Wikipedia:Reference desk/Archives/Science/2012 June 22

Science desk
< June 21	<< May | June | Jul >>	June 23 >

Welcome to the Wikipedia Science Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

June 22

Photosynthesis, CO2, etc.

So, I have a few questions concerning photosynthesis, carbon dioxide and this whole global warming issue:

1. How long does it takes green plants/trees to start photosynthesis?
2. On average, how much oxygen is produced by trees through photosynthesis?
3. Can plants get carbon dioxide "poisoning" (i.e., having too much?)
4. I came up with a thought a little while ago. Companies that burn fossil fuels for energy just dump that carbon dioxide gas into the atmosphere. Why can't companies transfer the gas into say, a greenhouse beside the factory, with plants that could simply convert that CO2 into oxygen, as a way to reduce emissions into the atmosphere?

Thanks, 64.229.5.242 (talk) 00:16, 22 June 2012 (UTC)

1: Plants start photosynthesis as soon as the cotyledons break the soil surface, not long after germination. (At least most of them. Some vascular plants never photosynthesize, such as Indian pipe or broom rape).

2: You'll have to specify what you mean. mass per year per plant? Which plant? Mass per year per hectare? What community? This is a broad area of research. For starters, put /plant "carbon fixation" estimate/ into google scholar, or see e.g. here [1] for some methods that focus on certain forest types (O2 production will be related to CO2 fixation, which is a more common key term).

4: Plants do tend to grow better/more with more CO2, but sometimes their insect pests and plant pathogens also do better too. So whether your proposal would help much is unclear. SemanticMantis (talk) 00:31, 22 June 2012 (UTC)

5: (which you didn't ask) I don't think that most air pollution comes in nicely sorted flows. It is probably very challenging and expensive to selectively isolate CO2 from industrial sources. But, still an interesting question: I think pairing greenhouses with factories in some way could probably work out well... :) SemanticMantis (talk) 00:31, 22 June 2012 (UTC)

I'm only going to touch on the last question. Plants are not infinite CO2-->Oxygen conversion machines, and that's because the CO2 is not actually being converted into molecular oxygen. Water is broken up into hydrogen ions and oxygen, while the carbon dioxide is converted into carbohydrates (don't get on me about all the ions and electrons, I don't feel like keeping track). Some of those carbohydrates are burned for energy, and actually just get spat back out as carbon dioxide (and water vapor). The carbon dioxide that disappears is from the carbohydrate mass that is used to build the physical stuff of the tree itself. In this sense, the tree is acting as a carbon sequestration system. While a tree is growing, it is certainly removing CO2 from the atmosphere, but once it stops growing it has zero net impact. You'd have to keep planting new trees in perpetuity to continually cancel out the emissions of a factory. In fact, the article I linked to gives a lot of ideas on this. Someguy1221 (talk) 00:36, 22 June 2012 (UTC)

3:It is possible, although plants use CO2 for a carbon source and produce O2, plants alos need to breath in O2 just like animals do. If you placed a plant into a jar of CO2 and gave it no light, it would suffocate to death. In the atmosphere, if CO2 levels rise, so will the global temperature which hurts plants in a vast number of ways, higher respiration (anti-photosynthesis) rates, increased pest levels and spread of pests to previously cold areas, more severe weather events, aka hurricanes, floods, droughts, decreased stability in percipitation, increased rate of evaporation from soils, etc.

4:Greenhouses often increase CO2 levels to increase growth rates, up to 1500ppm (4x normal), over that it begins causing headaches in workers and has diminishing economic returns. I know of greenhouses that burn coal for heating and buy CO2 to pump into because, to paraphrase the owner "the emissions would severly damage the crop"...so he put up a smokestack so the neighbouring farmers can deal with his problem. Unique Ubiquitous (talk) 01:29, 22 June 2012 (UTC)

Exhausts contain more than just CO₂. They may also contain CO and NO_x which are bad news for animals (including people). I don't know what they do to plants though. Is there an eqivalent of heme in plants? 203.27.72.5 (talk) 01:33, 22 June 2012 (UTC)

Several pollutants are known to mess with a plant's stoma. Either they force the stoma shut when it should be open - reducing CO2 uptake thus stopping photosynthesis, or forcing them open when they should be closed - increasing water loss to critical levels. By heme, I expect you mean something for gas transportation? If so, then no, live plant cells are never too far from the air, I say live because cells say in the middle of the trunk of a tree are dead and don't need air. Cells, apart from the epidermis, are kinda loose allowing air to diffuse through the air spaces between them. And yes, roots also breath on their own and for plants like rice, which grow on flooded land, they have special air spaces which go from the above water plant to down below. Unique Ubiquitous (talk) 02:42, 22 June 2012 (UTC)

To answer the OP's question 4: It is not practical for factories and processing sites to set up a greenhouse next door, as the land area required is huge. And its not necessary - oxygen and carbon dioxide difuse through the atmosphere with great facility. The percentage oxygen and percentage carbon dioxide in the air is negligibly different whether in rainforrest areas, deserts, or major industrial areas. Rainforrests in Indonesia can deal with carbon dioxide emitted in Australian industry for example. What we need politicians world wide to do is act more strongly to protect, nurture, and grow green plant areas. Wickwack120.145.68.66 (talk) 03:46, 22 June 2012 (UTC)

Actually, we'd be better of in terms of CO₂ sequestration if we grew green plant areas and then cut down all of the trees and stuck them somewhere where the cellulose won't break down and then grow more trees on that land and repeat. Also, massive sources of CO₂ are often located far away from built up areas (i.e. coal/gas fired powerstations, smelters, etc.) so the land requirements aren't the big issue you make them out to be. Also, the comments about CO₂ from Australia being dealt with by Indonesian rainforrests misses the OP's point; you can use the very high concentrations in exhaust gas to speed up the process. 203.27.72.5 (talk) 03:55, 22 June 2012 (UTC)

Yet for some reason we do the opposite, taking the stored carbon from out the ground and throwing it into the air for all to suffer from...there is no point in starting to sequester so long as we are digging up fossil fuels. Unique Ubiquitous (talk) 04:47, 22 June 2012 (UTC)

Sure there is; to reduce the net effect. If we did it enough we could even be carbon neutral through this process. I'm sure greenies would love that, "Save the Earth by cutting down old growth forrests, sequestering their carbon and planting fast growing weeds!" 203.27.72.5 (talk) 04:55, 22 June 2012 (UTC)

There's something called "Carbon capture and storage" that will reduce the released CO₂ by 80-90%, but will also consume 25%-40% more fuel and thus increase the cost with 21-91%. However with successful research, development and deployment (RD&D), sequestered coal-based electricity generation in 2025 may cost less than present unsequestered coal-based electricity generation. Electron9 (talk) 10:00, 22 June 2012 (UTC)

Deflecting a lead bullet with a magnetic field

Hi, I found this discussion on repelling bullets with a magnetic field. Since most bullets are made of lead, is it indeed possible to deflect bullets with a strong enough magnetic field, either using lead's diamagnetic properties, or eddy currents, or something else? How would this work? --Kreachure (talk) 02:29, 22 June 2012 (UTC)

If you shot a lead bullet at a magnetar, yes it would probably be deflected by the magnetic field. It would also be attracted by the extreme gravity, so catch-22. If you tried to make a massive magnet that would appreciably deflect lead bullets away from you, it would also cause damage to your tissues due to the diamagnetism of water (the effect a magnetic field has on water is about half of what it has on lead). 203.27.72.5 (talk) 02:44, 22 June 2012 (UTC)

Ah, interesting. I suppose the user of such a magnet would require a magnetic shielding suit of some sort to be effectively protected. Or is it too optimistic to think that the material's permeability wouldn't fail under such a powerful magnetic field? --Kreachure (talk) 03:16, 22 June 2012 (UTC)

The issue isn't magnetizing the user, but exerting magnetic force upon him. While the former is bounded as you suggest, the latter is not. Someguy1221 (talk) 03:19, 22 June 2012 (UTC)

Hmm, I don't follow. Isn't being inside a magnetic field required for magnetic forces to be felt? Magnetic shielding not only prevents magnetization, but "isolation from external magnetic fields" as the article says. What do you mean by "bounded"? --Kreachure (talk) 03:32, 22 June 2012 (UTC)

Sorry, I think I misread what you said. I thought you were saying that good shielding wasn't necessary because a material can only be magnetized so much. Also, see bounded function and boundedness for other uses. Someguy1221 (talk) 05:22, 22 June 2012 (UTC)

