I'm glad there's a discussion going on about this right now (though I haven't
been keeping up with it. It enables me to ask a question for a scenario I've
been thinking of building. I want to set a battle around a
pair of Roche worlds. They're a pair of giants ~20 MU diameter, semi-gas
planets. They co-orbit a center point with about 4 MU of space between
them. htey probably need to be distorted egg shapes. The pair rotate a clock
facing every turn.
Kickers are:
1) I want an atmosphere in the space between them - the main
habitable part of the system. 2) I'd needa handle ofn the gravitatinal evvects
of different zones around the pair.
If I get all that, I can set up a test PBeM scenario and perhaps draw up a
template for a live game table (It'd be nice to have something to un at ECC
IV). ANy help would be appreciated.
> "Izenberg, Noam" wrote:
What happened to your human computer over there at the lab, Karl??
He can calculate this out for you. ;-)
Mk
> "Izenberg, Noam" wrote:
> Kickers are:
The effect of the atmosphere would be to cause drag on any ship flying through
it. A simple method would be to apply a force to each ship that starts
in / ends
in / passes through (your choice) the atmosphere. This force would
applied directly against the ship's final vector for the turn (so would be
applied once all of the rest of the ship's movement is complete). It would be
proportional to the speed of the ship (eg if ship's overall speed <= 6, force
= 1, ship's speed
7-12 then force = 2 etc).
> 2) I'd needa handle ofn the gravitatinal evvects of different
Apply the gravitational forces for each planet separately as if they were
simple point masses, and you won't then need to produce a map of different
gravity zones.
> I'm glad there's a discussion going on about this right now
OK, but remember, you asked for it!
I actually kind of question if that particular configuration would be stable
(they seem awfully close), but let's roll with it...
We'll kick things off with the Universal Law of Gravitation:
F=(G*M*m)/(r^2)
...where G=6.67*10^(-11) Nm^2/kg^2, M and m are the masses of the two
bodies, and r is the distance between their centers of mass.
That'll help figure if your rotation is right. I don't know what you're using
for an MU.
The acceleration caused by each body will be: a=(G*M)/r^2
...where G is as above, M is the mass of your planet, and r is any given
distance from the surface.
It will help for you to draw a picture of each gravitational field to get an
idea on how they interact. On the exact line between the planets, there will
be no gravity, as the two vectors will cancel out. The field will grow
to the planet's normal value at about 60-70 degrees off the line
connecting the two, and then increase to a maximum on the far side of each.
> 1) I want an atmosphere in the space between them - the main
Doesn't affect the gravity equations (much).
If you need more info, ask.
> Apply the gravitational forces for each planet separately as if they
True, but you need to make sure to apply each individually to get the total
effect of both.
> Sean Bayan Schoonmaker wrote:
> >Apply the gravitational forces for each planet separately as if they
Yes, that's what I meant. You could represent the gravitational effects of
many
bodies in a solar system (moons, other planets etc - plus the obligatory
local
black hole). This could make an interesting one-off game - how about
racing ships (using vector movement) around a system of planetary bodies, each
with their own gravity field?