember those.

Thanks, NirocFX (talk) 10:11, 9 January 2010 (UTC)

You're welcome. GandM (talk) 10:39, 9 January 2010 (UTC)

Links added and fixed. ~AH1^(TCU) 17:55, 9 January 2010 (UTC)

I disagree that sleep is necessarily a form of unconsciousness. For example you are quite plainly conscious when dreaming (though not conscious of external stimuli). I can sometimes remember thinking about stuff while asleep, even while not dreaming. (I wouldn't know how to tell you how I knew I was asleep, which I suppose would be your next question. I just knew.) --Trovatore (talk) 21:15, 9 January 2010 (UTC)

The Consciousness article says that there is no proper definition of the term. Sleep says it is characterized by total or partial loss of consciousness. So by these two articles, I would say that yes, Sleep necessarily isn't a complete loss of consciousness. Dreams involve some awareness of the mind. Rkr1991 ^{(Wanna chat?)} 04:42, 10 January 2010 (UTC)

Don't forget lucid dreaming. Noodle snacks (talk) 08:16, 10 January 2010 (UTC)

How is this possible?

Hi,

Please help me understand how it is possible for us human beings to operate ourselves.

Take for instance a toy action figure or a car, those things have power sources. Where are our power sources? We're all flesh, fat, blood, bones and water basically.

How are we able to move our eyes, hands, legs; go to sleep and wake up when we want to without someone pushing a button? I'm even scared to ask how and where dreams fit in.

Thanks, NirocFX (talk) 10:33, 9 January 2010 (UTC)

1. Our power source can be understand by checking out the metabolism article.

2. We move because our brain sends signals to our muscles, which then use that metabolic energy to get to work.

3. Dreams are best understood in a psychological context. I would direct you to the article on subconscious for an overview, but it is of alarmingly poor quality. Dreams looks a little more up to snuff though it lacks confidence as to what the purpose of dreams are. Oh well. Vranak (talk) 10:52, 9 January 2010 (UTC)

I would dispute that dreams are best understood in a psychological context. The most compelling theories of why we dream and what they do are neurological—they are the brain's way of reorganizing information at the end of the day, and should not be deeply read into for content. Psychological theories of dreaming have led people down a number of paths that have absolutely no scientific rigor to them. --Mr.98 (talk) 15:15, 9 January 2010 (UTC)

This is probably because you don't understand or appreciate psychology. Vranak (talk) 18:52, 9 January 2010 (UTC)

Er, no, it's because they have no rigor to them. Seriously, there is a very large literature on the neurology of dreams, and the Freudian-etc. approach to dreams is generally considered to be totally bunk by the active scientific community, though it enjoys a lot of cache in popular culture and amongst people who peddle psychotherapy to pay the rent. --Mr.98 (talk) 02:45, 10 January 2010 (UTC)

The tricky conceptual point is that we operate ourselves as ourselves. It isn't that human beings are little creatures riding around in a human body—though it can certainly feel that way, especially when we realize, as we all do, how much our body is limited compared to what we would imagine it being able to do in our minds. But the mind is part of the body, a product of the brain, and the entire apparatus is connected quite inextricably.

Our cells generate power from the food that we eat, to put it simply. How they do that involves chemistry, and is complicated, but is definitely known.

In the end, the tough question is how consciousness works—how we are anything more than machines-made-of-guts, if we are. For that, we as of yet have no compelling scientific answer. --Mr.98 (talk) 15:15, 9 January 2010 (UTC)

It is magnetic. It's covered all over in little magnetic twitches and electrical signals. Although your question seems to be "What is my soul?" the most they know is that each movement and probably each thought is accompanied by a little electrical signal like a robot or a computer with wires and resistors. The fuel is sugar and oxygen which is probably well described on the metabolism article. ~ R.T.G 17:24, 9 January 2010 (UTC)

(No, it's not magnetic) SteveBaker (talk) 19:18, 9 January 2010 (UTC)

The oxygen is carried around the blood by iron magnetising with it. That's just part of the fuel but it is one of the amazing little technical things the body does to let you move around the place, carries fuel for burning one atom at a time. You've enough tiny little bits of iron in the blood to make a handful of small nails and without it you'd be some sort of plant. That's why foods are often "fortified with iron". ~ R.T.G 20:52, 9 January 2010 (UTC)

