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 1970 4 pinwheel Simon Norton 1970 5 octagon 2 Sol Goodman, Arthur Taber 1971 6 (?) $rats, sombreros David Buckingham 1972 7 burloaferimeter David Buckingham 1972 8 figure eight Simon Norton 1970 9 worker bee David Buckingham 1972 10 42P10.1 David Buckingham ≤1976 11 38P11.1 David Buckingham 1977 12 dinner table Robert Wainwright 1972 13 65P13.1 David Buckingham 1976 14 tumbler George Collins, Jr. 1970 15 pentadecathlon John Conway 1970 16 two pre-L hasslers Robert Wainwright 1983 17 54P17.1 Dean Hickerson 1997 18 117P18 David Buckingham ≤1991 19 None found 20 145P20 Noam Elkies 1995 21 124P21 Robert Wainwright 1995 22 168P22.1 Noam Elkies 1997 23 None found 27 123P27.1 Noam Elkies 2002 30 queen bee shuttle Bill Gosper 1970 31 None found 32 gourmet David Buckingham 1978 33 (?) Noam Elkies, Achim Flammenkamp 1997 34 No non-trivial examples found 37 None found 38 None found 39 134P39.1 David Buckingham, Noam Elkies 2000 41 None found 43 None found 46 twin bees shuttle Bill Gosper 1971 49 440P49.1 Noam Elkies 1999 51 112P51 Nicolay Beluchenko 2009 53 None found 54 P54 shuttle David Buckingham 1974 110 P110 traffic jam Bill Gosper 1994 144 Achim's p144 Achim Flammenkamp 1994

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 29P9.1 29 10 37P10.1, 37P10.2 37 11 38P11.1 38 12 dinner table 33 13 34P13.1 34 14 tumbler 16 15 pentadecathlon 12 16 Achim's p16 32 17 54P17.1 54 18 43P18 43 19 None found 20 mold on fumarole 30 21 Jam on 44P7.2 57 22 36P22.1 36 23 None found 27 94P27.1 94 29 pre-pulsar shuttle 29 56 30 queen bee shuttle 20 33 92P33.1 92 39 134P39.1 134 49 440P49.1 440 51 112P51 112 54 P54 shuttle 48 100 centinal 70

See also

• List of common oscillators
• List of oscillators
• Omniperiodic

External links

• Oscillator Stamp Collection by Dean Hickerson, via Archive.org
• Oscillator at the Life Lexicon