IF YOU found a self-replicating organism living inside your computer, your first instinct might be to reach for the antivirus software. If, however, you are Andrew Wade, an avid player in the two-dimensional, mathematical universe known as the Game of Life, such a discovery is nothing short of an epiphany.
When Wade posted his self-replicating mathematical organism on a Life community website on 18 May, it sparked a wave of excitement. “This is truly ground-breaking work,” wrote a fellow Life enthusiast, Adam Goucher, on the website Game of Life News. “In fact, this is arguably the single most impressive and important pattern ever devised.”
A first for the game, the replicator demonstrates how astounding complexity can arise from simple beginnings and processes – an echo of life's origins, perhaps. It might help us understand how life on Earth began, or even inspire strategies to build tiny computers.
The Game of Life is the best-known example of a cellular automaton, in which patterns form and evolve on a grid according to a few simple rules. You play the game by choosing an initial pattern of “live” cells, and then watch as the configuration changes over many generations as the rules are applied over and over again (see “Take two simple rules”).
The rules of the game were laid down by mathematician John Conway in 1970, but cellular automata first took off in the 1940s when the late mathematician John von Neumann suggested using them to demonstrate self-replication in nature. This lent philosophical undertones to Life, which ended up attracting a cult following.
Life enthusiasts have since catalogued an entire zoo of interesting patterns, such as “spaceships” that travel across the grid, or “guns”, which constantly spawn other patterns. But a pattern that spawned an identical copy of itself proved elusive.