To clarify, humans have abour 3-4 g of iron in their body, of which about 2.5 g is in hemoglobin in the blood. That's about one 2" nail. And the iron isn't "magnetising" with oxygen, but rather forming a coordinate covalent bond. Additionally, while many animals use iron to transport oxygen, there are some, such as octopuses that use a copper based molecule, Hemocyanin. You wouldn't necessarily be a plant if you didn't have iron in your blood; you might just be a squid. Buddy431 (talk) 22:13, 9 January 2010 (UTC)

The nervous system directs the bodily movements, and the heart and brain, among other parts of the body are "co-dependant". As for dreams, I would guess that it is the subconscious brain producing "images" that are experienced by the person's "mind" while the conscious mind is at rest. Dreams often occur during different sleep phases, for example REM sleep rather than deep sleep. ~AH1^(TCU) 17:54, 9 January 2010 (UTC)

The energy to power the human body comes from the food we eat - combined with the oxygen we breathe. Just like a car burns gasoline with oxygen - so we burn carbohydrates and fats. The "burning" is slower and gentler than for a car - but the chemical reactions produce similar results. The sugars are stored in our blood - longer term storage as fats. These are broken down as needed to produce the chemical energy to make muscle fibres contract and body parts move. The controls for all of this is our brains - which are a lot like computers - but immensely more complex. When something in our environment causes us to need to do something, it can either be entirely automatic (such as when your hand jerks away after touching a hot stove) or consciously driven. Signals are passed from brain-cell to brain-cell just like they travel from transistor to transistor in a computer. Eventually, commands to move a muscle travel down nerve fibres to the appropriate place and cause the chemical change that results in sugars being converted to energy to contract or relax a muscle. All of this is fairly easy and well-proven stuff - except for the fact that we feel like we're somehow "in command". It doesn't seem to us like we're all just a bunch of computer software running in a biological computer - even though that is undoubtedly the truth of what's going on. The experience of conscious behavior is hard to explain - and science has a long way to go to pin that part of the explanation down. If we knew that our computers had consciousness - we'd understand what was going on inside our own heads - but we don't. SteveBaker (talk) 19:18, 9 January 2010 (UTC)

Good general description there SteveBaker! --220.101.28.25 (talk) 01:46, 10 January 2010 (UTC)

Judging from the response to my question I would say that there is a bit more work to be done by our scientists to really see how it all comes together. From what I understand is that it all starts with the consumption of food which later is turned into energy. The energy in turn powers up all kinds cells including brain cells. In between there are a lot complexities, but (in short) after electrical signals appear due to the powered up cells, movement takes place.

Thanks Guys, Vranak,Mr.98, RTG, SteveBaker,Buddy431, and AstroHurricane001. Hope I haven't left anybody out.

41.193.16.234 (talk) 12:37, 11 January 2010 (UTC)

—Preceding unsigned comment added by 41.193.16.234 (talk) 11:32, 11 January 2010 (UTC)

Hot spots in cold water

(moved from article space) FOR A WHILE NOW I'VE WONDERED WHY WHEN I SWIM AT A PLACE CALLED DROMANA IN THE SAME BODY OF WATER THERE ARE WARM AND COLD PATCHES ESSENTIALLY COEXISTING. I GUESS MY QUESTION IS HOW IS THIS POSSIBLE WITHOUT IT SEEMS MIXING AND BECOMING A UNIFIED TEMPERATURE?Gazzasifu (talk) 10:50, 9 January 2010 (UTC)

See thermocline for something like this. --76.182.94.172 (talk) 13:39, 9 January 2010 (UTC)

This report (beware 2GB pdf!) gives some figures for thermal stratification at Dromana (assuming that this is the right location), with one example from December (Figure A3.6) showing a decrease of nearly 1.5° from 19.5 to 18 at about 2m depth, I guess you might notice that. Mikenorton (talk) 17:32, 9 January 2010 (UTC)

Also, some ocean currents such as the Gulf Stream can periodically fluctuate and produce warm and cool eddies more than 10C different in temperature less than a few hundred km apart. ~AH1^(TCU) 17:44, 9 January 2010 (UTC)

