Wikipedia:Reference desk/Archives/Science/2011 January 11

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January 11[edit]

Why are the 8 planets so far from the sun?[edit]

I'm asking in comparison to most of the discovered exoplanets, including the rocky kepler10b. These tend to be extremely close to their parent star, often closer than mercury is to our own sun. Are planets of such small orbits simply easier to locate, or is our solar system truly unusual in this respect? 131.215.3.204 (talk) 00:00, 11 January 2011 (UTC)

The reason that discovered exoplanets are closer to their respective stars is that our methods of discovering them require that they be located so close to their stars. Presumably there are lots of different ways in which solar systems may be organized. The type of organization we find in our solar system may be far-and-away the most common way they are organized, we just don't know because there's not really a good method to find a solar system which would look like ours. We definately have no way to locate an Earth-sized planet in the goldilocks zone using those techniques. --Jayron32 00:08, 11 January 2011 (UTC)
Doing a bit more research, it turns out that discovering a solar system like ours may just be possible; a similar system to our own has been discovered around the red dwarf star Gliese 581, the smallest identified planet around which, Gliese 581 e, is the smallest ever discovered exoplanet and is about 2x the size of earth. So it looks like, as of about 2009 we may have the means to correct the biases in the data I noted above. We probably just have a lot more looking to do. --Jayron32 00:13, 11 January 2011 (UTC)
It's a bit like asking what is the most common animals in that hay-meadow? The cows, the rabbits, the field mice, the crickets? We can't (yet) detect Earth-like planets 1AU from a sun-like star. The radial detection method favours massive planets, close to the star. See some earlier queries here. CS Miller (talk) 00:55, 11 January 2011 (UTC)
Reread the Gliese 581 article. There are several "Earth-like" candidates around that star's habitible zone. That's just one system. Given time and refinement of methods, we may be able to do better in the not-so-distant future. Still, most of the stuff so far discovered is of the "massive planet rediculously close to the star" type, for the reasons you note. --Jayron32 01:25, 11 January 2011 (UTC)
Kepler-10b is the smallest ever discovered exoplanet (though not the least massive, and anyway the article was only created yesterday). 81.131.69.118 (talk) 06:06, 11 January 2011 (UTC)
I read that it was discovered by the Kepler space telescope and "Kepler relies on the 'transiting' technique, which looks for planets that pass between their host star and the Earth." [1]. This implies that planets that go round their star faster are easier to spot - to spot one with an orbit the same length as the earth's, Kepler would have to stare at the star for a year. I assume (apologies for guessing) a planet closer to its star will generally have a shorter orbit. Kepler-10b's orbit is less than a day. 81.131.69.118 (talk) 05:59, 11 January 2011 (UTC)
Indeed, see Kepler's laws of planetary motion, specifically law #3, which strictly defines the orbital period of a planet as related to its distance from the star it orbits. --Jayron32 06:10, 11 January 2011 (UTC)
Dammit, I even read that recently while trying to absorb what "gravitational mass" is (for the question about falling feathers and hammers). "The concept of active gravitational mass is an immediate consequence of Kepler's third law of planetary motion", as it says in the Kepler section of mass. These things are hard to take in. 81.131.69.118 (talk) 06:23, 11 January 2011 (UTC)
Debris disk analysis methods such as for Fomalhaut b have produced direct detection of a planet relatively far from its parent star, for example. ~AH1(TCU) 03:32, 18 January 2011 (UTC)

Lewis structure[edit]

Hi, I'm drawing the Lewis structure for NO2. Because of the there is one extra electron available to use, but who gets it? I was taught oxygen is more electronegative than nitrogen and thus should get it, but which oxygen? In the structure I made it actually makes more sense to give it to the nitrogen, then you have one unbonded pair per atom and two covalent bonds and one coordinate bond between each oxygen and the nitrogen in the center. Thanks. 24.92.70.160 (talk) 02:20, 11 January 2011 (UTC)

Yes, an oxygen gets it. In simple terms, the nitrogen is double-bonded to one oxygen, and single-bonded to one negatively-charged oxygen. In reality, they are both half-bonded, but this can't really be shown in a drawing. --T H F S W (T · C · E) 02:46, 11 January 2011 (UTC)
See nitrite for a more thorough description, and some pictures. The bond order of each nitrogen-oyxgen bond in the nitrite ion is 1.5; they are the same length and strength; but a lewis structure does not allow you to draw fractional bond orders so you have to use resonance structures to fudge it. In your lewis structure, you should make sure each atom obeys the octet rule (that is some combination of 4 bonding pairs and lone pairs). --Jayron32 03:10, 11 January 2011 (UTC)
Though if you look at nitrogen oxides like nitric oxide and nitrogen dioxide a good-looking Lewis structure may not be possible. Wnt (talk) 03:58, 11 January 2011 (UTC)
They can be if you draw them as free radicals. Indeed, I think it is standard to draw both nitric oxide and nitrogen dioxide as have whole-number bond order and leaving the nitrogen as being electron deficient (with seven electron). Such a lewis structure would highlight the tendency of these compounds to spontaneously dimerize, as they do. --Jayron32 04:26, 11 January 2011 (UTC)
Sorry, by "good-looking" I meant "obeying the octet rule". Yes, you can draw them as radicals, and the dot on the nitrogen is a lot more common than the dotted line bond used in those articles. On the other hand, they don't dimerize with the eagerness you'd expect from the run of the mill free radical compound; and consider that molecular oxygen is also sort of a free radical compound despite its deceptively simple Lewis structure. The Lewis structure is a lovely idea, but these compounds are what show its weaknesses. Wnt (talk) 06:49, 12 January 2011 (UTC)
Not all radicals are created equal. Oxygen (a diradical) does not dimerize because it's radical-containing orbitals are antibonding orbitals; thus forming bonds using these orbitals is actually destabilizing rather than stabilizing. In nitrogen dioxide, the radical is in a bonding orbital, which is why it dimerized. --Jayron32 02:39, 13 January 2011 (UTC)

Theory of Evolution[edit]

Is there any possibility that the theory of evolution proposed by Darwin may have some loop holes? —Preceding unsigned comment added by 116.73.242.109 (talk) 04:23, 11 January 2011 (UTC)

Well, the theory of evolution has been added to and modified continuously during the century and a half since Darwin's initial writings. I am not sure what you mean by "loop holes". Can you elaborate on what sort of things you are looking for? --Jayron32 04:28, 11 January 2011 (UTC)

Well, the theory suggests the mutation of species from one form to another. It may seem childish, but does it actually imply extinction of one specie while giving rise to another more developed and well suited for surroundings? I do actually think the answer to be negative, but i'm still doubtful about my own opinion, Also the intermediate stages that the theory speaks of seem to be absent, or maybe well disguised. Why does no one see the intermediate stages between us humans and the apes, when we are supposed to be evolved from the apes themselves and they still do exist?! —Preceding unsigned comment added by 116.73.242.109 (talk) 04:47, 11 January 2011 (UTC)

