If you’ve ever played Conway’s Game of Life, you’ll be familiar with cellular automata and, more importantly, glider guns. So get this: a team of British chemists and computer scientists have created a chemical cocktail that behaves like a cellular automata and which reproduces this behavior: chemical guns firing chemical gliders across a chemical grid.
For those who haven’t played with it, Conway’s Game of Life is a two dimensional grid known as a cellular automata in which each square can be black or white. The game starts in an initial state–a pattern of black and white squares–and its evolution is determined by a set of rules that specify what color a square should become depending on the color of its neighbors.
The game was devised by the British mathematician John Conway in 1970 and has been studied in detail by countless generations of computer scientists, mathematicians and students ever since, not least because of the extraordinary patterns and structures that the game can produce.
One of these is the glider gun: a structure that periodically “fires” projectiles across the landscape.
Now Ben de Lacy Costello and pals from the University of West of England in Bristol have created a chemical version of all this. Their model is based on the famous Belousov-Zhabotinsky reactions in which a specific cocktail of chemicals can produce complex patterns of oscillating colors.
The team set up a grid in which each square could change colour via a BZ reaction and in which the reaction diffused across the boundaries of each square in way that mimics Conway’s Game of Life.
The oscillating patterns produced by BZ reaction have long been thought of as similar to cellular automata but this is the first time that the Game of Life has been reproduced in a chemical system.
That’s impressive but it looks as if the best is yet to come. It is well known that cellular automata can operate as universal Turing machines . The next step, says Costello and buddies, is to build a similar chemical grid capable of arithmetic.
Beyond that, the question is this: if we can do this in the lab, might evolution also have harnessed these reactions in a similar way. Let the search begin.
Ref: arxiv.org/abs/0902.0587: Implementation of Glider Guns in the Light-Sensitive Belousov-Zhabotinsky Medium