While my understanding is that you could shield the user from the magnetic field using concentric spheres of magnetically permeable metals, that metal in and of itself would probably be sufficient to stop the bullets. Then you'd only need to turn on the magnetic field to kill your enemies once they get close enough... 203.27.72.5 (talk) 04:13, 22 June 2012 (UTC)

In case the Mythbusters are an acceptable source to you, it may be worth noting that they played around with how powerful a magnetic field was necessary to significantly alter the path of a bullet in flight. [2] Jwrosenzweig (talk) 06:21, 22 June 2012 (UTC)

That website seems to be saying that the bullet was attracted by the magnetic field. If the magnetism was causing that effect those magnets would be very difficult to handle; since they apparently attract diamagnetic substances (assuming the bullets were Pb) they'd stick to flesh. Maybe there's more complex physics at work to explain why that happened. Or maybe it's just bollocks. 203.27.72.5 (talk) 07:11, 22 June 2012 (UTC)

Maybe the magnets were pulling the gun out of it's precise position and causing it to point further downward than before. 203.27.72.5 (talk) 07:15, 22 June 2012 (UTC)

Most modern bullets have a copper jacket around the lead core. They also spin at very high rates, modeling the induced eddy currents in such a situation is not easy. Roger (talk) 14:17, 22 June 2012 (UTC)

I just watched the Mythbusters episode. I'm pretty sure they used bullets either made of something other than lead, or made of lead jacketed with metal (copper, cupronickel, etc.). I'm gonna go with Ockham's Razor (usually a good idea :) ) and say that this is why the bullet was attracted to the magnets; and not because of "complex physics" or "experimentation flaw" (or "bollocks"). --Kreachure (talk) 15:37, 22 June 2012 (UTC)

But copper is also diamagnetic. 203.27.72.5 (talk) 20:15, 22 June 2012 (UTC)

Fine, not copper then. --Kreachure (talk) 23:31, 22 June 2012 (UTC)

And I wouldn't say they spin at very high rates at all. A typical rifling twist rate in a semi-automatic pistol is 1 revolution per 30". 203.27.72.5 (talk) 20:56, 22 June 2012 (UTC)

Eddy currents have easily observable effects, If the poles of a fairly strong magnet have a small gap between them, and you drop various flat pieces of material between them, non-electrically conductive substances like plastic and wood seem unaffected and drop as if there were no magnet there, but copper or lead seem to hesitate and slide v-e-r-y s-l-o-w-l-y through the gap. If a spinning disc of aluminum or other conductive material has an ordinary permanent magnet brought near it, it slows dramatically and noticeably. If a lead bullet were fired at a distant target, and early in its flight passed through a magnetic field achievable with common means (neodymium magnets near the path, or a modest electromagnet, even a small deflection would cause it to miss the aiming point far away at the end of the trajectory. The closer the magnet is to the target, the more extreme the magnetic field would have to be to modify the path meaningfully. All in all, deploying magnets to deflect bullets does not seem practical, compared to spending the same money and effort to build a barrier, or detection systems and weapons to shoot the shooter before he pulls the trigger. Edison (talk) 14:39, 22 June 2012 (UTC)

If the bullet is stopped in a bullet proof vest then the forces that make that happen are ultimately electromagnetic in origin. Count Iblis (talk) 17:57, 22 June 2012 (UTC)

Why are mammals smarter than other animals?

Not sure if this question has any meaningful answer, but I thought I would throw it out there. I was just reading Great white shark and I just thought to myself, why are they so dumb? Especially compared to Orcas. Assuming that mammals are indeed (typically) smarter than other animals, which I believe is true. But why is this? Is there a correlation with warm bloodedness and intelligence? Is it just that some mammals happened to (coincidentally) evolve intelligence, and then from there animals that evolved from them were intelligent as well? Dolphins are intelligent... Orcas are intelligent. Pigs are intelligent. Dogs are intelligent. Great apes are intelligent. Humans are intelligent. Seems that animals that eat meat are typically more intelligent that herbivores. But if I'm not mistaken we have a closer common ancestor with deer than we do with dolphins right? Not sure. In terms of lifespan, do mammals typically live longer than other animals? ScienceApe (talk) 04:21, 22 June 2012 (UTC)

Some birds are also very intelligent, such as crows. They are also warm blooded and many eat meat. A large brain does have a high energy demand, and energy density is higher in meat than in vegetation. Octopuses are apparently quite intelligent too. Hunting also requires a high degree of intelligence, so carnivores have an advantage in the evolutionary selection there. 203.27.72.5 (talk) 04:32, 22 June 2012 (UTC)

(ec)No, some of the longest living animals are reptiles, in the turtle family specifically. Also, there are some intelligent birds, like parrots, and even intelligent cephalopods, like cuttlefish. StuRat (talk) 04:29, 22 June 2012 (UTC)

Whales also have a very long lifespan. Trying to work out an average for two entire classes so you can compare them is both difficult and largely meaningless though. 203.27.72.5 (talk) 04:36, 22 June 2012 (UTC)

A higher body temperature and both a greater relative and absolute brain size. μηδείς (talk) 15:10, 22 June 2012 (UTC)

Anecdotally, my vegetarian friends are also much dumber than their meat-eating counterparts.Just kidding...friends don't let friends become vegetarians.203.27.72.5 (talk) 04:41, 22 June 2012 (UTC)

Paging Dunning–Kruger. Would Mr. Dunning & Mr. Kruger please come to the RD. --Tagishsimon (talk) 14:01, 22 June 2012 (UTC)

I don't know what relevant commentary they could have on the matter. Their hypothesis involved inept people who judge themselves to be better than they really were and vica-versa. My comment compared two groups of other people. 203.27.72.5 (talk) 22:29, 22 June 2012 (UTC)

• Deer and dolphins are actually pretty closely related; they both belong to the clade Cetartiodactyla. Regarding the main question, I think the answer is a combination of (1) mammals have larger brains in relation to body size; (2) mammal brains use myelinated axons, which make their internal connections much more efficient; (3) only mammals have a fully developed cerebral cortex. Looie496 (talk) 06:46, 22 June 2012 (UTC)

Also keep in mind some arthropods are very intelligent, and some mammals are very stupid. Salticids, particularly Portia labiata are said to "have hunting tactics as versatile and adaptable as a lion's" (see ref in our article). I think it is a general trend that, for a certain clade, predators tend to be more intelligent than herbivores. Omnivores may be smarter yet, such as the new caledonian crow, or the raccoon. Both of these can work simple latches to escape cages, and the former is celebrated for its tool use. SemanticMantis (talk) 13:10, 22 June 2012 (UTC)

Some insects/arthropods may appear to be intelligent, but, due to their brain size, that can't be true intelligence, but rather all instinct. The way to test this theory is to expose them to situations not encountered in nature (like the monkey that has to stack boxes to get the banana) and see if they can design a strategy to solve those problems, or not. StuRat (talk) 19:06, 22 June 2012 (UTC)

If you touch a cockroach often, does it have an instinct to start running farther and more furious as that's something that might happen in nature? If so, is it's instinct so good that it only displays the heightened response to things that look like what's chased it before, for example, things that look like shoes? Sagittarian Milky Way (talk) 17:33, 23 June 2012 (UTC)

Possibly. We seem to have similar instincts. For example, if we see insects, we then have a heightened sense of awareness and sensitivity on our skin, even to the point of imagining bugs crawling on us that aren't really there. However, insects probably do have a small ability to learn, only in their case it's like 10% of their behavior versus 90% for us. StuRat (talk) 20:05, 23 June 2012 (UTC)

I think mammals are relative latecomers, evolutionarily, thus they had to find a niche or an advantage that could allow survival, and intelligence provided that edge over the non-mammalian population that dominated the Earth. Intelligence itself is not good for anything under evolutionary pressure—except for survival. If intelligence helped mammals to survive then it would continue to accompany them in their competition for survival with one another, thus we have mammals competing with one another on the basis of intelligence, leading to greater intelligence in some species of mammals. But as humans we have to bear in mind that there is nothing intrinsically valuable about intelligence. It is merely one more factor that probably has bearing on the survival of a life-form. Bus stop (talk) 13:42, 22 June 2012 (UTC)

