Re: SCI: existance -vs- non-existance

michael k teehan (
Thu, 4 Dec 1997 07:00:03 -0500


> From: Anders Sandberg <>
> To:
> Subject: Re: SCI: existance -vs- non-existance
> Date: Thursday, December 04, 1997 5:12 AM
> Keith Elis <> writes:
> > I was under the impression that such travel would be impossible due
> > to the fact that wormholes tend to collapse as soon as they form.
> "Traditional" (Einstein-Rosen bridges) wormholes do collapse almost
> immediately, before anything can traverse them. But Thorne showed that
> in principle it is possible to stabilize wormholes by threading them
> with negative energy densities (for example from electric fields,
> negative matter or the Casimir effect). Later papers have shown that
> stable wormholes may be possible, but most involve violations of the
> energy conditions (which say there are no negative energy densities;
> they are however somewhat doubted) or dynamic wormholes that change
> "radius" (some do this so slowly they are traversable).
> >However, I was speaking with a friend a while back, and he brought up
> >the subject of Kerr (sp?) black holes. It seems that these are
> >theoretical black holes in which the singularity is larger than a
> >mathematical point, elongated perpendicular to an axis of
> >rotation. Some physicists seem to think that that this singularity
> >may be ring-shaped. If so, this would mean that one could follow the
> >axis of rotation into the very center, supposedly "passing through"
> >the singularity (which if I am not mistaken would have the properties
> >of a wormhole/gravity well).
> Yes, the Kerr-Newman solution to the equations (which is a rotating,
> charged hole) has many interesting properties, including a
> ring-singularity inside the black hole and the possibility of a
> wormhole through it. Unfortunately there seems to be results that
> suggests that natural black holes will not work, the wormhole
> connection is broken when the hole is formed.
> > If it were possible to begin a normal (Schwarzchild) black hole
> > rotating, would one be able to create such a ring-shaped
> > singularity?
> Maybe. Making a Schwartzschild hole rotate is simple, just throw in
> mass with angular momentum. But I'm not sure we can control where the
> "wormhole" leads, and it might be very hard to get out of the wormhole
> opening if that is another black hole. I think I prefer classic
> womholes...
> --
> -----------------------------------------------------------------------
> Anders Sandberg Towards Ascension!
> GCS/M/S/O d++ -p+ c++++ !l u+ e++ m++ s+/+ n--- h+/* f+ g+ w++ t+ r+ !y