Re: [Eighthfleet-development] Updates on 7-28

[Nathan C. <n_...@ho...>]

G is the gravitational constant, one of those mysterious constants you =
find profuse in nature, like Pi.

G =3D 6.67 * 10^-11
Its base units are m^3 / kg * s^2, so you shouldn't have to do any =
conversion if you plug in basic SI units.

Solving gravity on all objects for a system of N objects is (N-1)! time =
if you apply symmetry. It can get expensive very quickly. I think a good =
simplification for real simulators is to treat collections of objects at =
a distance as having just 1 center of mass. So if an asteroid field is =
very far away, you don't need to calculate the effect of all their =
individual gravitation on the ship, only a single gravitation with a =
single value from the asteroid field's center of mass. This lends itself =
rather nicely to treating discrete systems like an asteroid field, solar =
system, etc as logical objects for the purposes of gravitation. You =
could opt to only do extensive gravitational calculations on one of =
these objects only if their center was close enough to the ship to be of =
interest.
  ----- Original Message -----=20
  From: TIMOTHY K HAMILTON=20
  To: Nathan Clow ; eighthfleet-development=20
  Sent: Tuesday, July 31, 2007 6:18 PM
  Subject: Re: [Eighthfleet-development] Updates on 7-28


  That would be it, except... what is G, exactly?

  I'm curious what would happen if I stuck this in the asteroid field =
scenario.

  -Tim

  Nathan Clow <n_...@ho...> wrote:
    F =3D G (m1) (m2) / r^2