# Pattern of the Year

The **Pattern of the Year** (**POTY**) competition is held each year on the ConwayLife.com forums. Users are invited to submit interesting and noteworthy patterns, their own or others'; following discussion, a final list is then curated, and a public vote held. There are only two hard and fast rules: patterns must have been discovered in the year in question; and patterns must work in B3/S23 (Conway's Game of Life).

In 2020/2021, the **Pattern of the Decade** (**POTD**) competition is also being held in which users vote on the most noteworthy patterns discovered between 2010 and 2019.

## Contents

## Summary

Year | First place | Second place | Third place |
---|---|---|---|

2020 | Bandersnatch Speed Demonoid† |
Spaceship glider syntheses | |

2019 | David Hilbert | Spider synthesis | Scholar |

2018 | Sir Robin | 0E0P metacell | Reverse caber-tosser |

2017 | 2-engine Cordership | Tanner's p46 | Stable pulse-dividers |

2016 | Caterloopillars | Copperhead | Grandfather-less Pattern |

2015 | Syringe | Simkin glider gun | Demonoids |

2014 | Waterbear | Centipede | Half-baked knightship |

2013 | Snark | Loafer | CC semi-Snark Linear propagator† |

2011 | Fully universal Turing machine Lobster† |
Garden of Eden 6 | |

2010 | Gemini | Phi calculator | c/5 diagonal rake |

2004 | Caterpillar‡ |

‡ Result of informal consensus rather than formal competition;

† Patterns were tied on number of votes.

## Results by year

### 2020

The following patterns were voted on for the 2020 competition. Users were able to vote on as many patterns as they wished, awarding up to three stars to each one. MathAndCode organized the competition.

Final rank | Stars | Pattern | Author | Link(s) |
---|---|---|---|---|

Description | ||||

1 | 76 | Bandersnatch | Martin Grant and Entity Valkyrie | |

A color-changing glider-to-glider conduit, which can be used to solve glider color mismatches. | ||||

1 | 76 | Speed Demonoid | Pavel Grankovskiy, Dave Greene, Tanner Jacobi, and Goldtiger997 | |

A self-constructing diagonal spaceship with speed limit c/4 due to using a crab wickstretcher. | ||||

3 | 69 | Spaceship glider syntheses | Goldtiger997, Tanner Jacobi, Martin Grant, et al. | [2] |

Glider syntheses for 56P6H1V0, 58P5H1V1, turtle, 31P8H4V0, 44P5H2V0, 70P2H1V0.1, 55P9H3V0, and 44P5H2V0, many of which were the first of their unsymplified speed to be synthesized. | ||||

4 | 68 | Smaller 3c/7 spaceships | Dylan Chen | |

Anura and Soba, the second and third known elementary 3c/7 spaceships, both of which are smaller than the first known 3c/7 spaceship, spaghetti monster. | ||||

4 | 68 | Rob's p16 | Rob Liston | |

A useful sparker, as well as the smallest-known and first strictly volatile oscillator of its period, found when it occurred in the ash of an asymmetric Catagolue soup. | ||||

6 | 65 | Period-28 glider gun | Matthias Merzenich and Paul Callahan | |

The first true period-28 gun. | ||||

7 | 64 | Silverfish | Chris Cain, Dave Greene, Adam P. Goucher, and Nathaniel Johnston | |

A new smallest spaceship to use the 31c/240 Herschel climber. | ||||

8 | 61 | Cheaper fixed-cost universal construction | Chris Cain, Adam P. Goucher, and MathAndCode | [3] |

Reductions in the cost of reverse caber-tosser-based universal construction by figuring out how to split a target block with gliders instead of needing to use a block-laying switch engine, removing the need for a Sakapuffer, and reducing the number of glider-producing switch enginges required in the circuitry. | ||||

9 | 58 | 19-bit still life syntheses | Jeremy Tan, Dave Greene, Tanner Jacobi, Goldtiger997, Martin Grant, Alex Greason, Blinkerspawn, et al. | [4] |

Glider syntheses for all 19-bit still lifes. | ||||

10 | 56 | New 2c/7 technology | John Winston Garth, Andrew J. Wade | |

Two new 2c/7 spaceships, 186P7H2V0 and doo-dah used to help make puffers and rakes. | ||||

10 | 56 | Natural loafers | John Goodman, Rob Liston, Adam P. Goucher | [5] |

Catagolue soups in the C1 and G1 symmetries that produce the twenty-cell loafer, making it the first spaceship not at the maximum speed for its direction to be found in a random asymmetric soup in B3/S23. | ||||

12 | 55 | Stable barge crosser | Goldtiger997 | [6] |

A way to transmit a glider signal across an infinitely long barge without permanently damaging it. | ||||

13 | 50 | New grayship technology | Keith Amling, Hartmut Holzwart, and Matthias Merzenich | [7] |