Data mining, data is doubling every three years

Hi, on Data mining is says on the first sentence "...the amount of data is doubling every three years." The source is locked for subscription. Does someone have access to that source or can someone know offhand what data is doubling every three years? I assume it is about online data but who knows. Happy new year to you. ~ R.T.G 17:08, 9 January 2010 (UTC)

This report (which may be referring to the same thing) talks about "the amount of data storage required" as doubling every three years. Mikenorton (talk) 17:37, 9 January 2010 (UTC)

That would be less than the rate of Moore's law for hard drives - so such a rate of increase may well be just a matter of what businesses and/or government can afford to store for a given price. SteveBaker (talk) 19:06, 9 January 2010 (UTC)

So should I quote dictionary.com and change the article accordingly? I am thinking yes. This is the sort of data that data mining is all about right? ~ R.T.G 20:17, 9 January 2010 (UTC)

You lost me. What does dictionary.com have to do with this? Comet Tuttle (talk) 20:30, 9 January 2010 (UTC)

The ref Mike Norton showed us, encyclopedia.com sorry. ~ R.T.G 20:54, 9 January 2010 (UTC)

You can't use one encyclopedia as the reference for another - so that's not good enough. SteveBaker (talk) 06:22, 10 January 2010 (UTC)

Kind of seems like a factoid to me. I intend to remove that statement from the article. Noodle snacks (talk) 08:12, 10 January 2010 (UTC)

This particular factoid appears to have come from this UC Berkeley report, if we do decide to use it in the article. Mikenorton (talk) 11:55, 10 January 2010 (UTC)

About Sinkiang, phillippine sea and Noha’s flood

Hi,

I believe that once the world was struck by a broken star/something in China’s Sinkiang area and then fall into the phillippine sea. This event may be related with the Noha’s flood. Do you know anything about this event?

Regards --Mohsin —Preceding unsigned comment added by MohsinRaz (talk • contribs) 17:47, 9 January 2010 (UTC)

No. Can you tell us what makes you believe that? --TammyMoet (talk) 17:57, 9 January 2010 (UTC)

It struck China's Xinjiang area (North-Western China), then fell into the Phillippine Sea (South West Pacific Ocean)? You mean it bounced and the water from the Pacific Ocean ended up in the Middle East? Where did you get this information from, because it's news to me? --KageTora - (影虎) (Talk?) 18:34, 9 January 2010 (UTC)

(ec) Searching Wikipedia for "Xinjiang meteorite" came up with Fukang (meteorite). Couldn't find anything related to the Philippine Sea (which seems like it would be an awful long way away). When meteors fall into the Earth's atmosphere they're often called "shooting stars" but they aren't actually pieces of stars. Typically they're chunks of rock.

I think any connection to Noah's Ark is going to be purely speculative. Rckrone (talk) 18:41, 9 January 2010 (UTC)

You might be interested to see List of impact craters on Earth and Deluge (prehistoric). China and the Philippines seem to have got off very lightly.--Shantavira|^{feed me} 18:45, 9 January 2010 (UTC)

what's a a broken star/something? Dauto (talk) 18:50, 9 January 2010 (UTC)

I think we can assume it's a meteor or something. It's possible that our OP is not a native English speaker. If "Sinkiang" is really "Xinjiangm" in Urumqi, China (which is what Google-Maps says) - then I think that location is far too far inland (over 2000 miles inland) to have been struck by something that ended up in any ocean. While there may be some truth in that it was struck by a meteor, the details must have somehow been confused or exaggerated along the way. SteveBaker (talk) 19:04, 9 January 2010 (UTC)

Continental drift. Comet Tuttle (talk) 20:28, 9 January 2010 (UTC)

That could not explain changes over thousands of years. It is possible that a meteorite struck the Earth near the end of the last ice age as sea levels rose, and many places were innundated, for example the Black Sea's creation out of a freshwater lake. While a meteorite could have caused a tsunami, any direct connections to events in the Bible are again speculative. ~AH1^(TCU) 03:05, 10 January 2010 (UTC)

Deluge myth is a good article on this stuff... --Jayron32 04:03, 10 January 2010 (UTC)

You could flood a town back then and it'd seem like the end of the world. It's a mistake to think that most myths have much basis in fact. 67.243.1.21 (talk) 15:35, 10 January 2010 (UTC)

Disrupted food chains

What are some famous examples/consequences of food chains being disrupted i.e. one key species dying out/growing in number dramatically? No points for smartass "humans" answer. Pic related, it's a cane toad.  Skomorokh  19:45, 9 January 2010 (UTC)

Such as when someone introduced a pregnant cat to Stephens Island in New Zealand, which (along with it's kittens) proceeded to quickly wipe out the Stephens Island Wren?

