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 non-trivial oscillators are considered here, in the sense that there must be at least one cell that oscillates at the full period. In some cases, it is not known for certain what the first-discovered oscillator of a given period is, and in such situations all possible candidates are listed.

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 24 144P24, 186P24 Noam Elkies, Bill Gosper 1994 25 134P25 Noam Elkies 1994 27 123P27.1 Noam Elkies 2002 28 Newshuttle David Buckingham 1973 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 124P37 Nicolay Beluchenko 2009 38 None found 39 134P39.1 David Buckingham, Noam Elkies 2000 41 None found 43 None found 46 twin bees shuttle Bill Gosper 1971 47 pre-pulsar shuttle 47 David Buckingham 1982 49 440P49.1 Noam Elkies 1999 51 112P51 Nicolay Beluchenko 2009 53 None found 54 P54 shuttle David Buckingham 1974 72 47P72 Robert Wainwright 1990 110 P110 traffic jam Bill Gosper 1994 132 132P132 David Buckingham ≤1994 144 Achim's p144 Achim Flammenkamp 1994 156 P156 Hans Leo hassler Noam Elkies 1995 200 P200 traffic jam Bill Gosper 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 29 10 37P10.1, 37P10.2 37 11 38P11.1 38 12 dinner table 33 13 34P13 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 caterer on 44P7.2 56 22 36P22 36 23 None found 24 caterer on figure eight 24 25 104P25 104 26 pre-pulsar shuttle 26 200 27 94P27.1 94 28 pre-pulsar shuttle 28 54 29 pre-pulsar shuttle 29 54 30 queen bee shuttle 20 31 None found 32 gourmet 66 33 92P33.1 92 34 No non-trivial examples found 35 50P35 50 36 22P36 22 37 124P37 124 38 None found 39 caterer on 34P13 46 40 26P40 26 41 None found 42 unix on 44P7.2 60 43 None found 44 mold on 36P22 50 45 pentadecathlon on thumb 1 48 46 twin bees shuttle 28 47 pre-pulsar shuttle 47 84 48 69P48 69 49 440P49.1 440 50 P50 traffic jam 92 51 112P51 112 52 35P52 35 53 None found 54 P54 shuttle 48 55 pre-pulsar hassler 55 174 56 45P56 45 60 Mold on pentadecathlon 24 72 47P72 47 100 centinal 70 144 achim's p144 42

See also

• List of common oscillators
• List of oscillators
• Omniperiodic

External links

• Oscillator at the Life Lexicon