It's also worth remembering that from an evolutionary point of view, very high intelligence is pretty clearly a fluke (one species in 10 billion or so over Earth's history), and humanity has yet to demonstrate that high intelligence is, in the long run, a positive evolutionary adaptation (the last 300 years have been hell-bent on a path to unsustainable self-destruction; the last 10,000 years of civilization may prove to be just a weird blip on the evolutionary timeline). --Mr.98 (talk) 14:06, 22 June 2012 (UTC)

If you are talking about human intelligence, I agree, but a fair degree of intelligence seems to have developed independently on Earth several times. Right now we have some birds (crows, etc.) and octupi/squid/cuttlefish, in addition to mammals (some of which, like aquatic mammals, aren't very close to us). In the past, there were probably several others cases of intelligence developing independently. StuRat (talk) 04:16, 23 June 2012 (UTC)

And, in the same vein, there is not much of a correlation between intelligence and success. For instance, assuming that we are the "most successful" species on earth (beetles might disagree), one might expect chimps and bonobos to come up second; but they don't. In fact, the whole primate family doesn't make much of a dent. An for all the greter intelligence of carnivores over their prey, it would be hard to argue that the vast herds of herbivores which roamed the earth, from the bison to the elephants, were less successful than the wolves and big cats. Of course, this is all kind of off topic to the original poster. Gzuckier (talk) 02:23, 25 June 2012 (UTC)

"unsustainable self-destruction"? That's the one thing that doesn't need sustaining, 'cause it's once and for all. —Tamfang (talk) 03:50, 25 June 2012 (UTC)

Have to agree with Mr.98. IQ measurements seems to centre around solving puzzles dreamt up by other people who find solving puzzles fascinating and an end to themselves. Yet Mensa members can be found among the welfare queues because they can't feed themselves. Real intelligence means being able to survive this short sojourn on earth and eating and producing offspring before getting eaten oneself. Even the humble Cockroach has been around about 350,000,000 obits of this blue and green planet and it succeed in trained the Homo sapiens to provide the cockroach kinship with nice comfy all year round habitats and regular supplies of food. However, mice have long since overtaken both the cockroach, and Alan Turing. --Aspro (talk) 14:51, 22 June 2012 (UTC)

Just wait until the birds set an intelligence test for humans to take. HiLo48 (talk) 00:03, 23 June 2012 (UTC)

No problem. Us bird brains, will all come up with top marks... Oh hell,... that might just be part of the their cunning avifaunian plan. :-( --Aspro (talk) 01:00, 23 June 2012 (UTC)

Clindamycin

When and how was Clindamycin discovered?--Jsjsjs1111 (talk) 05:37, 22 June 2012 (UTC)

This article from 1970 says that the drug was "newly developed" from lincomycin. 203.27.72.5 (talk) 06:32, 22 June 2012 (UTC)

(edit conflict) 1966, modified from Lincomycin ("Chemical Modifications of Lincomycin", Antimicrobial Agents and Chemotherapy (1961-70) (1966), 1966, 727-36.), is the earliest reference I can find to it. Buddy431 (talk) 06:41, 22 June 2012 (UTC)

Here's a 1970 paper on its synthesis. It probably has the information you're looking for, but it's behind a pay wall. 203.27.72.5 (talk) 06:42, 22 June 2012 (UTC)

Apparently its synthesis was first announced in 1965 at the Fifth interscience conference on antimicrobial agents and chemotherapy by Robert Birkenmeyer, et al. 203.27.72.5 (talk) 06:50, 22 June 2012 (UTC)

Thank you very much! BTW, your IP address looks oddly familiar. You're from Brisbane?--Jsjsjs1111 (talk) 07:20, 22 June 2012 (UTC)

I'm in the NT, but my organisation is headquartered in Brisbane, so maybe that has something to do with it. 203.27.72.5 (talk) 07:23, 22 June 2012 (UTC)

Explosive question

In the news, whenever I hear about the number of people died and injured in a bomb explosion, the number of people injured is usually higher than those killed in it (a natural consequence of the fact that the bomb's destructive power is higher in lower distances, but the number of people is less in the area covered by that distance, but the destructive power is less in higher in further distances, while more people (area) is covered in that distance) now my question is, can people speculate what kind of a bomb used only knowing the number of the killed/injured and the <average> population area density at that time of the day in that place? Has it ever been done? How good an estimate is it?--Irrational number (talk) 09:25, 22 June 2012 (UTC)

Depends exactly what you mean. Firstly, yes, people can, and will, always speculate on just about everything. Secondly, if there is a massive death toll over a wide area it may be safe to assume the bomb was nuclear or even thermonuclear. Since you're probably talking about people being killed in the middle east or north Africa by IEDs and suicide bombs (unless you happen to be reading a newspaper from 1945), it would be much easier just to guess based on what the most common type of terrorist explosive is in that region. 101.171.127.238 (talk) 09:58, 22 June 2012 (UTC)

(EC)No. A small amount of a powerful explosive is presumably as destructive as a larger amount of a less powerful explosion. SO that rules out knowing exactly what sort of bomb you're dealing with. The vaguries of the position of the bomb, the environment in which is is placed, and a whole host of other uncontrolled variables would entirely frustrate the sort of analysis you;re looking for. --Tagishsimon (talk) 10:01, 22 June 2012 (UTC)

You can't determine the type of bomb, but you can estimate the explosive yield (that's a red link... try TNT equivalent - can anyone find a better article to redirect it to?). There is a whole field of study into estimating yields based on damage and injuries and things. Once you know the yield, you may be able to make a guess about what kind of bomb is likely to have that yield, but generally Tagishsimon's point is true and you can't distinguish between a small amount of high explosive and a large amount of low explosive (except from context - if you know who made the bomb you'll know what they usually use or what they have access to). --Tango (talk) 11:30, 22 June 2012 (UTC)

Another thing to consider, is that the detonation wave from say a 60lb charge is only about 50 feet. This wave can rupture lungs and things, bringing about eventual if not immediate death. Yet a bomb loaded with ball bearings and other such objects, can cause injures many times this distance. --Aspro (talk) 15:05, 22 June 2012 (UTC)

I was thinking that a shrapnel bomb might have a greater lethal/total injury index (to coin a phrase) than just an explosive of the same power, in that the additional blood loss from various wounds would probably provide significant additional lethality versus just the shock wave trauma you describe above.Gzuckier (talk) 02:27, 25 June 2012 (UTC)

The blast wave of a real bomb in an urban environment is by no means spherical; it follows the obstacles in its way. If the bomb happened to be under a car, the death toll will likely be small, especially if the only people around that car are surrounded by other cars. If it goes off in an open market square and sends shrapnel everywhere, many more people will be killed. Even putting the bomb behind a table leg can provide enough shielding to save someone on the other side of the table leg, as evidenced by the 20 July plot. --140.180.5.169 (talk) 05:06, 23 June 2012 (UTC)

Nuclear fusion in black holes

Could nuclear fusion theoretically occur in or around a black hole? If not, why not? And if so, what kind of superheavy elements might be synthesised? Evanh2008 ^{(talk|contribs)} 10:45, 22 June 2012 (UTC)

Nothing of any meaning to human comprehension can happen "in" a black hole. Around it, yeah potentially fusion could happen, especially if it's a quasar. Neutronium might be made there. That's not really an element though since even if you take it to be a nucleus, it's atomic number is still zero. It's pretty heavy though. Strange matter could also be made there, shortly before plunging into the blackhole itself. 101.171.127.238 (talk) 11:11, 22 June 2012 (UTC)

Since when is an atomic number greater than zero a definition requisit for an element? Plasmic Physics (talk) 11:24, 22 June 2012 (UTC)

Well, an element is a category of atoms with the same atomic number, and atoms are a nucleus surrounded by a cloud of electrons. Neutrons cannot hold electrons, so they cannot form atoms by themselves, therefore neutronium cannot be a chemical element. That's just my logic in deriving my conclusion though. It's such an inconsequential grey area that I don't think anyone really cares whether or not neutronium is considered an element. 101.171.127.238 (talk) 11:40, 22 June 2012 (UTC)

An atom is a nucleus, composed of x protons and y neutrons, surrounded by x electrons. In neutronium, x = 0, so there are 0 protons, y neutrons, and 0 electrons. So despite the lack of electrons, neutronium is still an element, composed of atoms. Whoop whoop pull up ^{Bitching Betty | Averted crashes} 14:33, 22 June 2012 (UTC)

By the way, if an atomic number of zero can still be an element, can an atomic weight of zero also constitute an element? That would make the lightest isotope of neutronium nothing. I'm going to name it now (assuming I'm the first to consider this). I shall call it vacuumium. It's the most plentiful element in the universe. 101.171.127.238 (talk) 11:42, 22 June 2012 (UTC)