The article on Keystone species gives a few examples. The canonical examples that come to my mind are the reef-building corals (see coral bleaching) and the Easter Island Paschalococos palm. --Dr Dima (talk) 20:07, 9 January 2010 (UTC)

The Dodo of course ~ R.T.G 20:56, 9 January 2010 (UTC)

Lythrum salicaria can destroy the food chain when introduced to wetlands --Digrpat (talk) 21:02, 9 January 2010 (UTC)

Try also Invasive species and related articles ~ R.T.G 21:04, 9 January 2010 (UTC)

Gulf stream collapse & European winter storms of 2009–2010

In this article for The Times, Giles Coren has a bit of a rant about all the "where's global warming now?" remarks that are occurring due to the current weather in the UK. If you don't want to click the link, he basically claims that this weather is due to the Gulf Stream collapsing (which — spookily — was predicted to happen by the Observer just over a month ago). I'd like to know if this is plausible (not that the Gulf Stream will collapse, but that it has collapsed). Although I know next to nothing about climatology, there is no need to dumb down answers if it's a complex matter. --Mark PEA (talk) 20:06, 9 January 2010 (UTC)

You'd be nuts to believe opinion pieces in newspapers. They always (like for many decades) give an hysterical view of events to entertain their readers and have something to write about. 89.242.112.19 (talk) 10:44, 10 January 2010 (UTC)

So if an opinion piece states that 2+2=4, I'd be nuts to believe it? Just because opinion pieces like to be hysterical, it doesn't mean they are automatically factually incorrect. Instead, I chose to post this on the RefDesk to see what others think. Looking at some Wikipedia articles, it appears that global warming could cause the Gulf stream to collapse, and this could cause "Canada-like" weather in the U.K, therefore it really isn't that hysterical. --Mark PEA (talk) 13:47, 10 January 2010 (UTC)

I'm no expert, but I live in Norway, which is heavily heated up by the Gulf Stream, and climate would certainly be worse than the slightly heavy winter we've been having over the last weeks if this was the case. I checked ice sheet coverage, and from this image (from this page) it clearly seems that, as usual, there is no sea ice where the Gulf Stream goes. Jørgen (talk) 20:33, 9 January 2010 (UTC)

I live in Ireland. A lot of countries at our latitude are covered in snow most of the year but we usually have snow only in some areas and only for a few weeks. Around 4 or 5 years ago we had two hottest years on record. We always have a few heatwaves but these were full summer and autumn heatwaves and the heat had been increasing for a decade. Then all of a sudden we had the wettest and one of the darkest years on record. Now we are getting -8 degrees at night and snow and frost on the ground even if the sun is shining. But, the record in the last 50 or 60 years is -10 so can't just say it has collapsed yet by that info alone but it did get very hot then very cold. ~ R.T.G 21:12, 9 January 2010 (UTC)

Whilst I find anecdotes interesting, I'm hoping a climate expert can confirm/falsify this hypothesis. --Mark PEA (talk) 22:24, 9 January 2010 (UTC)

If the Gulf Stream had collapsed it would be in all the mainstream news, which it isn't. It isn't even in the article you link to - he says: "I am not saying that the snow we are having now is because of global warming. It is not." He just says this is the kind of weather we can expect if the stream collapses. --Tango (talk) 22:34, 9 January 2010 (UTC)

This Met Office report about their model analysis of the possible failure of the conveyor shows "rapid" onset of "anomalies", but in terms of climate rapid means (as that report says) starting to be evident in 10 years and markedly so in 30. As Tango says, there's no evidence the conveyor has collapsed or the salinity conditions necessary to weaken it actually exist (and there hasn't been a wholesale Heinrich event which might precipitate rapid change), and even if it had the Met office thing suggests you wouldn't see real climate change for years. So just as a really warm summer isn't evidence of global warming, a really cold winter isn't evidence against (that's the difference between weather and climate, but weather sells newspapers and climate doesn't). The papers like to embiggen the horror of the current cold snap, but it's only the coldest it's been in 30 years - the Grand Match won't go ahead, and we're nowhere near holding frost fairs. -- Finlay McWalter • Talk 01:06, 10 January 2010 (UTC)

