Monster Crumbs

The 'monster crumbs' shown here are a certain type of a cellular automata, invented by David Griffeath of the University of Wisconsin at Madison. I'll assume you're familiar with the general working principles of cellular automata. The monster crumbs have the following main features:

Provided here is a simple Java applet which implements the monster crumbs. You may select the number of states (within a certain range), the number of simulation steps after which to paint the current state and the box size. The box size is the size of the square of pixels which represents each cell. At most you may have 600 times 600 cells (box size equals 1), but in this case the simulation is quite slow.

After you've changed one of these settings, click 'init' to re-initialize the simulation. A click on 'start' starts the simulation. The 'restart' button re-starts the simulation with the same cell states as after the last init.

The right-hand side of the graphics area shows the percentage of cells which changed their states during the last time step. From top to bottom the last 20 time steps are visualized.

You may notice certain features as the simulation progresses. Although the initial states for each cell are random choices, there are four distinct phases during the simulation:

The reason for this behaviour is quite simple, but I leave it to you as an exercise ;-)
For an answer, see the article referenced below.

Have fun with it !

Please click here to start the applet.

Disclaimer: I got the original idea from a article by A.K. Dewdney in Spektrum der Wissenschaft (October 1989, page 10), the german edition of Scientific American.

Peter Uelkes
Last modified: Thu May 30 17:15:09 CEST 2002