Thought experiment on potential energy

[snoopies622]

By "potential energies of all the particles", are you including gravitational potential energy?

 

[JesseM]

By "potential energies of all the particles", are you including gravitational potential energy?

That's a good question. I'd guess it would contribute to the "inertial mass" of a bound system in the usual way for an asymptotically flat spacetime (where all the mass is in the bound system, so as you get far from the mass spacetime gets arbitrarily close to the flat spacetime of special relativity), and if you look at pervect's comment #13 and pmb_phy's comment #14 on this thread, they seem to confirm this. But as pervect's link points out, talking about gravitational energy in more general circumstances (not confined to asymptotically flat spacetime) can be tricky.

 

[snoopies622]

Thanks, JesseM; that's quite a thread. It looks like there's more to this than I thought. Maybe after another year of studying GR (I haven't learned killing vectors yet) I'll finally understand the answer to my question.

Thanks to everyone who participated in this thread!

 

[Schrodinger's Dog]

Read the first eight entries of this thread.

Still doesn't make it any clearer.

But Jesse's post appears to answer your question anyway. I was just wondering exactly what you meant, because it seemed there were a few things flying around, that might confuse the issue.

 

[snoopies622]

Well, I guess the questions were: does energy always have a mass-like manifestation, and if so, where is it in the case of gravitational potential energy? I thought it might be in the mass of the objects experiencing gravitational "pull", but entry #8 suggested that it was in the field itself, which I didn't understand, since I don't know how such mass/inertia could be perceived or measured.