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The notion of relativistic mass is highly misleading, misused by many people, and has been discarded by most modern scientists. It should be removed from this article. Using it to teach people causes more confusion in the long run than the good it does. The only thing preventing me from giving a link to this article to my students as a good resource is the presence of the relativistic mass notion. — Preceding unsigned comment added by 50.25.85.90 ( talk) 18:52, 29 January 2023 (UTC)
The article says :
In particle physics, energy is typically given in units of electron volts (eV), momentum in units of eV/c, and mass in units of eV/c2
But, eV is a unit, but c is a number. How does this work? Ptarjan ( talk) 07:29, 16 August 2009 (UTC)
Isn't momentum the product of mass and velocity? Surely then, in a massless object, momentum too is nil? —Preceding unsigned comment added by 61.9.146.174 ( talk) 11:55, 10 December 2010 (UTC)
Latest revision as of 20:01, 3 July 2013 Maschen (the lead eqn should stand out ideally in LaTeX and compare the code to E2 = (pc)2 + (mc2)2)
If it's just an issue of standing out, i'm sure we could make it bigger/bolder/whatever. DavRosen ( talk) 01:19, 4 July 2013 (UTC)
\boxed
parameter does work, but not for PNG rendering. If needed, the reader can zoom in to see details for the one equation.Pop-up/zoom-in image like with mathjax shouldn't be necessary except for more complex equations, which probabably shouldn't be in the lead section anyway. Maybe the lead section should favor compatibility and accessibility, while the rest of the article can use the full-blown math display. BTW, what do you think about using the inherently-superscripted unicode characters as in "c²" -- too small?
Speaking of notation, I'm thinking the lead section would be clearer if it always used the explicit subscripts as in m0 and ETot. At the end of lead section we can say we're dropping the subscripts for the remainder of article.
DavRosen ( talk) 21:28, 9 July 2013 (UTC)
(outdent) I meant that there's a trade-off between using native vs latex equations, and the decision *could* go a different way in the lede, which should be a standalone summary that has the widest possible readership, with symbols that actually match between the equations and the inline, with equations that can be read aloud by screenreaders and searched for as text and copied-pasted into a document and then edited, but no complex equations, vs. the rest of the article which usually does have more complex equations but also is directed at a somewhat narrower audience who may be more accustomed to the way latex works in wikipedia and how to copy the source.
Also, I do want the pop-up of the article itself to be readable, which means the lede can't use unrenderable latex, but I'm less concerned about whether the popup of a link to a specific non-lede section is readable, as links from one article to a specific section in another is less common and less essential than the the ability to simply link to an article.
DavRosen (
talk)
23:04, 12 July 2013 (UTC)
Maschen, you point out that it's simple enough "to just use E = mc2 for total energy and mass, and E0 = m0c2 for rest energy and mass".
But that's not what's being done in this article, which uses E to represent the total energy but a bare m to represent the rest mass, which may be a common convention but it's confusing when you're trying to talk about all four combinations of total vs rest with mass vs. energy in the same sentence, as in
where I resorted to square brackets and referencing both with and without the subscripts in order to try to be consistent with the main eqn (1) while still explicitly distinguishing rest from total. I'm thinking this paragraph may be the only one that needs this distinction, so maybe I should use explicit subscripts in that paragraph (maybe shorten TOT to T), saying that I'm doing so, and then saying that they'll be dropped in the rest of the article.
Or maybe best to switch only once: start the lede with the explicit subscripts 0 and T to avoid ambiguity, and then after this paragrah, or at the end of the lede/begining of the 1st main section say that we're dropping them.
BTW, the importance of that paragraph is that it dispels the notion that E=mc2 isn't correct in general without the momentum term, which is only the case if you (mis-)apply it with mixed meanings as in E[Tot] = m[0]c2
DavRosen ( talk) 22:59, 12 July 2013 (UTC)
I don't mean to be dismissive. The image File:Energy-Mass-Momentum Pythagorean Relationship.jpg in the lead may have pedagogy, but it doesn't mean much. It shows the relation geometrically by the Pythagorean theorem which applies in Euclidean space, when actually the energy-momentum relation is the magnitude of a four-vector in Minkowski space. Sooner or later I will draw another to represent the hyperbolic nature of the relation (not circular) and replace, or possibly just delete the one in the lead. M∧Ŝ c2ħε Иτlk 09:02, 14 July 2013 (UTC)
Sorry for the delay. The diagram is ready and it will be replaced. M∧Ŝ c2ħε Иτlk 09:05, 15 July 2013 (UTC)
Maschen, I think the early part of the lede is hard to follow now, too long, and too technical in its 2nd paragraph. Especially since the first paragraph now has no trace of any information about the relationship itself or its form, the reader has to go to the 2nd para to find the relation and then that should still be a simple paragraph before getting into details. I don't see how rearranging the main eqn with a minus sign helps. Definitions of eqn 1's symbols are scattered, m_0 before it, and for p the reader has to go down five lines (two being additional equations) and find it in the middle of that line. I think it's good practice to state what each symbol represents (not necessarily a complete definition or derivation which can be later) all together and immediately without being separated by a lot of additional symbols needing to be defined. And not introducing any other symbols or equations until afterwards, if possible. For example, E can be said to be the total energy without immediately writing out the equation , which could be part of the derivation of the main relation but doesn't need to be this soon.
