Re: PHYSICS: Time to collapse of universe?

Mitchell Porter (
Thu, 2 Jan 1997 11:41:20 +1000 (EST)

[Anders Sandberg]
> I have been working a bit on the Dyson scenario (slow, cold life in an open
> universe), and there we have to deal with baryonic decay (if matter is stable
> it will still decay to black holes sooner or later, which then evaporate into
> leptons). Does anybody have a serious idea of how to implement life in a
> substrate of electrons, positrons, photons and neutrinos? Billiard ball
> computers?

I recall Dyson saying in an interview (in OMNI?) that the ultimate
constituents of an open universe with proton decay might be positron-electron
pairs orbiting common centres of gravity. In that case, the basic
processing operations might consist of breaking apart such pairs (through
gravitational perturbation?) or causing them to form (through
gravitational attraction).

> Another thing I would like to hear opinions on: can a part of spacetime
> be collapsed into something like a closed universe (i.e. not a black hole
> singularity)?

Vic Stenger ( once said on
the omega-point-theory list that he couldn't see why this wouldn't be
possible. There might be something about this in Hawking and Ellis's
_Large-scale structure of space-time_.