Re: A partial black hole?

On 2008-02-25, James Burns <burns.87@[EMAIL PROTECTED]
> wrote:
> Consider a particle inside the event horizon, just as you describe.

So for a solar-mass black hole it will meet the singularity within a
few milliseconds. Certainly no particle can "hover" near the inside of
the event horizon.  From the particle's point of view, the event
horizon is receding "outwards" faster than light.


> Certainly, the event horizons of the first and second black holes
> will be affected. I would think that the EH's would be closer to
> their respective singularities than otherwise, because of the
> gravitational forces canceling each other to some degree, in between
> the two, at least.

It could actually be worse.  For example, you could draw an analogy
between the event horizon in GR and a Newtonian gravity potential of
-c^2.  Adding a second mass in Newtonian gravity always deepens the
potential, and hence enlarges the equivalent of the horizon.

The situation in GR is much more complicated, but I don't see any
reason to suspect that the outcome must be opposite.


> Is it possible that a particle that would have stayed below the
> event horizon without the second black hole's intervention

There are no particles that "stay below the event horizon" for
extended periods of time.


- Tim