From Intelligent Perception
Cellular automata include:
- Conway's Game of Life,
- erosion and dilation.
Some people believe that the universe could be a cellular automaton itself.
The problem with this idea is that the universe, unlike any grid, is isotropic (or appears to be). That must be the reason why you don’t see examples of, for example, circular waves in the whole Wolfram's book or elsewhere. See Cellular Automaton Explorer.