Talk:Energy/Archive 3

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Archive 1 Archive 2 Archive 3 Archive 4 Archive 5 Archive 6

Talk page has been archived

For previous discussions, see /Archive 2. Cheers. --DavidHOzAu 02:24, 16 October 2006 (UTC)


Kinetic v. Potential

This article cites examples of kinetic energy and calls it potential. Needs some clear thinking about sorting out kinetic and potential. For example, the "energy released by lightning" is not an example of potential energy. This needs a lot of work by knowledgeable people. John 05:54, 8 January 2007 (UTC)

Okay, then what IS the paragraph on exploration about, then?

Originally this section DID actually suggest going into space to look for new kinds of usable energy. The main articles referenced were oil exploration and space exploration and oil exploration wasn't discussed. I thought this extremely bizarre. And yes, it really did say: "While some scientists are busy in exploring the possibility of cold fusion (what??) many countries are diverting significant economic resources towards space exploration in the hope that new energy resources may be discovered elsewhere in the universe." And it mentioned antimatter. One gets the feeling of Captain Kirk running around looking for dilithium crystals.

In the interests of good faith and no science fiction, I assumed this paragraph was really TRYING to be about the use of compact energy sources for space exploration. No, apparently not, you say. I pointed out that "antimatter" as a way to store energy (and that is all it is-- an incredibly inefficient and dangerous storage medium) is certainly more dangerous than bombs or reactors (are you really going to argue this point??) and THAT got reverted.

And what is this going on about "artificial photosynthesis"?? That's a way of trapping sunlight for chemical purposes, but you need sunlight for this, and sunlight isn't a concentrated form of energy, even near the earth, let alone outside Earth's orbit (It's no coincidence that all outer planet probes are powered by SNAP generators). Considering all of the many alternatives to fossil fuels (including ordinary solar power in one form or another to product electricity), this doesn't rate a sentence. And it has nothing to do with space exploration, except to keep astronauts alive wtihout plants. WAY off topic.i really dont care about these What in the world are you trying to do with this section? Decide. Don't just delete. SBHarris 05:40, 25 October 2006 (UTC)

So you are back with vengenance, not sense. And you have discovered a new way for carrying out discussion about the page by adding lengthy comments. Ingeneous indeed. But dear friend SBHarris, we are here not to compete but to cooperate, to make the page more useful and attractive. I hope you will give this thought a few minutes of your abundant time.

And by the way, I gave the title, if you think the paragraph needs more substance you are welcome to edit/add few more sentences on what you think is missing. Charlie 17:38, 25 October 2006 (UTC)

Since I cannot think of how to write a good paragraph incorporating "space exploration" and "new energy-source exploration", I can't help you. They don't really go together. Does anybody else out there want to help Charlie in his quest to marry these totally disparate subjects in a block of a dozen sentences? Or even several paragraphs? Are you thinking of solar satellites? What? SBHarris 20:16, 27 October 2006 (UTC)

Vibrational heat capacity

Vibrational modes contribute to heat capacity of substances as soon as the temperature rises to the point where they begin to be populated. But whatever the vibrational heat capacity contribution to the total is, that extra vibrational heat capacity contribution ITSELF, is always composed of a 50% kinetic and 50% potential component (on average-- integrating though each vibrational cycle). Each of these components for each vibrational mode gets (1/2)kT per atom, when T has risen so that energy is fully (equi)partitioned and hv << kT. Please don't revert me until you have a better way of saying this, or you think I'm wrong. In which case, here's the place to make your argument. SBHarris 20:30, 27 October 2006 (UTC)

While I don't have any problem with your statement in the article, in my experience it doesn't correspond to the way people in the field think about these concepts. The whole business of identifying "contributions" to the heat capacity is bound up with the idea that these contributions are in some sense independent of one another. Mathematically, the partition function factors, and when you take its logarithm you get a sum of terms that can be computed individually. Thus for a classical liquid, the partition function factors into kinetic and potential parts, giving you an average kinetic energy that can be evaluated by inspection (giving the appropriate multiple of kT), then you go do some hard work to get the the potential energy. This is valuable because it allows you to deduce, for example, that the velocities in a classical limit obey a Maxwell distribution in spite of the strong intermolecular forces. But this factorization fails when you move away from the classical limit, since the kinetic and potential energy operators do not commute, so the exponential of the Hamiltonian does not factor. Of course you can still write the thermodynamic internal energy as the sum of the ensemble averaged kinetic energy and the ensemble averaged potential energy, and then you can formally identify the temperature derivative of each term with its "contribution to the heat capacity", but this provides no computational simplification, and the individual terms do not, AFAIK, correspond to any experiments that are commonly done. It's just talk, and IME people in the business don't talk this way. (BTW, don't forget that kinetic and potential energy expectation values are only equal in the harmonic approximation. That's not going to be very accurate for, say, a hydrogen-bonded complex or the low-frequency torsional modes - hindered rotations - of a polyatomic molecule.)--Rparson 18:42, 30 October 2006 (UTC)

The warfare paragraph

Can we delete this? This basically says that a nuke war would blow up all our energy, so it would be a good thing to avoid. OOOOKAY. How banal is that? I could add such a paragraph to just about any Wiki that exists. A nuclear war would blow up the Eiffel tower, so should be avoided, wouldn't you think? A nuclear bomb would cause phenomenal damage to a Pearl Jam concert, so don't forget the importance of a nuclear proliferation treaty there... SBHarris 21:40, 27 October 2006 (UTC)

I agree. 128.12.108.47 02:54, 31 October 2006 (UTC)

Agree. Deleted. --24.52.254.62 22:28, 11 November 2006 (UTC)

hydrothermal vent organisms

I could be wrong about the ultimate source of the energy used by the organisms around geothermal vents. However, the Chemosynthesis article says, "Chemosynthesis is the biological conversion of 1-carbon molecules (usually carbon dioxide or methane) and nutrients into organic matter using the oxidation of inorganic molecules (e.g. hydrogen gas, hydrogen sulfide) or methane as a source of energy, rather than sunlight, as in photosynthesis." So it seems to me that either the energy article or the chemosynthesis article is incorrect, since they contradict each other. A third possibility is that the energy needed to make the unstable sulfur compounds does actually derive ultimately from sunlight, but I don't think so; I'd assume the energy of the sulfur compounds originates from geothermal energy, and geothermal energy is mostly from (a) gravitational potential energy released when the earth came together, and (b) natural radioactivity. There is also supposed to be a huge biomass of subterranean extreomophile bacteria, much of which is down extremely deep, and I can't imagine how it could be getting its energy from sunlight. Any thoughts, Sbharris? --24.52.254.62 05:47, 15 November 2006 (UTC)

