Difference between revisions of "Oscillator"
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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 [[generation]]s (known as its [[period]]). The term is usually restricted to finite patterns that are not [[still life]]s, though still lifes may be thought of as oscillators with period 1. An oscillator is divided into a [[rotor]] and a [[stator]]. | 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 [[generation]]s (known as its [[period]]). The term is usually restricted to finite patterns that are not [[still life]]s, 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== | ==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. | 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, [[:Category:patterns found in 2013|2013]] [[Mike Playle]] found a small 90-degree [[stable reflector]] that allows oscillators of all periods 43 or greater to be constructed. | ||
{| class="wikitable" style="margin-left:auto;margin-right:auto;" | {| class="wikitable" style="margin-left:auto;margin-right:auto;" | ||
Line 61: | Line 61: | ||
| 1972 | | 1972 | ||
| | | | ||
| [[28P7.1]], [[28P7.2]], [[burloaferimeter]] | | [[28P7.1]], [[28P7.2]], [[28P7.3]], [[burloaferimeter]] | ||
| [[:Category:Patterns with 28 cells|28]] | | [[:Category:Patterns with 28 cells|28]] | ||
|- | |- | ||
Line 105: | Line 105: | ||
|- | |- | ||
! [[:Category:Oscillators with period 13|13]] | ! [[:Category:Oscillators with period 13|13]] | ||
| [[ | | [[Buckingham's p13]] | ||
| David Buckingham | | David Buckingham | ||
| 1976 | | 1976 | ||
| | | | ||
| [[ | | [[Beluchenko's p13]] | ||
| [[:Category:Patterns with 34 cells|34]] | | [[:Category:Patterns with 34 cells|34]] | ||
|- | |- | ||
Line 141: | Line 141: | ||
| [[:Category:Patterns found in 1997|1997]] | | [[:Category:Patterns found in 1997|1997]] | ||
| | | | ||
| [[ | | [[honey thieves]] | ||
| [[:Category:Patterns with 36 cells|36]] | | [[:Category:Patterns with 36 cells|36]] | ||
|- | |- | ||
Line 149: | Line 149: | ||
| ≤[[:Category:Patterns found in 1991|1991]] | | ≤[[:Category:Patterns found in 1991|1991]] | ||
| | | | ||
| [[ | | [[p18 bi-block hassler]] | ||
| [[:Category:Patterns with 43 cells|43]] | | [[:Category:Patterns with 43 cells|43]] | ||
|- | |- | ||
Line 168: | Line 168: | ||
| 1995 | | 1995 | ||
| | | | ||
| [[caterer on | | [[caterer on 28P7.3]] | ||
| [[:Category:Patterns with | | [[:Category:Patterns with 40 cells|40]] | ||
|- | |- | ||
! [[:Category:Oscillators with period 22|22]] | ! [[:Category:Oscillators with period 22|22]] | ||
Line 176: | Line 176: | ||
| 1997 | | 1997 | ||
| | | | ||
| [[ | | [[Jason's p22]] | ||
| [[:Category:Patterns with 36 cells|36]] | | [[:Category:Patterns with 36 cells|36]] | ||
|- | |- | ||
Line 195: | Line 195: | ||
| 1994 | | 1994 | ||
| | | | ||
| [[p25 honey farm hassler]] | | [[98P25|p25 honey farm hassler]] | ||
| [[:Category:Patterns with 88 cells|88]] | | [[:Category:Patterns with 88 cells|88]] | ||
|- | |- | ||
Line 215: | Line 215: | ||
|- | |- | ||
! [[:Category:Oscillators with period 28|28]] | ! [[:Category:Oscillators with period 28|28]] | ||
| [[ | | [[newshuttle]] | ||
| David Buckingham | | David Buckingham | ||
| [[:Category:patterns found in 1973|1973]] | | [[:Category:patterns found in 1973|1973]] | ||
| | | | ||
| [[mold on | | [[mold on 34P14 shuttle]] | ||
| [[:Category:Patterns with | | [[:Category:Patterns with 46 cells|46]] | ||
|- | |- | ||
