Chapter 6: Starting from Randomness

Section 2: Four Classes of Behavior

States of matter [and cellular automaton classes]

As suggested by pages 944 and 1193, working out whether a particular substance at a particular temperature will be a solid, liquid or gas may in fact be computationally comparable in difficulty to working out what class of behavior a particular cellular automaton will exhibit.

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