Last time I checked, a simple neutron does not weigh nothing. Why are electrons required for an element, neutronium consists of nucleons. There are several arguements available from acedemic sources, supporting the classification of the neutron as element 0, under several proposed names: Neutrium, Neutronium, Nilium, Nihilon, or just Neutron. Plasmic Physics (talk) 13:31, 22 June 2012 (UTC)

I think the point was, that if neutronium is an element, and you removed one neutron to make a lighter isotope of neutronium, you'd have nothing left. 203.27.72.5 (talk) 22:32, 22 June 2012 (UTC)

That's true, I'm not argueing against that. What does that prove though? Plasmic Physics (talk) 01:13, 23 June 2012 (UTC)

Nothing. It just forms the basis of a reductio ad absurdum that results in the vacuum being considered an isotope of neutronium. The debate is just over semantics anyway. Call it an element, don't call it an element, potato, potata. 203.27.72.5 (talk) 03:38, 23 June 2012 (UTC)

Yes, that would be an extreme interpretation to the point of being absurd. It ventures into the domain of philosophy, akin to the 'nothing' paradox: any definition of 'nothing', leads to the logical conclusion that 'nothing' is 'something'. Therefore 'nothing' cannot exist. It is not absurd to say that a glass is empty, it is absurd to say: I have a glass of water, it contains 0 mL of water. Plasmic Physics (talk) 05:57, 23 June 2012 (UTC)

Does anyone really say potata? Plasmic Physics (talk) 05:58, 23 June 2012 (UTC)

I think so, but the pronounciation of the second a is like in tater tots. 203.27.72.5 (talk) 06:14, 23 June 2012 (UTC)

thumb|The Immaculate Spaghettification

Contrary to 101.171.127.238's answer, it's certainly possible for nuclear fusion to occur inside of a black hole. From the perspective of an object that falls into a black hole, spacetime is locally unremarkable as the object crosses the event horizon. So for example if a star undergoing fusion falls into a supermassive black hole, there's nothing immediately that would stop the fusion within the star from continuing after it crosses the event horizon. (The same can't be said after the star hits the gravitational singularity, though.)

However, there's nothing particular about falling into a black hole that would cause nuclear fusion to occur. As you get further inside of a black hole, tidal forces become extremely strong, eventually resulting in the spaghettification of infalling objects. However, in spaghettification, the compression experienced along two spatial dimensions is counterbalanced by stretching along the third, resulting in no change in the object's volume. So the tidal forces aren't likely to cause the pressure within the object to get high enough to cause fusion. Of course, all bets are off as to what happens in the very last little bit right near the gravitational singularity. Red Act (talk) 15:17, 22 June 2012 (UTC)

As I understand it, as you fall towards a black hole, there is always a point in front of you from which you cannot observe light returning to you i.e. a point at which the required velocity to reach your eyes is greater than c. That's why nothing remarkable happens, from your perspective you never actually hit the event horizon, it always receeds away from you. When you look out towards the rest of the universe, there will be no event horizon behind you, just a very blue shifted universe. So there is no observer who can see inside the black hole, not even one who to another far away observer has crossed the event horizon. 203.27.72.5 (talk) 22:25, 22 June 2012 (UTC)

Nuclear fusion occurs everywhere you have hydrogen (and other light elements too). You need high temperatures and/or pressures to make the rate significant, but even at room temperature there is a nonzero chance at any given moment that two hydrogen nucleii in a bag of hydrogen will fuse. So, of course fusion occurs around a black hole. If the matter gets hot and/or dense there, then fusion will occur faster. --Srleffler (talk) 03:06, 23 June 2012 (UTC)

I should point out that around black holes is an accretion disk, which is one of the most efficient methods of turning mass into energy. Up to and perhaps exceeding 40% efficiency, which far beats nuclear fusion which is only about .7% efficient. Black_hole#Accretion_of_matter. ScienceApe (talk) 14:41, 23 June 2012 (UTC)

From the article on accretion disks it isn't really clear to me the mechanism that results in matter being turned into energy. Obviously, any chemical bonds will be broken by the heat and pressure releasing their stored energy. The heat and pressure will also be high enough to enable fusion. But what accounts for the really efficient mass to energy converstion? 203.27.72.5 (talk) 23:13, 23 June 2012 (UTC)

(ec)The mechanism would likely still be fusion, simply more complete (higher temperature and repeated) fusion than one finds in main-sequence stars where not all the matter is fused to iron before the star explodes or fusion otherwise stops. Excitation strong enough to create high-energy gamma rays could produce matter-antimatter pairs. However, the energy released by their annihilation would be the same as the energy needed to create the gamma-ray in the first place. The mechanism of gamma-ray bursts, which are short lived, are not understood according to http://en.wikipedia.org/wiki/Gamma-ray_burst#Energetics_and_beaming μηδείς (talk) 01:02, 24 June 2012 (UTC)

No, the mechanism is simple friction. ScienceApe (talk) 01:00, 24 June 2012 (UTC)

How does friction convert mass to energy? Normally friction as I know it converts kinetic energy to heat. 203.27.72.5 (talk) 01:05, 24 June 2012 (UTC)

(EC)That doesn't really add up. If you fuse 2H⁺ to make ²H⁺ then fuse thatwith another H⁺ to give ³He and fuse two of those to make 2H⁺ and ²He, you still have ~6 atomic mass units just like you did at the start. A small fraction is now energy, but not all that much. No where near 40%. Even if you continue through to ⁵⁶Fe, there's no way 40% of the mass is now released as binding energy; and after that point fusion is endothermic. 203.27.72.5 (talk) 01:05, 24 June 2012 (UTC)

Actually, assuming the friction can make gamma rays of high enough energy, it would be the equivalent of the annihilation of matter-antimatter pairs. I was assuming that this would have to be driven by fusion, but I think ScienceApe is correct that friction alone might excite the matter enough to produce gamma rays of such high energy. I am not competent to work that out. μηδείς (talk) 01:15, 24 June 2012 (UTC)

That's still only converting kinetic energy to heat, and then radiating it as a gamma ray, and then creating and annihilating some matter and antimater. There's not net change of matter to energy there. How does the matter become energy? 203.27.72.5 (talk) 01:43, 24 June 2012 (UTC)

But it is a huge amount of heat, and, as I mentioned above, a high energy gamma ray is the energetic equivalent of a matter-antimatter annihilation, so the radiation of the gamma ray itself carries away the mass-energy, no additional annihilation required. μηδείς (talk) 02:15, 24 June 2012 (UTC)

There's an unsourced claim on the article for pair production that says near a black hole, one of the created anti particles could be sucked into the hole before it gets to annihilate, so then there's a net creation of energy from matter only when one particle and not the other gets sucked into the hole and only when that particle is the electron. In the other case where you end up with an electron outside and a positon sucked in, you actually create mass from energy cancelling out the effect of the first case. 203.27.72.5 (talk) 01:59, 24 June 2012 (UTC)

That's Hawking radiation, and it's only significant in small black holes without accretion disks. As for converting matter to energy by friction, shouldn't the kinetic energy of mass falling into a black hole be relatively easy to calculate? I'll leave it to some math or physics major. μηδείς (talk) 02:10, 24 June 2012 (UTC)

Of course it's easy to calculate. It's also completely beyond the point. A huge amount of kinetic energy being converted into a huge amount of heat is just that. A conversion from one form a energy to another. There's no converstion of mass to energy. According to ScienceApe, >40% of the mass can be converted to energy (according to the wikipedia article on accretion discs it's 10 percent and neither of them has cited a source). How does that happen? 203.27.72.5 (talk) 03:18, 24 June 2012 (UTC)

You seem to be missing the fact that black body radiation can be emitted at any energy, and that while it is often called heat, since we equate it in most cases with infrared radiation, it can have any energy, up to x-ray and gamma radiation. Remember, also, that E=mc^2, and hence gamma rays are the equivalent to a certain amount of mass. μηδείς (talk) 03:35, 24 June 2012 (UTC)

