Time for me to talk about another program I’ve come across, downloaded and thoroughly enjoyed, so hopefully others can do the same.

This time it’s Golly, a desktop application for simulating cellular automata. And I use the general term intentionally: rather than just Conway’s Game of Life (CGOL, GOL or even just “Life”) for which it is named, it supports:

  • variations like High Life, Diamoeba, and Day and Night
  • “Generations” patterns like Star Wars where dead cells take up space for a few generations
  • The one-dimensional “Wolfram” rules, like rule 110
  • Non-totalistic rules where relative position around a cell matters, such as “Just friends” which won’t let a cell be born when its neighbours are on opposite sides
  • “Larger than life” rules that take into account cells beyond the neighbouring ones
  • Automata with many uniquely-interacting states like Langton’s ant, Wireworld and John von Neumann’s automaton

And really, that last one basically means “anything.” It also supports the HashLife algorithm which allows huge patterns to be computed quickly by effectively skipping intermediate generations (but still resulting in the correct pattern). I strongly recommend increasing its maximum memory from the pitiful default of 500MB under File -> Preferences -> Control and changing settings for HashLife (Generations, JvN and RuleLoader also have similarly low limits) so you can compute very large timesteps more easily.

It comes with a large collection of patterns and rules already, most unsurprisingly for Conway’s original rule. If you’re as confused as I was about how to access John von Neumann’s CA, there are simulations under Patterns/Self-Rep/JvN. I’m not sure if the words “John von Neumann” actually appear anywhere.

Another site of interest is the aptly-named LifeWiki, which contains lots of information about various cellular automata, again with a focus on regular “Life”. You’ll find that the people who have studied this stuff apparently had a sense of humour, with a set of “blinkers” forming a “traffic light,” four “loaves” making a “bakery,” and a “knightship” that involves a “half-bakery” being dubbed the “half-baked knightship.”

It’s quite easy to get lost in looking at the vast collection of patterns and being in awe of quite a fair few of them, but it’s fun too.