Todd Rowland presented an in-depth investigation of CA rule 37R, a rule which unlike many reversible rules does not destroy order in it initial conditions. This rule represents an interesting partial analogy with physical processes. Since it is reversible, it creates an evolution that can be de-evolved in time, but it does not degrade the order present in its initial conditions. If rule 37R were a physical process, it would violate the 2nd law of thermodynamics, which holds that the entropy of any physical process must increase over its evolution in time.
He also discussed the possible universality of reversible rules. There is an apparent problem with getting reversible rules to emulate irreversible ones, since irreversible rules lose (possibly all) information about their previous states as they evolve, but he presented a solution. Rowland ended with a list of open problems related to this rule that he still hopes to explore in the future.
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