Oh, I see, I only read your edit summary, and thought you'd just reverted me. Now I see that you added an explanation in a footnote. However, I still think that's not quite right. Both the sulfur and the oxygen are thermodynamically unstable. I think these organisms are getting their energy partly from geothermal sources (the sulfur) and partly from photosynthesis (the oxygen). I've made an appropriate edit to the footnote.--24.52.254.62 20:41, 15 November 2006 (UTC)

My thinking is that native or free sulfur *is* thermodynamically stable in anaerobic conditions (away from free oxygen). Certainly to the point that it occurs in native form without any organic input (as here from deep vents spewing stuff which has been down there for billions of years, or on the surface of say the moon Io). Absent an O2 supply, I really see no obvious "reservoir" of chemical energy lying around "free" in elemental sulfur, to be potentially used by living organisms. Ultimately, I think sulfur-burners wherever you find them are basically living off sunlight free-energy in the O2, albeit in a very tricky way. The early reports on this failed to note the crucial role of O2 in the process, because the discoverers were probably eager to have discovered something completely different. But I think by now everybody agrees that they haven't. In short, no, I don't think it's fair to count the native sulfur as an energy source per se.

And yes, the chemosythesis article should be updated to note that the energy for the process is coming from sunlight, but indirectly. Just as it does for the metabolism of other anaerobic organisms, which all use chemicals that (at least to my knowledge) must include at least ONE photosynthetically derived-one. If you can find me an anaerobic chemosynthetic bacterium which doesn't rely on ANY products previously produced by aerobic (therefore sunlight-driven) processes, that will be interesting, and I'll make no objection to adding it here. SBHarris 21:03, 15 November 2006 (UTC)

My thinking is that native or free sulfur *is* thermodynamically stable in anaerobic conditions (away from free oxygen). Well, O2 is thermodynamically stable if there's no hydrogen around. If the earth was in thermodynamic equilibrium, there'd be no free O2, and no free elemental sulfur, either. If you can find me an anaerobic chemosynthetic bacterium which doesn't rely on ANY products previously produced by aerobic (therefore sunlight-driven) processes, that will be interesting, and I'll make no objection to adding it here. If you look at my most recent edit, I didn't say that it gets all of its energy from geothermal sources, only that it got some of it from that, and some (indirectly) from photosynthesis. I'm a physicist, not a chemist or a microbiologist, so I could be wrong, but I think some of the organisms listed in the Lithotroph article (the section starting with methanogens) don't require any free oxygen, and might still be able to live if photosynthesis ceased entirely.--24.52.254.62 23:46, 15 November 2006 (UTC)
Sorry for the delay in answering. I agree that the lithotrophs are your best argument, rather than the vent organisms. Pretty poor pickings, though, and poorly understood. SBHarris 03:23, 12 January 2007 (UTC)

Exploration and research

I'm proposing to rewrite this completely. The mentioned technologies are simply new ways to store or use energy, not to produce it from known resources. We need some discussion of the latter. SBHarris 03:22, 12 January 2007 (UTC)

Rewriting introduction

The disambiguation tag already notes this page is as regards the use of this word in the natural sciences (it actually says "the mainstream sciences" but that's a very poor term). Or to be even more specific, this page refers to energy as used in the physical and life sciences, where it is quantitated in joules, or other equivalent quantities. There is no need to discuss broader definitions on this page, because this page is not about broader definitions. It is about the sort of energy that can be expressed in joules or other suitable units of [force times distance] = work.

Worse still, this introduction does not use the most common dictionary definition of energy as used in the natural sciences, which is the capacity of a system to perform work. I'm trying to fix that, but am being reverted by somebody who apparently would like to include a definition not specific to the natural sciences, and does not include the specific and short definition, which is. So, let me try again. SBHarris 23:51, 12 January 2007 (UTC)

Separation of Social and Science

The introduction sounds horrible at the moment, and I think that is mostly because of poorly defined scope for this page. I suggest the following:

  • change the disambiguation line back to {{otheruses1|the use of the word Energy in the natural sciences}}
  • move most of the definition ambiguity stuff to the disambiguation page
  • move the entire "Energy in society" section to a new article
    • as that section says, the definition is quite different
  • flesh out the disambiguation page a touch to highlight the new page scopes

I'm keen to kick this off, awaiting a discussion. LightYear 00:56, 17 January 2007 (UTC)

Bravo. I agree with all your suggestions. That makes two of us. SBHarris 05:39, 17 January 2007 (UTC)
I am open to any useful edits, but let me add, as I have maintained for a long time, let us have the diambiguation page as the main page of energy, so that every person who wants to know about energy in general, hits it first. Let us have an energy in physics article that would exclusively deal with the physics about energy. The trouble, as far as I can discern with you two, is that your education has taught you that physics (as taught in physics texts) is the exclusive domain for anything about energy. The world has advanced much beyond that ever since you were taught that in your school. People like you need to wake up.

Charlie 08:55, 17 January 2007 (UTC)

Please refrain from adding insults to your arguments. It really spoils the discussion and makes you look like an enemy. Obviously, no one is claiming that the physics definition of energy is exclusively correct. I do indeed have a scientific education background, so that's where my interest and knowledge prodominantly reside. On the other hand, all the other encyclopedic material on the topic of Energy is important - all I'm claiming is that the organisation needs to improve. One can easily see that the flow is currently awful. In fact, it looks like you're arguing for a similar outcome, so lets work together to come up with the best solution. LightYear 01:19, 22 January 2007 (UTC)

Touching off a revert war

I see that user:Hallenrm has reverted all of my edits to this article with the rather rude comment: "as the later edits are really extraneous." Which means he believes the article is already in a pristine and unchangable state, including the (IMHO) inappropriate definition it begins with. Sigh.