I'm not missing that at all. As I said earlier "That's still only converting kinetic energy to heat, and then radiating it as a gamma ray". I know you can radiate internal energy as gamma rays. ScienceApe said "an accretion disk...is one of the most efficient methods of turning mass into energy.". The only possibile interpretation of that is "rest-mass into energy". Otherwise it just becomes "Mass energy to mass energy". Gamma rays are the equivalent of a certain amount of mass, but what mass? What mass is gone? I can see where there was some gravitational potential energy, which became kinetic energy in the motion of the accetion disc, and then friciton converts it to heat which is then radiated as gamma rays. I can't see how any mass went to being energy. 203.27.72.5 (talk) 03:46, 24 June 2012 (UTC)

There are two questions. First is that of the balanced equation. If the kinetic energy is sufficient to create powerful enough gamma rays, they will carry away a certain amount of energy, and hence, by E=mc^2, a certain amount of mass. Surely you agree with that? Second, there is the question of the intermediate steps. There's the rub, apparently, since the sources we have in wikipedia don't seem to give the proposed mechanisms. But that doesn't mean we don't know that we start with a certain amount of friction and end up with apparently 40% of the mass being converted to radiative energy? Or do you disagree at some point? μηδείς (talk) 03:54, 24 June 2012 (UTC)

The second part is fully and absolutely understood. The first part is what I'm having trouble with. The net change is kinetic energy to gamma rays, correct? Yes, mass is equivalent to energy, but if you talk about mass being converted to energy (as ScienceApe did), clearly, you're delineating between rest-mass (which is converted to energy in nuclear fusion) and other mass energy. Gamma rays have no rest mass and kinetic energy is by definition the non-rest-mass component of total energy. The rest mass is therefore unchanged i.e. there is no converstion of mass to energy at all. 203.27.72.5 (talk) 04:27, 24 June 2012 (UTC)

That seems easily addressed. Imagine a particle and an antiparticle next to each other. They are moving towards each other with negligible but real velocity. They touch and are annihilated. A huge amount of energy is released. Almost none of this is from the original kinetic energy of the particles. That is what is happening in the accretion disk. Friction is creating gamma rays. The gamma rays are as energetic as matter-antimatter pairs. Hence they spontaneously create matter-antimatter pairs. Whose relative velocities are negligible, but real. So the pairs annihilate each other. Converting a huge amount of mass into an even huger amount of energy. μηδείς (talk) 04:54, 24 June 2012 (UTC)

Ok, from reading a couple of non-wiki sources on the subject, I think I get it now. The logic of it still seems a bit odd, but I think I know what they're getting at now when they say 10% of the mass is converted to energy (the 40% estimate is now considered wrong because it would require almost all known quasars to have black holes rotating at 99% of the maxiumum allowable speed, and that was based on incorrect early mass estimates of the black holes themselves). If you throw something into the blackhole, friction, and the simple act of radially accelerating charged particles to near light speed causes it to emit light, and the total amount emited is proportional to its graviational potential energy, which is proportional to its mass. The total amount emitted sums to ~10% of it's rest mass. The reason this is a bit odd, is because even after it has emited most of that energy, but before it has crossed the event horizon, it still has the same rest mass it started off with so it's mass is not really being converted to energy. But still, the amount of electromagnetic energy that is extracted is still a fraction of it's mass, and the mass certainly cannot be recovered once it has crossed the event horizon. 203.27.72.5 (talk) 05:11, 24 June 2012 (UTC)

Yes, your saying it emits light now, rather than heat, is the important part. But I myself find it hard to believe or understand that the rest mass stays exactly the same. (Is it just that c in E=mc^2 is so large?) Can you link to your source? μηδείς (talk) 05:38, 24 June 2012 (UTC)

I've just left work, so I don't have the links in front of me, but they didn't discuss the fact that the rest mass stays the same anyway. Whether it's light or heat doesn't matter; gravitational potential energy is converted to light through the various mechanisms, including friction which is by definition the conversion of kinetic energy to heat. The rest mass must remain the same because rest mass is invariant by definition. Imagine a single atom of H flying into the black hole. When the distance is still great, is accelerates towards the hole, as it would towards any other graviational field. At first it emits very low frequency EMF, but as its velocity increases, it goes right through the spectrum to gamma. Tidal forces will strip the electron from it and if it's path curves towards the black hole, it will emit synchrotron radiation. If it bumps into another particle, it will lose kinetic energy and impart heat energy into the thing it hit. The amount of energy it will emit in total is about 10% of its rest mass. But right up until it crosses the event horizon, it will still have ~1 atomic mass unit of rest mass. 101.173.170.147 (talk) 11:03, 24 June 2012 (UTC)

I should also point out guys that a great deal of the mass-energy generated in the accretion disk is imparted to the polar jet aka relativistic jet if the particles are moving at extremely high velocities. The jets are essentially titanic sized particle accelerators. The mechanism for how they are formed is not well understood yet. ScienceApe (talk) 14:22, 24 June 2012 (UTC)

"The rest mass must remain the same because rest mass is invariant by definition" doesn't make a whole lot of sense. Invariant isn't the same as conserved. The rest mass of each of the elementary particles is a constant, but rest mass isn't conserved in general.

When you pull objects apart against their mutual gravitational attraction, you're adding gravitational potential energy to the system. In general relativity that energy is mass and gravitates, so this system's rest mass and distant gravitational field are larger after this procedure than before. That's the "mass" that's being "converted into energy" in the accretion disc. But you'll never get an objective answer to a question about whether mass is being converted into energy in any given situation because the laws of physics just don't distinguish between mass and energy at all. The answer depends on which energy you've chosen to call mass. -- BenRG (talk) 18:02, 24 June 2012 (UTC)

As I understand Wikipedia's article on it, by pulling two objects under mutual gravitational attraction apart, you increase the invariant mass of the system, but the sum of the rest masses of the components remains unchanged. I don't really like the way the article defines those terms though. Why is it called the "invariant mass" of the system if it varies with gravitational potential? 101.171.42.164 (talk) 20:50, 24 June 2012 (UTC)

Invariant here means Lorentz invariant. A quantity that doesn't change over time is called conserved, not invariant. I'm not sure how much sense it makes to talk about the individual rest masses of components of a system when one of the components is a black hole. It may make sense, but I'm suspicious. -- BenRG (talk) 22:28, 24 June 2012 (UTC)

I want to import chemical feedstocks from Chinese suppliers at alibaba.com

This is for a possible laboratory / business to make biochemical products (finished goods) to resell in the United States (to other research labs). Is it true that all you need to do at customs is for someone to "positively" certify that "all chemical substances in this shipment comply with all applicable rules or orders under TSCA and that I am not offering a chemical substance for entry in violation of TSCA or any applicable rule or order under TSCA"? i.e. I could just get a customs broker to do this for me? 72.229.155.79 (talk) 14:30, 22 June 2012 (UTC)

Which China? Whoop whoop pull up ^{Bitching Betty | Averted crashes} 14:34, 22 June 2012 (UTC)

We cannot give legal advice, consult a qualified professional. Roger (talk) 15:32, 22 June 2012 (UTC)

This is not legal advice, just the obvious: Quite simply -don't try. Iodine, pseudoephedrine, phosphorous, hydrogen peroxide and a host of others are just some of the chemicals one can buy freely abroad. When it comes to biochemicals you are getting into a minefield. Unless you are already an established US business with good paper trail audits (and ways of fiddling them when there are not so good) and millions to spend lobbing those in high government office that you are really the good guys. Then you are open to letting your competitors to get you arrested for supporting terrorism, attempted insurrection and anything else they can dream up that sounds impressive on Faux News. The present laws, regulations and what-not have been angled to keep the small guy out of it.--Aspro (talk) 15:37, 22 June 2012 (UTC)

Whatever your personal opinion, please don't use this desk to mock Fox News Channel. DriveByWire (talk) 20:00, 24 June 2012 (UTC)

As you know Faux is French for false. I don't live in the US! If fox news has has gained this moniker (and by Googling -I see that they have - it a US news channel right) -that is their problem. Now that you have brought it to my notice however, I'll give you others option on this channel that I've found by Googling. It sucks! An' if you singled out an other Faux News channel ( I meant it in the generic) I might have possible Googled the same thing. So by what right do you think you have to tell me what adjectives to use to agree with your personal feeling of fairness and NPOV in your autocenrtic world? --Aspro (talk) 20:41, 24 June 2012 (UTC)

why don't swampies use non-exchanging heat exchange with air?

