Breeder

A breeder is any pattern that exhibits unbounded quadratic growth. This term also refers to the first example in Conway's Game of Life, Breeder 1.

Breeders fall into one of eight types:

• SSS breeder - A stationary pattern that generates copies of an SS infinite growth (e.g. a slide gun that shoots out a blockstacker-like mechanism).
• SSM breeder - A stationary pattern that generates guns.
• SMS breeder - A stationary pattern that generates puffers.
• SMM breeder - A stationary pattern that generates rakes (i.e. a rake gun).
• MSS breeder - A moving pattern that generates SS infinite growth.
• MMS breeder - A moving pattern that generates puffers periodically. Examples include Riley's breeder, metacatacryst, Jaws and pufferfish breeder.
• MSM breeder - A moving pattern that generates guns. Breeder 1 was a MSM breeder; so was Lucas Brown's LWSS breeder.
• MMM breeder - A moving pattern that generates rakes periodically (i.e. a rake rake).

The ones in bold require the use of slide guns, so are not very frequently constructed. MSS-type breeders without slide guns are similarly rare; the remaining four types are more common.

An unusual type of breeder, which can be loosely categorised as a MMS breeder, is the spacefiller. This does not create puffers in the classical sense, but instead stretches an infinite line of wickstretchers.

Many small quadratic growth patterns, for example mosquito 5, utilize switch engines because they are easy to construct, compared to the next easiest linear growth pattern, the Gosper glider gun. Simkin glider gun breeders have also been constructed.

The original breeder

Main article: Breeder 1

The original breeder is composed of several rakes. These produce periodic waves of gliders, which collide to incrementally form guns. These guns then produce a steady output of gliders. Since the guns themselves are producing gliders at a linear rate, and the guns are being created also at a linear rate, the whole pattern grows quadratically. Since then, numerous improvements have been made. For example, Helmut Postl has made a much more compact version of the original breeder.

Also see

• List of breeders

External Links

• Breeder at Wikipedia

• Breeder at the Life Lexicon