Charlie, please go to WP:BOLD and read what it says about use of reversion on Wikipedia. This is editorial policy here. Use reversion for vandalism, not to keep an article in the condition you like, so that you own it personally (if that's what you want to do, write for a journal or book, not here). Otherwise, come here to TALK to discuss changes. This is NOT your article. Nor is it for you to determine which edits are "extraneous." That's a group concensus decision. You may think you have the most "expertise" to determine such matters, but professional credentials of expertise on Wikipedia are largely irrelevant. Deal with that. If you don't like it, post a comment in protest on the TALK page of Jimbo Wales, since this is his policy, not mine. But his policies are the rule here. SBHarris 00:26, 13 January 2007 (UTC)

I see user SBHarris wants to take up the mantle of the administrator of this article. Therefore he cannot tolerate opinions that are at a variance then his own. I have been contributing to this article for more than a year and almost half of the present article has been my contribution. The veracity of the content can be judged from the fact that it has survived months of edits from many serious and knowledgeable editors, other than SBHarris. for such a long time. SBHarris, very unfortunately has the old habit of imposing his irrational or rather very conservative views on this page. I would like therefore that he is advised to restrain himself and learn to work in a group and respect other's views also which are not contrary to the facts and controversial. Charlie 05:20, 15 January 2007 (UTC)

I do not consider myself this article's administrator. There's nothing to "take over" unless you consider yourself the "previous" administrator. There is no administrator here, just a collection of editors.

The veracity of the content cannot be judged from anything about this article's history. Sorry, but that's not the way Wikipedia works. Some people haven't been paying attention. Some have given up. Some are waiting for others to finish. I myself have had other projects. And so on.

I do respect other people's "views", but "views" in articles may be scientific or political. Politics in science articles should be kept to a minimum.

I'll also be found here arguing for simplicity. There is no reason why an article on energy in the natural sciences (this one) should say ANYTHING about definitions in other fields. The one given at the beginning of the article as it stands is NOT inclusive. Energy is the natural sciences is not really the capacity to cause "change". Very many changes in natural sciences are the result of entropic processes (mixing, diffusion, radiation, etc, for examples) and have nothing to do with energy (although some involve difusion of energy from more to less concentrated forms, other types of mass diffusion and mixing don't even involve that). The technical way to state this is that system states may evolve in phase-space (i.e., change) while their energy remains constant. Indeed, they may evolve while all the types and forms of energy remain constant (as in gas mixing). Energy has nothing to do with many changes. That is the truth in the physical sciences, and it does not fit the way this article begins, which is actually WRONG. It's easy to fix so that it's not wrong; so why not do that?

Finally, stop calling my views "irrational." It's uncivil. If you think my ideas are scientifically incorrect, post your reasons here, and your math. I'll post the answering cites, and the answering math. If you think I'm not capable of defending my positions formally, try me. SBHarris 15:20, 15 January 2007 (UTC)

I suppose, that you will agree that wikipidea is an encyclopedia, not a textbook of physics, or science for that matter. An entry in an encyclopedia does not limit itself to a particular meaning, it deals with it in totality. Therefore an article on the terrm energy in wikipedia cannot be limited to its usage in physics (or science) alone. At least the introduction has to be all inclusive. I suppose that you are mature enough to understand that, and stop treating this article as if it were a part of a physics textbook.Charlie 04:03, 16 January 2007 (UTC)

You seem to be unable to write entries without insult. This time to my maturity. For your information, there is no Wiki rule that the LEAD for any article need be inclusive in any sense. A great many (in fact most) articles in wikipedia direct to the primary and usually scientific use of a word (if there is one), without any reference to other meanings, except for the redirect tag. For example, water will direct you to an article about the chemical sustance, without subjecting you first to a paragraph on water as metaphor for life in the Christian Gospels, and other such stuff. SBHarris 05:29, 17 January 2007 (UTC)
Just take a look at the top of this page, you will find a To do List it clearly indicates the scope of this article, and it is most definitely not limited to physics alone. I can swear that I am not the author of that box, most likely someone responsible for the content on wikipedia is responsible. That should be enough to trst your mind Mr. SBHarris Charlie 18:13, 17 January 2007 (UTC)
That to do list is not written in stone, but a simple template somebody decided to put up. It can as easily be taken down. For some articles and topics, it's not appropriate, due to the fact that it invites over-length, and when the length is cut, the result is so general as be meaningless. Energy is the perfect sort of article to disambiguate from the start. So far I have 3 other editors who agree with me, and you're the only one still holding out. I can remove the tag if it's too authoritative for you. You'll soon discover that a lot of stuff on Wikipedia which LOOKS authoritative, isn't. SBHarris 23:50, 20 January 2007 (UTC)
I agree. That "To do list" is not really a good idea for a single article and should not be considered authoritative. I think we should cool tempers here and decide on how to best divvy up this article into separate articles. I suggest that the article titled "Energy" is probably best made a disambig page. -Joshua Davis 02:16, 21 January 2007 (UTC)
It was indeed like that, but then some overenthusiastic physicsts came along, and removed a lot of stuff from the main energy page to another new page energy (disambiguation). My suggstion would be to rename the present energy (disambig) page to be the main page on energy, and break the present energy (main page) into several pages like energy (society), energy (physics); energy (etymology), energy (natural science) etc. etc. Charlie 04:23, 21 January 2007 (UTC)
That's a reasonable suggestion. The Wikipedia:Disambiguation page is required reading. Note also the Wiktionary entry, where the physics definition is marked as jargon. I think there could be evidence that "energy" is ambigiuous enough to warrant the disambiguation page be the lead and the scientific treatment be its own page, similar to Lift and Mercury. IME however, as SBHarris says, I felt I would be taken to a reasonably scientific article if I were to browse to Energy. I guess I don't mind either way - the article of interest is only a couple of links away. Improving the current Energy article is the most pressing requirement in my mind. LightYear 01:19, 22 January 2007 (UTC)
Given that I can think of at least two very big topics with the label "energy"(the technical scientific meaning and the industrial sense), the main page should probably be a disambig page. -Joshua Davis 03:48, 22 January 2007 (UTC)
Okay, I say we go for it. SBHarris 04:40, 22 January 2007 (UTC)

