Re: [VV] Vectorverse FTL

Okay, I'm about a week behind in keeping up with the list so I hope this
hasn't been discussed too much already, but I have a bit to add.

On Mon, 31 Jan 2005, Allan Goodall wrote:
>
> That I don't know, though I have some ideas based on the fact that
it's
> warping space time around itself. I think outside objects would travel
> "around" the outer edge of the bubble. The bubble would go through the
> object without the object even noticing. If that's the case, then
> presumably light would go around it and the bubble would be invisible
> (and would look like a totally black sphere to the object in the
> bubble). Invisible, but blind, transit.
>

I think I remember the Scientific American article you're referring to,
and I think it was discussing a version of the Alcubierre warp metric
(http://www.npl.washington.edu/AV/altvw81.html for a general, if
out-dated
description, or
http://www.astro.cf.ac.uk/groups/relativity/papers/abstracts/miguel94a.h
tml
for more detail).  The warp bubble works by contracting space in front
of
the ship and expanding space behind.  Any object in the path would
essentially be crushed by very strong tidal forces like near a black
hole,
and then spread out by the expanding space behind.  I'd imagine enough
energy or mass would mess up whatever means you were using to create the
bubble.  But I guess it could make for a nasty weapon.

As for how things would look, the contraction in front would draw in
light
(again like a black hole) but the expansion would repel light.	To the
sides there would be very little distortion, but if you're using it to
go
faster than light, I don't know that you would be able to really see in
or
out, at least not very well.

As a side note, I don't know Miguel Alcubierre personally, but he works
in
my field of physics (Numerical Relativity).  It's almost annoying
because
he wrote that paper, as far as I can tell as a little toy project, not
really serious, but it's enough that if the damned thing is ever really
made, it will be named after him.  Same thing with Matt Visser (who I do
know) and traversable wormholes.

Randy Wolfmeyer
Dept. of Physics
Washington University
http://www.artsci.wustl.edu/~rwwolfme