Re: Gravity, Tech & others (was Re: Orbits, etc)

Hi.

Richard Slattery wrote:

> As an aside, in our setting we limit how close to a body you can
> enter FTL, but do allow it inside system, between planets. We are
> also toying with the idea of having special entry/exit points for
> FTL, initially we used Lagrange points, but it felt like too much
> PSB. So I'm searching for definable places in systems that can be
> used as places that FTL drives can be used nearish to planets for
> travel between them, and for between systems. Any ideas?

In several SF systems, the writers suggest that FTL drives only work in
near-flat space.
Because a planet is in orbit around a sun,
the attraction between the sun and the planet would be near neutral
(near-flat space),
at a point proportional to the masses of the sun and planet and the
distance between them.

An easy way to under stand this to place two heavy but unequal weights
on
a soft bed.
The heavy weight represents a sun, the light weight represents a planet.
Note that the bed surface curves under the weights and changes curvature
between the weights.
The point where the bed surface becomes flat is analogous to a FTL
transition point in space.
If I recall correctly, these are also Lagrange points.
Around our Earth and Moon, there are, if I recall correctly, six L
points.

Naturally, as multiple planets move around their sun, these FTL
transition
points move as well.
So, you will need a navigator to plot and predict where these transition
points are.
If your background allows, this can allow FTL travel between planets in
one system.
It also seems to be the system used in Star Wars.

I hope this helps.
Andrew Martin
Al.Bri@xtra.co.nz
http://members.xoom.com/AndrewMartin