Potential energy in nitroglycerine

There seems to be some confusion about the energy in nitroglycerine. Chemical bonds do not "contain" positive energy. It always takes energy to break them. Explosives like nitroglycerine contain potential energy not because of chemical bonds in the molecule which are to be broken, but because of new bonds in the product gases (primarily N2) which are to be formed. It would REQUIRE energy to disassemble nitroglycerine into atoms. The only reason energy is liberated when nitroglycerine explodes, is that it explodes into gases like nitrogen. No "outside" influences are necessary. The molecule is thermodynamically unstable with regard to decomposition productions, at normal temperatures, and will spontaneously decompose given (arbitrarily small) thermal energy of activation. SBHarris 15:32, 15 January 2007 (UTC)

Energy is not a reserve of physics alone

Unfortunately, some users, who have been editors on wikipedia for some time are under the mistaken impression that energy can best be dealt exclusively by physiciste. They would therefore like to limit the content of this page to physics alone. In the present world, this is not true. The word energy is widely used in fora that are not inhabited by physicists alone. Time and again, there is an attack on this page by people of this genre. This is inspite of an announcement on the top of this page, which set the task for this article. It clarly mentioned that what is needed to be added was a section on Energy in society. Now, a user: LightYear has again popped up the issue. I think this matter should be settled once for all, by an announcement from responsible admins of wikipedia, about the reach of content of this article, so as to minimize any such confusion in future. —The preceding unsigned comment was added by Hallenrm (talkcontribs) 09:12, 17 January 2007 (UTC).

Well, the word "energy" refers to many things and it is not really appropriate to discuss them all in one long article. In physics alone, energy is a big topic that requires its own article. Likewise, energy as a natural resource in the industrial world(i.e. "Energy in society") is a whole other article. There are also more colloquial uses of the word which might merit their own articles. But it is a mistake to try to cram together one big article with all of these senses of the word discussed. I think the Energy in Society section should be moved to another article(I'm not sure what to name it) and this article might be better named "Energy(physics)" or "Energy(physical sciences)". -Joshua Davis 19:12, 19 January 2007 (UTC)


Nitrogen is not an exception

In chemistry as in nuclear physics, binding energy represents energy LOST from the system. The stronger the bond, the more energy lost, the lower the system energy, and the less the mass. All bond energies are negative; none CONTAIN energy. Energy is made in chemistry by breaking weak bonds and making stronger ones. Never by simply breaking bonds. Nitrogen is no exception. It is a good example of the rule. The formation of the strong nitrogen bond in N2, with energy release from this, drives most explosives and propellants in the modern world. And stop being insulting, Charlie, especially when you're eggregiously wrong on facts. If you belittle a man's education (and BTW I have far more of it across a far, far wider range of science than you do) it behooves you to do it after being right about the physics. Otherwise, you just embarrass yourself. SBHarris 19:31, 19 January 2007 (UTC)

I have studied chemistry upto the graduation level rather seriously, but I have not come across the idea that " Energy is made in chemistry by breaking weak bonds and making stronger ones." Please let me know the source of your statement, I shall retract. and forget about my embarassing myself, Face a knowledgable jury anywhere in the world, your postings shall stand a witness of your poor understanding of the subject.Charlie 07:55, 20 January 2007 (UTC)
Please do not attack other editors about their poor understanding. It is not civil. Critise the edit not the person. The sentence you object to may be badly worded but consider A + B -> C + D where all four compounds are covalent and in the gas phase (if solid or liquid, we have to take into account other energy terms). Consider breaking the bonds of A and B to give atoms. This is the combined energy (or enthalpy - it depends on conditions) of atomisation of A and B. Let us call that energy X. Now consider atomising C and D, to give the combined energy of atomisation of C and D. Let us call that Y. Each process leads to the same atoms of course. If the bonds in C and D are on average stonger than those of A and B, Y will be larger than X and energy Y - X is released. That is what the sentence is trying to say. Do you have a problem with my analysis? If not we have to word it more briefly and simpler. You are the science communicator. Go for it. --Bduke 08:41, 20 January 2007 (UTC)
My understanding is what I have put on the page. There are x number od bonds within the molecules of chemical reactants, having certain energy content (say A) by virtue of their chemical bonds. When they undergo a chemical reaction, the products may have say y number of bonds between the atoms in the molecules of the products, having some energy (say B kcals) the energy is released only if B is lesser then A. Where does the strength of the bonds come in the picture? I really do not like to talk harshly, but JBHarris insists and I cannot take his classes in elementary chemistry here on wikipedia. He must check the facts before he starts editing Charlie 12:48, 20 January 2007 (UTC)
I should indeed have qualified my statement by noting that it holds in comparing the same numbers of bonds on both sides of a reaction, or in comparing one bond to another. You can indeed, as you note, release net energy by breaking a few strong bonds and making many weak ones. However, it is still true that the strength of a bond is how much energy is required from outside the system, to break the bond into free atoms. That's the definition of bond strength. It takes MORE energy to break strong bonds, as in N2. Conversely, when strong bonds are formed, they give up MORE energy, per bond, as heat (or light or other active energy). Again, nitrogen is NO exception to any rule of this sort. SBHarris 20:01, 20 January 2007 (UTC)
I should have added two things to my example above. First, in a gas phase reaction, if there are no hydrogen bonded dimers or whatever (low in energy anyway compared with covalent bonds) the number of bonds is equal if you count double and triple bonds as 2 and 3. For example in CH4 + 2O2 -> CO2 + 2H2O, there are 4 bonds in CH4, 2 in O2, 4 in CO2 and 2 in H2O giving 8 bonds on each side of the equation. Second, the term Y - X is the energy of reaction. It is exactly what I described that is used to obtain the molar enthalpy of reaction using bond enthalpies to calculate enthalpies of atomisation of each species in the reaction. This is standard General Chemistry or at least the first course on Physical Chemistry. I think it was this that SbHarris was refering to, but whether it should be in the article or how it is put for the article is something else to determine. You are both correct, so you should work together to get a consensus of how it goes in the article. I would however comment that you description above is not clear. Whether "B is lesser then A" depends on how you define A and B. If A and B are negative quantities defined as energy of molecule - energy of atoms then B is lesser then A. If they are sum of bond energies as normally defined then A and B are positive energies of atomisation and B is greater then A. --Bduke 23:18, 20 January 2007 (UTC)