A large collection of new grayship components of varying speeds. | ||||

14 | 46 | Beehive push catalyst | Tanner Jacobi | [8] |

A stable catalyst that allows the beehive push reaction, where a beehive affects an active region while being displaced by one cell orthogonally, to be used repeatedly in situations where there is not another synchronized mechanism to push it back, such as in conduits. | ||||

15 | 45 | New longest-lasting 16x16 methuselah | Rob Liston and Goldtiger997 | |

An asymmetric 16x16 soup found with Catagolue that takes longer to stabilize than any previous asymmetric non-infinite-growth 16x16 soup, and a related 16x16 pattern that takes one generation longer to form generation five of said random soup. | ||||

16 | 44 | New c/5 diagonal spaceships | AforAmpere, Sarp, Aidan F. Pierce, John Winston Garth, and Dylan Chen | [9] |

Several new c/5 diagonal spaceships of varying shapes. | ||||

17 | 43 | Small c/5 diagonal puffer | Peter Naszvadi | [10] |

An elegant period-1540 c/5 diagonal puffer that uses only three copies of 58P5H1V1. | ||||

18 | 42 | New small Corderships | wwei23 and Ian07 | |

Several new three-engine and four-engine Corderships found using a custom apgsearch symmetry. | ||||

19 | 41 | New agar crawler/agar bubble/skimmer/agar clearer technology | Arie Paap, Keith Amling, Harmut Holzwart, et al. | [11] |

Mechanisms to add, remove, travel along, or travel within agar. | ||||

19 | 41 | c/5 and c/6 guns | Entity Valkyrie, Goldtiger997, et al. | [12] |

The first known guns for c/5 orthogonal, c/5 diagonal, and c/6 orthogonal spaceships. | ||||

21 | 39 | New exotic spaceship eaters and spaceship-to-G converters | Jeremy Tan, Luka Okanishi, Dave Greene, Adam P. Goucher, Tanner Jacobi, Aidan F. Pierce, et al. | [13] |

New mechanisms to eat spaceships or turn them into glider signals | ||||

21 | 39 | Glider syntheses from Glider_stdin | testitemqlstudop, Tanner Jacobi, Arie Paap, GUYTU6J, goldenratio, et al. | [14] |

Glider syntheses based on a result from a custom Catagolue symmetry where gliders are fired at each other in a random configuration. | ||||

21 | 39 | Period-9 heavyweight sparker and associated R shuttle | wwei23, Aidan F. Pierce, and David Raucci | |

Period-nine domino sparker that has two dot sparks displaced (2.5, 1) from the center of the domino spark, making it a heavyweight emulator, and has better clearance than the previous known period-nine domino sparker, allowing it and an eater 2 to form a periodic RFx9R conduit that can be attached to another copy of itself to form a shuttle | ||||

24 | 38 | Stable L122 | Aidan F. Pierce | |

A stable version of the L122 conduit, which previously only had periodic versions. | ||||

25 | 35 | New c/10 orthogonal technology | Christoph Reinthaler | [15] |

Arrangements of copperheads and fireships that perform various tasks, such as firing a stream of loafers backwards. | ||||

26 | 34 | New XWSS signal technology | Dave Greene, Adam P. Goucher, and Goldtiger997 | [16] |

Improved mechanisms for detecting XWSS signals. | ||||

26 | 34 | Cordercolumn and extruder | wwei23, Luka Okanishi, and Ian07 | [17] |

Two ways to stabilize a switch engine with another switch engine behind it and an extruder that emits a line of switch engines using one of the methods. | ||||

26 | 34 | New c/6 diagonal pushalong | Aidan F. Pierce | [18] |

The first new piece of low-period c/6 diagonal technology in 9 years. | ||||

26 | 34 | Better universal regulator | Louis-François Handfield | [19] |

A device that can align a set of input glider signals with no period constraints to any output period greater than 73 that is smaller and faster than any previous universal regulator. | ||||

26 | 34 | c/61 near-spaceship and slide gun support | Tanner Jacobi and Goldtiger997 | [20] |

A reaction consisting of a pulsar interacting with two blocks that results in the same confirmation 61 generations later shifted by one cell orthogonally if supplied with two dot sparks or certain fishhook-type interactions, which can be provided with gliders from slide guns. | ||||

31 | 33 | Record-setting diehards | Rob Liston, goldenratio, and Moth Wingthane | [21] |

Patterns found from soup searches searches that take longer to settle without leaving any ash than any previously known patterns fitting in a bounding box of the same size. | ||||

31 | 33 | 4×N block agar construction | Goldtiger997 | [22] |

A way to extend the pseudo still life consisting of a 4×3 rectangle of blocks to a 4×N rectangle for arbitrarily high N using gliders. | ||||

