Reply #16: I suppose a definition of thin air would be needed, however,

[EST]

Hawking described a form of radiation that does emanate from a black hole, suggesting that, should a b.h. stop accumulating mass, it will eventually evaporate, satisfying the demands of entropy. I haven't quite doped it out to my own satisfaction how the zero entropy (or infinite entropy, if you prefer) inside a singularity (or, more accurately, its event horizon,) with its stopped clock, can allow even Hawking radiation. I am not clear that singularities can be said to create their own energy, since their own source is the accumulation of energy to become a b.h. in the first place.

Gravity does not appear to derive, particularly, from an energy, although energy in the form of mass and radiative energy does have effect on its local volume of space-time, creating a three-or-more dimensional funnel that attracts even more mass/energy.

Can energy emerge from nothing? This comes down to definitions, or maybe even philosophy, as in: can that nothing contain a particular form of nothing, called singularities-points with zero size, being not so empty points, or a single point, in that nothing. This time limited, entropy related language starts losing all specificity, thus demanding mathematics. Whew!

The physics inside a b.h. or a singularity likely do not resemble the physics out here in this lower pressure environment, where energy cannot be created out of thin anything. Almost all the available energy is wrapped up in the form of mass, and is not created or destroyed, merely modified in form.

There are many, many unanswered questions in this whole field of discussion but we've probably hijacked this thread long enough. Let's meet again soon and kick it around a bit more.