! [[:Category:Oscillators with period 29|29]] | ! [[:Category:Oscillators with period 29|29]] | ||
Line 239: | Line 239: | ||
|- | |- | ||
! [[:Category:oscillators with period 31|31]] | ! [[:Category:oscillators with period 31|31]] | ||
| [[ | | [[Merzenich's p31]] | ||
| [[Matthias Merzenich]] | | [[Matthias Merzenich]] | ||
| [[:Category:patterns found in 2010|2010]] | | [[:Category:patterns found in 2010|2010]] | ||
| | | | ||
| [[ | | [[Merzenich's p31]] | ||
| [[:Category:patterns with 48 cells|48]] | | [[:Category:patterns with 48 cells|48]] | ||
|- | |- | ||
Line 266: | Line 266: | ||
|- | |- | ||
! [[:Category:Oscillators with period 35|35]] | ! [[:Category:Oscillators with period 35|35]] | ||
| [[ | | [[p35 beehive hassler]] | ||
| Dean Hickerson | | Dean Hickerson | ||
| 1995 | | 1995 | ||
Line 274: | Line 274: | ||
|- | |- | ||
! [[:Category:oscillators with period 36|36]] | ! [[:Category:oscillators with period 36|36]] | ||
| [[ | | [[p36 toad hassler]] | ||
| Robert Wainwright | | Robert Wainwright | ||
| 1984 | | 1984 | ||
Line 282: | Line 282: | ||
|- | |- | ||
! [[:Category:Oscillators with period 37|37]] | ! [[:Category:Oscillators with period 37|37]] | ||
| [[ | | [[Beluchenko's p37]] | ||
| [[:Category:Patterns found by Nicolay Beluchenko|Nicolay Beluchenko]] | | [[:Category:Patterns found by Nicolay Beluchenko|Nicolay Beluchenko]] | ||
| [[:Category:Patterns found in 2009|2009]] | | [[:Category:Patterns found in 2009|2009]] | ||
| | | | ||
| [[ | | [[Beluchenko's p37]] | ||
| [[:Category:Patterns with 124 cells|124]] | | [[:Category:Patterns with 124 cells|124]] | ||
|- | |- | ||
Line 297: | Line 297: | ||
| [[:Category:Patterns found in 2000|2000]] | | [[:Category:Patterns found in 2000|2000]] | ||
| | | | ||
| [[caterer on | | [[caterer on Beluchenko's p13]] | ||
| [[:Category:Patterns with 46 cells|46]] | | [[:Category:Patterns with 46 cells|46]] | ||
|- | |- | ||
! [[:Category:oscillators with period 40|40]] | ! [[:Category:oscillators with period 40|40]] | ||
| [[ | | [[p40 B-heptomino shuttle]] | ||
| David Buckingham | | David Buckingham | ||
| ≤1991 | | ≤1991 | ||
| | | | ||
| [[ | | [[Beluchenko's p40]] | ||
| [[:Category:patterns with 26 cells|26]] | | [[:Category:patterns with 26 cells|26]] | ||
|- | |- | ||
Line 312: | Line 312: | ||
|- | |- | ||
! [[:Category:oscillators with period 42|42]] | ! [[:Category:oscillators with period 42|42]] | ||
| [[ | | [[p42 glider shuttle]] | ||
| Noam Elkies | | Noam Elkies | ||
| 1994 | | 1994 | ||
| | | | ||
| [[unix on | | [[unix on 34P14 shuttle]] | ||
| [[:Category:Patterns with | | [[:Category:Patterns with 50 cells|50]] | ||
|- | |- | ||
! [[:Category:oscillators with period 43|43]] | ! [[:Category:oscillators with period 43|43]] | ||
| [[ | | [[p43 glider loop]] | ||
| [[Mike Playle]] | | [[Mike Playle]] | ||
| [[:Category:patterns found in 2013|2013]] | | [[:Category:patterns found in 2013|2013]] | ||
| | | | ||
| [[ | | [[p43 glider loop]] | ||
| [[:Category:patterns with 228 cells|228]] | | [[:Category:patterns with 228 cells|228]] | ||
|- | |- | ||
! [[:Category:oscillators with period 44|44]] | ! [[:Category:oscillators with period 44|44]] | ||
| [[ | | [[p44 pi-heptomino hassler]] | ||
| David Buckingham | | David Buckingham | ||
| 1992 | | 1992 | ||
Line 360: | Line 360: | ||
|- | |- | ||
! [[:Category:oscillators with period 48|48]] | ! [[:Category:oscillators with period 48|48]] | ||
| [[ | | [[p48 toad hassler]] | ||
| Bill Gosper | | Bill Gosper | ||
| 1994 | | 1994 | ||
| | | | ||
