Anders Sandberg (
06 May 1998 10:58:27 +0200

"warren olson" <> writes:

> Is anyone else interested in the idea of time travel via a macroscopic
> wormhole? In theory the idea doesnt necessarily contradict any physics
> laws, and presently only one known thing could damper the idea based on
> chronological laws, but even that isnt proven to be a formidable
> problem. Anyone else think anything of it or just a waste or research
> time?

At present wormhole research is a fun area for people in general
relativity, but it is largely theoretical ("Wow! This wormhole is
traverable, rotates and just breaks the null energy condition on a
hypersphere in the throat!"). As far as I know there are no
chronological laws, just a few conjectures as the Chronology
Protection Conjecture and the common assumption of causality.

Recently I have begun to move away from classical causality towards
Novikov's consistency principle instead: the universe is consistent
(i.e. no paradoxes) but there is no a priori ban on time travel. This
means you can get "causal loops", but no physical laws are broken at
any point and you won't get any paradoxes.

As for time travel through wormholes, I think they are much more
useful for communication and transport - if they can be made usefully.

Anders Sandberg                                      Towards Ascension!                  
GCS/M/S/O d++ -p+ c++++ !l u+ e++ m++ s+/+ n--- h+/* f+ g+ w++ t+ r+ !y