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Hello, Asplace, and welcome to Wikipedia! Thank you for your contributions. I hope you like the place and decide to stay. Here are some pages that you might find helpful:

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Portal/Intro

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This is necessarily an extremely short introduction to the subject. There just isn't room on this page for any more. That is why there is a link to "read more", which is a link to the article. 199.125.109.45 02:21, 18 October 2007 (UTC)[reply]

well, not sure if its necessarily extremely short, short,simply and clear, would i think do it, so either don't mention energy/mass or if you do then it needs to be right, and if there's a shorter/clearer way of saying it, then great. but thats actually very difficult to do.82.14.67.192 15:59, 18 October 2007 (UTC)[reply]

Its been written that way for an awful long time for it to be wrong. 199.125.109.45 21:58, 22 October 2007 (UTC)[reply]
if you read the "Mass-energy_equivalence" article, it explains why you dont in fact convert between energy and mass, they both NEVER change, unfortunately the article on energy is basically confused on the point. its one of those things that is really nice and simple when its understood, but theres SO much confusion you'll find many more references to it getting it wrong, i just really didn't want to see a basic mistake right up there at the top of the basic intro, really just increases the confusion later on. — Preceding unsigned comment added by Asplace (talkcontribs) 17:28, 27 October 2007 (UTC)[reply]
You may wish to re-read that article. What it says is that mass can be measured as energy, and that in a closed system the total mass/energy never changes, not that each never changes. What that means is not that the number of atoms and photons each never changes, but when you add up the energy equivalence of all the atoms and the energy equivalence of all the photons, plus every other form of mass and energy in the closed system and convert it into a single number, that number, a mass/energy number, which can be either in Kilograms (mass) or in Joules (energy), using the conversion factor E=mc^2, in a closed system never changes. Unfortunately Wikipedia can be edited by anyone, and there is no guarantee that when you read the article it was accurate. If you read the same version I did, then it should be revised so that it doesn't cause confusion. 199.125.109.45 00:24, 3 December 2007 (UTC)[reply]

from the start of the mass/energy equivalence article;

"in physics, mass–energy equivalence is the concept that any mass has an associated energy and vice versa."

so if mass is lost,( from a system ) then energy HAS to be LOST as well.

which is pretty much there, but here it is a lot more clearly; ( from the same article.)

"The concept of mass–energy equivalence unites the concepts of conservation of mass and conservation of energy, allowing rest mass to be converted to forms of active energy (such as kinetic energy, heat, or light) while still retaining mass. Conversely, active energy in the form of kinetic energy or radiation can be converted to particles which have rest mass. The total amount of mass/energy in a closed system (as seen by a single observer) remains constant because energy cannot be created or destroyed and, in all of its forms, trapped energy exhibits mass. In relativity, mass and energy are two forms of the same thing, and neither one appears without the other."

BTW much of the rest of the article contradicts this, mostly by sloppiness and implication, and is basically confused over what mass is.( and so what energy is, ho ho.)

i think there is a nice richard feynmann quote on this, but will have to look it up.

also check out this; http://plato.stanford.edu/entries/equivME/

Asplace (talk) 00:36, 12 December 2007 (UTC)[reply]

Conservation of momentum and conservation of energy requires that to convert one particle to energy requires a second particle of the same mass, so you can change the mass of a particle by heating it or cooling it, but to convert it into energy you need to transfer the momentum from a second particle, such as in an electron/positron annihilation. Did you notice that the article you referenced was from the Stanford Encyclopedia of Philosophy and was not written by someone from the physics department, but by someone who teaches philosophy? Further, did you see at the top, "First published Wed Sep 12, 2001; substantive revision Sun Dec 9, 2007". I am curious what this recent change was. Looking at the references, I would guess that it incorporates information from the paper, "Does nature convert mass into energy?" by Ralph Baierlein. While I can't read the paper[1] without going to a library or paying $19, the blog at [2] indicates that the paper may point out that in converting mass to energy we still need to deal with the properties of particles: "rest" energy, kinetic energy, spin, possibly charge, and particle number conservation; and the properties of light: having energy, momentum, and spin. The blog states that the paper "partially addresses the validity of the idea of "energy conversion" when there is a change in mass." 199.125.109.135 (talk) 16:13, 12 December 2007 (UTC)[reply]


ummmm, actually mass-energy, momentum and the quantum stuff, charge etc, are conserved, anything else goes. ANY particle/particles can spontaneously change into any others, with all the above conserved, which restricts it quite a bit, but if you crash a particle head-on with its antiparticle ( the one with all the quantum stuff reversed.) you remove all the restrictions except conservation of mass/energy, and the faster you do it, the more mass-energy, and then you have the possibility of any particles, with up to that energy being produced, which obviously includes just photons, (which i guess is what you refer to as energy above, and they all generally end up as thermal energy anyway, and so have 'relativistic mass' from the brownian motion), that is why its done.

