Re: Black hole question

From: Stirling Westrup (sti@cam.org)
Date: Tue Feb 15 2000 - 15:36:23 MST


John Clark wrote:

> Stirling Westrup <sti@cam.org> Wrote:
>
> >Many interesting things happen when black holes collide (at least
> >theoretically). One is that the final resulting black hole has an apparant
> >volume less than the sum of the apparant volumes of the two colliding holes.
>
> It's better to talk about the area of the event horizon because it's not at all clear
> what "the volume of a black hole" means. You need a radius to figure the volume
> and although a black hole has a circumference and a area it has no radius. I don't
> mean its radius is zero I mean it has no radius, at least not a number that means
> much. Also the area of the merging hole is always larger than before not smaller.

I said 'apparant' volume, since you can calculate a 'volume' from the area of
the event horizon. Of course, this assumes that space is flat in the vicinity
of the black hole which, I'll grant, is what you might call a grand bull-moose
winner of a bad assumption. I'm unable to pull up the reference in which I read
about merging black holes, and it was some time ago, so I may have gotten the
inequality wrong anyway. Oh well.

-- 
 Stirling Westrup  |  Use of the Internet by this poster
 sti@cam.org       |  is not to be construed as a tacit
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