Frost fairs took place before the phrase "health and safety" was coined - I doubt they would happen these days, even if we did get several inches of ice on the Thames. --Tango (talk) 02:38, 10 January 2010 (UTC)

This [6] article suggests and presents evidence, for whose veracity I do not vouch, that the North Atlantic Current offshoot of the Gulf Stream has been temporarily diverted from Europe to the west of Greenland by currents caused by winds caused by the Arctic oscillation responsible for the cold air mass currently affecting Northern Europe and other areas (and corresponding warmer air currently over Canada, etc. 87.81.230.195 (talk) 01:38, 10 January 2010 (UTC)

I'm not a climate expert, but I have been monitoring global sea surface temperatures for the past five weeks. If you're interested, I've posted a lengthy discussion on what I've observed here. A word of caution however, because it does contain a fair amount of the big picture of things, but my last post is more than five days old and I have yet to provide an update.

The reason why none of this information has been mentioned in mainstream news sources is because everybody is busily examining individual news events, and has no time to put everything together. One user on the website Weather Underground who is skeptical of global warming said perhaps I am seeing something that the climatologists will miss for months. But really, this whole weather pattern started as a simple El Nino "Modoki", then it progressively spun out of control.

The Gulf Stream has diverted temporarily west of Greenland to a glacial outlet known as Jakobshavn Isbrae, where generally ice-free SSTs have entered the area. Two days ago, an area west of Spitsbergen (this is also the site of methane clathrate releases in the summer of 2009[7]; other clathrate release sites in 2009 include the Barents Sea in Alaska and off Oregon) warmed to 14C while the section of the Gulf Stream's temperatures warmer than 8C steadily retreated southwestward. For periodic monitoring of global SSTs and anomalies, here's just one link: http://www.climate4you.com/SeaTemperatures.htm.

Looking through the almost daily archives of global SSTs I have saved on my computer, by 24 December the Gulf stream weakened in intensity. By 27 December, the Gulf stream took a shortcut northeastward, east of Bermuda at the latitude of Cape Haterras to the branch of the stream east of Newfoundland (the part that headed toward west Greenland). By 29 December, this shortcut had also weakened, and a deep cold eddy appeared to its east, about 10C cooler than the warm eddy produced by the shortcut. By 1 January, this cold eddy had disappeared and the Gulf Stream started to resume its usual course. By 3 January, a northerly shortcut merged with the broken main Gulf Stream. By 6 January, the Gulf stream again weakened, leaving behind a trail of warm eddies, while an area off Reykjavik, Iceland warmed to 14C. On 7 January, the cold eddy re-appeared east of the Newfoundland-Greenland diversion.

It isn't just the Gulf Stream, either. The Humboldt Current is becoming overwhelmed due to El Nino. Instead of drifing eastward, the warmest part of the Central Pacific El Nino warm pool has drifted south—toward the Ross Ice Shelf. One week ago, the Humboldt came very close to being cut off at its source in Chile, but the 20C "isotherms" have since rebounded. The biggest warm anomaly is actually not in the Equatorial Pacfic, but in the South Pacific, in the middle of the South Pacific Gyre, and the ENSO pool is feeding into this warm "bulge". In addition, large storms have re-inforced these SST anomalies around the globe. Throughout December 2009, massive continent-wide storms (for example, the North American blizzard of 2009 and the 2009 Christmas winter storm) developed over North America roughly once a week, and I've tracked a single Nor'easter that underwent cyclogenesis to develop into five separate storm centers that hit Europe after tracking over the North Atlantic. So while a single storm kills 20 people over a week in the US, five storms hit Europe in a week. All this has disturbed the path of the Gulf Stream. In the most recent such North American storm, a nor'easter developed east of New England and hit Nova Scotia after spinning around itself due to a blocking high over Greenland. While the storm was in Halifax, here in S. Ontario we got 25 cm (10 inches) of snow—the local forecast was predicting only 10 cm. After this, the storm tracked into the Labrador sea, and more storm centers developed from its frontal system, tracking west of Greenland. Thus diverting more of the Gulf stream northwestward.