To answer your first question, no, it does not mean that one species must go exitinct. It may, or it may not. For example, many types of Crocodiles have remained essentially unchanged as a species for millions of years. Certain specific crocodile species likely descended from earlier forms, and both the earlier form and its descendent still exist today. Also, evolution doesn't produce better forms on an absolute scale; it produces forms better suited to the environment contemporaneous to that form; but since the climate of the earth often changes dramatically as well, what is "best" at one time is not "best" at other times. Also, the fact that new species are evolving is itself changing the environment. As far as intermediate forms go, we actually do have some very good records for intermediate forms for some species lines, and not so much for others. One explanation is that of punctuated equilibrium; that is that sometimes changes happen rapidly, often too rapidly to leave much data behind, while at other times changes happen slowly and gradually. The other explanation is that we likely only have, as yet, found evidence of a tiny fraction of the total number of species ever to exist; there are clearly enough "complete" lines with transitional forms to show the concept of evolution works as expected, but the lack of a complete record of every species ever to exist isn't itself a problem for evolution. Heck, we don't even have anything close to a complete record of every species alive today, not even CLOSE. Never mind those species likely to have lived in the past. Finally, human evolution does not show that humans evolved from (modern) apes. Humans and our modern ape cousins evolved from a common ancestor, not one from the other. In that sense, chimpanzees and humans are equally "evolved" from that common ancestor, we are just evolved in different manners. There are hundreds of intermediate forms between humans and that "nearest common ancestor" with Chimpanzees. The best candidate right now for the closest common ancestor between humans and chimpanzees is probably Nakalipithecus or Ouranopithecus. To an earlier question you had, that doesn't mean that such an ancestor had to die out. It did in the case of modern humans, but there are many times in the fossil record where earlier human species lived for long periods of time side-by-side with an ancestor species. --Jayron32 05:09, 11 January 2011 (UTC)
You might be interested in the Frequently Asked Questions section near the top of Talk:Evolution, particularly Q7: What about the scientific evidence against evolution? Sean.hoyland - talk 05:50, 11 January 2011 (UTC)
Our article on speciation discusses an assortment of ways by which a new species can arise. TenOfAllTrades(talk) 05:58, 11 January 2011 (UTC)
Depending on how you look at it, many forms of genetic engineering may provide us with 'loop holes' that let us get evolution's positive effects without the negative effects, and without waiting a zillion generations.
If a scientist can design a new bacteria on his computer instead of waiting for one to evolve naturally, then I'd call that a loophole. In the future that same loophole may let our species skip the more tedious aspects of the process. APL (talk) 06:42, 11 January 2011 (UTC)
I wouldn't call sex tedious :) Anyway punctuated equilibrium does explain that you don't get all intermediate steps at equal frequencies. The theory is basically that the species gets suited to its surroundings like water at one end of a pan. If the pan is slightly tipped the water may run over to another section. New species would normally arise in the same way by the environment changing or a new environment being exploited which leads to a quick burst of change followed by equilibrium again. Dmcq (talk) 10:50, 11 January 2011 (UTC)
Sure, but even those faster changes are going to be slower than a scientist fiddling genes on his computer and injecting them into an egg. Especially as the scientist can create organisms with traits that do not benefit the organism. (bacteria that produce some chemical that's worthless to the bacteria but valuable to us.)
I would call that a loophole. I dunno if that's the sort of "loop hole" the question-asker was looking for, though. He might have just been looking for a "Oops, didn't carry the two, turns out God did it after all." sort of thing. APL (talk) 15:17, 11 January 2011 (UTC)
The biggest loopholes are surprisingly reminiscent of Lamarckism and Lysenkoism. Organisms can respond to their environment in some way which (hopefully) has evolved to be adaptive in nature, and pass this acquired characteristic to their offspring. See epigenetics. Now epigenetics per se is not a long-term force in evolution, because it simply marks genes to be more or less active in the next few generations. Exposure to the right environmental stimulus reverts the epigenetic change. However, one component of these epigenetic marks is DNA methylation, and this methylation encourages nucleotide transitions from methylcytosine to thymidine. This alters (typically decreases) activity of CpG islands, for example. In this way it is possible that altered environmental circumstances can permanently alter the expression level of a gene, or perhaps even encourage more rapid exploration of the effect of other mutations to it. This is an ongoing topic of current research, and one expects interesting news. See [2], [3], [4], etc. - search terms like "transgenerational", "epigenetic", "vernalization" (for a classical Lysenkoist case) or a favorite organism. However, bear in mind that such mechanisms only work when some regulatory mechanism has evolved to make them work - at least most of the time they cannot replace standard Darwinian selection. Wnt (talk) 18:59, 12 January 2011 (UTC)
The OP refers to "the intermediate stages between us humans and the apes." (As mentioned above, both humans and other modern primates evolved from earlier species, but that's not my point here.) Why do evolution skeptics always refer to the human race only in regard to "apes" (or "monkeys," etc.)? The fact is, we evolved "from" e.g. small shrew-like mammals; and we evolved "from" bacteria. A big clue to the ignorance of evolution skepticism is the obsession with "apes." Why aren't "shrews" (so to speak) or "bacteria" the typical sound-bite? 63.17.73.245 (talk) 03:44, 15 January 2011 (UTC)

Negative Matter[edit]

Can darkmatter be negative matter? How would negative matter interact with a blackhole? If the antiproton is made from antiquarks, then what would a negative proton be made of? Does negative matter fall under the domain of supersymmetry? --Plasmic Physics (talk) 05:12, 11 January 2011 (UTC)

What do you mean by "negative matter" and how is it different than antimatter? Matter is defined by its quantum numbers; what sort of quantum number profile would "negative matter" have? --Jayron32 05:20, 11 January 2011 (UTC)

Another name for negative matter is antimass. Antimass is to easy to confuse with antimatter; I chose to use negative matter. If negative matter was more then just a hypothetical placeholder concept, then it would be measured in kg, or if you want to go relativistic, J s2 m-2.

