Simple systems, with simple rules, can develop interesting phenomena. You can learn a lot about a system of equations by watching what macroscopic effects accrue when you let the system evolve.

The rules of this system are simple: Objects have a position, momentum and charge. They interact by an electric-like force between them: (The ~ sign means "proportional to")



When objects hit the wall, they bounce elastically (without losing energy). Actually, that's not quite true. If they go too fast, I make them slow down when they hit a wall. I do this because there is little in place currently to slow down objects except accidental dragging from other charges. As I update this, the simulation will become more realistic.

This was derived from my very first Cocoa program, which was just a bouncing ball program. I still get emails from people asking for it to be kept up, so just recently I created a Snow Leopard-compatible version. Thanks for all the nice comments and emails!

Charged Spheres is freeware. Use it, redistribute it, pass it around, enjoy it.