What I think is happening is that, while the global ocean currents are slowing down, the "floodgates" for cold Arctic air are letting up, allowing cold Arctic air to sink into continental North America, Europe, East Asia and India, clashing with weather systems carrying warm air to form large storms (resulting in at least 500 total deaths). While the cold air is descending over the continents, more warm air is staying in the oceans, especially in the Southern Hemisphere, and especially in the warm anomalies in the South Pacific, South Atlantic, and South Indian oceans. Warm SST anomalies have recently reached the Antarctic Peninsula and several glaciers in East Antarctica. There are warm anomalies over cool currents and cold anomalies over warm ocean currents.

Recently, it has been warmer in parts of Alaska and Greenland than in parts of Texas and Florida. Today, areas across Florida all the way down to the southeast are seeing snow. By early December, much of Texas had more snow than my location in S. Ontario.

Perhaps global warming is no longer occuring on the scale of decades, or even years. Now, the situation appears to be changing every day, even every hour. Many storms are forming directly over sensitive SST "tipping point" areas, and some of them have intensified past 950 hPa. Recent tropical cyclones have also been erratic. Super Typhoon Nida in the West Pacific may have started this whole process in late November, after creating a gap in the subtropical ridge, cooling the entire west Pacific basin, and allowing West Central Pacific warm SSTs to drift east. Cyclone Laurence over Australia tracked toward the Ross Ice Shelf in Antarctica by early January. The remnants of Cyclone Mick in the South Pacific churned warm water southeastward after hitting Fiji in mid-December, and this was intensified after a Fujiwara interaction with two other extratropical systems, and the South Pacific "bulge" accelerated in development. Along with other osciallations such as the PNA, AO and NAO, El Nino (ENSO) has produced a co-reinforcing, self-reinforcing cycle. "Modoki" El Ninos are supposed to be fairly predictable after this pattern emerged roughly 30 years ago. This winter, however, the pattern has been so erratic that it is difficult to guess what will happen a week in advance, in terms of SSTs and computer model weather forecasts.

There have actually been far more "signs" of an unusual climate shift in the past few months than I've mentioned here, including anectodal personal observations within my local area. This may at times sound like science fiction, and indeed, this does remind me of the movie The Day After Tomorrow, but I don't think an ice age could be caused by this due to the warmer ocean temperatures. I'd say this is Gaia's Revenge for the faliure of the world leaders at the Copenhagen Conference. ;)

If at all possible, please include more citations in this RefDesk post, then include the relavent cited information in some articles. Again, more information is available in the WikiProject discussion I've linked, along with more links with raw data. ~AH1^(TCU) 02:41, 10 January 2010 (UTC)

Why don't you write up this research formally and submit it to a climate science journal? If, as you suggest, you have a several month headstart on other climate scientists, you ought to submit it. Subjecting it to peer review seems like a good idea, because Wikipedia isn't the appropriate place for original research. We don't have the rigor or concentrated expertise to evaluate those claims. Nimur (talk) 12:06, 11 January 2010 (UTC)

It is physically impossible for the Gulf Stream to "collapse" as long as the Earth rotates and the Atlantic Ocean remains liquid. Short Brigade Harvester Boris (talk) 04:11, 11 January 2010 (UTC)

Younger Dryas. Shutdown of thermohaline circulation. Or were you simply making the picky point that the North Atlantic Drift is not the whole of the Gulf Stream? Synecdoche is a pretty common feature of human communication. 86.178.229.168 (talk) 03:57, 12 January 2010 (UTC)

It's not a picky point. If people mean the Gulf Stream they should say Gulf Stream. If they mean something else, then they should say that instead. Short Brigade Harvester Boris (talk) 04:06, 12 January 2010 (UTC)

Structure of guanosine

I stumbled across File:Guanosine.jpg while wasting time with the random image feature, and I noticed that it shows a hydrogen atom that isn't present in File:G chemical structure.png, the image currently used in the guanosine article. I don't know much about chemistry; is there an error in one of the diagrams? (Perhaps this is what the discussion at Talk:Guanosine is about.) —Bkell (talk) 21:09, 9 January 2010 (UTC)