Resolved

reading the "swampy" (evaporative cooling) article, most problems seem to be related to the humidity it generates. But why not just use a swampy in a gridlock maze of long (very large surface area) celophane compartments filled with air but with a maze structure such that the inside air is actually cut off from the swampie-cooled air, and the latter circulates out of the house at the end of the maze? Then you would have the cooing effect without the humidity, at a cost of almost 0 in materials and a very low volume of sacrificed space (representing a huge surface area of exchanged heat).

what I mean is that the exchange should be conductive through the celophane between the swampie-cooled air and the inside air. at the end, the swampie-cooled air becomes warmer and the inside air becomes colder, but the inside air isn't filled with humidity. thoughts? — Preceding unsigned comment added by 188.6.90.91 (talk) 18:28, 22 June 2012 (UTC)

What article are you reading? Our article called "Swampy" is about a person. --Tango (talk) 18:38, 22 June 2012 (UTC)

Evaporative cooler. StuRat (talk) 18:52, 22 June 2012 (UTC)

Because inevitably most of the "coolth" is carried away with the water vapor. And, in the dry climates where an evaporative cooler works well, the added moisture inside is actually welcome. StuRat (talk) 18:55, 22 June 2012 (UTC)

What do you mean? Given enough surface area in a tunnel-shape, by the time the swampie (topologically "outside") air gets to the end of it it will be in equilibrium with the inside air. i.e. both be warm. I imagine it like this:

100 s> 75 -> 76 -> 77 -> 78 -> 79 -> 80 -> 81 -> ... -> 87 -> outside
-------------------------------------------------------...---------
100 -> 99 -> 98 -> 97 -> 96 -> 95 -> 94 -> 93 -> ... -> 87 -> inside

i.e. the swampy cools the air down a lot, but it's very moist. By the end it's at equilibrium. If you don't want to "waste" the heat difference between 87 and 100, you can again use the difference between 87 and 100 to cool some of the air before it even enters the system through a second loop (again it's closed so it doesn't make the newly entering air any wetter, just colder). Then the air would enter at e.g. 90 instead of 100, if 90 is the equilibrium temperature between 87 and 100. You see what I'm getting at? You can get the two things to equilibrium if you just expose a long surface area through conductive celophane. This can be bundled up in a maze-like structure that is topologically equivalent to the above... --80.99.254.208 (talk) 19:23, 22 June 2012 (UTC)

in other words, if my calculations are correct you can make a swampy arbitrarily close to an "perfect air conditioner" (not wet and humid output) without wasting heat, by increasing the number and length of loops to arbitrary length. Of course, if you have to add another 100 meters of heat exchange wall to keep from emiting 98 degree humid air instead of 99.2 degree humid air (when the outside is 100 degrees), then it's probably not worth it. So you would probably draw the line and say: We will capture 96% of the swampy's cooling power and let it exit slightly cooler than the outside air because we don't want to build a long enough exchange to equalize over such a small temperature differential. But the point is initially the temperature differential is quite large, and the closed exchange wouldn't have to have a prohibitively large inner surface area, would it? Link title — Preceding unsigned comment added by 80.99.254.208 (talk) 19:30, 22 June 2012 (UTC)

( note that this is our relevant article: http://en.wikipedia.org/wiki/Heat_exchanger ) — Preceding unsigned comment added by 80.99.254.208 (talk) 19:31, 22 June 2012 (UTC)

• I lived in Tucson for 20 years and relied on swamp coolers for most of that time, so I can answer this question from personal knowledge. First, the added moisture is definitely not a benefit, because it makes the air feel muggy in spite of being cooler. But regarding the main question, the thing you have to realize is that swamp coolers are only moderately effective at best, and anything that makes their effects less direct would make them essentially useless. I don't follow the calculations above, but the conclusions have nothing to do with reality. Looie496 (talk) 22:59, 22 June 2012 (UTC)

If I understand the OP's idea/question correctly, he is talking about using water evaporation to cool air drawn in, as in anormal "swampy", but instead of using that now cool and high humidity air inside the building, pass it through an air-to-air heat exchanger (maze in the OP's words) to transfer the "coolth" without the humidity. This idea is quite valid, and has been tried in remote areas of Australia, where the only electricity available is local solar power - so energy consumption by aircon must be kept to an abolute minimum, due to solar power cost. It works just fine, bu the trouble with it is the huge size of the heat exchanger (termed "flat-plate counter-flow" heat exchangers) actually required - the ones I have seen have the heat exchanger occupying the same volume as the building. A number of patents have been granted for manufacturing methods to get the leargest possible surface area without requiring prohibitive power to force the air through the heat exchanger - this is the reason for the huge size. You can make the heat exchanger small, and by suitable laborithian design, get enough surface area. But then the air path will be too tortuous and require too much fan power to force the air through. Huge size means high cost as well - essentially, if you need to to build a building twice as big as what you need for its' function, it will cost twice a much as well.

Another problem is that the heat exchnager must be kept scrupulously clean inside. Only a small amount of dust on the plates significantly reduces heat transfer and obstructs air flow. And wasps and other creepies reckon its a good place to set up residence. This means high maintenace costs.

On the other hand, using a cooling system like this in conjunction with solar power gneration makes some good sense, because you get maxium solar power during the heat of the day on hot summer days - just when you need cooling. So if you size the solar panels for adequate power in winter, you have some excess power in summer to run the fans in the airconditioning.

Keit58.164.229.57 (talk) 03:52, 23 June 2012 (UTC)

That's right Keit. (I'm the OP here.) I am glad to know the invention works and has been used by others. In fact I have over 3000 ideas in every branch of humanity that fall into four categories and a separate category (5): 1) things I think are "very easy" (like two lines of code, e.g. a single SQL join, but nobody has thought to do it or knows why it works), 2) moderately difficult (things that I have completed and can, for example, patent, but would take an R&D budget to refine into something you can start selling), 3) mostly finished or risky (not completely ready to write the patent or don't have complete design specs, however the idea is finished) 4) not sure I could do it myself (working on it, but I have a proof that it is physically possible), 5) not really the same category as the others, but "probably possible" (strong evidence but no proof that it would work), this means it is not done (e.g. I've devoted time to it and have reason to do so but the problem is open to me. It may be impossible or I may hear of another team's solution.)

Without including any of the fourth or fifth category, I am happy to share all 3000 ideas with someone who would finance the "best" of them. I propose the following methodology: I send you 3 thousand ideas each encrypted with a different private key, you pick a random selection of 50 of them, giving me the numbers that you have selected, and I will share the keys for those numbers. This makes it statistically impossible for me to "fluff" the number or quality of the ideas. You evaluate the fifty (much as you evaluated the present idea) and seeing the merit in them begin to fund me as a 1-man R&D firm. Straight up-front I would like funding for a great many patents, some web apps, and other practically no-cost ways to begin certain businesses. As I fbegin to accrue IP I will be able to seek outside funding and pay you a return on your initial investment. Obviously, the reason I have 3000 solid ideas to my name is that I have devoted a great deal of thought to working them out. Initially I will invest your money in filing for several patents - those most easily manufactured - and then immediately begin to shop them around to very large companies. the total cost here is about 5000-7000 buckses (based on my initial research). I believe no follow-on investment will be necessary before I can pay you a big multiple of your investment, and of course the patent may be joint if you require or until you have been repaid on your investment it can be assigned to you. all this is after you review the 3000 ideas (that is, a statistically significant sample of 50 you choose at random). Please let me know if you are interested. You may reach me at ranbir.bacchan at gmail.com. I hope to hear from you. --84.3.160.86 (talk) 15:41, 23 June 2012 (UTC)

Um I think you've misunderstood where you are. This is the wikipedia reference desk, not a venture capital firm or the Dragons' Den internet edition. I suggest you put some thought in to finding appropriate places to ask for funding rather then spending all your time coming up with random ideas then spaming about them to random places. You may also want to look in to whether your ideas have already been tried before spending too much time on them, or asking for funding. Alternatively, perhaps rather then coming up with 3000 ideas, spend more time on one idea and then perhaps when it makes the megaloads of 'buckses' you expect, you can self fund the other 2999. Nil Einne (talk) 16:36, 23

Hi, I was surprised that this has already been done and works. I wasn't sure, it's outside my main areas of expertise. I'm not looking for venture capitalists and I don't have a company. I'd just like to monetize a great many ideas with a partner, such as the one who evaluated this one. The monetary needs are minimal, such as the collaboration between a certain mathematician and Mr. Hardy. It wasn't really about the money. At any rate I've put a "resolved" next to this item. I do appreciate that your suggestion not to "spend all my time coming up with random ideas" is probably appropriate to most traditional businesses, and I have nothing to say on this subject. 84.3.160.86 (talk) 17:41, 23 June 2012 (UTC)June 2012 (UTC)

