an enigma inside a hole (was: Re: Beating a dead ...)

Damien Broderick (damien@ariel.ucs.unimelb.edu.au)
Tue, 14 Apr 1998 12:40:34 +0000


At 09:50 PM 4/12/98 -0700, JKC wrote about Reilly Jones
<Reilly@compuserve.com>

> >Black holes are just like glaciers, if you want to free up the

> >matter in them, just raise the background temperature around
them.

>No, that would only make them larger because the increased Blackbody
>Radiation would fall into the Black Hole increasing its mass.

Just so. Black holes evaporate when the external temperature is *lower*
than that of the hole, not higher.

This discussion seems wrong-headed anyway, because the canonical view of
Hawking radiation is that it's due to the infall of one half of a virtual
particle pair ripped out of the vacuum beyond the hole, and the slingshot
escape of the other. Positive energy is *not* tunnelling out of the hole,
negative energy is being imported into it. I can imagine that this is the
kind of claim that will set Reilly's teeth on edge, but let's at least play
with the net up. Or agree to play an entirely different game, with equally
interesting rules.

Damien Broderick