Re: A partial black hole?

On 2008-02-29, sigidunum@[EMAIL PROTECTED]
 <sigidunum@[EMAIL PROTECTED]
> wrote:
> -- If two black holes merge, what would a hypothetical observer inside
> the event horizon of one of them see?  If you're falling into
> Singularity A, can your course be shaped to fall into Sing B?

I expect so, but they'd have to have been already in the process of
merging before the observer passed through the event horizon.


> -- Spinning black holes supposedly have ring-shaped singularities.  I
> assume there's still no way to avoid falling into the singularity?

As far as I know, it's not known what shape their singularity would
actually have.  Ring-shaped is unstable.


> -- So you fall into a (very large) black hole and look inwards
> towards the singularity.  What do you see?

You might see light emitted or reflected by stuff that fell in ahead
of you.  If there wasn't any recently, you see nothing.


> On the other hand, its intense gravitational field would tend to
> redshift and trap EM radiation.

It's not a trade-off.  There is simply nowhere for the EM to radiate
*to*.  The only place futureward of the singularity is the
singularity.


> Would the singularity seem to be everywhere at once, filling the
> sky?

No, just blackness ahead.  You do still receive light from outside, in
a decreasing patch of "sky".


> As you got closer to the singularity -- putting aside
> spaghettification issues, at least for as long as possible -- would
> its appearance change?

Not unless you count pitch black changing to just as black.  The patch
of "sky" you see from the outside would shrink toward a point behind
you though.  I expect it would get brighter too, since it is being
focussed toward the same point you're heading for.  I haven't done the
math on that though.


- Tim