Another question, would negative matter be visible, since it would radiate negative photons which, are gravitationally repelled by positive matter hence, darkmatter? --Plasmic Physics (talk) 06:51, 11 January 2011 (UTC)

Well, if you invent concepts like antimass and negative photons, you can give them any properties you like. It is like asking "I just drew a purple dragon, what does it eat?" 88.112.59.31 (talk) 07:06, 11 January 2011 (UTC)

Hey, don't be a funny guy, negative mass is not my idea. --Plasmic Physics (talk) 07:36, 11 January 2011 (UTC)

We have a negative mass article, which has some discussions about its properties. However, it also states that it is a hypothetical concept, so although it's a real idea, it really is in part "let's make up stuff for it based on what we propose it to be" based on existing rules, and given that one has to choose which existing rule(s) to follow vs knowingly violate. DMacks (talk) 07:46, 11 January 2011 (UTC)

I have read it, but it does not discuss my questions? There are some verified discoveries which breaks or contradicts scientific paradigms, such as the heavy proton recently observed. --Plasmic Physics (talk) 09:04, 11 January 2011 (UTC)

The problem with calling it negative matter is that you do not specify which property is negative (for example, electrons are negative matter because they have negative charge or would it be better to call the positron "negative"?). If you do mean negative mass, then no, this could not be dark matter because this is known to have positive mass. It is interesting to speculate, but, as far as I know, no exotic particles have ever been discovered that exhibit any of the properties expected of negative mass. Our best guess at the moment is that negative mass does not exist, but at one time it was believed that antimatter wouldn't exist, so who knows what will be discovered in the future? An antiproton is indeed made of antiquarks, and is a negative proton in the charge sense, but it has positive mass equal to that of the positive proton. Current theories of supersymmetry do not include any particles with negative mass. Dbfirs 09:49, 11 January 2011 (UTC)

A similiar case exists for antimatter, the term does not define what antimatter is anti to. Your answer is nonetheless helpful. How would darkmatter behave differently if it was nagative mass? Since it does not associate with positive mass, would we have to search for it in a different place all together? --Plasmic Physics (talk) 07:19, 12 January 2011 (UTC)

You are correct, of course. The original suggestion of "antimatter" had negative mass, but the modern definition applies only to matter with the opposite charge (at quark level in the case of the antineutron). Because people often think of charge as being positive and negative, the term "negative matter" is often taken to mean antimatter in the modern charge sense. Perhaps "unmatter" could be used for matter with negative mass? I don't quite understand how the antineutrino fits my analysis, other than in its helicity. Why is it not its own anti-particle? Perhaps an expert can explain? Dark matter was proposed purely to explain the extra mass in rotating galaxies, so it must have positive mass. This does not preclude the possibility that dark "unmatter" (your negative matter, with negative mass) could not also exist between galaxies, though it might eventually be detectable if it occurs in large quantities. Dbfirs 08:25, 12 January 2011 (UTC)

I don't know about unmatter, the prefix un-, does not make sense when used in this way. --Plasmic Physics (talk) 08:46, 12 January 2011 (UTC)

OK, I agree that "unmatter" is no more suitable than "negative matter". What else can we call it? Dbfirs 18:21, 12 January 2011 (UTC)
Dark Matter does associate with matter of positive mass. The way we know Dark Matter exists is due to it's gravitational interaction with visible matter of positive mass. Are you thinking of the idea that Dark Matter is Weakly Interacting Massive Particles (WIMPs)? Wevets (talk) 17:06, 12 January 2011 (UTC)
The big problem with "negative matter" as dark matter is that the only way we know about dark matter is that it contributes unexplained positive mass to a system. For example, galaxies spin like dinner plates rather than with central portions greatly outpacing the more distant parts, which is explained by the presence of a vast unseen shroud of dark matter in a rough ball, which makes the galaxy seem heavier and heavier the further you go out.
There are other problems with negative matter, like that one expects negative matter to have negative gravity, pushing positive matter away from it - but positive matter exerts normal gravity that pulls in things at the same rate regardless of mass (even if it is negative!). So a pair of positive and negative matter objects should start flying away at faster and faster speeds through the cosmos. (Actually this doesn't violate conservation of energy because the negative matter gets a more and more negative energy the faster it goes, cancelling out the increased energy of the positive matter...) Wnt (talk) 19:24, 12 January 2011 (UTC)

Thank you all, these are good answers, I have all I need.

In my opinion, dark matter seems like a bunch of hooey - I think it is just an illusion caused by some undiscovered modification to an existing physical law which, only becomes apparent at extreme distances, just like relativistic effects. At the moment it looks like an astrophysical fudging like the cosmological constant.

P.S. Wevets: I meant negative matter does not associate, not dark matter. --Plasmic Physics (talk) 04:28, 13 January 2011 (UTC)

Yes, it is possible that dark matter, dark energy and dark flow will all turn out to be unnecessary like Phlogiston theory and Aether theories when more sophisticated theories are developed. Antimatter (in the modern sense of "opposite charge") is, of course, real, and work is continuing to "make" a significant quantity of it. Dbfirs 21:20, 13 January 2011 (UTC)

Chevrolet Volt heater operation[edit]

A typical gasoline engine car provides no heat for the first several minutes/miles of operation, until the engine is hot and the thermostat opens. I've heard that some cars of the 1940's and 1950's had additionally a gasoline-burning heater which provided instant heat, which would be highly pleasing in the northern US in the winter. My question is, does the Chevy Volt heat the passenger compartment only with waste heat from the gasoline engine, or does it provide instant electric resistance heat? If so, does it also use waste heat from the gasoline engine to heat the passenger compartment after the gas engine has started and warmed up after long distance driving? Instant heat would be a big selling point for those in areas where it gets extremely cold in winter. Edison (talk) 05:15, 11 January 2011 (UTC)

Yes to both[5] it uses both waste heat and electric heat. But using electric heat cuts the range significantly. Apparently this problem is one of the reasons that pure electric cars are not more common - it's very hard to store enough power to both heat the cabin (or cool it) and power the wheels. Ariel. (talk) 06:39, 11 January 2011 (UTC)
Even if the all electric range decreased significantly, it would seem like a strong selling point. A car plugged in could also be "preheated" off the grid, by a timer or by electric signalling (Tweet your car heater). I wonder if an electric block heater on a gas engine car provides heat immediately, or if it does not get the engine and coolant warm enough for that? Edison (talk) 15:33, 11 January 2011 (UTC)
You might be interested to know how the Prius handles the early heating issue: when you turn off the car, it pumps the coolant into an enormous thermos which keeps it hot for a few days! --Sean 16:32, 11 January 2011 (UTC)
Is there an article or website somewhere which describes this? With gasoline engines, there is a danger of damaging the block if hot coolant is placed in a very cold engine or vice versa. Edison (talk) 20:24, 11 January 2011 (UTC)
This page has a picture of it. Googling "prius thermos" gets a lot of hits. --Sean 21:42, 11 January 2011 (UTC)

inversions[edit]

on what basis the inversions are classified....the inversions are provided a specific number why?.. for single slider crank chain.. 1.steam engine 2.whitworths mechanism 3.crank and slotted leverquick return 4.hand pump,pendulum pump

for double slider crank chain 1.elliptical trammels 2.scotch yoke.. 3.old hams coupling

so my basic question is that why the inversions are number specific.is there any rule that says we must fix this link first and this one to be fixed second. dplease help me —Preceding unsigned comment added by 115.248.161.154 (talk) 05:20, 11 January 2011 (UTC)

I'm sorry, I can't find any reference to "inversion" in articles such as mechanical engineering or linkage (mechanical), so I have no idea what you are asking about. Can you give a little more context, such as where you see these number? --ColinFine (talk) 20:57, 15 January 2011 (UTC)

flicker[edit]

please anyone help me that which industries require controlling the flicker in a flame.orr any equipment ...if any? —Preceding unsigned comment added by 115.248.161.154 (talk) 06:33, 11 January 2011 (UTC)

