Talk:Energy (physics)/Archive 2

message: This is pretty much a ramble showing the sort of thing that might be included. I find that in conversation with smart non-physicsts, they light up when I can get the unifying reason for using the concept of energy across to them.
There might be better examples to include, a satellite launch lower bound is orders of magnitude lower than practice, maybe energy in oscillators (pendulum, LC etc) would be good.
What do you think?
A Noob's first wiki contribution. Sorry about the link out to a new page, I didn't spot the next section [+] until I came to this Talk area, too late at night to change it now.
NeilUK 00:39, 11 January 2006 (UTC)
replies: text: Fixing CuteNess: "the energy of moving objects" fixing "the energy of stopped objects"
Sigh.... Terry King 23:25, 26 February 2006 (UTC)
thread_title:  Why use energy? 

message: My history of physics is a bit rusty, but if I remember correctly, didn't Huygens first suggest a way of quantifying kinetic energy (albeit not knowing it was energy)? As I recall, he felt the need to introduce a new scalar quantity for mechanics. And then didn't Young find that work equals the change in energy? I felt compelled to suggest this, as the history section is a bit nebulous when it comes to the history of the topic before thermodynamics. Gershwinrb 07:36, 27 February 2006 (UTC)
thread_title:  History 

message: this link in the bottom of the page:
# Website in the United States of America (www.isitel.com/ufoenergyball.htm[2]) capturing a fire or energy ball
What is that? it's a page full of ads with a very doubtful photo of what seems a spot on the lens of the camera and claims to be an "energy ball"
It's obviously a marketing trick. I think it should be removed right away. I don't do it myself cause i'm just a newbie, who just happened to reafd the article, and i leave it to discussion.
:Wikipedia:Be bold. Piet 09:35, 3 April 2006 (UTC)
thread_title:  bad link? 

message: Apologies to all the scholars; this is a question from the masses...
The initial definition of energy appears to be a description of how matter behaves; not a definition of energy in its own, intrinsic nature.
If I accept this definition; then energy has no individual existence - it is merely a concept of activity, a way to place a generic definition on the many ways in which matter can and does interact with itself.
Following on from this (pardon the macro-leaps in logic) if quantum particle physics claims that matter seems to be a result of the interaction of energy, confined into extremely small, relativistic volumes of space/time - this would suggest that energy is the action of matter; that (in itself) is the action of energy confined; that is matter in action; that is energy confined.......
See my dilemma?
Can Science actually explain to me: What is matter and what is energy, without referring one to the other?
To explain away the actual definition of matter, by suggesting that it is some form of 'confined energy' -  simply places the responsibility back on science to define energy. However, as energy seems to be defined as an action of matter -- you can see why I am dissatisfied with this definintion.
Please note;
This is a genuine request for further explanation. I am not being silly. I am an individual who represents the readers/consumers of the Wikipedia experience. Although I appreciate the depth of knowledge being provided for me to use; I feel that there is both room for scholars to better explain their claims to the uninitiated AND use this forum to carry on their important work at the forefront of human knowledge.
Sincerely, Greg Chalmers.
cool!
---unfortunately, the only way to define energy is by mentioning matter.  I know this may bug you but there is a reason: energy is relative.  Think of it this way: from the frame of a person standing on the road, a truck has huge amounts of energy, this energy can only exist because the truck has mass.  To say that anything relative to anything else has energy, that thing needs to have mass.  In fact, Einstein noticed this relationship and found that mass itself is energy.  The formula "E=mc(sq)" states that all matter is energy.  In the same sense that time was found to be another dimension like space, space and time became the space-time, when mass was found to be another relative view of energy, mass and energy became mass-energy.  Energy is nothing more than what matter is doing compared to what you are doing.
:: The statement that energy is a concept relating to the potential for changes, is in my opinion the most inclusive definition of energy, if the author of the above mentioned concern can offer a more inclusive definition, please tell it, rather than just complaining. Charlie 06:11, 21 September 2006 (UTC)
thread_title:  Fuzzy on the primary definition of Energy 

message: Proposal  :            	→ Energy (Physics)
Rationale :  	At the moment the title is too general, and the article is tainted with off-topicness about emotional energy and human energy supply.
Proposer :             	User:DavidHOzAu
I agree to the proposal, with a minor correction, let there be a general page, for example, that on action, with links to various pages dealing with specific contexts. 
Charlie 09:12, 18 April 2006 (UTC)
thread_title:  Requested move 

