Breeder (cellular automaton)

Evolution of a "puffer that leaves guns in its wake" type breeder

Charts showing the change of cell count per generation of the four different breeder types. A polynomial trend line demonstrates the quadratic growth rate.

In Conway's Game of Life, a breeder is a pattern that exhibits quadratic growth, by generating multiple copies of a secondary pattern, each of which then generates multiple copies of a tertiary pattern.^[1]

Classification

Breeders can be classed by the relative motion of the patterns. The four basic types are:^[1]

• A gun that fires out rakes. (The primary pattern is stationary, whilst both the secondary and tertiary patterns move.)
• A puffer that leaves guns in its wake. (The secondary patterns are stationary, whilst both the primary and tertiary patterns move.)
• A rake that fires out puffers. (The tertiary patterns are stationary, whilst the primary and secondary patterns move.)
• A rake that fires out more rakes. (All the patterns move.)

A spacefiller (which also undergoes quadratic growth) may be thought of as a fifth class of breeder. However it differs from a true breeder in that it expands a single island of cells, rather than creating independent objects.

References