| [[ | | [[unix on Rich's p16]] | ||
| [[:Category:patterns with | | [[:Category:patterns with 52 cells|52]] | ||
|- | |- | ||
! [[:Category:Oscillators with period 49|49]] | ! [[:Category:Oscillators with period 49|49]] | ||
Line 372: | Line 372: | ||
| [[:Category:Patterns found in 1999|1999]] | | [[:Category:Patterns found in 1999|1999]] | ||
| | | | ||
| [[p49 | | [[p49 bumper loop]] | ||
| [[:Category:Patterns with | | [[:Category:Patterns with 206 cells|206]] | ||
|- | |- | ||
! [[:Category:oscillators with period 50|50]] | ! [[:Category:oscillators with period 50|50]] | ||
| [[ | | [[p50 glider shuttle]] | ||
| Dean Hickerson | | Dean Hickerson | ||
| 1992 | | 1992 | ||
| | | | ||
| [[ | | [[p50 traffic jam]] | ||
| [[:Category:patterns with 92 cells|92]] | | [[:Category:patterns with 92 cells|92]] | ||
|- | |- | ||
! [[:Category:Oscillators with period 51|51]] | ! [[:Category:Oscillators with period 51|51]] | ||
| [[ | | [[Beluchenko's p51]] | ||
| Nicolay Beluchenko | | Nicolay Beluchenko | ||
| 2009 | | 2009 | ||
Line 392: | Line 392: | ||
|- | |- | ||
! [[:Category:Oscillators with period 52|52]] | ! [[:Category:Oscillators with period 52|52]] | ||
| [[ | | [[Four eaters hassling lumps of muck]] | ||
| David Buckingham | | David Buckingham | ||
| 1977 | | 1977 | ||
| | | | ||
| [[ | | [[Four eaters hassling lumps of muck]] | ||
| [[:Category:Patterns with 35 cells|35]] | | [[:Category:Patterns with 35 cells|35]] | ||
|- | |- | ||
! [[:Category:oscillators with period 53|53]] | ! [[:Category:oscillators with period 53|53]] | ||
| [[ | | [[p53 glider loop]] | ||
| [[Mike Playle]] | | [[Mike Playle]] | ||
| [[:Category:patterns found in 2013|2013]] | | [[:Category:patterns found in 2013|2013]] | ||
| | | | ||
| [[ | | [[p53 glider loop]] | ||
| [[:Category:patterns with 228 cells|228]] | | [[:Category:patterns with 228 cells|228]] | ||
|- | |- | ||
! [[:Category:Oscillators with period 54|54]] | ! [[:Category:Oscillators with period 54|54]] | ||
| [[ | | [[p54 shuttle]] | ||
| David Buckingham | | David Buckingham | ||
| 1974 | | [[:Category:patterns found in 1974|1974]] | ||
| | | | ||
| [[ | | [[p54 shuttle]] | ||
| [[:Category:Patterns with 48 cells|48]] | | [[:Category:Patterns with 48 cells|48]] | ||
|- | |- | ||
Line 424: | Line 424: | ||
|- | |- | ||
! [[:Category:oscillators with period 56|56]] | ! [[:Category:oscillators with period 56|56]] | ||
| [[ | | [[p56 B-heptomino shuttle]] | ||
| David Buckingham | | David Buckingham | ||
| ≤1991 | | ≤1991 | ||
| | | | ||
| [[ | | [[p56 B-heptomino shuttle]] | ||
| [[:Category:patterns with 45 cells|45]] | | [[:Category:patterns with 45 cells|45]] | ||
|- | |- | ||
! [[:Category:Oscillators with period 57|57]] | ! [[:Category:Oscillators with period 57|57]] | ||
| [[ | | [[p57 Herschel loop 1]] | ||
| [[:Category:patterns found by Dietrich Leithner|Dietrich Leithner]] | | [[:Category:patterns found by Dietrich Leithner|Dietrich Leithner]] | ||
| 1997 | | 1997 | ||
| | | | ||
| [[ | | [[p57 bumper loop]] | ||
| [[:Category:patterns with | | [[:Category:patterns with 152 cells|152]] | ||
|- | |- | ||
! [[:Category:oscillators with period 58|58]] | ! [[:Category:oscillators with period 58|58]] | ||
| [[ | | [[p58 toadsucker]] | ||
| Bill Gosper | | Bill Gosper | ||
| 1994 | | 1994 | ||
Line 448: | Line 448: | ||
|- | |- | ||
! [[:Category:oscillators with period 59|59]] | ! [[:Category:oscillators with period 59|59]] | ||
| [[ | | [[p59 Herschel loop 1]] | ||
