'This raises an important point: though we think of general relativity and quantum theory as ‘nice’ theories from the point of view of philosophical investigation, in a very real sense they are not the whole story and break down at extreme scales."
Quantum Gravity
okay but they do signal a failure of the theory and you were asking why I thought GR breaks down, and that's why im asking what does high energies mean in this context
more specifically what does high energies mean in this context, does it actually mean a high amount of energy? I can intuitively understand why it breaks down at small scales where quantum effects take place. for example it is said that high speed collisions produce a lot of energy and general...
also this paper, says
then is the mechanism discussed in the paper an actual perpetual motion machine?
This other paper that mentions the original "Mining energy" paper says:
"As Edward Harrison emphasized: 'The conclusion, whether we like it or not, is obvious: energy in the universe is not...
@PeterDonis hey on this same topic, I came across this 2 threads, (second thread) that discuss this paper where is argued that energy can be "mined" from the expansion of the universe, is this "energy extracted" the same as the increased dark energy in an expanding universe that we talked about...
when Carroll says energy can be said to be conserved because the increase in total dark energy is balanced by gravitational energy-which I understand are global concepts- is he saying then that dark energy is in fact not created out of nowhere?
okay then, speaking only about global concepts like "increase in total dark energy" and "there is energy in the gravitational field but it's negative so it exactly cancels the energy you think is being gained in the matter field"
what about this:
okay but from that "total energy contained in dark energy viewpoint" that Sean Carroll talks about, you said
so you are saying that “there’s energy in the gravitational field, but it’s negative, so it exactly cancels the energy you think is being gained in the matter fields” that this means...
I have a doubt, when Sean Carroll talks about dark energy increasing as the universe expands and then says “there’s energy in the gravitational field, but it’s negative, so it exactly cancels the energy you think is being gained in the matter fields” doesn't that still mean that new dark energy...
This is a comment by Phillip Gibbs "To define energy over a region including a black hole we need a space-like hypersurface that passes through it. It is a feature of ordinary black-holes that the singularity inside is in the future light cone so the hypersurface can easily be chosen to avoid...
Also from the Feynman lectures quote I included in #1 I think Feynman himself didn’t think energy was a mere mathematics but I maybe misinterpreting it.