Yes this File:Guanosine.jpg is incorrect, you will also notice a Nitrogen atom with a valence of 4. instead of 3. COnfiemed with one of my biochemistry text books. Graeme Bartlett (talk) 22:22, 9 January 2010 (UTC)

It looks wrong to me too. Does anyone else agree? If it's wrong, I'll nominate it for deletion so it doesn't get used accidentally. We can't have violations of our strict Wikipedia policy of occasionally recognizing the laws of physics! :) Franamax (talk) 00:14, 10 January 2010 (UTC)

The image was definitely incorrect. I have been bold and just deleted it. -- Ed (Edgar181) 00:42, 10 January 2010 (UTC)

Human-great ape hybrid

Has any research been done about breeding a human and any of the great apes? (if there are lion/tiger combinations it's possible, no?) Thanks for info., --AlexSuricata (talk) 23:59, 9 January 2010 (UTC)

See Humanzee. Some experiments were carried out by a Soviet scientist in 1927, without success (perhaps fortunately). Tevildo (talk) 00:01, 10 January 2010 (UTC)

Obligatory pointing out that humans are themselves great apes, and that you probably mean "any of the other great apes". 86.178.73.74 (talk) 00:39, 10 January 2010 (UTC)

A factor probably making such theoretical (and unethical) crossbreedings more difficult than they might otherwise be the case is that Humans' closest living great ape relatives - Chimpanzees, Bonobos, Gorillas and Orangutans - all have 24 pairs of Chromosomes, but Humans have only 23. This is almost certainly because, since the Chimp/Bonobo and Human lines of descent diverged from their 24-pair possessing common ancestor (4 to 6 million years ago?), two of those 24 merged in Humans, resulting in only 23 pairs: see for example [8]. The resultant extra large Human Chromosome 2 still carries obvious internal signs of this merging.

Initially the merged chromosome would probably not have much impeded cross-fertility (else its presumed single original possessor would not have been able to reproduce - see Chromosomal polymorphism), but subsequent further changes in Human Chromosome 2 and the corresponding two non-Human chromosomes will have made successful Gene locus matching and Chromosomal crossover more difficult if not impossible. 87.81.230.195 (talk) 01:26, 10 January 2010 (UTC)

Different numbers of chromosomes doesn't rule out hybrids. Horses have 64 chromosomes and donkeys 62, but we still get plenty of mules (with 63 chromosomes). Those mules are usually infertile, of course, so we could reasonably expect a hybrid of a human and one of the other great apes to be infertile. --Tango (talk) 02:34, 10 January 2010 (UTC)

There is also the Humster. There is also the mouse human hybrid. (with no article) Graeme Bartlett (talk) 06:43, 10 January 2010 (UTC)

There are in fact many varieties - see transgenic mice. Matt Deres (talk) 22:22, 10 January 2010 (UTC)

I don't think sticking in a gene or two really counts as a hybrid. The question seems to be about an organism with more-or-less-equal contributions from human and ape. --Trovatore (talk) 22:28, 10 January 2010 (UTC)

Agreed, but that seemed to be what Graeme was referring to. Matt Deres (talk) 00:27, 11 January 2010 (UTC)

heater efficiency

What type of air room heater would be more efficient, one that has an orange glowing resistance heating element or a heating element that is simply a large iron core that is using the same wattage but has a top temperature that is less than boiling water? In other words is room air heater efficiency a function of element temperature? 71.100.160.154 (talk) 23:59, 9 January 2010 (UTC)

All _heaters_ will have close to 100% thermal efficiency, as all the electricity supplied to them is converted into heat. The main difference is in how long the heater will continue to deliver heat for after it's switched off, and how much air movement it produces. See Electric heating and the links to the various types of heater on that page. Tevildo (talk) 00:10, 10 January 2010 (UTC)

Wouldn't the thermal efficiency be -exactly- 100%? I see the article also says "at or very near 100%". What would make up the difference for "very near"? Franamax (talk) 01:57, 10 January 2010 (UTC)

Light which escapes the room without heating it? Sound which escapes the room without heating it? 86.178.72.55 (talk) 02:13, 10 January 2010 (UTC)