There are a lot of things people like us realize after they have said it, that could have been said more clearly and accurately. The comments by SBHarris and Bduke support my this contention. A monkey can spoil a decent setup given the freedom. Wikipedia provides this apparent freedom. So, if some editor like SBHarris wants to go about acting monkeyly, as he has demonstrated in the past, I am nobody to prevent him. Charlie 04:14, 21 January 2007 (UTC)

I think both versions are correct. Perhaps speaking in terms of the binding energies is more precise. But saying that creating stronger bonds releases energy is more intuitive. Let us not fight about it. JRSpriggs 13:55, 21 January 2007 (UTC)
Well I can understand if someone says that chemical potential energy is energy stored as the bonds in a molecule of a chemical substance. That's the way it was put originally, but then came SBHarris with his opinion that chemical potential energy is not only energy in the bonds; it can be more; I understood, (because enen an atom can have chemical potential energy) and came to the present standpoint; but friends here will agree that if an edit has to survive, at least it should be coherent. SBHarris time and again puts in incoherent sentences and then comes back complaining. What can one do then? Quit editing? Charlie 04:00, 22 January 2007 (UTC)
Chemical potential energy can be negative or positive. However, going beyond what the signs mean, A single chemical bond has no potential energy in the usual way we think of this: as something which can be converted to useful work. It simply does not. An existent bond contains no stored energy which can be used to do work. Is that simple enough for you? Coherent enough? Do you understand it? Then write it.

And by the way, since this is an article on energy, have the grace to USE energy in your chemical equations. Enthalpy is a lazy chemist's attempt to pay attention to heat, ignoring energy absorbed or created by pressure-volume work, because it's easier to do so. But the relationship is not exact unless volume doesn't change. And we are talking about energy of reactions, not just the heat that happens to come from them or is absorbed by them at constant pressure. SBHarris 04:38, 22 January 2007 (UTC)

Now for sense sake, please stop talking total nonsense. If you have support to what you have said in the above paragraph, cite a good reference a hyperlink, a publication (reputed book or paper) or just keep quite. I dare say, your education in science and its understanding is very poor! I have been rather couteous with you, but if you continue with this behavior i will have just two options leave you to your designs and say what you can on this article and wait it to be reverted back someday by some sensible editor, when you would have got tired and stopped visiting this page everyday; or else, engage in a revert war with youCharlie 07:28, 22 January 2007 (UTC)
There is a wiki on enthalpy. It is defined as E + PV. This is an article about E, not E + PV. Is that succinct enough for you? SBHarris 00:38, 25 January 2007 (UTC)

Please you have been told often enough. The Wikipedia way is to be civil, to not threaten, to not attack the other editors but critices politely the edit. You have been far from courteous. "stop talking total nonsense" is hardly courteous even with a "please" in front of it. You know nothing of other editor's education in general. Revert wars usually end with both parties being banned from wikipedia. --Bduke 08:40, 22 January 2007 (UTC)

Well, if you think I sounded uncivil, I am sorry for that. It was SBHarris who started threatening me to get me banned (you can see it on my talk page).The science is universal, some people understand it and can communicate it, while others can not do so with same felicity. Those, who are not really conversant with the intricacies of science should not attempt to sound authoritative about topics they understand little. My interaction with SBHarris on this page has a long history that is very well documented. Sure, I don't know about his education, but I can get an idea of it from his edits, as can any mature person. Spare sometime and go through it and his as well as mine edits on the article, before passing a judgement. I, atleast, do not edit on wikipedia just as a time pass, I do so because i do think that it is a useful contribution to humanity, as I believe most other serious editors of wikipedia believe, but I don't go about complaining and asking people to intervene.Charlie 12:30, 22 January 2007 (UTC)
Assume good faith - WP:AGF. We are all trying to produce a good encyclopedia. My judgement is that you could both do better. Go for it. Working together gets you there better than argueing. --Bduke 12:41, 22 January 2007 (UTC)
How can I assume good faith when every time I say something quantitative, I'm accused of speaking nonsense? There are plenty enough examples of this. The very last one is right up above. SBHarris 00:38, 25 January 2007 (UTC)

Remove incorrect generalization

Article states: "Thus, explosives simply are fuels chemically bonded to a surrogate of O2". This is either wrong or made trivially true by requiring any product molecule at all (even a polymer) to be a "surrogate of O2". But there's no reason to view it that way, any more than there is to view O2 as a surrogate of explosives, or fuels, which react without need of it. Consider silver acetylide, which derives considerable explosive force simply from the heat released in polymerizing acetylide ions, and without formation of any gasses. This actually is a case of energy released by destroying a few strong bonds to make many weaker ones, so it goes against my own earlier broad statement. It can be done both ways. SBHarris 18:56, 24 January 2007 (UTC)

Chemical potential energy

I mentioned enthalpy because what are called "bond energies" in some introductory texts are in fact "bond enthalpies". However we should be concentrating on internal energy here because the energy change due to work against the atmosphere or by the atmosphere is not relevant to the topic but is included in enthalpy. It is also a good idea to keep reminding chemists that enthalpy is not the same as energy. --Bduke 22:42, 27 January 2007 (UTC)

Welcome, the enthusiastic editors of Energy article

I wholeheartedly welcome the enthusiasm of some editors in trying to improve the article. For months, I was feeling lonely, because it appeared that the article attracted none else but an occassional vandal. It is yet to be seen how long these editors remain interested in this article and will they really contribute towards improving the quality of the article. Because to me it appears this is a sudden burst of enthusiasm on the call of SBHarris, who felt humiliated by my remarks. So, happy editing dear friends, I shall visit the article after sometime and see if you still maintain the interest in the article and bring about some improvements in the article at that stage.Charlie 08:08, 29 January 2007 (UTC)

Do I hear my name take in vain? I'm happy to see other editors contributing, naturally, but have no need of being humiliated or or feeling "humiliated" by any of YOUR remarks, Charlie. For you don't know this particular topic in science any better than I do, overall. Perhaps you're the last person to realize that, but if so, it's not my problem. In any case, I've been mostly ignoring this article to see what happens to it. I expect that in future, this article will draw in various experts on various subsections, according to their expertise, and I welcome that. For example, I think it's a good point that energy is sometimes defined as capacity to do work, but indeed that's incorrect, when the energy spoken of is in the form of heat, and so must contend with conversion efficiency problems. SO that should be clarified. And so on. SBHarris 02:31, 1 March 2007 (UTC)

Exacting definition?

