Black Holes

Wayne Hayes (
Wed, 15 Apr 1998 10:33:38 -0400

Reilly Jones <> writes:
>In one instant, the black hole turns from an everyday ordinary
>melting ice cube into a refrigerator powerful enough to suck in every bit
>of matter and energy that drifts by it, to suck in the whole universe if we
>could maneuver it into the black hole's vicinity. The only way out of the
>eternal mega-refrigerator scenario is to wait for the death-worshipper's
>ultimate paradise - the heat death of the universe. I just don't feel
>comfortable with this.

I don't see why you're uncomfortable with this. It won't suck the whole
universe in because you *can't* maneuver it into the black hole's vicinity.
Furthermore, if the universe is open, then it (the U.) will expand until
it's temperature is lower than the BH's, at which point the BH will again
start to evaporate. (This could even happen if the U. is not open, but
expands for a sufficiently long time.) And since the U. is expanding, it
gets harder and harder to maneuver stuff into the BH's vicinity, since
things are getting further and further apart. And if the U. is closed
tightly enough that it starts to contract before it gets cool enough to
cause the BH to start evaporating, then it will collapse long before
the BH has any chance to gobble everything up --- except during the last
instance, when all the BH's in the universe get close enough to touch,
merge, and swallow everything up just before the universal singularity.
(In fact, I'm not enough of a GR expert to say if this will happen;
perhaps some matter/energy will remain outside BH's right down to the
last Planck moment before the collapsed universal singularity.)

So, what exactly is it that makes your teeth uncomfortable?