Wolfram's Classification and Computation in Cellular Automata Classes   III and IV
  We conduct a brief survey on Wolfram's classification, in particular related to the computing capabilities of Cellular Automata (CA) in Wolfram's classes III and IV. We formulate and shed light on the question of whether Class III systems are capable of Turing universality or may turn out to be "too hot" in practice to be controlled and programmed. We show that systems in Class III are indeed capable of computation and that there is no reason to believe that they are unable, in principle, to reach Turing-completness. 
Genaro J. Martinez, J. C. Seck-Tuoh-Mora, Hector Zenil
nlin.CG cs.CC cs.IT math.DS math.IT