Chapter 7: Mechanisms in Programs and Nature

Section 6: The Phenomenon of Continuity

Spinodal decomposition

The separation into progressively larger black and white regions seen in the cellular automata shown here is reminiscent of the phenomena that occur for example in the separation of randomly mixed oil and water. Various continuous models of such processes have been proposed, notably the Cahn–Hilliard equation from 1958. One feature often found is that the average radius of "droplets" increases with time roughly like t1/3.

From Stephen Wolfram: A New Kind of Science [citation]