There is a flame speaker, but other than that I can't think of anything. Not sure what you mean by "or any equipment" - are you controlling a flame, or something else? Ariel. (talk) 06:41, 11 January 2011 (UTC)
Electric utilities are generally required to limit the amount of high speed recurring voltage variation so that the lights do not "flicker" noticeably due to industrial operations such as motor starting or arc furnaces at some other customer. This often has required putting in much heavier power supplies than would otherwise be required, at a cost of millions of dollars. "My friend flicker". Edison (talk) 15:37, 11 January 2011 (UTC)
Flickering flame is a form of combustion instability. Mechanical and aerospace engineers study flame stability in the design of combustion engines (including automobiles engines, jet engines, and rocket motors). Controlling "flicker" may involve careful timing of fuel injection, valve control, and mechanical design of the combustion chamber. Nimur (talk) 19:29, 11 January 2011 (UTC)
See also Inductively coupled plasma 75.41.110.200 (talk) 22:27, 11 January 2011 (UTC)

condensation in car[edit]

Hi, several times I have found when I place a book (or road map etc) on the front passenger floor, I get condensation, enough to leave significant water damage on the book. It seems to mainly happen when I have the aircon on, but I think it has happened at other times too. I'm more careful these days with books, but it seems to still happen on the carpet, although it is less noticeable then, perhaps because it doesn't accumulate. Does it mean I have a leak, or is it just something that happens to cars? It's been emotional (talk) 06:43, 11 January 2011 (UTC)

I know that on many Jeep Wrangler models, the drain for the air conditioner goes through the firewall of the vehicle on the passenger side. This drain often becomes clogged and the water will then spill over into the cabin by the passenger side foot well. If you open the hood and look for a small tube coming out of the firewall on that side of the vehicle, you should be able to see it and clear it. See this link for an example of what I'm talking about. Or there is water coming in from the engine cowl. See this link for more on that. Note: I'm familiar with Jeeps, so both links are to a Jeep forum that I'm familiar with. You didn't mention what kind of car you have or if you drive a Jeep, so your mileage may vary.  :-) Dismas|(talk) 08:06, 11 January 2011 (UTC)

Toyota Starlet, thanks for the help. I'll look into it; anything more specific is also appreciated. Thanks again, It's been emotional (talk) 08:42, 11 January 2011 (UTC)

It's not a Starlet but there are a couple links that discuss something similar going on with the Toyota Yaris. Link 1 and Link 2. Dismas|(talk) 08:55, 11 January 2011 (UTC)
It could be condensation on the airconditioning pipe that feeds cold air to the footwell dripping down onto the carpet. I vaguely recall someone I know who had a car that actually DRIPPED water slowly onto the carpet when the aircon was run. Can't remember the car, whether or not it was old or new or had a known problem etc. Zunaid 12:04, 11 January 2011 (UTC)
My 1990 Oldmobile Cutlass would drip water on your feet when the AC was running, but by then the car was about 16 years old. Googlemeister (talk) 14:15, 11 January 2011 (UTC)

Thanks, yes, I suspect it is the aircon causing condensation, but I'll check out some of those links as well when I'm less busy. 130.95.106.139 (talk) 09:26, 13 January 2011 (UTC)

Nectar as a food[edit]

Can we collect nectar collected by the bees before it becomes honey? Will it taste like, say, maple syrup?

On the other hand, can we use natural or artificial enzyme to process collected nectar? Is it possible to "brew" honey in a factory? Let's say we may build a man-made beehive with a built-in nectar collector. Then we collect the nectar from the beehive and let the poor bees work day by day without getting anything. We can "brew" honey using the high-tech regurgitation vessel.

I just finished watching Bee Movie the third time. This movie gives me some kind of desire to control the nature and enslave the animals and destroy small farmers. -- Toytoy (talk) 08:34, 11 January 2011 (UTC)

Yes, but the average honey bee will make only one twelfth of a teaspoon of honey in its lifetime and I doubt whether a human could do the work much faster. The nectar tastes of the flower from which it is collected. You can drink the nectar from clover flowers quite easily, but in minute quantities.--Shantavira|feed me 09:48, 11 January 2011 (UTC)
Where do you get the 1/12 of a teaspoon per bee-life from please? I've heard that before, I'd like to check its validity, as I'm awed that a teaspoon of honey is the life's work of twelve bees. 92.24.190.219 (talk) 21:28, 11 January 2011 (UTC)
There was some talk of this here: Wikipedia:Reference desk/Archives/Science/2010 December 28#Clover. You can directly eat (drink?) the nectar from many flowers. Ariel. (talk) 09:53, 11 January 2011 (UTC)
I think the fuschia has a lot of nectar because it's pollinated by hummingbirds. (This fact, coupled with the absence of any British hummingbirds, only increases the puzzlement I expressed in that thread. Will have to look out for insects on fuschias ... maybe a butterfly with a long tongue could get at the nectar.) 81.131.11.15 (talk) 15:24, 11 January 2011 (UTC)
Fuchsias (note spelling) are not native to Britain; they are (or originally were) imported, propagated artificially by nurserymen and gardeners, and probably never get pollinated naturally in Britain (although it's just possible that some hawk moths, such as the Elephant hawk moth whose caterpillars will apparently eat fuchsias, might adapt themselves to some varieties of the plant. 87.81.230.195 (talk) 16:42, 11 January 2011 (UTC)
What puzzles me is that I like to rob their nectar myself, which worked great in the cold north of the country in my childhood, but I never seem to get any these days, so something else must be getting there first, but what? Like you say, maybe it's hawk moths depriving me of what's rightfully mine. I've consciously noted the spelling before, it doesn't help. 213.122.45.159 (talk) 17:19, 11 January 2011 (UTC)
Hmm, interesting that fuschia redirects to fuchsia isn't this encouraging careless spelling. How could it be fuschia when it is named for Leonhart Fuchs? Richard Avery (talk) 18:28, 11 January 2011 (UTC)
I had a similar objection to those sorts of redirects years ago when I first arrived at WP. But I got over it. We have to deal with the fact that vast numbers of people say "few-she-ah", not having the slightest idea, and even less care, that it was named after anyone calld Fuchs, and if they were to be so advised, they'd still in most cases avoid "fooks-ia", partly because it sounds quasi-rude and partly because nobody else they know ever calls it that, and they don't want to be the odd man/woman out. This is a good example of what I call the Schnitzel Syndrome. People tend to say "snitzel", or worse, "snitchel" - and then spell the word to conform to their mispronunciation. The world is full of people with tin ears when it comes to anything that's even slightly out of the ordinary for their idiolect, and for those who do hear the differences, it can be very unsafe to risk appearing pretentious. -- Jack of Oz [your turn] 19:03, 11 January 2011 (UTC)
To complicate matters, I imagine many people hear of it as a color name first. While 'fooks-ia' can be argued as correct pronunciation of a (latin-ish) scientific name, I'm not sure this applies to the color. Also, my copy of the (descriptivist-leaning) NODE gives /ˈfyoō sh ə/ as the only pronunciation for the color and plant. SemanticMantis (talk) 20:01, 11 January 2011 (UTC)
See, I even knew already that it was named for Mr. Fuchs, and I still got it wrong. 213.122.28.103 (talk) 20:37, 11 January 2011 (UTC)
I understand your question is somewhat tongue-in-cheek, but the whole point of eating honey is that the bees do all the 'leg-work', and we get a delicious treat with a long shelf life. I don't think you'll find a way to harvest nectar that is more efficient or less costly. SemanticMantis (talk) 20:05, 11 January 2011 (UTC)

Anyone with new ideas for theories in creation of solar system[edit]

I am A. Mohammadzade, and I live in Iran, and graduated in Iran University of Science and Technology. I have some studies in astronomy and physics thus, I want to have scientific discussions about my favourite course, without political or religion based matters.