message: Please add  * Support  or  * Oppose  followed by a brief explanation, then sign your vote using "~~~~".
* Conditional support if...
* Oppose per Lumos3 below. Keep this article on the topic of energy as per physics; disambiguate other (mis)uses. David Kernow 02:22, 13 April 2006 (UTC)
thread_title: Survey and discussion

message: *No move, as per majority vote of 62.5% (5/8) of Oppose.
Interestingly, majority of voters also suggested creating some sort of disambiguation on the topic. As per WP:D#Primary topic, Energy (physics) will redirect to Energy, and the top of this article will contain a note about Energy (disambiguation). --DavidHOzAu 11:16, 28 April 2006 (UTC)
thread_title: Result of Discussion

message: Get the details here.  The beginning was too unweildy, so I cleaned it up to just a raw definition, moved the remaining content to a new section, and glued the paragraphs together to make it more readable. --DavidHOzAu 13:27, 11 April 2006 (UTC)
replies: text: I agree that this article should offer small summaries of the word's usage in other circles (see my comments in the move discussion above), but like I said, I don't think that this article can do everything.  It can't fully cover all the various fields that use the word in such different ways without completely confusing the reader.  — Laura Scudder ☎ 13:27, 18 April 2006 (UTC)
replies: text:  I do believe that you are well aware of the nature of wikipedia. One does not need to do every thing in an article. All one needs in an article in wikipedia is to highlight words and provide links to other pages providing details about that topic. In fact, that is being attempted in the nonscientific forms section in energy. I firmly believe that wikipedia cannot afford to be as puritanical as some people appear to be. 07:50, 20 April 2006 (UTC)
thread_title:  Attempted Cleanup 

message: To mathematicians, engineers, physicists and scientists, the word "energy" has a strict and quantifiable definition. Mixing of the non-scientific and scientific definitions of the word is deprecated and leads to confusion.  Despite this, the fact remains that the word Energy is often used in contexts that are not as specific as the natural sciences. 
For example, in the context of economics, the term energy is used in discussions related to resources, such petroleum products and electric power generation that enable us to use machines.
In the context of psychology, sociology, politics etc., energy can be in in the form of emotional energy, embodied energy, and perhaps psychic energy.
In the context of colloquial language, that is in common speech, the word energy is used to describe the behaviour of individuals. This may be similar to the physical use of the term work (force x distance), although this form is in fact quite different. Energy can be used to describe someone with a vigorous, enterprising, hard working or ambitious drive, or to describe someone’s physical and mental capacity when applied to a particular activity, or to describe someone with an vivid imagination implying vitality and intensity of expression. Similarly, The term "energy" is widely used in a spiritual or non-scientific way that cannot be quantified or even defined. The term energy, in such contexts, is used in traditional and New age mysticism and in fields such as  parapsychology, acupuncture, IRECA method and reiki, prana anf yoga. Paranormal researchers will often refer to "psychokinetic energy" when attempting to explain paranormal phenomena or the concept of a spirit or soul. These forms of 'so called' energy are not quantifiable and are therefore unacceptable to the scientific community.
In traditional Chinese culture, energy is referred to as Qi.
:there really needs to be a simple, clear definition of Energy (physics) at the start of the article. Physical energy, in whatever form (potential, kinetic, chemical, electromagnetic, etc...) is the ability to do work; work is the ability to apply a force through a distance. Units for physical energy are in force x distance. For example, a Joule is defined as one Newton Meter. Lets make the article clearer and easire to understand, and not more convoluted.
Also, In my opinion, physical energy is the most common meaning when people think of energy, the article should focus on that --Sullevon 17:40, 29 April 2006 (UTC)
replies: text: Agree, I strengthened the intro as such.--Sadi Carnot 12:18, 2 May 2006 (UTC)
thread_title:  Non-scientific forms of energy 

message: There was a hidden comment at the top of the article that removing the link to Energy (disambiguation) was vandalism.  However, that page is now a redirect to :Category:Energy.  Also, there is no meaning of the word "energy" which is not covered by the article.  So, I think I'm removing it for good reason. -- Beland 01:49, 7 May 2006 (UTC)
thread_title:  Disambiguation removed 

