RE: accelerating universe and Leslie constraints

Billy Brown (
Fri, 26 Mar 1999 08:51:05 -0600

Damien Broderick wrote:
> Indeed, I wonder if it has any salience to the traditional explanation for
> Olber's paradox. Might the universe be eternal after all, except for
> bubbles like our own that are observable only under (somewhat) anthropic
> conditions?

That makes sense to me.

Of course, there are other ways that the universe could be eternal without causing a problem:

  1. If the universe is eternal but constantly expanding, cosmic red shift will render anything beyond a certain distance effectively invisible.
  2. If the universe contains significant expanses of something that eats light without re-emitting it (black holes, for instance), they could act as observation barriers and allow an infinite universe to appear finite.
  3. If new, connected regions of space-time are constantly being created (i.e. the big bang was not unique), you would have large areas that have not been saturated by light from arbitrarily distant sources.

I think there were a few other options, but I can't remember them at the moment.

Billy Brown, MCSE+I