| David Buckingham | | David Buckingham | ||
| 1997 | | 1997 | ||
| | | | ||
| [[ | | [[p59 glider loop]] | ||
| [[:Category:patterns with 228 cells|228]] | | [[:Category:patterns with 228 cells|228]] | ||
|- | |- | ||
! [[:Category:oscillators with period 60|60]] | ! [[:Category:oscillators with period 60|60]] | ||
| [[ | | [[p60 glider shuttle]] | ||
| David Buckingham | | David Buckingham | ||
| ≤ 1971 | | ≤ 1971 | ||
Line 464: | Line 464: | ||
|- | |- | ||
! [[:Category:oscillators with period 61|61]] | ! [[:Category:oscillators with period 61|61]] | ||
| [[ | | [[p61 Herschel loop 1]] | ||
| David Buckingham | | David Buckingham | ||
| [[:Category:patterns found in 1996|1996]] | | [[:Category:patterns found in 1996|1996]] | ||
| | | | ||
| [[ | | [[p61 glider loop]] | ||
| [[:Category:patterns with 228 cells|228]] | | [[:Category:patterns with 228 cells|228]] | ||
|- | |||
! [[:Category:oscillators with period 62|62]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| [[110P62]] | |||
| [[:Category:patterns with 110 cells|110]] | |||
|- | |- | ||
! [[:Category:oscillators with period 63|63]] | ! [[:Category:oscillators with period 63|63]] | ||
Line 478: | Line 486: | ||
| [[snacker on 38P7.2]] | | [[snacker on 38P7.2]] | ||
| [[:Category:patterns with 78 cells|78]] | | [[:Category:patterns with 78 cells|78]] | ||
|- | |||
! [[:Category:oscillators with period 64|64]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| [[Merzenich's p64]] | |||
| [[:Category:patterns with 34 cells|34]] | |||
|- | |- | ||
! [[:Category:oscillators with period 65|65]] | ! [[:Category:oscillators with period 65|65]] | ||
Line 484: | Line 500: | ||
| ? | | ? | ||
| | | | ||
| [[fumarole on | | [[fumarole on Beluchenko's p13]] | ||
| [[:Category:patterns with 52 cells|52]] | | [[:Category:patterns with 52 cells|52]] | ||
|- | |- | ||
Line 494: | Line 510: | ||
| [[caterer on 36P22]] | | [[caterer on 36P22]] | ||
| [[:Category:patterns with 48 cells|48]] | | [[:Category:patterns with 48 cells|48]] | ||
|- | |||
! [[:Category:oscillators with period 67|67]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| ? | |||
| ? | |||
|- | |||
! [[:Category:oscillators with period 68|68]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| ? | |||
| ? | |||
|- | |||
! [[:Category:oscillators with period 69|69]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| ? | |||
| ? | |||
|- | |- | ||
! [[:Category:oscillators with period 70|70]] | ! [[:Category:oscillators with period 70|70]] | ||
Line 500: | Line 540: | ||
| ? | | ? | ||
| | | | ||
| [[ | | [[fumarole on 34P14 shuttle]] | ||
| [[:Category:patterns with | | [[:Category:patterns with 52 cells|52]] | ||
|- | |||
! [[:Category:oscillators with period 71|71]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| ? | |||
| ? | |||
|- | |- | ||
! [[:Category:Oscillators with period 72|72]] | ! [[:Category:Oscillators with period 72|72]] | ||
| [[ | | [[two blockers hassling R-pentomino]] | ||
| Robert Wainwright | | Robert Wainwright | ||
| 1990 | | 1990 | ||
Line 510: | Line 558: | ||
| [[figure eight on 22P36]] | | [[figure eight on 22P36]] | ||
| [[:Category:Patterns with 36 cells|36]] | | [[:Category:Patterns with 36 cells|36]] | ||
|- | |||
! [[:Category:oscillators with period 73|73]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| ? | |||
| ? | |||
|- | |||
! [[:Category:oscillators with period 74|74]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| ? | |||
| ? | |||
|- | |- | ||
