Talk:Mass in general relativity

Untitled
"There is no such thing as the energy (or angular momentum, or charge) of a closed universe, according to general relativity..." Yes, because relativity do not explain this world... in general especially.


 * WP is not a soapbox. Pervect 19:02, 23 September 2007 (UTC)

Please add a section relating to the mass change in relativistic velocities. will the mass of the body increase in relativistic speeds or not, according to General theory of relativity?

Sajeevk 04:46, 8 August 2007 (UTC)


 * This question doesn't have a simple answer. It was intended that the question


 * The only difference between the "hot" and "cold" systems in our last question is due to the motion of the particles in the gas inside the pressure vessel. Doesn't this imply that a moving particle has "more gravity" than a stationary particle?


 * address this issue.

Comments on the re-write
I'm glad to see other people working on improving my original. I think that some of the emphasis on Noether's theorem as a unifying idea behind mass in GR. has been lost in the rewrite, however. While some of the material is currently still in the history section, I think the idea is of more than historical importance. Pervect 19:02, 23 September 2007 (UTC)

What is "gravitational field energy"? —Preceding unsigned comment added by 195.62.14.150 (talk) 13:22, 15 July 2009 (UTC)

good article!; removed expert-subject tag
I came across this article and thought it was quite good, so I thought I'd say so here on the talk page. I particularly appreciate the fact that great pains have obviously been taken to make the article as generally accessible as possible, which is what is supposed to happen on WP. I can't fathom why there was an expert-subject tag that had been sitting around on the page for over a year. There doesn't seem to be any active discussion here on what the problems might be that led to the tag. Therefore I've removed the tag.--75.83.69.196 (talk) 03:49, 9 February 2010 (UTC)


 * Good in your opinion, it seems. But sorry, the article is Amateur night, see below. I added it back. I am not really dead (talk) 23:30, 17 February 2016 (UTC)

The Relativity Amateur night
This article looks good to the uninitiated, but is far from complete. I added back the expert tag, as above. Take a look at Chrusciel et al Adv. Theor. Math. Phys. 8 (2004) 83–139 they give a reasonable, but still less than complete summary upfront. May fix from there. By the way Trautman is not mentioned in the page and Bondi energy redirects here, and has no definition. And please delete the section Questions, answers, and simple examples of mass in general relativity. It is totally unsourced, rambling and confused. Has no hope. And as usual in these pages the section on Review of mass in special relativity is confused on relative and rest mass and the majority/minority positions. I am not really dead (talk) 23:36, 17 February 2016 (UTC)

ADM Mass and technical details
This article should cover an important conceptual issue in general relativity.

But, at the moment, it does not serve as an encyclopedic reference. It lacks a formula for the ADM mass, although this is the most basic formula for the mass in general relativity. I propose substantially editing this article following Chapter 20 of the standard textbook by Misner, Thorne and Wheeler. I would like to add the formula for the ADM mass, and an explanation for why this formula makes sense by examining the weak field limit. In addition, I propose to add the generalization of this formula by Hawking and Horowitz, and also a discussion of mass in asymptotically AdS backgrounds.

All this is fairly standard graduate-level material. But please write in here if you have comments about this proposed program. Jacob2718 (talk) 09:33, 3 May 2022 (UTC)

mass in special relativity
I am wondering about the significance of the section on "mass in special relativity".

The bulk of this article deals with the definition of *energy* in general relativity. In some cases, such as asymptotically flat spacetimes, one can use the definition of the energy and momentum to obtain an invariant mass. But, in other settings, such as anti-de Sitter space, where the asymptotic symmetry group does not contain the Poincare group, this notion of an "invariant mass" may not be useful.

So is this section required, or would it be better to delete it?

Also wondering whether it would make sense to request a change in the title of the article to "Energy in general relativity"? Jacob2718 (talk) 10:20, 3 May 2022 (UTC)


 * In about 10 days no one has expressed a preference to keep the section on mass in special relativity. I find that this section might potentially be confusing as explained in the message above. So I will go ahead and delete the section. I plan to replace it with some additional text that links to the article on mass in special relativity. Jacob2718 (talk) 03:43, 13 May 2022 (UTC)