Tuesday, January 10, 2006

Conway's Glider and Minimal Life

The Game of Life is certainly the most familiar Cellular Automata. It was introduced by John Conway in 1970 and popularized by the Scientific American journal. The Glider, a simple oscillating pattern that moves in the life universe, is generally presented as an emerging structure that gives an idea of what could be a minimal living creature. Is the Glider a useful modelof a living system ?
The Glider is a configuration of five "on" (black) cells that moves diagonally every four cycles. It represents a good example of a self-reproducing loop but it is far more simple than the self-reproducing automata proposed by John von Neumann in his theory. The Glider is a coherent pattern in space-time that continuously reconstitutes itself in the meaning of Maturana and Varela's notion of Autopoiesis. In the figure, I have colored in blue the "off" cells that contribute to its structure, forming a sort of membrane. However, the glider cannot be considered as a full autopoietic system since it is very sensible to any perturbation: most interactions with other structures are destructive. I personnaly think that the glider is too simple to represent a convincing model for minimal life, but it gives us a feeling of what it could be.

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