Imagine a large office building where in the dark lights go on and off leading to interesting patterns. It has become a sport in some scenes to create shows of images visualizing songs. The lights are going on and off based on a central controlled mechanism. Suppose the lights would go on and off based on the state (on/off) of the lights of the neighboring windows. What kind of patterns do we get? Will it all be random and chaotic? Or will interesting patterns emerge? We can find out by using cellular automata.