31 | 33 | Width-12 c/6 orthogonal spaceship | Andrew J. Wade | |

The first width-12 asymmetric c/6 orthogonal spaceship, which has the minimum possible width for a asymmetric period-6 spaceship of this speed. | ||||

34 | 32 | Loafer bitmap printer | otismo | [23] |

A collection of loafer guns that can be toggled by a glider memory tape to produce a message in loafer-pixels. | ||||

35 | 30 | 34-bit still life enumeration | Nathaniel Johnston | [24] |

An enumeration of all 34-bit still lifes and pseudo still lifes, which confirmed that the quad pseudo still life is the unique 34-bit pseudo still life requiring a decomposition into 4 or more pieces. | ||||

36 | 27 | p5 drifter-like catalyst/lightweight volcano/periodic catalyst | wwei23 and Dongook Lee | [25] |

An oscillator that periodically creates then kills via overpopulation a "block face", allowing it to be used to perturb regions in the same manner as several catalysts without permanently harming the oscillator. | ||||

37 | 26 | New growing spaceships | Matthias Merzenich and Aidan F. Pierce | [26] |

Patterns in which spaceships create a wick that is consumed at a slower speed than it is created at. | ||||

38 | 25 | Period-10 glider shuttle | Martin Grant | [27] |

The lowest known period for a glider shuttle. | ||||

39 | 23 | Extensible LoM hasslers | JP21, wwei23, and Matthias Merzenich | [28] |

Extensible oscillators based on lumps of muck . |

### Pattern of the Decade (2010s)

The Pattern of the Decade competition for the 2010s is currently taking place, and is being organized by testitemqlstudop. All top-three winners from each previous Pattern of the Year competition during the 2010s are automatically added to the nomination list. It is unknown when nominations end for this competition. The results will be posted both on the wiki and on the forums when voting is complete.

### 2019

The following patterns were voted on for the 2019 competition. Users were able to vote on as many patterns as they wished, awarding up to three stars to each one. testitemqlstudop organized the competition.

Final rank | Stars | Pattern | Author | Link(s) |
---|---|---|---|---|

Description | ||||

1 | 74 | David Hilbert | Luka Okanishi, Aidan F. Pierce | [29] |

The first period-23 oscillator discovered. | ||||

2 | 66 | Spider synthesis | Martin Grant, Goldtiger997, Tanner Jacobi, et al. | [30] [31] [32] |

The first glider synthesis of a c/5 orthogonal spaceship, and the largest elementary spaceship synthesis to date. | ||||

3 | 53 | Scholar | Andrew J. Wade | [33] |

The second elementary 2c/7 orthogonal spaceship to be discovered, using a new search program named life_slice_ship_search. | ||||

=4 | 48 | 46P4H1V0 synthesis and gun | Tanner Jacobi, Matthias Merzenich, Martin Grant, Goldtiger997 | [34] [35] [36] |

The first synthesis and the first gun to produce a c/4 orthogonal spaceship. | ||||

=4 | 48 | Cheap still life syntheses | Tanner Jacobi, Goldtiger997, Jeremy Tan, Adam P. Goucher, Chris Cain, 2718281828, et al. | [37] [38] [39] [40] |

Among other things, the construction of all 17-bit still lifes in at most 16 gliders (less than one glider per bit) and all 18-bit still lifes in at most 38 gliders. | ||||

=6 | 45 | Knightwave stablization | Matthias Merzenich, Adam P. Goucher | [41] |

The discovery that Minstrel 2 can be used to support both ends of the knightwave, allowing for extensible knightships. | ||||

=6 | 45 | Remini | Michael Simkin | [42] |

A universal constructor-based puffer, made only with p30 technology theoretically available since the 1970s. | ||||

8 | 41 | Dueling banjos and p24 gun | Apple Bottom, Tanner Jacobi, Matthias Merzenich, et al. | [43] [44] [45] |

A new period-24 oscillator and resulting compact p24 gun. | ||||

9 | 39 | Slavic | Pavel Grankovskiy | [46] |

The current smallest universal-constructor based quadratic growth pattern. | ||||

=10 | 37 | 27P4H1V1 synthesis and gun | Goldtiger997, BlinkerSpawn, Entity Valkyrie, et al. | [47] [48] |

=10 | 37 | Stable glider-to-spaceship converters | Goldtiger997 | [49] [50] [51] |

Stable patterns that convert gliders into small synthesizable spaceships (crab, 25P3H1V0.2, 27P4H1V1). | ||||

12 | 36 | 66P13 | Bullet51, Aidan F. Pierce, et al. | [52] [53] [54] |

A sparky period-13 oscillator which can support wicks, bumpers, and p26 oscillators. | ||||