I think something like the following is much clearer (note that all four symbols in the equation are defined immediately within the same sentence below the eqn, with no new symbols or terms introduced until those 4 all been mentioned.
E2 = (pc)2 + (mc2)2 | (1) |
DavRosen ( talk) 08:06, 15 July 2013 (UTC)
Thanks, Maschen. Isn't moving the momentum term over to the energy side a bit unconventional? We shouldn't do it just because we may prefer it that way. DavRosen ( talk) 17:50, 15 July 2013 (UTC)
Proposal: move the segment with the numbered points on the mass-energy equivalence relation down to the special cases section, where such explications should ideally be made, and replace in the lead with a shorter sentence or two, like:
Or words to that effect. Seems better for a lead. Agreed? M∧Ŝ c2ħε Иτlk 15:05, 17 July 2013 (UTC)
I like the new diagram from above discussion, but it seems a bit too technical to be at the top with the lede (in fact it appears above and before the lede text if you have a narrow screen). I don't think most readers will be able to follow it until after they digest the lede and certain other parts of the article, and then they have to notice the connection with the diagram/caption. Can the diagram be moved down into one of the sections? (Or if not, then can its caption be shortened and refer the user to a particular section for more explanation, and maybe moved to near the bottom of the lede so it simply appears next to the Contents rather than alongside/above the very first introductory sentences of the lede.) DavRosen ( talk) 18:31, 17 July 2013 (UTC)
The page starts with
Per Lev Okun "The concept of mass" Physics Today June 1989 that statement is far from a forgone conclusion. That article has obviously not been read by the authors of this page. Hence the disputed flag. Please read that, it is straightforward, and fix. I am not really dead ( talk) 15:22, 16 February 2016 (UTC)
Under the equation there is a note saying that a factor V for potential energy needs to be added, but above that it says the equation is "assuming the special relativity case of flat spacetime". If spacetime is flat is the potential energy zero? (I'm over my head here.) RJFJR ( talk) 21:15, 27 April 2018 (UTC)
Many uses wikipedia as source of information. Wikipedia is often very useful. However there is a big job left to point to references who and when important formulas where published. This article contains a series of references but not a single reference on who came up with this relation first. I assume possible Einstein? And no reference of when first published. I do not understand why this has so low property for wikipedia editors? This is not only about this page, but about many pages on wikipedia describing important mathematical relations in physics and other fields, often totally lacking any info about who and when it was discovered. I find this also impolite. It is like having a long page about the Mona Lisa painting without even mention who painted the picture. QuantitativeGeometry ( talk) 20:12, 25 December 2018 (UTC)
It is told in the article that Dirac was the first to mention the relativistic energy momentum relationship. Please refer to a paper that show this and not only much older books that claim so. Is this in the 1928 Dirac paper on the electron, if so I could not see the relativistic energy momentum relationship there, at least not on the form mention in the wiki article. — Preceding unsigned comment added by QuantitativeGeometry ( talk • contribs) 23:17, 5 January 2019 (UTC)
Hello. I don't actually know the answer but I can assure that Einstein didn't discover this. Because he mentioned L/C^2 ( L is radiation which is equal to mass ) . So for sure he never mentioned this. Intelligent boy 13 ( talk) 15:03, 10 February 2022 (UTC)
Who arranges it: In physics, the energy–momentum relation, or relativistic dispersion relation, is the relativistic equation relating any object's rest (intrinsic) mass, total energy, and momentum:...