Agreed. I also list possible invention ideas I have, but more like 30 than 3000. The difference is that I try to filter out the impractical ideas and those which have already been done, neither of which have any any financial value. I suggest you go through that filtering process on your own ideas, before searching for investors. StuRat (talk) 17:35, 23 June 2012 (UTC)

The "filtering process" I have resources for is to separate great, workable ideas from ones that don't work or can't work. The question here has done just that for one of the category 4/category 5 ideas. I don't currently have the resources to see which have been independently discovered by other people and which have not. This is part of the patent-application process, which costs a few hundred buckses in attorney's fees. At any rate the offer is not to evaluate 30, but a random sampling of 3000 patentable or and marketable ideas. These are not business plans. I'm not soliciting an investment but given your helpful nature in evaluating my question - and thus resolving it - if you would like to get in touch with me I've told you how. 84.3.160.86 (talk) 17:41, 23 June 2012 (UTC)

Obviuosy none of you here are VC's, but I also don't think a VC is equipped to evaluate any mechanisms of the type that I have. They evaluate busineses. To be clear, I don't have a business. You are saying I shouldn't get involved with anyone who isn't already rich? No matter how talented and able to evaluate mechanisms and patentable processes in many disciplines, which is what I would like. 84.3.160.86 (talk) 17:55, 23 June 2012 (UTC)

And Sirs, I apologize if I have offended you. Perhaps as a separate question we can find a better forum for me, I do not think the VC plan is appropriate. 84.3.160.86 (talk) 18:00, 23 June 2012 (UTC)

On the chance that the OP genuinely thinks he has a stock of good ideas, and is not spamming/trying to find a sucker with cash, here's some further advice:-

1. People who think up literally thousands of good ideas are 10 a penny. But folks who think up good ideas that have have not been tried before are very rare.
2. If you think you have a good idea, keep it to yourself. Park it in the back of your mind. Over the next 3 months, 3 years, or whatever, consult relavent trade and academic journals - 99.99% or the time you will discover your idea is not new.
3. Read up appropriate textbooks and skill up on the applicable theory. This will either reveal that it has been done before, or why it's not a good idea after all.
4. Try and work out what the terminology/nomenclature of the various parts would be. Then web-search on this terminology. That will a) reveal further that it has been thought of before, & b) lead you to the right terminology. True understanding of technology is 70% knowing the terminology and 30% mastering relavent text book theory. Only with true understanding can you correctly filter good ideas from bad.

I have been a technician and succesful professional engineer for over 40 years. I too over the years have had thousands of "good ideas" for new products. But, using the above 4 principles, I have eliminated all but a dozen or so, and only a couple of things have had commercial success. Which leads me to one more principle, perhaps the most important of all:-

5 Commercial success depends principally on a) good marketing b) adquate finance c) excellent risk management and business management skills. Comming up with the good technical idea is just a tiny part of it. A person with a good idea but no business skills linking up with a person who has a bag of money but no technical skills or business skills generally just means a depleted bag of money and dissapointment. Succesfull venture capitalists are the way to go, but they won't just fund on an idea - they'll want a comprehensive package. If they don't, they are fools. Keit120.145.65.23 (talk) 03:56, 24 June 2012 (UTC)

Why do Neon lamps burn out?

I have several electrical devices, such as power strips, which have a Neon lamp to indicate the power is on. After a few years use, they flicker, or do not light at all, or go on and off randomly. They are cold cathode gas discharge devices, and there is no hot filament to burn out, as in an incandescent lamp, and they are just a resistor in series with the neon bulb, so there is not ballast or starter to fail, and no phosphors inside the tube to fail, as in a fluorescent lamp. So what gets "used up" in a neon lamp, when it is not operated at excessively high voltage or current? How many hours does a neon lamp such as an NE-2 operated, on average, before failure? Edison (talk) 20:30, 22 June 2012 (UTC)

The metal that makes up the electrodes evaporates over time. They may not be hot to you but metal atoms are getting continuously knocked off. Eventually the normal voltage is not sufficient to strike an arc. Place same flickering lamp across a transformer that provides a higher voltage and the lamp will shine brightly again. --Aspro (talk) 22:08, 22 June 2012 (UTC)

There must be more to it than that. The electrodes in a dud neon don't look much different to those in a good neon. Certainly any loss of material from the electrodes cannot significantly alter the spacing. The striking voltage depends on the spacing, the gas pressure, and the type of gas (ref http://en.wikipedia.org/wiki/Breakdown_voltage). So the gas pressure must be changing somehow, or the gas gets contaminated. As to how many hours of operation, that does seem to depend on the operating current density. Before zener diodes became available, neon tubes, both NE-2 type and larger types designed for the purpose, were used as voltage references in (tube-based) regulated power supplies. In my experience such regulator tubes in such equipment as oscilloscopes, TV cameras, etc, operated without failure all day every day for 10 years or more - but they glowed only dimly compared to NE-2 used as visual indicators. Keit121.221.1.107 (talk) 12:00, 23 June 2012 (UTC)

Here is a pons asinorum: Neon is more or less inert. So little is going to happen the gas pressure or composition. (2) Glass in a good insulator at these temperatures. (3) The electrodes are good conductors at these temperatures. (4) There is no oxygen in the bulb – just neon. (5) The metal ions that boil off the electrodes 'condenses' on the cool inside envelop of glass -i.e., it does not form a non-conductive oxide film . (6) The inside coat of conductive metal slowly reduces the potential across the xeon gap by conduction. (7) A point will come when the potential across the gap will not reach the afore said breakdown voltage. (8) As this condition is approached, flickering of light output will be observable. (9) If these electrodes did not evaporate, the lamp would not fail -unless for other reasons. (10) The metallic film on the inside of the glass envelope has a resistance – so if you increase the electrode voltage, the arc will eventually re-strike; as this current path (between the electrodes) will again form the lowest resistance. Platinum has a lower vapour pressure than tungsten, so this as electrode element might be better.

Unless you live in one of those countries that just trains its pupils to mechanically pass exams, you will come to learn all this, in your science lessons. Your CD's get their shinny aluminium coat by the same principle of vacuum deposition. There is likely to be many more example of this processes in your own home.--Aspro (talk) 20:16, 23 June 2012 (UTC)

How about those contries that spend more time on subject-verb agreement? μηδείς (talk) 21:09, 23 June 2012 (UTC)

Muphry's law rules those shinny contries. DriveByWire (talk) 19:54, 24 June 2012 (UTC)

It seems to me that if there was indeed a shunt forming on the inside of the glass consisting of evaporated electrodes (or any other source of conductor)

1. you would see a drop in the ~ infinite resistance across the electrodes when cold and
2. it would evaporate itself pretty quick while it was still thin enough and the line voltage was applied. See also metal whiskers in Nicad batteries

so i'm thinking either some sort of poisoning of the electrodes like surface oxidation or some sort of poisoning of the neon? (Anecdotal possibly relevant info: when you smash a dead Ne2 neon bulb with a hammer because that's what you do when you're a prepubescent male with a dead Ne2 bulb and a hammer, it gives one last burst of orange light as in triboluminescence; which indicates that there is still neon present in the bulb, eliminating my other blue-sky hypothesis, that the neon has all diffused out through the glass.)Gzuckier (talk) 02:51, 25 June 2012 (UTC)

Either the tubes break or the electrodes burn out. Or God intervenes. μηδείς (talk) 21:09, 23 June 2012 (UTC)

Skin color and temperature

If a black person is standing next to a white person in sunlight, shouldn't the black person feel hotter? Maybe African-descended persons are better adapted for high heat than say Northern Europeans but is that enough to compensate? Sagittarian Milky Way (talk) 21:57, 22 June 2012 (UTC)

I remember my biology teacher from grade 12 talking about how pigmentation causes black people to lose heat to the environment much faster. I don't remember why, but now it's got me interested... 203.27.72.5 (talk) 22:35, 22 June 2012 (UTC)

It's because they have higher emissivity, of course. I was thinking they were standing the sun and still getting colder than a white person. So yeah, black people should get hotter in direct sunlight without going into any other adaptations some people may possibly have. 203.27.72.5 (talk) 22:41, 22 June 2012 (UTC)

Dark surfaces reflect less solar radiation than light surfaces, so of two otherwise identical persons of different skin pigmentation in your scenario, the darker-skinned person would absorb more solar radiation. That's a purely physics explanation (it could apply to any surface, not just human skin) - heat and the perception of heat are going to depend on more factors than simply the skin colour. As to the evolutionary reasons for the variation in skin pigmentation in humans, see Skin pigmentation#Evolution of skin color. LukeSurl ^{t c} 22:47, 22 June 2012 (UTC)

If an object is darker at all wavelenghts (visible light and infrared), then it won't get any hotter. It is only when an object is darker at visible wavelengths but less dark in the infrared, that it will get hotter. Count Iblis (talk) 22:53, 22 June 2012 (UTC)

I'm not sure you are right. An object at human body temperature will want to emit radiation at much longer wavelengths than the peak of the solar spectrum. Heating of such an object in direct sunlight will be dominated by absorption in the near infrared, while cooling will be dominated by absorption (emission) in the mid- to far-infrared.

