A Short History of Agent-Based Models — and Why Software Engineers Should Care

In the 1940s, John von Neumann proved that a cellular automaton could replicate itself. His design required 29 possible states per cell and a pattern of roughly 200,000 cells. It was mathematically rigorous and practically useless — too complex to study, too large to visualize, too unwieldy to teach anyone anything. John Horton Conway, a mathematician at Cambridge, thought the interesting question wasn't whether self-replication was possible but how simple a system could be and still produce complex behavior. During tea breaks through the late 1960s, he tested rule after rule on pencil grids, discarding anything that died immediately or grew without bound. He was searching for a minimum — the fewest rules that would sustain unpredictable, open-ended behavior. In 1970, he found four. A cell on a grid lives or dies based on its neighbors. Fewer than two, it dies. Two or three, it survives. More than three, it dies. Exactly three neighbors bring a dead cell to life. Von Neumann needed 29