13 | 35 | p49 skewed pulsar hassler | Martin Grant, Jason Summers | [55] |

The first known p49 oscillator that is not a glider loop. | ||||

=14 | 34 | Phoenix agars | Alex Greason, BlinkerSpawn, Dongook Lee, and Arie Paap | [56] [57] [58] |

Oscillating patterns living on a period-2 phoenix background that emulate some bounded Rule 18 patterns. | ||||

=14 | 34 | 60-line c/10 printer | GilGil | [59] |

An easy-to-use c/10 orthogonal printer that can copy and print a picture 60 lines tall. | ||||

=16 | 33 | R49 | Entity Valkyrie, Luka Okanishi | [60] |

A useful and compact pre-Herschel turner/advancer conduit. | ||||

=16 | 33 | New gun designs | Tanner Jacobi | [61] [62] |

Clever new gun components that allow the reduction of a large number of glider guns in the small guns collection. | ||||

=16 | 33 | Systematic survey of small patterns | Nick Gotts | [63] [64] [65] |

A systematic survey of all patterns up to 9 cells, as well as a survey of all single-cluster 10-cell patterns resulting in the discovery of two record-breaking 10-celled methuselae, bunnies 10a and bunnies 10b. | ||||

=19 | 32 | 99 Bottles of Beer on the Wall | Michael Simkin | [66] |

A pattern that prints the song "99 Bottles of Beer on the Wall." | ||||

=19 | 32 | Spaghetti monster eater and Heisenburp | Martin Grant, Goldtiger997 | [67] [68] |

The first patterns capable of cleanly deleting and detecting a 3c/7 orthogonal spaceship. | ||||

21 | 29 | 47575M | Adam P. Goucher | [69] |

A record-breaking methuselah (excluding switch engine-based methuselahs) found with apgsearch. | ||||

22 | 27 | Mountain range patterns | Dean Hickerson | [70] |

Various patterns experiencing irregular growth due to complex glider interactions in a similar vein to jagged lines. | ||||

=23 | 26 | New mid-period sparkers | 2718281828, Aidan F. Pierce, Martin Grant, Dongook Lee | [71] [72] [73] [74] [75] [76] [77] |

=23 | 26 | Stably supported cyclotron gun | Goldtiger997, Paul Callahan, Adam P. Goucher | [78] |

A modification of Dean Hickerson's cyclotron which uses only stable components. | ||||

25 | 25 | 230P8 | Arie Paap | [79] |

A high-clearance p8 domino sparker that can be used to create a p32 phase shift oscillator. | ||||

26 | 23 | p250 c/10 orthogonal rake | christoph.r | [80] |

The lowest-period c/10 orthogonal rake constructed to date. | ||||

27 | 19 | Hackersaw | Gustone | [81] |

A logarithmic-growth pattern with a sawtooth-shaped population graph. |

### 2018

The following patterns were voted on for the 2018 competition. Users were able to vote on as many patterns as they wished, awarding up to three stars to each one. 77topaz organized the competition.

Final rank | Stars | Pattern | Author | Link(s) |
---|---|---|---|---|

Description | ||||

1 | 106 | Sir Robin | Adam P. Goucher, Tomas Rokicki | [82] |

A (2,1)c/6 spaceship, and the first elementary oblique spaceship discovered in Conway's Game of Life. | ||||

2 | 90 | 0E0P metacell | Adam P. Goucher | [83] |

A unit cell which does not require a background grid of metacells to function, proving the existence of unusual classes of patterns such as quadratic replicators and RROs in Conway's Game of Life "imported" from other rules. | ||||

3 | 79 | Reverse caber-tosser | Adam P. Goucher, Dave Greene, Chris Cain | [84] |

A complex mechanism which theoretically allows any glider-synthesisable pattern to be synthesised in just 35 gliders, by encoding the pattern's complexity into the distance between the gliders rather than their quantity. | ||||

4 | 52 | Turing Machine simulator | Michael Simkin | [85] |

A script which can simulate arbitrary Turing machines in Conway's Game of Life using a finite tape. | ||||

5 | 45 | Camelship | Chris Cain | [86] |

A self-constructing oblique spaceship with the minimum possible step size for a slope 3 spaceship. | ||||

=6 | 41 | New self-constructing spaceships | Dave Greene | [87] |

A loopship, along with HashLife-friendly variants of Orthogonoid and Demonoid. | ||||

=6 | 41 | c/2 diagonal telegraph recipe | Martin Grant | [88] |

A 140-glider recipe to create a detectable c/2 diagonal signal traveling non-destructively along an arbitrarily long barge or ship. | ||||

8 | 35 | Period-52 glider gun | Dave Greene, Matthias Merzenich, Adam P. Goucher, Chris Cain, Entity Valkyrie | [89] [90] [91] |

The first true-period 52 gun constructed, which was later vastly reduced using 53P13. | ||||