holds for a system, such as a particle or macroscopic body, having intrinsic rest mass m0, total energy E, and a momentum of magnitude p,
you can't read it — Preceding unsigned comment added by 31.183.229.101 ( talk) 22:26, 4 January 2020 (UTC)
![]() | This ![]() It is of interest to the following WikiProjects: | |||||||||||||
|
The notion of relativistic mass is highly misleading, misused by many people, and has been discarded by most modern scientists. It should be removed from this article. Using it to teach people causes more confusion in the long run than the good it does. The only thing preventing me from giving a link to this article to my students as a good resource is the presence of the relativistic mass notion. — Preceding unsigned comment added by 50.25.85.90 ( talk) 18:52, 29 January 2023 (UTC)
The article says :
In particle physics, energy is typically given in units of electron volts (eV), momentum in units of eV/c, and mass in units of eV/c2
But, eV is a unit, but c is a number. How does this work? Ptarjan ( talk) 07:29, 16 August 2009 (UTC)
Isn't momentum the product of mass and velocity? Surely then, in a massless object, momentum too is nil? —Preceding unsigned comment added by 61.9.146.174 ( talk) 11:55, 10 December 2010 (UTC)
Latest revision as of 20:01, 3 July 2013 Maschen (the lead eqn should stand out ideally in LaTeX and compare the code to E2 = (pc)2 + (mc2)2)
If it's just an issue of standing out, i'm sure we could make it bigger/bolder/whatever. DavRosen ( talk) 01:19, 4 July 2013 (UTC)
\boxed
parameter does work, but not for PNG rendering. If needed, the reader can zoom in to see details for the one equation.Pop-up/zoom-in image like with mathjax shouldn't be necessary except for more complex equations, which probabably shouldn't be in the lead section anyway. Maybe the lead section should favor compatibility and accessibility, while the rest of the article can use the full-blown math display. BTW, what do you think about using the inherently-superscripted unicode characters as in "c²" -- too small?
Speaking of notation, I'm thinking the lead section would be clearer if it always used the explicit subscripts as in m0 and ETot. At the end of lead section we can say we're dropping the subscripts for the remainder of article.
DavRosen ( talk) 21:28, 9 July 2013 (UTC)
(outdent) I meant that there's a trade-off between using native vs latex equations, and the decision *could* go a different way in the lede, which should be a standalone summary that has the widest possible readership, with symbols that actually match between the equations and the inline, with equations that can be read aloud by screenreaders and searched for as text and copied-pasted into a document and then edited, but no complex equations, vs. the rest of the article which usually does have more complex equations but also is directed at a somewhat narrower audience who may be more accustomed to the way latex works in wikipedia and how to copy the source.
Also, I do want the pop-up of the article itself to be readable, which means the lede can't use unrenderable latex, but I'm less concerned about whether the popup of a link to a specific non-lede section is readable, as links from one article to a specific section in another is less common and less essential than the the ability to simply link to an article.
DavRosen (
talk)
23:04, 12 July 2013 (UTC)
Maschen, you point out that it's simple enough "to just use E = mc2 for total energy and mass, and E0 = m0c2 for rest energy and mass".
But that's not what's being done in this article, which uses E to represent the total energy but a bare m to represent the rest mass, which may be a common convention but it's confusing when you're trying to talk about all four combinations of total vs rest with mass vs. energy in the same sentence, as in
where I resorted to square brackets and referencing both with and without the subscripts in order to try to be consistent with the main eqn (1) while still explicitly distinguishing rest from total. I'm thinking this paragraph may be the only one that needs this distinction, so maybe I should use explicit subscripts in that paragraph (maybe shorten TOT to T), saying that I'm doing so, and then saying that they'll be dropped in the rest of the article.
Or maybe best to switch only once: start the lede with the explicit subscripts 0 and T to avoid ambiguity, and then after this paragrah, or at the end of the lede/begining of the 1st main section say that we're dropping them.
BTW, the importance of that paragraph is that it dispels the notion that E=mc2 isn't correct in general without the momentum term, which is only the case if you (mis-)apply it with mixed meanings as in E[Tot] = m[0]c2
DavRosen ( talk) 22:59, 12 July 2013 (UTC)
I don't mean to be dismissive. The image File:Energy-Mass-Momentum Pythagorean Relationship.jpg in the lead may have pedagogy, but it doesn't mean much. It shows the relation geometrically by the Pythagorean theorem which applies in Euclidean space, when actually the energy-momentum relation is the magnitude of a four-vector in Minkowski space. Sooner or later I will draw another to represent the hyperbolic nature of the relation (not circular) and replace, or possibly just delete the one in the lead. M∧Ŝ c2ħε Иτlk 09:02, 14 July 2013 (UTC)
Sorry for the delay. The diagram is ready and it will be replaced. M∧Ŝ c2ħε Иτlk 09:05, 15 July 2013 (UTC)
Maschen, I think the early part of the lede is hard to follow now, too long, and too technical in its 2nd paragraph. Especially since the first paragraph now has no trace of any information about the relationship itself or its form, the reader has to go to the 2nd para to find the relation and then that should still be a simple paragraph before getting into details. I don't see how rearranging the main eqn with a minus sign helps. Definitions of eqn 1's symbols are scattered, m_0 before it, and for p the reader has to go down five lines (two being additional equations) and find it in the middle of that line. I think it's good practice to state what each symbol represents (not necessarily a complete definition or derivation which can be later) all together and immediately without being separated by a lot of additional symbols needing to be defined. And not introducing any other symbols or equations until afterwards, if possible. For example, E can be said to be the total energy without immediately writing out the equation , which could be part of the derivation of the main relation but doesn't need to be this soon.