I wrote some letters to physicists and scientific researchers, to send my new idea to them. In these contacts, I learned some knowledges, and will use them for further researches.

I named my theory "Great Cojunction" which, is based on the new observations in astronomy. I want to publish that.

As we know, the explaining of world creation guides us to two parts of observations:

  1. Are there such as our solar sytem in other places and galaxies?
  2. Are there some universes same to our one?

I think that is not correct that we say something about God and creation when we have so shortages in our theories and calculations, and I try to find out that our solar system is special one.

Finally, I say it is so.

First, I wrote some questions to them about the shortages in recent theories of Big Bang and solar system mechanism, such as this (that I copy from my letters):

Some questions:
If the matter and space in 0.0001 second of Big Bang expanded in the radius of solar system, then the first hadrons might have 1000c speed, because the light moves this radius in time about 1000 seconds. If hadrons were 10 to the power of 14 degrees centigrade hot, then all nuclei of atoms might have such tempreature now. Cand we use thermodynamic rules for first hadrons or quasars?
And for the solar system:
Otherquestions:
  1. How can invisible fine particle orbit in any orbital around the Sun?
  2. The cloud in density, 3 atoms or 100 atoms in one cubic centimeter can be visible? We live in ocean of atoms of air 1 milion atoms in one cubic centimeter and it is not visible.
  3. What made the center of earth 6000 degrees centigrade? Can condensing make this heat, and it still be warm for 4 billion years?
  4. Where did made the water?
  5. Why Phobos is not spiral and Icarus has such orbital?
  6. What made Titan so seemed to Earth?
  7. What made heavy metals and elements in Earth?
  8. What made Cassini discontinue in Saturn?
  9. What made the sun spots?
  10. How did the fine particles condense together?
  11. Smallest moon of Mercury, Fubus has more density than semi-star Jupiter, why?
  12. Why the orbital of Pluto has so angle with orbital of other planets?
  13. The coma of comets move ahead of that and has about 150 million kilometers length with any core.
  14. Less than moon, which gravity formula can display thus movement?

My remarks are these. And I hope that I be sucsessful to publish them and and day write them here. Thoses problems in desription are not for my less knowledge about the solar system, those are some real undiscript subjects in recent theories, I hope to solve.—Preceding unsigned comment added by 78.38.28.3 (talk) 10:00, 11 January 2011 (UTC)

I just fixed this to make it fit better, I did not change the wording. --Plasmic Physics (talk) 11:03, 11 January 2011 (UTC)
I have removed the email address. --Dweller (talk) 11:17, 11 January 2011 (UTC)
I've tried to understand your questions as best as possible. Your English isn't always very understandabale but that isn't a problem. Here are some answers:
  1. I didn't understand this question
  2. Nebulae are visible because the gasses absorb light from stars then re-emit them, some in the direction of earth. We can see them because of the light they re-emit and because they are against a background of black space. Air in Earth's lower atmosphere is not excited by radiation in the same way and we look through it to a background of tress mountains, whatever is in the way, not against empty black space, thus we do not see this effect. For something similar on earth see aurora (astronomy).
  3. See inner core, outer core, structure of the Earth and geodynamics
  4. Water is made from a combination of hydrogen and oxygen. Hydrogen is the most abundant substance in the universe. Oxygen is formed by nuclear reactions inside the core of stars. See Oxygen#Isotopes and stellar origin, helium fusion and neon burning process
  5. Phobos is a captured asteroid rather than a moon that was formed at the same time as Mars. You'll need some understanding of orbital mechanics to understand why the orbit is the shape it is (or someone with more knowledge will come along to explain). Same with Icarus.
  6. In which way do you mean Titan is similar to Earth?
  7. All the heavy metals (heavier than oxygen) are created in supernovas when VERY massive stars die and explode, which scatters the elements all throughout the universe. See supernova nucleosynthesis.
  8. See Cassini Division.
  9. See sunspot for an explanation
  10. Gravity
  11. You mean "smallest moon of Mars". Phobos is composed of mostly rock. Jupiter is composed of mostly gas. In fact all the rocky planets are denser than the gas giants.
  12. See Pluto for a possible explanation.
  13. See comet and coma (cometary) for a possible explanation. I couldn't understand your question.
  14. I don't understand this question.
Zunaid 11:54, 11 January 2011 (UTC)
Much of the guts of the question is beyond me. But the header grabbed my attention, reminding me of what King Alfonso X The Wise of Galicia, Castile and Léon, said:
  • Had I been present at the creation, I would have given some useful hints for the better ordering of the universe.

Pity he died 726 years ago; I would love to know what better ideas he had. -- Jack of Oz [your turn] 12:03, 11 January 2011 (UTC)

Thank you for correcting my remarks and for your replies. I ought to explain some of my questions. The gravity roles for all objects in universe is so that we have for planets and stars. I say that is there any formula for particls and icy matters in density less than gas in coma of comet that tide them togather in such distance 150 - 800 million kilometers? I know how the elements are made in supernovas thus, I think that if chondrites brought them here to our Earth, then they might be equal part of them in all over the earth, but we have so mines in parts of Earth: iron, copper, gold, and aluminum. So, what made the asteroids? Why such asteroids are not near the outer planets? Where did the temprture of Earth's core come from? If chondrites made the planets so the Jupiter, Sun, Saturn, and Uranus had more density, that observed that Earth is 4.5 billion years old, but the rocks of Moon are 3.5 billion years old? The Titan has atmosphere only nothing, no life condition and else other, I say: what happened that the Pluto lie in such orbital and else others?