9 | 34 | Stable line crosser | Dave Greene, Goldtiger997, Chris Cain | [92] |

A modernized rehash of a periodic circuit for transmitting a glider across a diagonal line of cells found by David Bell. | ||||

=10 | 33 | Jormungant's G-to-H | Louis-François Handfield (Jormungant) | [93] |

A 2G-to-H converter with a short recovery time, allowing for the optimization of numerous guns. | ||||

=10 | 33 | Period-33 glider gun | Arie Paap, Matthias Merzenich | [94] |

The first true-period 33 gun, which uses two interacting copies of Jason's p33. | ||||

=10 | 33 | Infinite distinct diagonal spaceships and infinite distinct orthogonal spaceships | Adam P. Goucher, Goldtiger997 | [95] [96] |

Two guns which each use sqrtgun mechanisms to fire infinitely many distinct spaceships, all of which are puffers whose outputs are eaten by spaceships arbitrarily far away. | ||||

=13 | 31 | Sierpinski triangle generator | Luka Okanishi | [97] |

A breeder that outputs gliders in the shape of a growing Sierpinski triangle. | ||||

=13 | 31 | Cottonmouth | AforAmpere | [98] |

An infinitely extensible pushalong for the copperhead and fireship. | ||||

=13 | 31 | 5c/9 signal injector | Rhombic, Simon Ekström, Chris Cain | [99] |

A method of transforming Herschels to 5c/9 drifters with a recovery time of 62. | ||||

16 | 30 | p46 gliderless LWSS gun | Nathaniel Johnston | [100] |

The smallest known gliderless LWSS gun, using three copies of Tanner's p46. | ||||

=17 | 29 | Bronco | Tanner Jacobi | [101] |

The second elementary glider-to-Herschel converter to be discovered. | ||||

=17 | 29 | New high-period oscillators | carybe | [102] [103] [104] [105] |

A collective entry for p36 shuttle, 34P14 shuttle, 68P16, and p64 thunderbird hassler, all discovered using apgsearch. | ||||

19 | 28 | Quinti-Snarks | Tanner Jacobi | [106] |

Period-quintupling reflectors useful for guns. | ||||

20 | 27 | Pseudo-period xWSS guns | Chris Cain, Adam P. Goucher, Entity Valkyrie, 2718281828, Goldtiger997 | [107] |

New xWSS guns with pseudo-periods ranging from 18 to 21, breaking the previous record of 22. | ||||

21 | 26 | Self-constructing oscillator with strict volatility one | Dave Greene, Goldtiger997 | [108] |

A method of constructing strictly volatile oscillators with any period 3,506,910 or above. | ||||

22 | 25 | p3 bumper | Arie Paap, Tanner Jacobi | [109] |

A periodic reflector to work at p39, which also allowed for the construction of a p57 bumper loop | ||||

=23 | 24 | Goldtiger997's Amazing 2 in 1 Reusable Multipurpose Minstrel Remover and Detector™ | Goldtiger997 | [110] |

A circuit capable of removing every known Minstrel from Sir Robin at the time of its construction. | ||||

=23 | 24 | New mid-period sparkers | Dongook Lee, Josh Ball, Martin Grant, Aidan F. Pierce, carybe, Bullet51 | [111] [112] [113] [114] [115] [116] [117] [118] |

A collective entry for various sparking oscillators with periods ranging from 7 to 10, including but not limited to 68P9 and 55P10. | ||||

=25 | 23 | Minstrel 4 | Entity Valkyrie | [119] |

A manually-assembled Sir Robin tagalong which combines Minstrels 1 and 3. | ||||

=25 | 23 | Period-doubling fireship tagalong | christoph.r | [120] |

A tagalong for a flotilla of three fireships which increases its period to 20. | ||||

27 | 22 | p4 bouncer | Arie Paap, Noam Elkies | [121] |

The fastest known p4 reflector. | ||||

28 | 21 | Huge 2D-extensible wick-supporting pushalong | Hartmut Holzwart | [122] |

29 | 20 | Non-monotonic 2c/5 orthogonal spaceship | Arie Paap, Matthias Merzenich, Bullet51 | [123] |

=30 | 19 | p9 bouncer | Matthias Merzenich, carybe, Noam Elkies | [124] |

A reflector capable of reflecting a p27 glider stream using 68P9, which was found using apgsearch the same day. | ||||

=30 | 19 | p6 180-degree reflector and related guns | Arie Paap, Tanner Jacobi, Louis-François Handfield | [125] [126] |

A reflector which can be used alongside other sparkers to create arbitrary guns with period (60n+30). | ||||

32 | 18 | Fast universal regulators | Dave Greene | [127] |

33 | 17 | 42883M | Adam P. Goucher | [128] |

A 16×16 soup found by apgsearch, and the longest-lasting known methuselah fitting within a 16×16 bounding box. | ||||

34 | 10 | New honey farm hasslers | Tanner Jacobi, Matthias Merzenich | [129] [130] [131] |

A collective entry for a few oscillators of periods 36 and 40 which use honey farm-hassling reactions. |

### 2017

The following patterns were voted on for the 2017 competition. Users were able to vote on as many patterns as they wished, awarding up to three stars to each one. Adam P. Goucher organized the competition.

