Chapter 3: The World of Simple Programs

Section 4: Turing Machines

Localized structures [in Turing machines]

Even when the overall behavior of a Turing machine is complicated, it is possible for simple localized structures to exist, much as in cellular automata such as rule 110. What can happen is that with certain specific repetitive backgrounds, the head can move in a simple repetitive way, as shown in the pictures below for the Turing machine from page 81.

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