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The Facts of Life

What if we alter the rules controlling the squares? Consider these rules: If a square is off, it turns on if exactly three of its neighbors are on. If a square is on, it stays on if exactly two or three neighbors are on; otherwise it turns off.

These rules are known as Life. When a square is on, you can think of it as "alive." A live square with more than three live neighbors dies of overcrowding. A live square with fewer than two live neighbors dies of loneliness.

Click Start to see Life in action. Notice that Life gliders look different than Seeds gliders. The Life glider cycles through four different shapes before returning to its original shape -- in a new position.

The Life rules were invented by John Conway in 1970. Conway wanted to explore how simple rules could give rise to life-like structures and behaviors. He believed that the "organisms" in his Life world could act just like those in the real world -- moving, growing, reproducing, evolving, and maybe even thinking! Of course, Conway was imagining Life worlds much larger than the one on this page.

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Mitchel Resnick and Brian Silverman
Epistemology and Learning Group
MIT Media Laboratory

Last modified: 2/4/96