Final rank | Stars | Pattern | Author | Link(s) |
---|---|---|---|---|

Description | ||||

1 | 50 | 2-engine Cordership | Aidan F. Pierce | [132] |

A successful refutation of the common belief that 3 engines are required to build a Cordership. | ||||

2 | 34 | Tanner's p46 | Tanner Jacobi | [133] |

A new sparky period-46 oscillator that various guns can be made from. | ||||

3 | 32 | Stable pulse-dividers | Tanner Jacobi | [134] [135] [136] |

The Snark and semi-Snark have been joined by new exciting tremi-Snark, quadri-Snark, and semi-cenarks, which are particularly helpful for optimising glider and spaceship guns. | ||||

4 | 29 | New Demonoid and Orthogonoid spaceships | Dave Greene, slmake | [137] [138] |

Geminoid variants which travel diagonally and orthogonally, respectively, showcasing interesting developments such as MWSS-based signalling and syringe syntheses. | ||||

5 | 27 | The efficient 16-bit still life synthesis project | Chris Cain, BlinkerSpawn, Luka Okanishi, Martin Grant, Matthias Merzenich, Bob Shemyakin, et al. | [139] [140] |

All still-lifes of 16 or fewer cells can be constructed at a cost of <= 1 glider per cell. | ||||

6 | 26 | Synthesis of 25P3H1V0.2, and reductions of many other small spaceships | Martin Grant, Chris Cain, 2718281828, gmc_nxtman, et al. | [141] [142] [143] [144] |

=7 | 24 | Sparse Cordership | David Bell | [145] |

All previously-known Corderships required interactions between two or more adjacent switch engines. This design, on the other hand, allows the individual switch engines to be separated by arbitrary distances, relying instead on long-range interactions mediated by gliders and stable objects. | ||||

=7 | 24 | Hydra | Oscar Cunningham, Dave Greene, slmake | [146] |

A single-channel quadratic-growth pattern which constructs an intricate mesh of splitting construction heads in all directions. Some well-positioned eaters prevent this behemoth from cannibalising itself. It uses similar technology to Dave's earlier triple wickstretcher, but is more complex owing to the necessity of splitting signals. | ||||

9 | 22 | Three-glider synthesis of a switch engine | Luka Okanishi | [147] |

It was previously believed that 4 gliders were necessary and sufficient to synthesise a switch engine. | ||||

10 | 21 | Synthesis of N-bit still lifes in 38 to 39 gliders |
Tanner Jacobi, Adam P. Goucher, Chris Cain | [148] [149] |

Syntheses of N-bit still lifes for all sufficiently large natural numbers N, using a bounded number of gliders (38 or 39, depending on the parity of N).
| ||||

11 | 18 | Life object having a bounded population with an unknown fate | David Bell | [150] |

A pattern which either becomes stable, oscillatory, or aperiodic, depending on the behaviour of 7 under the generalised Collatz iteration which maps a positive integer N to 5N+1 (if N odd) or N/2 (if N even).
| ||||

=12 | 17 | Completed Quest for Tetris challenge | PhiNotPi, El'endia Starman, K Zhang, Muddyfish, Kritixi Lithos, Mego, Quartata, et al. | [151] |

A game of Tetris simulated on a digital computer built out of logic gates formed from Brice Due's metacells. | ||||

=12 | 17 | Gliderless unit cell | Peter Naszvadi | [152] |

A cellular automata polyglot (pattern which runs in a range of rules) based on p46 technology, establishing Turing-completeness of B3[8]/S23[8] provided infinite patterns are permitted. | ||||

=12 | 17 | Garden of Eden 11 | Steven Eker | [153] |

An orphan with 45 live cells and 43 dead cells, the fewest total number of specified cells among all known orphans. | ||||

15 | 16 | Several new stable signal converters | Dave Greene, Goldtiger997 | [154] |

16 | 15 | 339P7H1V0 | Matthias Merzenich | [155] |

The narrowest odd-symmetric c/7 spaceship, and the second known elementary c/7 spaceship, after the loafer. | ||||

17 | 14 | Much smaller spiral growth pattern | Dave Greene, slmake | [156] |

A tightly-coiled loop of data reflected in a double-spiral of Snarks instructs a construction arm to encircle the construction indefinitely, gradually constructing an unbounded spiral of further Snarks. | ||||