I have good replies to these questions based on my developed theory development of the solar system mechanism theories by Coiper and Whitsicher. Best regards. —Preceding unsigned comment added by 78.38.28.3 (talk) 04:24, 12 January 2011 I WANT PUBLISH MY THEORY BUT I KNOW SOME MAGAZINS WONT BELIVE MY NEW THEORY > AND THAT FELT AWAY >SO I CHOSE UNUSAL WAY this is my CV: a. mohammadzade birth: may 23 1973 Ms in traffic and transportation engineering graduated in (IUST)iran university ofr science and technology 1998

Many of your questions are answered in Formation and evolution of the Solar System. Please note that Wikipedia is not a suitable place for publishing original research of any type. --ColinFine (talk) 21:04, 15 January 2011 (UTC)

Black holes and big bangs[edit]

Last night on a TV show called Into the Universe with Stephen Hawking Dr. Michio Kaku said the mathematical models for black holes and those for the big bang are very similar. "Similar" is a subjective word, and if I saw the models on paper next to each other, the best I could do is look at them as pictures. So I wonder out loud to any of you who have more understanding of the two models, how similar are they really? 20.137.18.50 (talk) 13:38, 11 January 2011 (UTC)

This is perhaps not a very helpful answer, but they have in common the fact that they are singularities, we can't see or measure anything in them, and we don't understand them. I'm sure an expert can give a much more useful and informed answer. Dbfirs 16:51, 11 January 2011 (UTC)
Roger Penrose has pointed out that a black hole and the big bang are fundamentally different in that in a black hole there are tidal effects that increase towards infinity as you come near the singularity, whereas there is not supposed to have been any tidal effects close to the big bang singularity. –Henning Makholm (talk) 19:52, 11 January 2011 (UTC)
Is that purely because the was no space-time "outside" the original singularity to have tides "in"? Dbfirs 07:38, 12 January 2011 (UTC)
I'm not sure that "outside" makes sense even in scare quotes here. If I remember correctly, there are big bang models where there are spacelike geodesics that end at the singularity; that would be as close to "spacetime outside the singularity" as one could reasonably hope for. –Henning Makholm (talk) 12:08, 12 January 2011 (UTC)
Michio Kaku, though technically a professional physicist, is not well regarded by his peers. He mostly talks to talk-show hosts and documentary filmmakers because none of his colleagues will listen to him. That said... he's correct about this. The general-relativistic model used to describe the big bang is the only way of modeling, in general relativity, a perfectly homogeneous and isotropic ball of matter that's expanding or contracting. That means that the perfectly homogeneous and isotropic big bang and an idealized black hole collapse (starting with a spherical cow) look basically the same. Maybe this means they are the same in some deeper way, or maybe it's just an example of the Strong Law of Small Numbers. But it's also true (as Penrose said) that the tidal forces near the singularity go to infinity in a Schwarzschild black hole, but to zero in the big bang. How do you reconcile these contradictory statements? I wish I knew. It may have to do with the Schwarzschild black hole being a vacuum (there's no matter anywhere), whereas real black holes would have to form from collapsing matter. If you looked at a more realistic model, the tidal forces would be small in the collapsing matter region, but large in the outside vacuum (which would be "before the big bang"/"after the big crunch"). Penrose thinks that the tidal force difference has deep implications related to the arrow of time, but he's certainly wrong about the philosophical implications of Gödel's theorems (The Emperor's New Mind) and he might be wrong about this too. -- BenRG (talk) 09:20, 12 January 2011 (UTC)
It's unclear to me how you get from "The general-relativistic model used to describe the big bang is the only way of modeling, in general relativity, a perfectly homogeneous and isotropic ball of matter that's expanding or contracting" to "the perfectly homogeneous and isotropic big bang and an idealized black hole collapse look basically the same". The premise does not seem to say anything about black holes. Even in an idealized black hole collapse, the initial situation is not isotropic at most points. –Henning Makholm (talk) 12:08, 12 January 2011 (UTC)
The black hole singularity is thought to lead into a white hole, arising a potential multiverse scenario. ~AH1(TCU) 03:24, 18 January 2011 (UTC)

Prison nutrition and strength training[edit]

(I guess this is a science question. Maybe it could be a humanities question too.) It is part of legend that incarcerated hoodlums spend their time lifting weights, such that they leave the penitentiary much bigger and stronger - and therefore more dangerous - than they entered it. But considering the restrictions of prison life, how is this nutritionally possible? Wouldn't it require a lot of protein-rich food to build up large muscles? Would not an inmate, in order to acquire and maintain such a physique, require a much richer diet than his sedentary fellows? How would he acquire the calories? By bartering with other prisoners? Or is penal alimentation handled in such a way that prisoners can decide for themselves how much they will eat? LANTZYTALK 13:41, 11 January 2011 (UTC)

I assume many a skinnier inmate's lunch is stolen by, er, given to a guy who starts out bigger and/or meaner who gets bigger, thus forming a cycle. 20.137.18.50 (talk) 14:22, 11 January 2011 (UTC)
There is an over-supply of protein in most Western diets. Adults eat far more protein than they need, and the surplus is normally just converted to calories. 92.24.181.78 (talk) 15:19, 11 January 2011 (UTC)
They aren't fed gruel. They're fed what is basically cafeteria food. Googling "prison food" comes up with many articles describes common practices in the US. It doesn't sound hard to get enough calories or protein. All-you-can-eat buffet style seems common for certain categories of food (e.g. potatoes, beans, etc.). --Mr.98 (talk) 16:52, 11 January 2011 (UTC)
In the US, not providing an adequately nutritious diet to prisoners (or, more bluntly put, deliberate starvation) would certainly count as a violation of the Eighth Amendment to the United States Constitution. Similar standards, whether codified in so many words or not, can be assumed to hold in other Western democracies. –Henning Makholm (talk) 20:02, 11 January 2011 (UTC)
Nutraloaf discusses just where US courts have considered the edge of "adequately nutritious" to be. There's not enough information there, or enough of a standard, to gauge whether that has enough protein to allow for much muscle building. -- Finlay McWalterTalk 21:21, 11 January 2011 (UTC)
In unconventional prisons operated by the United States federal government, including those operated to detain enemy combatants, "dietary manipulation" enhanced interrogation techniques (feeding prisoners nothing but Ensure drink) is considered acceptable and legal. "“This technique involves the substitution of commercial liquid meal replacements for normal food, presenting detainees with a bland, unappetizing, but nutritionally complete diet. ... “Although we do not equate a person who voluntarily enters a weight-loss program with a detainee subjected to dietary manipulation as an interrogation technique, we believe that it is relevant that several commercial weight-loss programs available in the United States involve similar or even greater reductions in caloric intake.”" Nimur (talk) 22:08, 11 January 2011 (UTC)
In "unconventional prisons operated by the US federal government", plain old torture is also used, both officially and unofficially. As we now know, neither the eights amendment nor basic human rights or decency count anything if the Shrub in the White House determines that somebody is an "enemy combatant" (no matter if that is true or not). --Stephan Schulz (talk) 02:21, 12 January 2011 (UTC)
Stephan, please don't editorialize here. Cla68 (talk) 04:55, 12 January 2011 (UTC)
After a cursory read of some of the references at Nutraloaf, it does not appear that any of the prisoner suits attempted to challenge the nutritional value of the food, so they don't really tell where courts would draw the nutritional line, were that question before them. As for Nimur's links, those who defend such techniques also seem to argue in general that the constitutional protections afforded domestic criminals do not apply to WoT detainees at all, so we cannot really infer anything about what they think about the effects of the 8th amendment when it does apply ... –Henning Makholm (talk) 22:37, 11 January 2011 (UTC)
I do believe that the original genesis of the US RDA (recommended daily allowance) of essential vitamins and trace minerals was the definition of the amount of such nutrients required to prevent disease in federal prisoners. Franamax (talk) 01:24, 12 January 2011 (UTC)
In a letter to Flex (Flex 28.10 (Dec 2010): p32(1).) a body-building inmate in Alaska's prison system states that he has access to as much whole food and protein as he wants and that he eats 5-6 meals a day. He adds that he has put on 30 lbs of muscle since the beginning of his incarceration. While anecdotal, this suggests that at least some of the US's prison population has access to additional nutrition if they need it to support a body building program. Cla68 (talk) 05:10, 12 January 2011 (UTC)