But that assumes the efficiency of the device is related to the enclosure, doesn't it? What if I wanted my heater to heat both the room and the near surroundings? Do my desires affect the math? The light and sound will still end up as heat. Are we talking about just the photons which leave Earth, travel through empty space, and never interact with any matter in the Universe? Franamax (talk) 02:21, 10 January 2010 (UTC)

Maybe I can answer my own question here. The thermal efficiency of an electric heater used to heat a room will be 100% minus the energy contained in what you can see and hear outside the room, and minus the radiant energy which strikes the walls and is immediately lost to the surroundings. The thermal efficiency of an electric heater used to heat its general surroundings will be exactly 100%. If I use a big incandescent bulb and shine the light out the window, it will be 95% efficient as a room heater. Right? Franamax (talk) 02:29, 10 January 2010 (UTC)

One source of loss is energy dissipated in the electrical wires outside the heated space. This is depends on the resistance of the wires compared to the resistance of the heating element. Since a low power heater has a higher-resistance heating element, and the resistance of the electrical wires is nearly constant, a low power heater that is on most of the time will have a lower wire loss than a high power heater that is on for a short time and off most of the time. --Jc3s5h (talk) 02:29, 10 January 2010 (UTC)

Good point, but now you're measuring the efficiency of a heating system, not of a heating device. If I get the power from within the room (a fuel cell, say) or from a distant nuclear plant, how does the heater "know" the difference? Franamax (talk) 02:36, 10 January 2010 (UTC)

Well exactly: if you want to know how efficient something is at doing something, you have to define exactly what these somethings are. A heating system that emitted 50% of its heat to the outside world and 50% to your room wouldn't be terribly efficient at heating your room, even if it was 100% efficient at converting electricity to heat. 86.178.72.55 (talk) 03:53, 10 January 2010 (UTC)

Okay, the answer I'm seeking here is whether constant induction heating to a desired room temp (or intermittent heating at slightly higher temp) of a blob, rod, or length of iron or copper tubing filled with water is more efficient in terms of electrical usage than a high temp electric resistance element that cycles much more often? 71.100.160.154 (talk) 12:26, 10 January 2010 (UTC)

No. At best, it'll be equally efficient, and an induction heater is likely to have a power factor that differs from 1.0 by a greater margin than a simple resistive element. That won't affect the thermal efficiency, but it will mean that your electricity bill (based on apparent power rather than resisitve power) will be higher for a given wattage. A simple resisitor is the most efficient form of heat generator possible. Tevildo (talk) 21:07, 10 January 2010 (UTC)

I thought that having a low power factor didn't increase your bill, and so made the power company unhappy because they still took the resistive losses in delivering you power that you then capacitively or (more often) inductively returned to the grid. --Tardis (talk) 15:34, 11 January 2010 (UTC)

That depends on your utility; some have been moving toward billing for apparent power (in va) by using a more sophisticated meter but the traditional 'spinning wheel' power meter knows only actual power (in w) and that's what you are billed for. In fact, I suspect it would violate some sort of public utility law to write 'watt hours' on your bill but actually charge you for 'volt-amp hours' which are demonstrably different. Most of the US still uses the watt, 'smart meters' have been five years away for god knows how long. --Jmeden2000 (talk) 18:19, 11 January 2010 (UTC)

The above is true. I've not seen a mechanical electricity meter for years in the UK - but, I'm not an electrician, and I'm sure there must still be a few about. The electronic ones are far more common, though. I anticipate that my original answer might prompt the question "why use induction heaters at all, in that case?" An induction heater will be more efficient than a resistive one in heating the block of iron. But they'll be equally good at heating the room, which is what the OP wants to do. Tevildo (talk) 19:02, 11 January 2010 (UTC)

I think the more important consideration here is the intended use of the heater. In a bathroom where you are going to be in there 10 minutes having a shower, a radiating red hot element heater is better because they don't take long to heat up and they do a good job of heating anything that is directly in front of them, i.e. YOU. In a bedroom, I think the better choice is one of those slower, oil filled radiators. They take longer to heat up but they also release their heat much more gradually and they have a much greater thermal capacity, so they are better at actually warming a whole room up. Vespine (talk) 03:10, 12 January 2010 (UTC)