Re:

He's referring (I think) to Marc Miller's Traveller.  Before the ships
can
activate their jump drives they must be a 20-diameter distance from a
source of gravity.  In reality, I think it has to do with being far
enough
from a gravitational source so that 1) spacetime is locally flat over
the
area of your warp bubble, 2) so that your warp bubble doesn't disrupt
things for you starting/destination point.  In the paper it says:

R << d << D

where R is the radius of the warp bubble, d is the distance from the
starting star, D is the distance to the second star.

I think d would depend more on the mass of the planet/star you're
starting
near than on the diameter.  You'd want to be more than 20 diameters away
from a black hole, I'd think (using the diameter of the event horizon of
course, the singularity has no diameter.)

Randy Wolfmeyer
Dept. of Physics
Washington University

On Wed, 20 Mar 2002, Brian Bilderback wrote:

> >From: Michael Llaneza <maserati@earthlink.net>
>
> >If it turns out to be a 20-diameter distance from the local body then
we
> >should all be buying Marc Miller drinks for the rest of his life.
>
>
> ???????? Ok, I'm missing something.....