I think something like the following is much clearer (note that all four symbols in the equation are defined immediately within the same sentence below the eqn, with no new symbols or terms introduced until those 4 all been mentioned.
E2 = (pc)2 + (mc2)2 | (1) |
DavRosen ( talk) 08:06, 15 July 2013 (UTC)
Thanks, Maschen. Isn't moving the momentum term over to the energy side a bit unconventional? We shouldn't do it just because we may prefer it that way. DavRosen ( talk) 17:50, 15 July 2013 (UTC)
Proposal: move the segment with the numbered points on the mass-energy equivalence relation down to the special cases section, where such explications should ideally be made, and replace in the lead with a shorter sentence or two, like:
Or words to that effect. Seems better for a lead. Agreed? M∧Ŝ c2ħε Иτlk 15:05, 17 July 2013 (UTC)
I like the new diagram from above discussion, but it seems a bit too technical to be at the top with the lede (in fact it appears above and before the lede text if you have a narrow screen). I don't think most readers will be able to follow it until after they digest the lede and certain other parts of the article, and then they have to notice the connection with the diagram/caption. Can the diagram be moved down into one of the sections? (Or if not, then can its caption be shortened and refer the user to a particular section for more explanation, and maybe moved to near the bottom of the lede so it simply appears next to the Contents rather than alongside/above the very first introductory sentences of the lede.) DavRosen ( talk) 18:31, 17 July 2013 (UTC)
The page starts with
Per Lev Okun "The concept of mass" Physics Today June 1989 that statement is far from a forgone conclusion. That article has obviously not been read by the authors of this page. Hence the disputed flag. Please read that, it is straightforward, and fix. I am not really dead ( talk) 15:22, 16 February 2016 (UTC)
Under the equation there is a note saying that a factor V for potential energy needs to be added, but above that it says the equation is "assuming the special relativity case of flat spacetime". If spacetime is flat is the potential energy zero? (I'm over my head here.) RJFJR ( talk) 21:15, 27 April 2018 (UTC)
Many uses wikipedia as source of information. Wikipedia is often very useful. However there is a big job left to point to references who and when important formulas where published. This article contains a series of references but not a single reference on who came up with this relation first. I assume possible Einstein? And no reference of when first published. I do not understand why this has so low property for wikipedia editors? This is not only about this page, but about many pages on wikipedia describing important mathematical relations in physics and other fields, often totally lacking any info about who and when it was discovered. I find this also impolite. It is like having a long page about the Mona Lisa painting without even mention who painted the picture. QuantitativeGeometry ( talk) 20:12, 25 December 2018 (UTC)
It is told in the article that Dirac was the first to mention the relativistic energy momentum relationship. Please refer to a paper that show this and not only much older books that claim so. Is this in the 1928 Dirac paper on the electron, if so I could not see the relativistic energy momentum relationship there, at least not on the form mention in the wiki article. — Preceding unsigned comment added by QuantitativeGeometry ( talk • contribs) 23:17, 5 January 2019 (UTC)
Hello. I don't actually know the answer but I can assure that Einstein didn't discover this. Because he mentioned L/C^2 ( L is radiation which is equal to mass ) . So for sure he never mentioned this. Intelligent boy 13 ( talk) 15:03, 10 February 2022 (UTC)
Who arranges it: In physics, the energy–momentum relation, or relativistic dispersion relation, is the relativistic equation relating any object's rest (intrinsic) mass, total energy, and momentum:...
holds for a system, such as a particle or macroscopic body, having intrinsic rest mass m0, total energy E, and a momentum of magnitude p,
you can't read it — Preceding unsigned comment added by 31.183.229.101 ( talk) 22:26, 4 January 2020 (UTC)