message: As Energy (disambiguation), thanks to me. --DavidHOzAu 07:12, 7 May 2006 (UTC)
replies: text: All the uses in that article are physical uses.  Is there an article that pertains to the colloquial usage of the term?   If not, then maybe the disambig should just have a short blurb with something like "energy means in colloquial speech a general attitude towards activity; see wiktionary.  For other technical uses of the terms....".  Or something like that. -lethe talk [ +] 07:28, 7 May 2006 (UTC)
replies: text: PS.  Thanks for making the disambig page.  I think it is the right direction. -lethe talk [ +] 07:30, 7 May 2006 (UTC)
replies: text: Thanks.  I've added the template for wiktionary, but it might be not be as verbose as we'd like. --DavidHOzAu 08:15, 7 May 2006 (UTC)
replies: text: I've moved the nonscientifc energy uses to their own pages, with pointers on the disambig page. This article needs to focus on only the kind of energy that can be quantitated in joules, and it's going to be long enough for that, as is.Sbharris 01:32, 18 May 2006 (UTC)

text: Agree. Can you fix it?  It's editorically hard to "reverse" this kind of thing.Sbharris 15:43, 18 May 2006 (UTC)
replies: text:  I partly support Lumos, but I would like that the disambiguation page be the main page, with seperate pages for Energy(general); energy(physics), energy(natural sciences), energy (econo,my) etc. Charlie 04:09, 19 May 2006 (UTC)
replies: text: Yes, that is what I meant. This is one of those few topics where the main direct should be the disambig page. There are simply too many common uses of this word to pick one. Though, if we had to, of course it would be the physics one :) Sbharris 05:24, 19 May 2006 (UTC)
thread_title:  Disambiguation page now up and running 

message: This article was nominated for inclusion into the Version 0.5 release of Wikipedia, but it was failed due to a complete lack of references. Titoxd(?!? - help us) 05:55, 31 May 2006 (UTC)
thread_title:  Failed [[Wikipedia:Version 0.5]] nomination 

