The web seems to be overflowing with cool stuff these days. If you’re a fan of cellular automata like me, Mushroom Life will provide at least a few minutes of time-wasting fun. Click on the square to add a few initial mushrooms, perhaps trying one of the patterns they have listed. The image below is the result after a few hundred generations from the simplest example pattern.
One of the coolest things in the world to me are fairy rings: naturally occurring circles of mushrooms. There are a couple of theories about why these rings occur. The first theory is that a spore pushes out fungal threads in all directions as it begins to grow underground. As it grows larger, the central part dies off, what’s left is a ring. The other theory is that if neighboring groups of genetically identical mushrooms connect and form an oval or arc, they continue to grow about the center of this object.
Briefly, cellular automata like those in Mushroom Life are based on Conway’s Game of Life. The “universe” consists of a two dimensional grid. Each square on the grid contains some image, shape, number, whatever. As time progresses, each square on the grid changes based on its contents and the contents of neighbors according to a series of simple rules. Amazing complexity can result. In the case above, where the fairy ring emerged from the seemingly unrelated initial pattern, we have an example of emergent behavior. The behavior is of the system, not of the individual mushrooms (which arguably have no behavior of their own). Just as in the real world, we see mushrooms growing according to some natural phenomenon that manifests in a ring. In the case of Mushroom Life, there is no rule that says “make a ring”, but the result of the rules acting on certain configurations of mushrooms leads to the creation of rings.
Cool, huh?
