On 21/06/02 10:18 AM, stargene wrote:
> Profs. Susskind, ’t Hooft and others have occasionally referred
> to black hole event horizons as having tiny fluctuations in their
> locations at the smallest micro-scales, due to QFT.
> For me, this implies that a graviton, say, just inside the horizon,
> may find itself suddenly just outside of the horizon,
You are wrong. Gravitons do not have a position, they are
spread out. Most of the relevant ones are even very much spread
out, in wavelenght modes as big as the entire blak hole.
In QFT the term "particle" has nothing to do with classical
point particles anymore, it has gotten a totally different
meaning, referring to the numbering of different sections of
the Hilbert space.
In contrast, the concept of "event horizon" still has its
classical meaning: infinitely thin shell with precise position
coordinates! (Probably this will have to change as well if the
theories are worked out further and then people will keep
using the old word with a new meaning also in that case,
adding further to the confusion..)
> Two theorists confirmed that this could happen, but that more
> work needed to be done on the union between QFT and the
> BH horizon.
Certainly! In particular we need to solve what happens if we
describe a state as a superposition of states with different
energy. The event horizon depends on this so it cannot be the
classical concept based on exact position coordinates.
The whole GR framework of classically describing the curvature
of space-time based on the contained energy-momentum cannot
work if there is a superposition of states with completely
different energy-momentum values.
> But doesn’t this imply that information from inside the horizon
> can indeed propagate out into our universe,
Well, if you first admit that there is "more work needed" then
concluding things like that seems a bit premature..
> ... at least in principle?
> And if so, doesn’t QFT make it a whole new ball game regarding
> connectivity between the two realms?
The basic question may remain the same: does everything leak
out into our universe again in the end (after BH evaporation) or
will a remnant be split off indefinitely?