! [[:Category:oscillators with period 75|75]] | ! [[:Category:oscillators with period 75|75]] | ||
Line 518: | Line 582: | ||
| [[6 bits]] | | [[6 bits]] | ||
| [[:Category:Patterns with 49 cells|49]] | | [[:Category:Patterns with 49 cells|49]] | ||
|- | |||
! [[:Category:oscillators with period 76|76]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| ? | |||
| ? | |||
|- | |||
! [[:Category:oscillators with period 77|77]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| [[77P77]] | |||
| [[:Category:patterns with 77 cells|77]] | |||
|- | |||
! [[:Category:oscillators with period 78|78]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| [[p6 thumb on Beluchenko's p13]] | |||
| [[:Category:Patterns with 61 cells|61]] | |||
|- | |||
! [[:Category:oscillators with period 79|79]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| ? | |||
| ? | |||
|- | |||
! [[:Category:oscillators with period 80|80]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| [[fumarole on Rich's p16]] | |||
| [[:Category:Patterns with 52 cells|52]] | |||
|- | |||
! [[:Category:oscillators with period 81|81]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| ? | |||
| ? | |||
|- | |||
! [[:Category:oscillators with period 82|82]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| ? | |||
| ? | |||
|- | |||
! [[:Category:oscillators with period 83|83]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| ? | |||
| ? | |||
|- | |||
! [[:Category:oscillators with period 84|84]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| [[52P84]] | |||
| [[:Category:patterns with 52 cells|52]] | |||
|- | |||
! [[:Category:oscillators with period 85|85]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| ? | |||
| ? | |||
|- | |||
! [[:Category:oscillators with period 86|86]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| ? | |||
| ? | |||
|- | |||
! [[:Category:oscillators with period 87|87]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| [[84P87]] | |||
| [[:Category:patterns with 84 cells|84]] | |||
|- | |- | ||
! [[:Category:oscillators with period 88|88]] | ! [[:Category:oscillators with period 88|88]] | ||
| [[P44 pi-heptomino hassler#Image gallery| | | [[P44 pi-heptomino hassler#Image gallery|p88 pi-heptomino hassler]] | ||
| Dean Hickerson | | Dean Hickerson | ||
| 1994 | | 1994 | ||
Line 526: | Line 686: | ||
| [[figure eight on rattlesnake]] | | [[figure eight on rattlesnake]] | ||
| [[:Category:patterns with 45 cells|45]] | | [[:Category:patterns with 45 cells|45]] | ||
|- | |||
! [[:Category:oscillators with period 89|89]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| ? | |||
| ? | |||
|- | |- | ||
! [[:Category:oscillators with period 90|90]] | ! [[:Category:oscillators with period 90|90]] | ||
Line 534: | Line 702: | ||
| [[fumarole on 43P18]] | | [[fumarole on 43P18]] | ||
| [[:Category:patterns with 61 cells|61]] | | [[:Category:patterns with 61 cells|61]] | ||
|- | |||
! [[:Category:oscillators with period 91|91]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| ? | |||
| ? | |||
|- | |||
! [[:Category:oscillators with period 92|92]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| [[twin bees shuttle on 22P4.3]] | |||
| [[:Category:patterns with 50 cells|50]] | |||
|- | |||
! [[:Category:oscillators with period 93|93]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| [[caterer on Merzenich's p31]] | |||
| [[:Category:patterns with 60 cells|60]] | |||
|- | |||
