Okay, hypothesize your standard wormhole:
two spherical manifolds in space-time which are
identified, so that an object that intersects with one
of them emerges from the other. Also, an object with
mass x that goes into mouth A and emerges from
mouth B increases the apparent mass of mouth A by x,
and decreases etc. mouth B etc.

Such a configuration seems to me to be
inherently unstable. Once A has a positive mass and B
has a negative mass, A will have a gravitational field
which will attract objects with positive mass and B has a
gravitational field that will repel objects with positive mass.
Over time, inevitably, the magnitude of the mass of each
mouth will increase without limit.

This would be a slow process at first, of course,
but inevitably one of the mouths would 'collide' with a
sizable body; say Jupiter. As it descends into the
atmosphere, pressure would be sufficient to drive gasses
through the wormhole, emerging in an expanding cloud
around the other mouth. As the process continues, the
mass of the mouth in Jupiter would gradually increase, so
that its gravitational pull would begin to supplement
pressure to drive the flow of material, and the other mouth
would begin to immediately repel the gasses that came
through. At the end of the process, you would have a
Jupiter-massed wormhole mouth, and a negative-Jupiter-
massed wormhole mouth inside a huge expanding cloud
of impure hydrogen.

I'm not sure how sensitive wormholes might be to
extremes of temperature and pressure, but one wormhole
mouth dropping into a star would be even more spectacular.

Eventually, the Schwarzchild radius of the mouth
with positive mass will exceed the radius of the mouth itself,
and that mouth of the wormhole will turn into a black hole.
I'm not sure what an object with a repulsive gravitational
field so strong that light can't reach it would 'look' like.
--
I'm not an actor, but I play one on TV!

George W. Harris For actual email address, replace each 'u' with an 'i'

George W Harris schrieb:

> I'm not sure what an object with a repulsive gravitational
> field so strong that light can't reach it would 'look' like.

Quite like a perfectly silvered ball (the Schwarzschild radius)
surrounded with a shell of material wit a negative IOR, I assume.

You'd get a view similar to the gravitational lensing effect of a black
hole, but of the universe on your side instead of behind the singularity.

Also, if both mouths of the wormhole are in the
same vicinity, they will both undergo an acceleration of
magnitude G*m/d^2 (where G is the gravitational
constant, m is the mass of each wormhole (positve for
one, negative for the other), and d is the distance
between them) and the vector pointing from the
negative-mass wormhole to the positive-mass wormhole.
This acceleration will be constant, so they will quickly
reach relativistic velocities.
--
They say there's air in your lungs that's been there for years.

George W. Harris For actual email address, replace each 'u' with an 'i'.

George W Harris wrote:

> Also, if both mouths of the wormhole are in the
> same vicinity, they will both undergo an acceleration of
> magnitude G*m/d^2 (where G is the gravitational
> constant, m is the mass of each wormhole (positve for
> one, negative for the other), and d is the distance
> between them) and the vector pointing from the
> negative-mass wormhole to the positive-mass wormhole.
> This acceleration will be constant, so they will quickly
> reach relativistic velocities.

The acceleration would also be minute if you're sending ordinary things
through it. And even if that were an issue, "in the same vicinity" is
an easy out; just move them far enough apart so that the 1/r^2 distance
becomes prohibitive to gravitational forces, but still close enough that
they'd be convenient.

--
Erik Max Francis && max@alcyone.com && http://www.alcyone.com/max/
San Jose, CA, USA && 37 18 N 121 57 W && AIM, Y!M erikmaxfrancis
War is the father of all, the king of all.
-- Hera****us

On Sat, 02 Feb 2008 22:10:50 -0800, Erik Max Francis <max@alcyone.com>
wrote:

:George W Harris wrote:
:
:> Also, if both mouths of the wormhole are in the
:> same vicinity, they will both undergo an acceleration of
:> magnitude G*m/d^2 (where G is the gravitational
:> constant, m is the mass of each wormhole (positve for
:> one, negative for the other), and d is the distance
:> between them) and the vector pointing from the
:> negative-mass wormhole to the positive-mass wormhole.
:> This acceleration will be constant, so they will quickly
:> reach relativistic velocities.
:
:The acceleration would also be minute if you're sending ordinary things
:through it. And even if that were an issue, "in the same vicinity" is
:an easy out; just move them far enough apart so that the 1/r^2 distance
:becomes prohibitive to gravitational forces, but still close enough that
:they'd be convenient.

I was generally speculating about untended
wormholes.

Actually, this might be a way to turn them into a
weapon. If you could orient them so that there is a
closed trajectory leading through the wormhole, just
send a massive object along the trajectory; the
magnitude of the masses of the mouths would increase
linearly. Orient the mouths so they're pointing towards
your target (that is, the positive-massed one is on a line
between the negative-massed one and the target, and
just slightly closer).
--
"The truths of mathematics describe a bright and clear universe,
exquisite and beautiful in its structure, in comparison with
which the physical world is turbid and confused."

-Eulogy for G.H.Hardy

George W. Harris For actual email address, replace each 'u' with an 'i'

On Feb 2, 8:52 pm, George W Harris <ghar...@mundsprung.com> wrote:
> Also, if both mouths of the wormhole are in the
> same vicinity, they will both undergo an acceleration of
> magnitude G*m/d^2 (where G is the gravitational
> constant, m is the mass of each wormhole (positve for
> one, negative for the other), and d is the distance
> between them) and the vector pointing from the
> negative-mass wormhole to the positive-mass wormhole.
> This acceleration will be constant, so they will quickly
> reach relativistic velocities.

If they are not of exactly equal mass, one will experience a greater
acceleration than the other and the mouths will separate. Even if
they are of equal mass, the arrangement will be unstable with respect
to any external perturbation. This can be seen by considering both
wormholes as a single zero mass object. Any outside force will lead
to an infinite acceleration on the net body. Since each mouth has a
finite mass, this means that there must be an infinite force acting
between the two mouths, which will necessarily overcome anything
keeping the mouths from drifting apart (or together). This will lead
to the wormhole mouths acquiring separate trajectories where, unless
they collide, the gravitational acceleration will quickly become
minuscule (what happens if they collide is an interesting and, at this
point in our knowledge of wormholes, unanswerable, question).

For my own sanity, in my settings I assume that wormholes destabilize
and collapse if the mass difference between the mouths gets too large,
preventing the mass of either mouth from ever becoming negative.
While there is no reason this should occur using a general
relativistic description of wormholes alone, it seems that quantum
effects will be necessary to support wormholes by providing the
negative energy fluctuations that allow stable wormhole geometries.
Quantum mechanics places certain restrictions on the magnitude,
duration, and extent of negative energy regions that seems to forbid
isolated regions of space with a net negative energy. This suggests
that negative mass wormhole mouths are, in fact impossible, although
the argument I gave is by no means rigorous.

Luke