basically the problem is with the mistaken conception that, 'rest mass' is fundamental and 'relativistic mass' is a correction, actually 'rest mass' is just a high level nebulous thing, and 'relativistic mass' is really fundamental.

example, the 'rest mass' of the sun, light bounces around inside the sun for thousands of years, so the 'rest mass' of the sun has a large component of light, which has no 'rest mass'?, this clearly effects the orbit of the earth etc., basically relativity says 'mass' can only be 'seen' from the total of all its forms, with are all are just energy.

example, thermal energy, heat something up and the particles go faster so gain 'relativistic mass', so 'rest mass' varies with temperature.

example, in all atoms electrons are orbiting so their mass is also relativistic,

example, all the potential energy in all the different fields holding matter together have mass, so what is 'rest mass', as you peel back matter,(or assemble it) 'rest mass' become useless for prediction, whilst mass-energy is the thing that is always conserved, its the thing that matters ( pun intended. ), basically it is the 'real' thing. — Preceding unsigned comment added by Asplace (talkcontribs) 15:42, 22 December 2007 (UTC)[reply]

Just a heads up. I have a degree in physics, and you? 199.125.109.45 (talk) 20:29, 23 December 2007 (UTC)[reply]
that would be US undergraduate degree i guess? — Preceding unsigned comment added by Asplace (talkcontribs) 21:16, 23 December 2007 (UTC)[reply]
sorry to break this too you, but that's none too impressive.
i spent some time writing above, am i wasting my time?
and that would be the time of 20year profession physicist with much better credentials, who is rapidly loosing faith with the wikipedia principle. — Preceding unsigned comment added by Asplace (talkcontribs) 21:34, 23 December 2007 (UTC)[reply]
BTW i found this quote from Einstein
"It followed from the special theory of relativity that mass and energy are both but different manifestations of the same thing -- a somewhat unfamiliar conception for the average mind."
i am just stunned how this is being misunderstood, it is actually the fundamental, crowning, conclusion of relativity, which is what, 60+ years old!!!! the wikipedia articles on energy and on mass, and on relativity, are, in effect, useless in understanding the very things they are about!!! Fundamental, concept defining, articles like these don't appear to be able to be constructed as a consensus ( by committee ), when the majority of people contributing just don't 'get it', but think they do. — Preceding unsigned comment added by Asplace (talkcontribs) 23:47, 23 December 2007 (UTC)[reply]
Um that is what I have been saying all along. But isn't there also a quote from Niels Bohr who says "If quantum mechanics hasn't profoundly shocked you, you haven't understood it yet"? Don't give up on WP - there are millions of suckers out there who actually use it - not as a reference for school papers, it isn't reliable enough for that, but as a first look at a subject - WP is one of the ten most popular websites, and comes up first on almost every search on a subject. So do try to keep WP honest, but not by going against Einstein. 199.125.109.45 (talk) 16:23, 26 December 2007 (UTC)[reply]
???? now im confused.
how do you get to me "going against Einstein", i thought the quote was a really clear bit of support for my point?
to clarify the point; its just wrong to say that energy and mass can be converted to one another, as is often stated or implied, because they ARE one another, and that thing (mass-energy) is always conserved, neither value ever changes.
the problem is that the idea of 'conversion' once implanted as a concept will resist later correction, which goes a long way to explain why it is so often misunderstood.
so when something is the first look at a subject, like WP, then it's MORE important to build on 'correct' fundamentals, or at least, if the concept is a bit 'hard', then take care not to confuse it, which was my original problem with the energy intro.
so the energy conversion reference on the energy intro should be removed, or corrected. — Preceding unsigned comment added by Asplace (talkcontribs) 15:06, 27 December 2007 (UTC)[reply]

Please sign your comments by adding four tildas ~~~~.

im expected to sign stuff on my talk page, when im logged in, really? — Preceding unsigned comment added by Asplace (talkcontribs) 22:06, 10 January 2008 (UTC)[reply]

Your arguments are not very convincing. 199.125.109.135 (talk) 21:07, 9 January 2008 (UTC)[reply]

sorry im not convincing, but ive thoroughly checked the correctness of what i say, and my reading of the principles of wikipedia, mean i should now just keep correcting this. — Preceding unsigned comment added by Asplace (talkcontribs) 15:51, 11 January 2008 (UTC)[reply]

Yes you are expected to sign stuff on your talk page. Otherwise how does anyone know that you wrote it instead of anyone else? I think you may be thinking of your user page, which you don't need to and shouldn't sign. By the way the energy portal is about applications of energy, not the physics of energy. 199.125.109.135 (talk) 05:54, 18 January 2008 (UTC)[reply]
well they know its me because im logged in and so my name is automatically added, but if thats the way then OK.
if the energy portal doesn't say its only about applications of energy, how is anyone meant to know that, anyway the big problem is that it quotes the basic physics equation of energy wrongly, i guess trying to look a bit more impressive.
woops, forgot to sign Asplace (talk) 19:38, 18 January 2008 (UTC)[reply]