Use the mouse only. Grid size determines how many squares there are. Radius determines how far out your crater measures. Rotate On? determines if you want to rotate it or just make neat effects. Phi detemines the conservation of energy. Lambda determines how much energy is exerted on click.
This could be used to model the stabilization of a force (lambda) over a given time. If the φ is very close to 1, it will take longer to stabilize. The model could represent speed and φ would be the friction that slows down the speed.
