Re: Singularity Worship

Hal Finney (
Mon, 16 Dec 1996 10:32:33 -0800

From: John K Clark <>
> On Sun, 15 Dec 1996 Eliezer Yudkowsky <> Wrote:
> >>John
> >>neither Special, General, or any other theory I've heard of
> >>says "The speed of light is whatever I make it".
> >Eliezer
> >Curved spacetime = tilted light cones.
> [...]
> Well OK, Tipler found a solution in General Relativity that shows that an
> infinitely long, extremely dense cylinder made of Neutronium (the stuff of
> Neutron Stars) and spinning at almost the speed of light would be able to tip
> a light cone enough to act as a time machine, but there are two very important
> problems.
> [...]

Actually today there are several ideas for FTL travel, including
wormholes (discussed at length on this list a few years ago) and
the Alcubierre "warp drive". These do raise the difficult question
of time travel. I found a detailed discussion of the problems with
these methods and various proposed ways of working around them at <URL: >. It is part
of a FAQ from but it is by a physics grad student
who seems to know his stuff.