A Pattern That Makes Pattern-Makers
A breeder in Conway's Game of Life does not merely produce moving patterns; it produces the machines that keep producing them.
The puffer-type breeder pictured in Conway’s Game of Life has three layers of activity. The puffer, marked red, leaves glider guns, marked green, in its wake. Those guns produce gliders, marked blue. Watching only the moving front misses what the wake is doing.
A glider gun produces spaceships; this breeder leaves behind the guns themselves. Its trail contains structures that keep producing further structures. All three layers arise under the same local rules, with each generation determined by the preceding one. “Breeder” names a hierarchy of production inside that uniform process.
Patterns of this scale also expose a second hierarchy: the one inside the simulator. Hashlife avoids recalculating repeated regions, while Golly supplies the workbench in which patterns like this can be loaded, inspected, edited, and accelerated.