message: Consider an ideal monatomic gas in a container. If it is allowed to do (adiabatic) work on a piston (ie, it is transfered out of the system as work), the gas cools (loses thermal energy) by exactly the amount of work done on the piston.  This does not represent an example of previous potential energy storage in the gas, since all energy transfered to the piston has come out of KINETIC energy of the gas molecules. No potential energy is involved at all, and the whole process only proceeds spontaneously because the amount of entropy created in expansion, is equal or more than the amount of entropy destroyed when the heat is destroyed to become work. 
This process can be reversed, but not spontaneously. Work can be done to push the piston back in to compress the gas adiabatically, and in that case the work appears as heat (which again increases entropy over all). But again it's all kinetic energy (monatomic ideal case) and no potential is involved.
You'd think that rubber as in a rubber band would be a good example of potential energy due to intramolecular forces in the band. For a metal spring this is approximately true, but for a rubber band, it's not. Rubber acts very much like an ideal gas, evolving heat at about equivalent to work done on it, and absorbing heat with work that it does. Thus, no work is ever stored as potential or released from potential, unless you cause the heat to remain in the rubber and count the 50% of heat in solids which is potential. But even that isn't stored as potential if you isothermally cool the rubber as it is being stretched (say, with a flow of ideal gas), or isothermally warmed it as it is doing work. Which is to say that the rubber itself simply converts heat to work (and vice versa). If heat is supplied or conducted away isothermally, the rubber band stores no energy as potential at all, like the monatomic ideal gas.
Careful consideration of free energy will show that this can only be possible if the rubber has a lot of internal entropy change associated with stretching or de-stretching, such that the TΔS term is so large that all W can appear as Q. When rubber is stretched the isoprenoid polymers are pulled into alignment, and the methyl groups line up to look more like a crystal. This causes so much entropy decrease that all the work must appear as entropy-increasing heat, to make up for the TΔS. Thus, none can be stored as potential. The same happens on de-stretch.
All of this makes a nice illustration of why energy per se doesn't drive natural processes, and not even energy conversion to heat, if what is stored is "orderliness". A stretched rubber band can do work, and absorb heat to do it with. That's only possibile because a stretched rubber band is essentially a reservoir of stored LOW ENTROPY, not stored potential energy. Sbharris 22:17, 8 June 2006 (UTC)
replies: text: I suggest you check out the Entropy article before you such an obviously false statement. Stretching a rubber band increases the potential energy between the molecules in the lattice that makes up the rubber band. E = F.s --DavidHOzAu 10:19, 10 June 2006 (UTC)
replies: text: And I suggest you actually read a comment before commenting on it. Had you simply typed in "entropy and rubber band" to google, you've have come across a dozen articles explaining the importance of entropy here. Energy is force times displacement, sure, but in a rubber band under moderate stress, that energy from work shows up as heat, to a good approximation. That means it's NOT being stored in potential. Therefore it does NOT increase the potential energy between the molecules in the "latice" which makes up a rubber band. To a high degree, rubber under moderate stress obeys the Joule criteria (similar for ideal gases) that isothermic dU/dL = 0, where U is internal energy and L is length. You can see the entropy contribution illustrated by the fact that heated rubber contracts, rather than expands. Anyway, read  and educate yourself. Sbharris 14:46, 10 June 2006 (UTC)
replies: text: Thanks for the link; that's an interesting read. While I understand it, (length affects thermal fluctuation far more than internal energy,) it appears that thermodynamics is not my forte.  Suffice to say, rubber bands probably do not need to be in this article. (that's what you said, wasn' it?) Some other article on thermodynamics would be better suited. --DavidHOzAu 13:39, 15 June 2006 (UTC)
replies: text: Yes, it might be interesting to put them in the article on entropy, as an example. Or perhaps even in the article on energy, which I've been trying to prod in the direction of mentioning that most energy transformations are entropy-driven. I may add an rubber section in the entropy article, and see if the other editors freak.  I think the better example to use for potential is a coiled metal spring. The only reason I haven't done it, is I haven't yet been able to find anything about heat evolution on spring compression and release, which would tell us how "efficient" they are at storing straight potential. Sbharris 17:03, 15 June 2006 (UTC)
replies: text: I think the the combined law of thermodynamics and Conjugate variables (thermodynamics) has \mathrm{d}U=T\mathrm{d}S - P\mathrm{d}V + \sum_i \mu_i \mathrm{d}N_i\, with \mathrm{d}S, \mathrm{d}V and \sum_i \mu_i \mathrm{d}N_i\, approximately held constant for metal springs at low extensions up to when the spring starts to deform at the yield point. After this point, \mathrm{d}S and \mathrm{d}V starts to change due to the changing shape from plastic deformation.  Hence increasing the pressure (extension) on the spring will mostly change the internal energy (kinetic energy required to move the spring) and temperature (heat from the movement) at a constant ratio up to the yield point. Afterward the yield point, \mathrm{d}S shrinks (or P\mathrm{d}V expands) causing a greater effect on temperature rather than energy with every increase of extension.  Bear in mind however that I have not been taught thermodynamics by a lecturer, (this is completely outside my field,) so I have likely gotten my signs mixed up and/or I might be on the wrong track entirely. Suffice to say, everything goes nonlinear when entropy comes into it.  Before that, so-called net "potential energy" in springs is a good approximation. --DavidHOzAu 08:19, 16 June 2006 (UTC)
thread_title:  The rubber band's stored energy 

message: The definition of energy, located at conservation of energy, is just plain wrong. It says that any transfer of energy results in a change in entropy. Entropy changes according to the Gibbs equation, which for a simple compressible system contains two terms, (1) work; and (2) the change in the internal energy. If these two terms are equal and opposite, the process is isentropic. Adiabatic expansion involving work being performed by the system on its surroundings will produce no change in entropy. --PotomacFever 15:13, 28 June 2006 (UTC)
thread_title:  Conservation of Energy 

