COMPUTER SIMULATION.

Computer simulation as a technique for studying many body physics is nearly as old as electronic computers. The 1953 paper by Metropolis et al introduced what has become a standard technique for simulating complex systems in equilibrium at some finite temperature. Simulation may be a practical alternative to experiment. In fact, questions of principle can sometimes be addressed more directly through simulation of simple model systems than by experiments carried out on actual complex, materials. In these lecture notes, I will describe work on one simplified model, the percolation threshold, and its extension to a real, although somewhat unlikely system, the evolving structure of a spiral galaxy.