I read about the Demons of Cyclic Space in the Computer Recreations column of Scientific American written by A.K. Dewdney. The article described a simple cellular automata. I found the idea a bit fascinating so I spent some time and implemented a simple version on my PC. I kept writing new versions as I upgrade my computer but sometime around 1995 I put it aside and haven’t touched it in a long time.

Recently I was digging around old disks and backup files and I came across the Windows version I wrote using MFC and Visual C++. Surprisingly it worked without changes and is so fast that I can’t watch the changes as they occur.

I think it’s time to dust off my old friend and experiment some more. What happens if I increase or decrease the number of cell types? What about restricting growth in certain directions? How would giving one type of cell a higher starting population change the outcome?

Below the cut I’ve placed some images of the simulation as it runs. It is a pale imitation because you can’t see the transformation from noise to ordered little cells marching along.

	This first stage shows the “debris” stage. The field is filled with a random collection of cells.
	After a few hundred generations isolated single cells have devoured their neighbors to create waves of a single color that spread across the field. Of course every type of cell can be eaten so the waves roll back and forth as the cells eat each other.
	The defects, or demons as Dewdney called them, start to appear. A demon is a small circle of cells that eat each other. Since they are tightly knit we have thin bands of them spreading out instead of the large areas in the earlier phase. There still are droplets spreading there waves and groups of individual cells.
	We’ve reached the final “demon” stage of the simulation. All of the cells are consuming and being consumed by their neighbors each generation. The colors just spin around and round the center of each defect without end. Time to end the simulation.