Melanin absorbs strongly in the near ultraviolet, and not much at all in the infrared.[3] It's not clear whether dark skin will cause a person to get hotter or cooler in direct sunlight, but clearly the apparent dark color in the visible will have much less effect than one might suppose, because it is not dark in the infrared where the solar spectrum is much stronger.--Srleffler (talk) 02:49, 23 June 2012 (UTC)

The Sun's radiation peaks around 500 nm, which is in the green band of the visible spectrum. See [4]. If it peaked in the infrared, our eyes would have evolved to see infrared, and we would name it "visible". Because of the long high-wavelength tail, there might be more total radiation in the infrared than in the visible (it's hard to tell from the graph, and I'm too lazy to do the integration), but in any case absorption in the visible is highly significant.

I'm also not sure that the predominant source of cooling for a human body is radiation. Do you have a source for that? If the main source of cooling isn't radiation, black skin should definitely be hotter, unless it's much less absorptive in the infrared than white skin. — Preceding unsigned comment added by 140.180.5.169 (talk) 04:55, 23 June 2012 (UTC)

Humans have three main ways to loose heat: 1) radiation from skin, 2) conduction from skin to air passing over it, 3) evaporation of sweat. (1) is very ineffective compared to (2). (3) is vastly more effective than (2), but the body automatically adjusts sweating from zero to dramatic as required. The body can also adjust the blood flow to the skin in order to control (1) + (2). For thse and the other reasons posted above (the visual colour has little to do with the radiation coefficient at infrared), it matters not a whit what your skin colour is. When I was a first year at university, they had us do a series of lab experiments measuring the heat loss from a piece of aluminium, unpainted and shiny, painted red, painted black, unpainted and roughened, various airflows from zero to a gentle breeze. These lab tests proved convicingly that radiation in all manner of practical applications, where the object temperature is only moderate (say up to 40 C above ambient), is unimportant, though measureable. Surface roughness is just as, and often more, important re radiation than is visual colour. Wickwack58.170.139.183 (talk) 06:45, 23 June 2012 (UTC)

But the question was in sunlight does the black person feel hotter. The difference in temperature need only be very slight for a person to feel it. And the heat radiated from the sun will rapidly change the temperature of the skin's surface before mechansims (2) and (3) start to respond. 203.27.72.5 (talk) 07:09, 23 June 2012 (UTC)

Ultimately, I suppose this cannot be answered, as there is an acute shortage of people who change colour. However, the difference is so slight that I expect that acclimatisation would render it impreceptable - much as folks in London feel warm on a 25 C day (hot for London) but folks in Perth Australia feel cool on a 25 C day (average for Perth). Wickwack58.170.139.183 (talk) 10:42, 23 June 2012 (UTC)

see text to left

(1) Regardless of skin colour, body shape is different in long-limbed Africans and thick-trunked Northern Europeans. (2) Yes, Black people whom I have touched normally feel warmer than White people. (3) Anyone who has lived in NYC will know you will often see Black people bundled in heavy jackets or hats in weather of 70 degrees Fahrenheit, while you will rarely see the same in White people above 60 degrees Fahrenheit. μηδείς (talk) 21:05, 23 June 2012 (UTC)

Yes, a darker skinned individual will probably feel hotter, but they won't burn, or their risk of getting burned is significantly reduced. Melanin very efficiently converts ultraviolet radiation into heat which is harmless, so while you may feel a little hotter in the sun, you won't get sunburned. I know it's possible for a dark skinned person to get sunburned at a certain point, but I'm a dark skinned guy myself, and I've never been sunburned in my life. Considering the risk of sunburn, melanoma, and other skin cancers, I'll take my dark skin any day. ScienceApe (talk) 22:45, 23 June 2012 (UTC)

A "thick-trunked Northern European" with some "long-limbed Africans". "African" is completely as useful a genetic subset as "Northern European", right? Now to find a way to accurately measure their surface area (volume is easy)... 86.164.77.7 (talk) 17:22, 24 June 2012 (UTC) [I moved this comment from under the image to the right in order to maintain continuity. -μηδείς]

What is relevant is body proportion, not stature. See Allen's rule. μηδείς (talk) 19:18, 24 June 2012 (UTC)

Allen's rule implies that to survive in Antarctica a cow should be spherical. DriveByWire (talk) 19:44, 24 June 2012 (UTC)

Have you ever seen a non-spherical cow in Antarctica? --Carnildo (talk) 02:14, 26 June 2012 (UTC)

It sounds like you think you've disagreed with something I said. 86.164.77.7 (talk) 20:27, 24 June 2012 (UTC)

Sun's magnetic field doubled?

Has the Sun's magnetic field doubled over the last 100 years? Bubba73 ^{You talkin' to me?} 23:23, 22 June 2012 (UTC)

The Solar variation#Changes in the solar wind and the Sun's magnetic flux article section says it has. However, despite a couple surprising statements in that section, there isn't a single citation in that section, and solar variation is something that people into climate change denial like to bring up (see Global warming controversy#Solar variation), so it might not be good to blindly rely on that article section as being accurate. Red Act (talk) 01:17, 23 June 2012 (UTC)

The statement (the one that made me ask) that it had doubled most likely came from a climate change denier. Bubba73 ^{You talkin' to me?} 01:41, 23 June 2012 (UTC)

Yes, the open magnetic flux has increased by something like a factor of two in the past century, a rough number given the uncertainty in the reconstructions. See e.g., Lockwood (2003), figure 12. Notice that the flux was about as high as now back during the late 1700s, a period that was a good bit cooler than now (see Little Ice Age). Short Brigade Harvester Boris (talk) 01:42, 23 June 2012 (UTC)

Why would there be any connection between the global temperature and the Sun's magnetic flux? 203.27.72.5 (talk) 03:33, 23 June 2012 (UTC)

The Sun's magnetic flux correlates with the intensity of the solar wind, which could hypothetically influence cloud formation, which itself influences global temperatures and other climate effects. But since the flux has doubled in a hundred years (allegedly) and we're not all dead, I assume the influence is small. I leave it to climate modelers to say what the influence might actually be. Someguy1221 (talk) 03:38, 23 June 2012 (UTC)

"But since the flux has doubled in a hundred years (allegedly) and we're not all dead, I assume the influence is small." So would you say the same thing about atmospheric CO₂? 203.27.72.5 (talk) 03:49, 23 June 2012 (UTC)j

Wow, I didn't even see myself walking into that one. Someguy1221 (talk) 04:10, 23 June 2012 (UTC)

(edit conflict)None, basically. There's the supposed effect of galactic cosmic rays on production of cloud condensation nuclei (which is what I assume you're referring to). That GCR can affect production of tiny particles is accepted, but those particles are orders of magnitude smaller than the actual particles that serve as CCN. Short Brigade Harvester Boris (talk) 03:51, 23 June 2012 (UTC)

Yeah, look up Svensmark, the current hero of the lack of cosmic rays because of the sun cause AGW theory. There are a few problems preventing my, for instance, taking it too seriously, such as the very short period their original publications referenced to show correlation, the lack of correlation seen since then, the possibility that the sun's magnetic field and things like actual solar output, in the UV for instance, which are known to cause cloud cover, are vaguely correlated, possibly accounting for a spurious correlation seen between magnetic field and cloud cover, the difficulty in accurately estimating the historical solar magnetic field before we began to measure it, and, last but not least, the existence of a perfectly acceptable theory with a well defined mechanism of action which already covers the data much more accurately than the cosmic ray thing, i.e. AGW via CO2, and therefore the cosmic ray thing can't logically shed any doubt on AGW until it gets a lot more meat on its bones. Gzuckier (talk) 03:15, 25 June 2012 (UTC)