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Black Holes and Gravity
Name: Unknown
Status: N/A
Age: N/A
Location: N/A
Country: N/A
Date: Around 1993
Question:
How does gravity get out of a black hole? If gravity is mediated
by a particle, say graviton, and the particle is subject to the usual
limitation that nothing can travel faster than light, how do gravitons get
across the event horizon? The part of the gravity of a black hole that is due
to stress of space time outside the event horizon can certainly be mediated by
gravitons without them needing to exceed the speed of light, but that just
postpones the question: Why is space time stressed outside the event horizon,
if gravitons cannot escape from it? Do they perhaps escape by Hawking-Penrose
radiation? That does not seem right, because the intensity of Hawking-Penrose
radiation decreases with increasing mass of the black hole.
Replies:
Like I have said before, gravity and quantum mechanics have yet
to be reconciled, and I think your question points out one possible place
where reconciliation maybe difficult. I am sure there are resolutions for
this though - for example, if you are actually outside the event horizon, then
there is no way for you to distinguish a real black hole from something that
is just barely about to become a black hole but has not quite made it yet
because the last bit of matter between you and the black hole-to be is a
little too far from the center. So, gravitons can, perhaps, escape just
before the black hole forms, and that historical event of the black holes
formation may provide enough information to keep up the gravitational field on
the outside. I do not actually does gravitation could answer?
A. Smith
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Update: June 2012
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