Excitation of electron[edit]

A photon interacts with an electron in an atom which excites the electron causing it to jump to a higher energy level. but what happens to that particular photon involved in the process. I mean a photon is a particle and it doesn't makes sense for it to just go poof! -Raky rough (talk) 14:33, 11 January 2011 (UTC)

Well sometimes it is useful to think of photons as particles, and at other times it is clearer to think of them as waves that can be generated or absorbed by electrons or in many other situations. See Photon#Stimulated_and_spontaneous_emission and Absorption_(electromagnetic_radiation) for some examples. Remember that the photon as a particle has zero rest-mass (all of its apparent mass is "really" just energy), so it can appear and disappear as energy levels change. You say "particular photon", but they are actually indistinguishable because they can all be considered as just "packets of energy". Dbfirs 17:22, 11 January 2011 (UTC)
Richard Feynman compared the absorption and emission of photons to an acoustic wave (as a metaphor only - don't try to read too deeply into this). Here's his explanation in The Pleasure of Finding Things Out... "The view is that photon numbers aren't conserved, they're just created by the motion of the electron." Then Feynman makes an analogy of emitting and absorbing photons as a comparison to a person speaking or hearing words. There's no "word bag" that runs out of the word "cat" if you say it too often, or don't hear/absorb enough words. You aren't conserving the count of the words - the words only exist as a phenomenon of interaction when you speak or hear something. Similarly, photons only exist as a "phenomenon" that exchanges energy and momentum when matter undergoes an electromagnetic interaction. Nimur (talk) 19:36, 11 January 2011 (UTC)
Actually, photons aren't just packets of energy - they also have a certain fixed angular momentum (irrespective of wavelength, interestingly enough). This angular momentum is what allows the electron to jump up the energy level; it is also experimentally detectable as a force applied by circularly polarized light. (See also here) Wnt (talk) 06:09, 12 January 2011 (UTC)

what is this red and yellow flower/plant[edit]

Fremontbartflower.jpeg

I saw this plant at the Fremont (BART station) and wanted to know what species it is.Thisbites (talk) 14:34, 11 January 2011 (UTC)

Could be what gardeners call a geranium (or what botanists call a Pelargonium). DuncanHill (talk) 14:50, 11 January 2011 (UTC)
If its not that, it might be a candelabra primrose. But I think they do not have leaves up stalks, so it probably isnt. 92.24.181.78 (talk) 15:15, 11 January 2011 (UTC)
I think it is a lantana variety. I am going by the way the outer flowers are opening first and the shape of the leaves. There are many varieties so a better photograph is required to get a better identification Richard Avery (talk) 18:20, 11 January 2011 (UTC)
Looks more like a lantana than the other suggestions to me too. SemanticMantis (talk) 18:30, 11 January 2011 (UTC)
Lantanas are very common around here (I live about 20 miles from Fremont BART), so that's a reasonable suggestion, but although I'm quite familiar with what they look like, that picture is just too fuzzy for me. Looie496 (talk) 19:47, 11 January 2011 (UTC)
Hmmm, by the way... Is any of the fancy software for sharpening images from ground-based telescopes usable on photos like this, and is it freely available? Wnt (talk) 06:11, 12 January 2011 (UTC)
You could try Iris, but I think this image is too small and noisy to be deblurred effectively (I may be wrong). For what little it's worth, I'm pretty sure that's a lantana. I know nothing about flowers, but I do live in the Bay Area. -- BenRG (talk) 08:40, 12 January 2011 (UTC)
thanks guys, its definitely lantana

Top speed of the NHSL[edit]

What is the tops speed of any Norristown High Speed Line rolling stock? --Perseus, Son of Zeus 18:24, 11 January 2011 (UTC)

70 miles per hour[6] 71.198.176.22 (talk) 07:07, 12 January 2011 (UTC)

bubbles[edit]

Is the centerpoint of a soap bubble filled with air more dense than any other point in within the bubble? —Preceding unsigned comment added by 165.212.189.187 (talk) 19:15, 11 January 2011 (UTC)

No, the air pressure (and thus the density) is equal at all points inside the bubble, in the simplest approximation. Insofar as you can consider a bubble in "equilibrium", the gas pressure is uniform at all points in the bubble, and is equal to the surface-pressure exerted on the interior of the liquid bubble surface (that is, the sum of atmospheric pressure plus the surface pressure of the liquid, related to its surface tension). In a more detailed, dynamic and time-varying analysis, the pressure at each (x,y,z) point in the bubble varies with time and satisfies an acoustic wave wave equation, with boundary conditions defined by the liquid-gas interaction at the surface. The actual bubble surface will "wobble" dynamically, varying in shape around the approximately spherical "steady state" eigensolution (which is only satisfied when the pressure is exactly uniform at all points in the bubble). Other effects you might consider include: whether the bubble is moving as a whole entity (and potentially undergoing force due to net acceleration of the entire unit); the force of gravity, which does set up a vertical pressure gradient in the bubble (mostly insignificant for small bubbles in normal atmospheres); and anything the bubble edge bumps into (such as a liquid surface, another bubble, the ground, and so on). Nimur (talk) 19:23, 11 January 2011 (UTC)
A soap bubble in air is interesting, because to first approximation it is very simple, but as you point out, the details quickly become complicated. The dynamics seem to be very neutral, and thus the familiar 'wobble'. Do we have any articles that discuss neutral stability (or perhaps more precisely neutrally stable equilibria)? Surprisingly, the word 'neutral' does not occur in stability theory, dynamical system, or even equilibrium. Linear dynamical system does have 'centers' listed on the classification diagram, but no definition or discussion (and this is obviously not a linear system anyway). Is there some terminology I'm missing? SemanticMantis (talk) 19:50, 11 January 2011 (UTC)
You might be looking for information contained in the perturbation theory article? The "neutral equilibrium" is properly called an eigenfunction - specifically, it is the 0th order, or zero-frequency, solution of the acoustic wave equation with boundary conditions applied. It may also be called the "trivial solution," the "steady state solution", and so forth. The wobbles would be other higher-order harmonic eigenfunctions; it so happens that in this case, these solutions are oscillatory, so the bubble "wobbles" back and forth. I think the message we need to convey to the original poster is that the actual answer depends on how accurately and completely you want to analyze the bubble. Nimur (talk) 20:02, 11 January 2011 (UTC)
I'm thinking more of spectral theory than perturbation theory, but it's been several years since I studied it. Not to de-rail too much, but would the all the wobbles be part of the continuous spectrum? SemanticMantis (talk) 20:48, 11 January 2011 (UTC)