18 | 13 | p148 B29 gun | Luka Okanishi, Dave Greene, Adam P. Goucher | [157] |

A compact gun for a c/4 diagonal spaceship. | ||||

=19 | 12 | Cumulative sum generator | gameoflifeboy | [158] |

=19 | 12 | Triple wickstretcher | Dave Greene | [159] |

A single-channel glider loop which extends zigzags of Snarks. | ||||

=19 | 12 | The first 3c/7 orthogonal puffer | Luka Okanishi | [160] |

Exclusively using 3c/7 spaghetti monsters (the only known spaceship of its velocity). Owing to its faster-than-c/4 speed, a c/2 spaceship is necessary to catch up with the front of the engine to continue the reaction. | ||||

22 | 11 | The first c/6 orthogonal puffers | Nico Brown, Matthias Merzenich | [161] |

Messy albeit elegant puffers where gliders collide with large sparky spaceships in perpetuity. | ||||

23 | 9 | Fixed-length tail for a lightspeed bubble of arbitrary width in the zebra stripes agar | Arie Paap | [162] |

Gabriel Nivasch showed that arbitrary-width lightspeed bubbles in the zebra stripes agar are supportable, requiring a fixed-length head and variable-length tail. It was hitherto an open problem to replace the variable-length tail with a fixed-length counterpart. | ||||

24 | 7 | 28P7.3 | Bullet51 | [163] |

The smallest known (tied with previous record) period-7 oscillator. | ||||

25 | 6 | Runny nose | 83bismuth38 | [164] |

A period-3 oscillator which showed an unexpected gap in lists of small objects. |

### 2016

The following patterns were voted on for the 2016 competition. Users were able to vote on as many patterns as they wished, awarding up to three stars to each one. Alexey Nigin organized the competition.

Final rank | Stars | Pattern | Author | Link(s) |
---|---|---|---|---|

Description | ||||

1 | 49 | Caterloopillars | Michael Simkin, David Bell et al. | [165] |

Previously, all engineered spaceships had speeds that were either fixed (Caterpillar) or adjustable but always very low (Gemini). Caterloopillars have the best of both worlds: their speed is variable, and the fastest ones can travel as quickly as c/4. So far all caterloopillars have been orthogonal, but a project to build one with adjustable slope is underway. | ||||

2 | 47 | Copperhead | zdr, Simon Ekström et al. | [166] [167] |

In addition to being the first of its speed, this c/10 orthogonal spaceship is so small that it is surprising nobody discovered it before. Its small size allowed the creation of a 22-glider synthesis, and a gun was made soon afterwards. A pseudo-tagalong known as the fireship found a bit later made it possible to create c/10 puffers and rakes. Much of copperhead's fame is due to the mystery surrounding its discovery: it was posted by a newly-joined anonymous user who became inactive afterwards. | ||||

3 | 39 | Grandfather-less Pattern | mtve | [168] |

"Is there a configuration which has a father but no grandfather?" This is the statement of the grandfather problem, one of the longest-standing open problems in Life, having been unsolved for decades in spite of a $50 prize offer from John Conway Himself in September 1972. It was only this year that the first grandfather-less pattern was discovered using a SAT solver. | ||||

4 | 31 | Spaghetti monster | Tim Coe | [169] |

This is the first spaceship with a speed of 3c/7, which has been one of the most sought-after speeds in the last 15 years. The ship was discovered with knightt, a relatively new search program. The search took about two months, even though the width was continuously tweaked to make it faster. | ||||

5 | 28 | 8-bit computer | Coban | [170] |

This is the first 8-bit computer in any cellular automaton, and easily the most realistic computer ever constructed in Life. It has a ROM which contains the program, consisting of 32 instructions which are stored in 21 bits each. For RAM, it has a register bank containing eight 8-bit registers. For output, it has a "printer" with 8 pixels. | ||||

6 | 19 | Herschel splitter | Luka Okanishi | [171] |

This is an elegant solution to an old circuitry problem: a direct Herschel signal splitter that recovers in less than a hundred ticks. People had been looking for something exactly like this for very nearly twenty years, ever since the original 1996-97 universal set of Herschel conduits. It was made by extending an Fx119 conduit with a partial copy of itself to extract the second Herschel output. | ||||

7 | 14 | Bumper | Tanner Jacobi | [172] |

This reflector mechanism can be attached to a variety of sparky oscillators to make reflectors of the corresponding periods. Since the resulting reflectors have different timing than the Snark, they solve a range of "my glider is in the wrong phase" wiring problems. A small wave of record-breaking guns followed soon after the bumper's debut. | ||||

=8 | 12 | New gun periods | Luka Okanishi, thunk, Matthias Merzenich, Chris Cain | [173] [174] [175] |

In three days, three new true gun periods were discovered: p61, p58, and p57. | ||||

=8 | 12 | Statorless p5 | Josh Ball | [176] |

This is the first statorless oscillator of its period. Since the period is prime, the lack of stator implies that the oscillator is strictly volatile, which is a rare property. | ||||

