In this lecture, and the next few, we investigate cellular automata. Similar to naturally occuring cellular structures, these simple devices are often collectively capable of performing arbitrary computation.

1. A review of Turing's machine, structurally.
2. von Neumann's self-reproducing machine.
3. The Penrose self-reproducing analog.
4. Conway's Life simulation.
5. Digital logic equivalence.
6. Langton's ant (including some open questions)
7. Fredkin and Toffoli.
8. The Big, Bad Wolfram
9. Biological equivalents to 1D automata.

Resources needed for this topic:

• Martin Gardner's chapter on Conway's Game of Life
• A Life Applet
• For Macs, Trevorrow's Life Lab is great.
• A simulator for Langton's Ant
• Applets for playing with 1D automata:
  • An applet for experimenting with rules.
  • An applet for experimenting with Langton's lambda.

Other resources for this topic:

• Wolfram's site supporting on A New Kind of Science.
• Reviews of the above text.
• Melanie Mitchell's Review of Cellular Automata (1996) while at the Santa Fe Institute.
• Fredkin's site on Digital Philosophy (including his book on Digital Mechanics)

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These items are Java applets, and require Java to be installed on your machine.