message: This reaction, with a cite, has been added to the article by somebody else. Since it improves the quantitative aspect of the article enormously, and since it's a good statement of just WHERE the energy involved in making living protoplasm goes, including the the elements which are involved, I think it should stay. One editor is simply deleting it, saying it's irrelevant. May we have some votes on the issue to reach concensus? Meanwhile, it stays. If nobody else likes it, I'll abide by concensus view. Perhaps a shortened version is more appropriate. I am tired of one editor assuming he's in charge of this article. As noted, the material in question was NOT written by me, but I happen to like it. So that's two votes in favor of keeping. SBHarris 18:39, 21 August 2006 (UTC)
replies: text: It appears SBharris has taken over the mantle of administrator of this page, as he keeps on reverting my edits. I really do not see any point in citing an obsolete "equation" regarding energy in biological organisms without citing any references; at best it should be a short reference. Wikipedia is not a textbook, hence editing sections on Energy in Natural sciences is called for. I have been editing this page for more than a year, just to see a sane treatment of the topic, but if physicians like SBHarris keep on reverting others edit, I really do not see any great future for this article in wiki Charlie 04:03, 22 August 2006 (UTC)
replies: text: Gosh, it appears that Charlie Hallenrm has taken over the mantle of administrator, as he keeps on reverting MY edits!  The equation you removed did have a reference, and here it is again, since you missed it the first time you removed it: p42 “Energies:an illustrated guide to the biosphere and civilisation” Vaclav Smil (MIT Press, Boston). In taking it out, you managed to remove 50% of the references of an already badly under-referenced article. Congrats! If you believe the equation obsolete, say why.  I do not automatically revert edits. I do tend to object when people delete quantitative material without putting anything of substance back in. The result tends to be very bland. This article, rapidly losing quantitative material and references, becomes increasingly bland. I'm amused that you seem to see yourself as the only "sane" person working on the topic of explanation of energy, but I assure you that you aren't. SBHarris 04:16, 22 August 2006 (UTC)
replies: text: I think SBHarris is obsessed with entropy concept, and there really cannot be any cure for obsessions of freaks. This discussion seems to turning a verbal duel between SBHarris and me. Which is not very comfortable, atleast to me. So, if SBharris really wants a free hand to express his non sensical views on Wiki, I shall wait for a couple of months till some wiser people get interested in editing the article. So Good luck SBHarris you would not have to suffer any edits by me in the near future atleast,Charlie 18:33, 24 August 2006 (UTC)
replies: text: Charlie, it doesn't matter if you think entropy is "wrong"; verifiability, not truth is the criteria for inclusion into Wikipedia.  The fact that SBHarris has also used a respectable source makes removal of the said equation all the more questionable. (Consider this: false information is hard to verify, but truth often is immediately verifiable; if you are going to remove it, replace it, and cite a better source.)  However, assuming good faith, I implore you to please be careful because removing references is heavily frowned upon, and I don't want to see a valuable Wikipedian such as yourself get blocked. --DavidHOzAu 07:41, 30 August 2006 (UTC)

text:  Well, if you care to compare the versions you will find that none of the references were ever removed. The only reference that was there continues to be in the article. Charlie 15:38, 2 September 2006 (UTC)
replies: text: We have compared versions. You removed note p42 “Energies:an illustrated guide to the biosphere and civilisation” Vaclav Smil (MIT Press, Boston), the second of two, when you removed the equation of life 20:42 on 20 August. When I replaced it again, you removed it again. This has now been explained to you by two people, and you have ignored both of us. SBHarris 16:44, 2 September 2006 (UTC)
replies: text: I really do not believe that the so-called The net chemical reaction of "life" really conveyed any really useful information about energy, that is really pertinent in this article. However, if other editors on wikipedia really feel strongly in favor of retaining it, they are free to go ahead and replace it. I can only feel sorry for the article and promise that I shall not delete it in future.Charlie 03:58, 3 September 2006 (UTC)
thread_title:  The net chemical reaction of "life" 

message: Inside the http://en.wikipedia.org/wiki/Energy#Conservation_of_energy section of this article, the following paragraph can be found
"Despite being seemingly insignificant, this principle has profound impact on processes in our Universe. It results in the existence of virtual particles which carry momentum, exchange by which with real particles is responsible for creation of all known fundamental forces (more accurately known as fundamental interactions). Virtual photons (which are simply lowest quantum mechanical energy state of photons) are also responsible for spontaneous radiative decay of exited atomic and nuclear states, for the Casimir force, for Van der Vaals bond forces and some other observable phenomena."
There is a a problem with what it says next to "Virtual photons", in the parenthesis and after the parenthesis: to say "are also responsible for spontaneous radiactive decay... [etc]" gives the impression that they are actual particles, not theoretical (or "virtual") particles as the very article on them says they are. The sentence previous to "virtual photons" is entirely confusing too, presenting a clear oxymoron: "it results in the existence of virtual particles", if they are virtual they can't exist, if they exist, they are not virtual.
I suggest rewording that paragraph, I would do it myself but I'd run the risk of making it even more misleading. If it was up to myself, I would actually remove that paragraph entirely, it does little good by not being clear enough to be explanatory, and is instead prone to cause more than one confusion.
Anybody supporting or opposing removal of that paragraph please say so and explain why. thank you Pentalis 11:44, 5 October 2006 (UTC)
thread_title:  Misleading "simplification"