Hi.

It's said on this page that a "precise" definition of energy is "of interest only to specialists". So then we refrence a book, which requires money to get (around $100). But what if someone is curious about the definition but does not want to spend $100 to get it? Why couldn't a description be included here, on Wikipedia? Many things on here are not really of interest to the "general public" at large, like, say the Cantor–Bernstein–Schroeder theorem. I don't know of too many people who would care about such a thing, except for a mathematician. 74.38.32.195 00:37, 1 March 2007 (UTC)

Any response? 74.38.32.195 22:52, 7 March 2007 (UTC)

There is a clear definition of energy in physics - look up any good textbook or encyclopedia - energy = the amount of work one system is capable of doing on another. There are no other (non-circular) definition of energy in physics. The book cited (Misner, etc) uses circular definition: energy=time-derivative of action, but action is then defined via lagrangian which is defined via energy again (!).

Enormousdude 23:08, 8 March 2007 (UTC)

Isn't action more fundamental than energy? Isn't it action that is quantized rather than energy? Alfred Centauri 03:27, 9 March 2007 (UTC)

intro

I can't rewrite it myself, but I'm pretty sure the third sentence shouldn't mention the "shift symmetry of time". The whole intro should be comprehensible to a smart sixth grader. There is plenty of room for depth and precision later in the article. ike9898 19:00, 10 April 2007 (UTC)

Don't underestimate sixth graders!. On the other hand, I agree that the sentence is inappropriate for the intro. Why don't you remove it? Time shift invariance is covered in the energy conservation section further down in the article. Alfred Centauri 02:24, 11 April 2007 (UTC)

Intro needs to be right

I'm all for simple intros, but this one as it stands actually defines "free energy", not energy. There's a difference. Whenever heat is present, energy is the ability to do work only in the limit of having a reservoir at absolute zero to dump the heat into. Or some other way to absorb the entropy. Otherwise, some of it (heat energy) CANNOT be used to do work. Period.

Heat is degraded energy that CAN'T be used to do work, unless you have some way to get rid of the T*S term. So long as you insist on defining heat as a sort of energy (i.e., thermal energy) then you cannot define energy as the ability to do work, without SOME kind of qualifier. We can maybe reference this qualification lightly in the intro (for those sixth graders) and get to it later. But we should say something about it, and I think we shouldn't start out this article with a definition which tells an untruth. Which we do, as the article stands. SBHarris 19:44, 11 April 2007 (UTC)

