Difference between revisions of "Oscillator"
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| 1972 | | 1972 | ||
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| [[28P7.1]], [[28P7.2]], [[burloaferimeter]] | | [[28P7.1]], [[28P7.2]], [[28P7.3]], [[28P7.4]], [[burloaferimeter]] | ||
| [[:Category:Patterns with 28 cells|28]] | | [[:Category:Patterns with 28 cells|28]] | ||
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| 1995 | | 1995 | ||
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| [[caterer on | | [[caterer on 28P7.4]] | ||
| [[:Category:Patterns with | | [[:Category:Patterns with 40 cells|40]] | ||
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! [[:Category:Oscillators with period 22|22]] | ! [[:Category:Oscillators with period 22|22]] | ||
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| [[:Category:patterns found in 1973|1973]] | | [[:Category:patterns found in 1973|1973]] | ||
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| [[pre-pulsar shuttle 28]], [[mold on 41P7.2]] | | [[pre-pulsar shuttle 28]], [[mold on 41P7.2]], [[T-nosed p4 on 28P7.4]] | ||
| [[:Category:Patterns with 53 cells|53]] | | [[:Category:Patterns with 53 cells|53]] | ||
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| 1994 | | 1994 | ||
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| [[ | | [[p6 thumb on 28P7.4]] | ||
| [[:Category:Patterns with | | [[:Category:Patterns with 55 cells|55]] | ||
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! [[:Category:oscillators with period 43|43]] | ! [[:Category:oscillators with period 43|43]] | ||
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| 1994 | | 1994 | ||
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| [[ | | [[unix on Rich's p16]] | ||
| [[:Category:patterns with | | [[:Category:patterns with 52 cells|52]] | ||
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! [[:Category:Oscillators with period 49|49]] | ! [[:Category:Oscillators with period 49|49]] | ||
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| [[P54 shuttle]] | | [[P54 shuttle]] | ||
| David Buckingham | | David Buckingham | ||
| 1974 | | [[:Category:patterns found in 1974|1974]] | ||
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| [[P54 shuttle]] | | [[P54 shuttle]] | ||
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| ? | | ? | ||
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| | | [[110P62]] | ||
| | | [[:Category:patterns with 110 cells|110]] | ||
|- | |- | ||
! [[:Category:oscillators with period 63|63]] | ! [[:Category:oscillators with period 63|63]] | ||
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| ? | | ? | ||
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| [[Merzenich's | | [[Merzenich's p64]] | ||
| [[:Category:patterns with 34 cells|34]] | | [[:Category:patterns with 34 cells|34]] | ||
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| ? | | ? | ||
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| [[ | | [[p6 thumb on 34P13]] | ||
| [[:Category:Patterns with | | [[:Category:Patterns with 61 cells|61]] | ||
|- | |- | ||
! [[:Category:oscillators with period 79|79]] | ! [[:Category:oscillators with period 79|79]] | ||
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| ? | | ? | ||
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| [[ | | [[fumarole on Rich's p16]] | ||
| [[:Category:Patterns with | | [[:Category:Patterns with 52 cells|52]] | ||
|- | |- | ||
! [[:Category:oscillators with period 81|81]] | ! [[:Category:oscillators with period 81|81]] | ||
Line 652: | Line 652: | ||
| ? | | ? | ||
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| [[ | | [[52P84]] | ||
| [[:Category:patterns with | | [[:Category:patterns with 52 cells|52]] | ||
|- | |- | ||
! [[:Category:oscillators with period 85|85]] | ! [[:Category:oscillators with period 85|85]] | ||
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| ? | | ? | ||
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| | | [[84P87]] | ||
| | | [[:Category:patterns with 84 cells|84]] | ||
|- | |- | ||
! [[:Category:oscillators with period 88|88]] | ! [[:Category:oscillators with period 88|88]] | ||
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| ? | | ? | ||
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| [[twin bees | | [[twin bees shuttle on 22P4.3]] | ||
| [[:Category:patterns with | | [[:Category:patterns with 50 cells|50]] | ||
|- | |- | ||
! [[:Category:oscillators with period 93|93]] | ! [[:Category:oscillators with period 93|93]] | ||
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| ? | | ? | ||
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| | | [[caterer on 48P31]] | ||
| | | [[:Category:patterns with 60 cells|60]] | ||
|- | |- | ||
! [[:Category:oscillators with period 94|94]] | ! [[:Category:oscillators with period 94|94]] | ||
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| ? | | ? | ||
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| [[ | | [[22P4.3 on 56P27]] | ||
| [[:Category:patterns with | | [[:Category:patterns with 78 cells|78]] | ||
|- | |- | ||
! [[:Category:Oscillators with period 110|110]] | ! [[:Category:Oscillators with period 110|110]] | ||
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| ? | | ? | ||
| ? | | ? | ||
|- | |||
! [[:Category:oscillators with period 135|135]] | |||
| [[106P135]] | |||
| Bill Gosper | |||
| [[:Category:patterns found in 1989|1989]] | |||
| | |||
| [[pentadecathlon on 56P27]] | |||
| [[:Category:patterns with 68 cells|68]] | |||
|- | |- | ||
! [[:Category:oscillators with period 138|138]] | ! [[:Category:oscillators with period 138|138]] | ||
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| 1994 | | 1994 | ||
| | | | ||
| | | [[figure eight on centinal]] | ||
| | | [[:Category:patterns with 82 cells|82]] | ||
|- | |- | ||
! [[:Category:oscillators with period 312|312]] | ! [[:Category:oscillators with period 312|312]] | ||
| | | period-tripled [[p104 gun]] | ||
| | | Dave Greene | ||
| | | 2004 | ||
| | | | ||
| [[60P312]] | | [[60P312]] |
Revision as of 17:11, 21 April 2018
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.
Cellular automaton theory recognizes shift periodicity, which refers to a configuration reappearing in shifted form after a lapse of one or more generations. Without the shift, it is an oscillator, but if it moves it would be called a glider or spaceship. Strictly speaking "glider" means the little figure so prevalent in Conway's Game of Life, but the more general usage has now become popular.
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. For any period 61 or greater an oscillator can be constructed using the Herschel track method. In April, 2013 Mike Playle found a small 90-degree stable reflector that allows oscillators of all periods 43 or greater to be constructed.
See also
External links
- Oscillator at the Life Lexicon