! [[:Category:oscillators with period 94|94]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| ? | |||
| ? | |||
|- | |||
! [[:Category:oscillators with period 95|95]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| ? | |||
| ? | |||
|- | |- | ||
! [[:Category:oscillators with period 96|96]] | ! [[:Category:oscillators with period 96|96]] | ||
Line 542: | Line 750: | ||
| [[caterer on 68P32]] | | [[caterer on 68P32]] | ||
| [[:Category:patterns with 80 cells|80]] | | [[:Category:patterns with 80 cells|80]] | ||
|- | |||
! [[:Category:oscillators with period 97|97]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| ? | |||
| ? | |||
|- | |||
! [[:Category:oscillators with period 98|98]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| ? | |||
| ? | |||
|- | |||
! [[:Category:oscillators with period 99|99]] | |||
| ? | |||
| ? | |||
| ? | |||
| | |||
| ? | |||
| ? | |||
|- | |- | ||
! [[:Category:Oscillators with period 100|100]] | ! [[:Category:Oscillators with period 100|100]] | ||
| [[ | | [[centinal]] | ||
| Bill Gosper | | Bill Gosper | ||
| ≤[[:Category:patterns found in 1987|1987]] | | ≤[[:Category:patterns found in 1987|1987]] | ||
Line 556: | Line 788: | ||
| ? | | ? | ||
| | | | ||
| [[figure eight on | | [[figure eight on Beluchenko's p13]] | ||
| [[:Category:Patterns with 46 cells|46]] | | [[:Category:Patterns with 46 cells|46]] | ||
|- | |- | ||
Line 572: | Line 804: | ||
| ? | | ? | ||
| | | | ||
| [[ | | [[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]] | ||
| [[ | | [[p110 traffic jam]] | ||
| Bill Gosper | | Bill Gosper | ||
| 1994 | | 1994 | ||
Line 592: | Line 824: | ||
|- | |- | ||
! [[:Category:Oscillators with period 124|124]] | ! [[:Category:Oscillators with period 124|124]] | ||
| [[ | | [[p124 lumps of muck hassler]] | ||
| Dean Hickerson | | Dean Hickerson | ||
| 1994 | | 1994 | ||
| | | | ||
| | | [[mold on Merzenich's p31]] | ||
| | | [[:Category:patterns with 60 cells|60]] | ||
|- | |- | ||
! [[:Category:Oscillators with period 132|132]] | ! [[:Category:Oscillators with period 132|132]] | ||
| [[ | | [[p132 pi-heptomino hassler]] | ||
| David Buckingham | | David Buckingham | ||
| ≤1994 | | ≤1994 | ||
Line 606: | Line 838: | ||
| ? | | ? | ||
| ? | | ? | ||
|- | |||
! [[: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]] | ||
Line 624: | Line 864: | ||
|- | |- | ||
! [[:Category:Oscillators with period 156|156]] | ! [[:Category:Oscillators with period 156|156]] | ||
| [[ | | [[p156 Hans Leo hassler]] | ||
| Noam Elkies | | Noam Elkies | ||
| 1995 | | 1995 | ||
| | | | ||
| [[ | | [[Jason's p156]] | ||
| [[:Category:Patterns with 92 cells|92]] | | [[:Category:Patterns with 92 cells|92]] | ||
|- | |- | ||
Line 636: | Line 876: | ||
| ? | | ? | ||
| | | | ||
| [[ | | [[Karel's p177]] | ||
| [[:Category:patterns with 104 cells|104]] | | [[:Category:patterns with 104 cells|104]] | ||
|- | |- | ||
! [[:Category:Oscillators with period 200|200]] | ! [[:Category:Oscillators with period 200|200]] | ||
| [[ | | [[p200 traffic jam]] | ||
| Bill Gosper | | Bill Gosper | ||
| 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]] | ||
Line 663: | Line 903: | ||
==External links== | ==External links== | ||
{{LinkWikipedia|Oscillator_(cellular_automaton)}} | |||
{{LinkLexicon|lex_o.htm#oscillator}} | {{LinkLexicon|lex_o.htm#oscillator}} | ||
{{LinkWeisstein|Oscillator.html}} | {{LinkWeisstein|Oscillator.html}} |
Revision as of 14:56, 31 December 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 Wikipedia
- Oscillator at the Life Lexicon