Why do you insist on harboring the misconception that "Heat is degraded energy that CAN'T be used to do work," It is simply not true. Arn't you aware of steam engines and themoelectric power stations? Heat is used in many life situations to do useful work. It is responsible foe life that enables an organism to do work. I must say you are too adamant and too ignorant, I really don't understand the reason for your getting stuck up in spoiling the quality of this article. You seem to miss no opportunity to fulfil your ambition in life, that is somehow succeed to spoil this article with your half baked knowledge.Charlie 17:52, 13 April 2007 (UTC)
  • Charlie, you have removed the qualifiers in my statements, and then now you attack me for misunderstanding. Read the above again. I said "Whenever heat is present, energy is the ability to do work only in the limit of having a reservoir at absolute zero to dump the heat into. Or some other way to absorb the entropy. Otherwise, some of it (heat energy) CANNOT be used to do work." Thus, some heat is not available to do work in most real situations (not too many absolute zero reservoirs out there), and is not available to do work in any cyclic or reversible situations. I said: Heat is degraded energy that CAN'T be used to do work, unless you have some way to get rid of the T*S term. (You deleted the qualifying phrase). Which in practice means it (heat) cannot be fully utilized unless you have (again) an absolute zero thermal dump, or some other (usually irreversible) way of dumping the entropy, as with (say) gas expansion. Otherwise, some heat must stay as heat.
Arn't you aware of steam engines and themoelectric power stations? Heat is used in many life situations to do useful work.
  • Yes, but not at 100% efficiency. Thus, some of any heat reservoir represents energy which is NOT available for work, in a cyclic process such as an engine. And never will be. This part of the heat is energy which is NOT available for work. In contradiction to the simplistic definition which the article began with.
It is responsible foe life that enables an organism to do work. I must say you are too adamant and too ignorant, I really don't understand the reason for your getting stuck up in spoiling the quality of this article. You seem to miss no opportunity to fulfil your ambition in life, that is somehow succeed to spoil this article with your half baked knowledge.Charlie 17:52, 13 April 2007 (UTC)
  • You seem to be incapable of writing without being insulting, and you've been warned about this before. Learn from Robert K S. There are many situations in which heat energy cannot be used to do work, and if that wasn't so, there would be no energy crisis-- we could simply use the heat all around us to do all the work we wanted. This is an important point, and I'm glad the article starts right out by addressing it. It's not energy, but free energy that the world is short of. Writing the LEAD to suggest otherwise would indeed be half-baked. There's energy all around us. What isn't all around us is energy with the ability to do work for us. SBHarris 19:52, 13 April 2007 (UTC)
I think what Steve is pointing out is that no theoretical heat engine cycle is fully efficient. I would like Steve to help us out by more fully explaining and sourcing his position. The lead needs improvement and needs to be both accurate and simple. I'm coming to realize that it should be no surprise we are having a difficult time defining energy simply; it has always been a conundrum. About the only clear thing about energy is that it is conserved. This article is an interesting read and it and other sources might be able to help us out coming to a consensus. In any case, the present lead does not fulfill Wikipedia's "perfect article" goal for a lead that "starts with a clear description of the subject; the lead introduces and explains the subject and its significance clearly and accurately, without going into excessive detail." We should try to avoid words like "sometimes" and "loosely" in a lead, but phrases such as "is difficult to define" are equally unhelpful insofar as they convey no concrete information, which should be the purpose of an encyclopedia article. Robert K S 19:30, 13 April 2007 (UTC)
I just re-read Steve's first paragraph of this talk section. Steve, its seems to me that your objection is that not all of the heat in some system is available to do work in the absence of a perfect vacuum. Is this not analogous to saying that not all of the potential energy in a rock at the top of a cliff is available to do work, simply because the rock must come to rest at the bottom of the cliff rather than falling right through to the center of the Earth, only at which point will its gravitational potential be fully dissipated? Robert K S 19:53, 13 April 2007 (UTC)
Yes, not all the heat in an object is available to do work, in the absense of some kind of entropy dump (in the form of a thermal reservoir at absolute zero, which is never seen). Or some other kind of infinite capacity entropy dump (like a place to put expanding gas, or difusing solute, indefinitely). That means some of the heat in the universe will never be usable to perform further work. Ever. No matter what anyone does or how clever they are. It will never again be transformed to work. I don't seem to be getting this point across. But it means that energy can't be simply defined as ability to do work, because our own universe contains all kinds of energy that has no ability to do work, and NEVER will. So there is no ability. The ability is gone for good. This is not quite analogous with the rock example, because the only thing that prevents total conversion there is practical design (you could make the mass so big as to collapse it all into a point, ala black hole, and get all the G potential work out), but no physical law. In the case of getting work from heat, there's a physical law involved which prevents conversion (second law of thermo), and that's connected with the fact that disordered states are more common than ordered ones. And you need ordered states to do work with energy. To get an idea of how hard this is, you can't even get the work from heat by dropping it down a black hole. Rather, black holes themselves convert into heat (see Hawking), and work capacity from that energy never appears. SBHarris 21:35, 13 April 2007 (UTC)
Thanks for the explanation. Robert K S 22:00, 13 April 2007 (UTC)
That's indeed some progress, some sensible discussion. But, I hope you will agree with me, that no brief sentences suffice to communicate fully the relationship between energy and entropy, as done by SBHaaris in the above paragraph. What then is needed is very careful phrasing of sentences that are not misunderstood on first reading. We can cooperate with each other on such a venture.Charlie 18:29, 14 April 2007 (UTC)
I have tried to make the intro very brief and factual. I wpould like to invite any comments on the present intro. Charlie 05:44, 18 April 2007 (UTC)
The first problem I note with the present lead--after my adjustment of the etymology, which I hope will see consensus as it traces the word to a less ambiguous root, and displays correctly on your browser--is its virtually non-informational introduction of energy as "an important concept in science." Things shouldn't be judged to be important or unimportant on Wikipedia--they are merely notable, which is entirely superfluous to mention since non-notable topics do not get articles about them. How about something more like "Energy is a quantifiable property of matter by virtue of its position, motion, or other characteristics, known since the early development of physics to be conserved even when undergoing transformations between its various forms, including the kinetic energy of mass, light, heat, and nuclear energy." I'm sure that too could use improvement--it is certainly not exhaustive and it may not even be entirely correct--but at least it is much less vague than the present sentence, which pointlessly pontificates about energy's supposed "importance". Cheers, Robert K S 09:42, 18 April 2007 (UTC)
Sounds OK except your sentence is rather long, and a normal reader will tend to forget what has been said in the begining while reaching the end. In my opinion, the intro should remain least controversial and plain, because anyone hitting the page would ber already familiar somewhat with the concept. I do not think that the article should be ambitious to give the total jnan in one go. The introduction in its present form fulfils that purpose. All about the various forms of energy and its conservation follows almost immediatly and one must not feel so insecure about losing the reader. Brevity is the key.Charlie 12:08, 18 April 2007 (UTC)
Your reply does not address my points made above. "an important concept in science, with its origins in physics" does nothing to say what energy is or does, and states an opinion rather than a fact. Stating that "energy is an important concept" is no more valid than saying "energy is not an important concept", to say nothing of it being not in the least enlightening about energy. Robert K S 13:42, 18 April 2007 (UTC)
Look at it carefuly. you will find that this short and very crisp intro has a lot of info too. It says that energy is a concept; which negates any misconceptions a young reader may have that it is some kind of substance, a very common misconception. Ot say energy is an measurable attribute of physical systems that can have values only in the realm of real numbers not imaginary numbers. The word important is a truism which no one can afford to ignore. Anyway, can you suggest any intro that is very enlightening and interesting too, without going into unneccesary at the wrong place in the article. Charlie 18:32, 18 April 2007 (UTC)
Wikipedia is not for truisms. Wikipedia is for verifiable, attributable facts. Robert K S 06:29, 19 April 2007 (UTC)
But, no one can escape truth in life. It is futile. Truism hhave origins in the truthCharlie 11:19, 19 April 2007 (UTC)
Good observation, but irrelevant to the discussion of a Wikipedia article. Please see my note on your talk page. I am reverting your changes to the lead for the reasons stated there, along with the fact that it introduces, without necessity, a double definition ("concept", "attribute"), wikilinks to a disambiguation page, and adds a non-sequitur (the "therefore" does not follow from the previous sentence). Here is your most recent version of the lead (for the purposes of preservation within the context of this discussion). Robert K S 11:55, 19 April 2007 (UTC) In physics and other natural sciences, energy (from the Greek ενεργός, energos, "at work") is a concept, a quantifiable attribute of physical systems. It can therefore neither be created nor destroyed; it can only be transformed.
Well if you are bent on a confrontation attitude, let it be and let some other editors resolve the disputeCharlie 18:02, 19 April 2007 (UTC)
I get the feeling you're modifying the lead just for the sake of modifying it. You've replaced "therefore" with "It follows that", except it still doesn't follow. You've re-added "concept", but between "concept" and "attribute of physical systems", why opt to include the vaguer of the two at all? You've re-wikilinked attribute, but pointlessly, as it goes to a disambig page. I won't get into an edit war with you, but I hope other editors will notice the nonsensicality of these edits and find creative, sensible ways to obviate them, in addition to expanding the lead as called for by the WP:LEAD guidelines. Robert K S 18:52, 19 April 2007 (UTC)
The latest edit by you contributes the futher confused statements "It is not an object...", "...forms of energy can be visualized...", and "Energy in any of its forms can be transformed...". I object to all of these. They are muddled, imprecise, and/or incorrect--in short, they constitute bad writing. Robert K S 19:03, 19 April 2007 (UTC)
Your mental make up appears to be like that of a lawyer or an office clerk, a stickler of rules and laws. I do not think that there are any sacred laws that are to be follower on the wikipedia. You point me to WP:LEAD guidelines, but have you noticed that they are also subject to change after discussionCharlie 19:11, 19 April 2007 (UTC) What is incorrect? That energy is a concept and not an object, a widely held misconception. Or that any form of energy can be transformed to another form. It's your obstinacy and not your reason that is leading you to write the above sentences Robert K S. I can only pray thyat reason dawns on you. Charlie 19:17, 19 April 2007 (UTC)
You are welcome to propose your changes to WP:LEAD over on its talk page. In the meantime, this article could benefit from following the spirit of its guidelines, which are evolved and not unreasonable. As to your rebuttals to my criticisms of your edits:
  • That energy "is not an object" is not incorrect; it is merely superfluous. It is no more relevant to say energy is "not an object" than it is to say energy "is not a philosophy", energy "is not a procedure", energy "is not a purple banana", etc. If it is really a common misconception that energy "is an object" (and I challenge this as well), then the best way to combat this misconception is to state succinctly and accurately what energy is in the lead. If indeed some (notable, citable) controversy or misconception exists regarding energy, then this would deserve fuller treatment with proper attribution. Calling energy "not an object", especially in the lead, merely muddles things. (Imagine for a moment that you want to know what "tergiversation" is, and, looking it up in the dictionary, you find it says "tergiversation is not a mixed drink". That's unhelpful, even if, for some reason, you might have thought tergiversation was a mixed drink.)
  • "...forms of energy can be visualized..." is imprecise, even though I kind of know what you mean when you say this. It may just be a lack a faculty with the English language on your part that is preventing you from arriving at some more precise formulation like "some energy transformations are manifest in ways that are observable to the unaided eye". But indeed all, not some, forms of energy transformation, and indeed anything that can be modeled mathematically, can be visualized. And at least one form of energy transfer (to sound) is not visible (note the distinction with visualizable) but is instead audible. Still and all, this point (that some forms of energy transfer bring about physical changes visually perceivable to humans) carries virtually no relevance to the lead.
  • "Energy in any of its forms can be transformed..." My own personal objection is the inartful repetition of "form" in the sentence ("Energy in any of its forms can be transformed into another form"), but I also question whether the sentence is strictly correct given the limitations explained by Steve above.
Cheers, Robert K S 19:50, 19 April 2007 (UTC)
I've qualified it in the LEAD, but the bad definition from some wrong source still stands out like a sore thumb in the definition section:

