From: utzoo!decvax!cca!JGA@MIT-MC@sri-unix
Newsgroups: net.physics
Title: weighty problems
Article-I.D.: sri-unix.3167
Posted: Wed Sep  8 09:17:57 1982
Received: Thu Sep  9 03:16:59 1982

From: John G. Aspinall 
The question of "do gravitons escape from a black hole" brings another
related question to mind.  Since charge is conserved also, when you drop
an object into a black hole, could we not ask the same question about
virtual photons, which are considered to carry the electric field?

We all "know" that real photons don't escape (tunneling aside) from the
black hole, but apparently virtual ones do.  Perhaps the gravitons that
carry the gravitational field behave analagously.

As an aside to the questions about radiation - the spectrum is
determined by the acceleration of the charge.  Synchrotron radiation
has a characteristic spectrum because the acceleration is the circular
motion of a charge in a magnetic field.  But a particle dropping into
a black hole also feels gravitational acceleration.  So I suspect
there's very little you could see from a spectrum - it'd be pretty
smeared.

John Aspinall.