Now that you mention it, as "accurately and completely" as presently possible. I made the mistake of assuming that is how all questions are answered here. —Preceding unsigned comment added by 165.212.189.187 (talk) 21:19, 11 January 2011 (UTC)

Well, I could dive deeper into a presentation of the wave equation solution, if you are interested in the complete "answer" to this question; but I somewhat hold the opinion that either (a) you already understand techniques for solving partial differential equations, and can easily apply them to analytically or numerically solve for soap dynamic pressures; or (b) you do not already know how to solve those types of equation, and even if I provided a flawless overview of them here, the brief few paragraphs I might write would be insufficient preparation to train you in how to apply those mathematics to this problem. (I'm sure you're capable of learning them, if you're interested to learn; it's just that this is a complicated subject and takes a long time to master). Are you interested in books on soap bubble dynamics? Many prestigious physicists have written extensively on the topic of soap bubble physics; in fact, entire textbooks exist to explore their dynamic solutions. Here are a few Google search results to peruse; those will expose you to some of the techniques you need to analyze the problem "as accurately and completely as presently possible." If you need help finding a more specific resource, I can recommend numerous fantastic textbooks on mathematical methods and/or mechanical dynamics. Nimur (talk) 21:45, 11 January 2011 (UTC)

Then why don't you just answer every question with, "go look it up yourself here is the link."? To me that is not answering the question asked. I asked, "if the centerpoint of a soap bubble filled with air more dense than any other point in within the bubble?" A logical expectation is a yes or no followed by supporting evidence, not "it depends" that is the most absurd cop-out answer there is. From the way this question is answered I could answer every question on the desk with a bunch of wish wash, say depends a couple of times and then create a link to a site that i google. —Preceding unsigned comment added by 165.212.189.187 (talk) 13:40, 12 January 2011 (UTC)

It looks like you've received a very thorough answer and discussion from individuals who have a fair bit of expertise. In response, you've mocked and berated these generous volunteers who contributed their time and effort to try to help you. Nimur, I note above, didn't just tell you to 'go away and read the links'; he asked for clarification from you about the degree of assistance (and depth of explanation) that you sought, and was prepared to offer you additional, specific recommendations of references and textbooks that you might find useful depending on your interests and abilities. The Reference Desk is not a magic answer machine, and the volunteers here aren't automatons to be ordered about for your convenience. The correct answer to your question is in the very first answer, and boils down to 'No, to a reasonable first approximation, but for real bubbles it depends." How far you want to take the 'it depends' is up to you. It's not our fault that the laws of physics don't always generate simple and simplistic results. Would you be this rude to a real librarian at a physical library reference desk? TenOfAllTrades(talk) 15:51, 12 January 2011 (UTC)
Trying hard to assume good faith from the OP, I'll point out that it is not obvious that a soap bubble is an extremely complex system that requires years of advanced study to understand. This may contribute to the OP's frustration, if not excuse hir rudeness. SemanticMantis (talk) 16:13, 12 January 2011 (UTC)
I think the problem here is that Nimur's initial two sentences are a perfect answer to the question, and everything after that is an unfortunate over-analysis contemplating very rare special cases of acoustic standing waves which would be so transient if they occurred as to be negligible. The answer is no. 71.198.176.22 (talk) 10:58, 13 January 2011 (UTC)

Ten, that depends. But seriously, Obviously people come to this desk to satisfy their curiosity about odd and mysterious things. And I like it for that, but when questions are not answered as asked, I don't believe that is ordering you around, just answer the question. if the OP wants more they will ask more. 71.198, thanks for the answer. —Preceding unsigned comment added by 165.212.189.187 (talk) 13:52, 13 January 2011 (UTC)

History of explosives[edit]

Do we have any articles relating to this? --T H F S W (T · C · E) 21:02, 11 January 2011 (UTC)

For now we've just have this. --98.221.179.18 (talk) 21:25, 11 January 2011 (UTC)
Yes, it's very short. Maybe I should write something a bit longer. --T H F S W (T · C · E) 21:27, 11 January 2011 (UTC)
It's worth noting that many of our articles on explosive materials include sections on their history. (See, for example, black powder, nitroglycerine, trinitrotoluene.) TenOfAllTrades(talk) 22:17, 11 January 2011 (UTC)

Organometallic compounds[edit]

I've read the article about organometallic chemistry, but I still don't understand what determines whether a metal can bind to carbon or not.

Sincerely, Nirmos (talk) 21:06, 11 January 2011 (UTC)

The metal needs to be a good lewis acid. Carbon is actually a pretty shitty lewis base, so lots of tricks are used to make carbon a better lewis base, or the metal a better lewis acid. --Jayron32 23:04, 11 January 2011 (UTC)

Dymaxion map[edit]

We have an decent article on the Fuller projection, which has a couple of nice examples of it. What I can't find anywhere on the web (and this would seem like an obvious thing that people would like to produce as a project) is a nice black-and-white outline version, such as you could easily print out and copy, colour in, cut out, and assemble. I'm quite prepared to add the tabs myself, but my graphic design skills fall sadly short of converting the thing to a simple, clean, outline version.

So, does anyone know of such a source, or feel generous enough to make one? I'm sure such a thing would be heavily linked-to and used in all manner of schools and clubs, so you'd be contributing to the global education of at least one generation! 86.163.214.50 (talk) 21:40, 11 January 2011 (UTC)

Fortunately, this map is an SVG file. You only need remove the 1st, 3rd, and 4th path groups (enclosed in <g> tags) to reveal only the continent outlines. I have uploaded a modified version, File:Fuller projection rotated (land only).svg. You should be able to save this as a PNG or other file; or print it directly. If you need the dashed-lines, or want any color or line-thickness changes, those are easy modifications. Please abide by the license if you reuse this image. (If you aren't sure how to use this file, click here for a version without grids and with grids). Nimur (talk) 22:53, 11 January 2011 (UTC)
Oh wow, thank you so much! And yes, I'll abide by the license. It will be quite cool to tell them they're using something a volunteer made just so people could see it and use it :) 86.163.214.50 (talk) 00:32, 12 January 2011 (UTC)
Glad to help. Technically it is the work of many volunteers. The source dataset came from the National Geophysical Data Center (funded by the United States federal government); the original image was created by Eric Gaba, and all I did was remove the colors... It's a collaborative effort to keep information free and free. Nimur (talk) 00:51, 12 January 2011 (UTC)