Energy, in physics, is defined as the amount of work a physical system can do on another.[1]

Well, the energy of a black hole is NOT the amount of work this physical system can do on another. SBHarris 21:46, 19 April 2007 (UTC)

Collaboration

Hi everyone. It was recently pointed out at Wikipedia:WikiProject Physics that this article is the current "Core Topic of the Fortnight" for Wikipedia' "Version 1.0 Editorial Team." Because of that, I imagine there'll be a lot of editors coming here to help out for the first time. At the same time, there seem to already be some debates about the article raging on this talk page. It might be asking a lot for all the new editors coming here to have to read through those lengthy discussions.

Given the above, could someone please concisely and neutrally summarize what are the relevant issues being discussed here, and what other work the article might need? A bulleted list would be great. The usefulness of this exercise will be severely limited if it just turns into another long fight, so let's all do our best to keep things civil and professional so we can focus on improving the article. I, for one, would love to help, but I don't think I have time to read all the arguments. Gnixon 14:16, 22 April 2007 (UTC)

Hi Gnixon, thanks for your leadership on this task.
  1. The lead needs to be improved for clarity and completeness, in accordance with the guidelines at WP:LEAD.
  2. The "Definitions" and "Historical perspective" sections could benefit from revision in the interest of maintanence of encyclopedic tone and clear, precise English.
  3. The article also would be improved with an overall audit to remove repetition. Some concepts are fleshed out multiple times, and some are covered in-depth, unnecessarily, since they are covered more fully in their own articles.
Robert K S 16:14, 22 April 2007 (UTC)
Thanks. Not trying to lead; just want to help. Gnixon 14:26, 24 April 2007 (UTC)
It's indeed a nice feeling to know that some people may seriously be interested in improving the article, rather then just imposing their point of view, from a position of assumed authority. I am saying so because one the word goes around there would be hardly anyone serious who would be willing to spend time in trying to improve its quality!Charlie 14:46, 24 April 2007 (UTC)

Definitions

I've cut most of the text under "Definitions" in this version. To me, it read like a talk page discussion of how to define "energy," not an article-appropriate description of various definitions. As the section stands now, it's not worth having, but I wanted to leave all the information and just cut the POV arguments. I think we should either (a) decide on what definition to use and cut that section, or (b) simply explain how and why different authors define energy differently, giving their reasons, but without inserting our own discussion about which way is better. Gnixon 14:26, 24 April 2007 (UTC)

It is not really so; a lot of debate is going about in the academic circles about how to define energy in the modern context. True energy has been defined in many authoritative sources, but it is equally true that energy like lifedefies a global definition. The word energy is used in very many contexts and any attempts to define energy on an encyclopedia like wikipedia must, in my opinion, reflect the differences in opinions and not shove them under cover. We have to remember the special character of wikipedia, which in my opinion is different from Encyclopedia Brittanica or Encyclopedia Americanna.Charlie 14:39, 24 April 2007 (UTC)

Historical perspective

I removed the following from the start of this section. It was already deleted once but got restored in a general revert... it seems to be a sort of fairy-tale reconstruction of the history of energy; I don't think it has any historical value and the valid points it makes about the physics of energy are well covered elsewhere

The concept of energy, a long time ago, was used to explain easily observable phenomena, such as the effects observed on the properties of objects. It was generally construed that all changes could in fact be explained through some sort of energy. Soon the idea that energy could be stored in objects took its roots in scientific thought and the concept of energy came to embrace the idea of the potential for change as well as change itself. Such effects (both potential and realized) come in many different forms. While in spiritualism they were reflected in changes in a person, in physical sciences it is reflected in different forms of energy itself, for example, electrical energy stored in a battery, the chemical energy stored in a piece of food (along with the oxygen needed to burn it), the thermal energy of a water heater, or the kinetic energy of a moving train.

If anyone wants to put it back again, please explain why! PaddyLeahy 20:48, 26 April 2007 (UTC)