Oscillator

An oscillator is a pattern that is a predecessor of itself. That is, it is a pattern that repeats itself after a fixed number of generations (known as its period). The term is usually restricted to finite patterns that are not still lifes, though still lifes may be thought of as oscillators with period 1. An oscillator is divided into a rotor and a stator.

In general cellular automaton theory the term oscillator usually covers spaceships as well, but this usage is not normal in Conway's Game of Life.

Important oscillators by period

A list of the first-discovered oscillator of each period, as well the current smallest-known oscillator of that period, is provided here. Note that only true period oscillators are considered here. In some cases, it is not known for certain what the first-discovered oscillator of a given period is, in which situation a question mark (?) is presented along with the oscillator that has the earliest known date of discovery.

Period First discovered Discoverer Year of discovery 2 blinker John Conway 1970 3 pulsar John Conway Unknown 4 (?) Gray counter Unknown 1971 5 octagon 2 Sol Goodman, Arthur Taber 1971 6 (?) $rats, sombreros David Buckingham 1972 7 (?) airforce, burloaferimeter David Buckingham 1972 8 figure eight Simon Norton 1970 14 tumbler George Collins, Jr. 1970 15 pentadecathlon John Conway 1970 30 Queen bee shuttle Bill Gosper 1970 46 Twin bees shuttle Bill Gosper 1971 51 112P51 Nicolay Beluchenko 2009

Period Smallest known Minimum # of cells 2 blinker 3 3 caterer 12 4 mazing, mold 12 5 pseudo-barberpole 15 6 unix 16 7 28P7.1, 28P7.2, burloaferimeter 28 8 figure eight 12 9 worker bee 34 14 tumbler 16 15 pentadecathlon 12 16 Achim's P16 32 30 Queen Bee shuttle 20 51 112P51 112

See also

• List of common oscillators
• List of oscillators
• Omniperiodic

External links

• Oscillator at the Life Lexicon