Computational Irreducibility and the Predictability of Complex Physical Systems

Navot Israeli, Nigel Goldenfeld
2004 Physical Review Letters  
Using elementary cellular automata (CA) as an example, we show how to coarse-grain CA in all classes of Wolfram's classification. We find that computationally irreducible (CIR) physical processes can be predictable and even computationally reducible at a coarse-grained level of description. The resulting coarse-grained CA which we construct emulate the large-scale behavior of the original systems without accounting for small-scale details. At least one of the CA that can be coarse-grained is
more » ... educible and known to be a universal Turing machine.
doi:10.1103/physrevlett.92.074105 pmid:14995857 fatcat:en2ffu5uizdbfieloxucnatptq