The Underlying Theory Behind Life, the Universe, and Everything
The Game of Life is played out on an infinite grid. The selves of the grid exist in two states: alive or dead. Time advances in steps in the toy universe and the fate of every cell at each step is decided by the living or dead cells surrounding it. If three of the eight cells abutting an empty cell are filled then in the next time step that dead cell comes to life. If you cell has two neighbours it stays alive at the next time step. If it has less than two or more than three neighbours it dies.
Langton found that there was a fine line between the patterns that never changed or dwindled into nothing and those that bloomed into unpredictable chaos. Between disorder and boredom was a “sweet spot” where the most complex patterns emerged. In this region patterns propagated, extended over long distances before being superseded. Patterns bloomed, died and popped up again. Fractal patterns, a phase transition, the critical point. Universality.
Rather grandly Langton christened this point the “edge of chaos”. The cusp between death and disaster. He found a small region in which the dynamics of organisation and information dominated. His work suggests the possibility that information dynamics which gave rise to life came into existence when global or local conditions brought some medium – perhaps water, perhaps some other material – through a critical phase transition.
Langton speculates that this is the niche that all living organisms occupy. At the critical junctures complex structures emerge and persist. Persistence, staying alive, demands the ability to process information about your surroundings and use it. Langton believes that this makes the critical region are good candidate for the place that life got going.
Langton suggests that at this point, the edge of chaos for want of a better term, the ability of the system to use and process information improves dramatically. Information in this sense means the ability of the different cells to influence each other and how well this is passed on or correlated.
The ferromagnet at the critical point is permanently uncertain. The clouds of magnetism that form and flutter along it and within it are formed when the microscopic magnets are “persuaded” to reverse their polarity by neighbouring units or thermal noise. This choosing – the flipping polarities in the magnet and alive or dead cells in the cellular automata – is what Langton means by a dynamics of information coming to dominate.
In essence the units make a decision about what they want to do based on the past behaviour of the other elements in the system. Order is preserved, propagated and acted upon. At this point then exists a tense struggle between the storage of information and its transmission. The cells in the CA struggle to stay alive (storage) but could easily be killed off by changes anywhere in the CA universe (transmission).
At the critical point order and structure are all-important. Physical properties cease to matter. It is this Langton suspects that gave rise to living organisms and, once and running, flying or swimming, is the dynamics they used to keep going. He, and many others in the Alife movement, think that this is more than just an analogy.
They see it as the defining organisational principle of all living things. They believe that organisms are riddled with critical points and the cause of this information, genetic or structural, is the key measure of life. Changes rippling through the system, which represent information, helpe the organism keep itself going. They are the motor of evolution and reveal how it is adapting to its environment. What is important about life is what did does, the process, not what it is made of.