Galaxy Simulator

The Galaxy Simulator application was designed to be a small tool that starts animating a universe of 200 stars, which runs in real time.

The name is probably a bit of an exaggeration, but basically it starts with a group of stars placed randomly in a 3D volume of space. Then it computes the gravitational attraction between all the stars and moves them all a little. Then it does it again.

That's about it, really. I added some extras for fun (like making a movie since it *does* take awhile to compute a large enough number of stars.

And I am considering 2000 to be a large number, which is not really accurate in the 'galaxy' sense, of course. But it's a lot of little dots on your computer monitor.

My 'scientific goal' for the program was to establish that given time, a random placement of stars would turn into a rotating disk (my hypothesis) and it more or less seems to be the case.

Since the stars start off at rest (yeah, yeah, I know that would make a nice feature addition to give them initial velocities), they are initially drawn to the center of mass of the universe, and a few encounter each other closely right away and are whipped outwards at high velocity.

The rest pass each other on their way through the center, bound out the far side, and eventually slow down and orbit the center. Eventually one plane becomes dominant (mainly by hurling out the stars which aren't in it.) and then one direction of rotation dominates (took me over a week of computation to get to this point, and about half the stars had reached what appeared to be escape velocity in the process.)