10 | 11 | Aperiodic tiles | NotLiving | [177] |

This is an implementation of a particular set of [Wang tiles] in the Game of Life. The Life tiles form a stable pattern if and only if the corresponding arrangement of Wang tiles is valid. Since this set of Wang tiles can only form aperiodic arrangements, so can the Life tiles. | ||||

11 | 10 | Rich's p16 | Rich Holmes | [178] |

This is a small p16 oscillator that appeared naturally. It is compact for its period and has easily accessible sparks. Most notably, it can filter glider streams similarly to the blocker, which led to reductions in many guns that previously utilized other filter mechanisms. | ||||

12 | 9 | Small GoEs | Steven Eker | [179] [180] |

A few record-breaking Gardens of Eden and orphans were found, including an orphan with only 89 defined cells. | ||||

=13 | 6 | 15-bit still life syntheses | BlinkerSpawn, Goldtiger997, Bob Shemyakin, Mark Niemiec, Martin Grant, Chris Cain, et al. | [181] [182] |

A project to find syntheses of all 15-bit still lifes in under 15 gliders turned out to be a very prolific collaboration. Using Catagolue soups along with known and new converter mechanisms, several hundred new syntheses were created. The goal was achieved in just 41 days. | ||||

=13 | 6 | p7 sparker | Dongook Lee | [183] |

This pattern adds a new relatively strong heavyweight emulator to the p7 collection, which previously only had the pipsquirter. It was used to complete a p28 wick with no prior stabilization. |

### 2015

The following patterns were voted on for the 2015 competition. Users chose as many pattern as they wanted and ranked them from best to worst; the votes were then tallied with a custom Delphi program.^{[1]} Alexey Nigin organized the competition.

Final rank | Points | Pattern | Author | Link(s) |
---|---|---|---|---|

Description | ||||

1 | 107 | Syringe | Tanner Jacobi | [184] |

Syringe is the fast G-to-H that Herschel plumbers have been wishing for a decade, also allowing for fast signal splitters and other much more efficient logic circuits, including self-constructing circuitry. | ||||

2 | 102 | Simkin glider gun | Michael Simkin | [185] |

The Simkin glider gun is the smallest gun ever constructed. The previous record holder, the Gosper glider gun, was constructed as long ago as 1970. | ||||

3 | 91 | Demonoids | Chris Cain and Dave Greene | [186] [187] |

Demonoids are highly-simplified, diagonally-moving variants of the original Gemini spaceship. The 0hd Demonoid is the only case where a spaceship gun pattern was completed before the actual spaceship. | ||||

4 | 55 | Syntheses of spaceships | Martin Grant, Tanner Jacobi, and Chris Cain | [188] [189] [190] [191] [192] [193] [194] [195] [196] |

Syntheses of B29, X66, half-X66 with HWSS, Pushalong 1, 25P3H1V0.2, 30P5H2V0, 30P4H2V0.4, a pufferfish spaceship, and the weekender were discovered in 2015, which exceeds the number of spaceship syntheses found in any previous year, including 1970. | ||||

5 | 48 | Recursive filter | Alexey Nigin and Kiran Linsuain | [197] |

Recursive Filter allows the creation of extremely slow-growing patterns. A single recursive filter gives the growth rate of log*(t), which is slower than the growth rate of any pattern constructed before. Recursive filters can be stacked to obtain even more mind-boggling growth rates. | ||||

6 | 45 | Glider-to-Weekender | Chris Cain | [198] |

G-to-Weekender splits a single input glider into 82 separate signals, and successfully synchronizes them to produce an output weekender spaceship. The previous record synchronization was Goucher's glider-to-Cordership converter, which produced 19 synchronized gliders from one input signal. | ||||

7 | 34 | Bob Shemyakin's syntheses | Bob Shemyakin | [199] |

Bob Shemyakin's syntheses are often cheaper than what could be found in Mark Niemiec's database (and those were already pretty good). This was the result of a lot of patient script-writing and collecting collision results, starting with adding two gliders (within a certain range) to every possible two-glider collision. Many new 4-, 5-, and 6-glider still life recipes were found, and optimizations for many larger still lifes up to 15 bits. | ||||

8 | 33 | HBK gun | Chris Cain and Michael Simkin | [200] |

HBK gun is an extremely large and complex gun that fires parallel HBKs. It is the only gun to produce non-self-constructing macro-spaceships. | ||||

9 | 31 | Herschel-to-MWSS | Tanner Jacobi | [201] |

H-to-MWSS is the smallest converter of Herschels into (non-glider) standard spaceships. Prior constructions of XWSSs required many Herschel tracks and a large area. | ||||

10 | 30 | Sawtooth 177 | thunk, Tanner Jacobi, Chris Cain, Adam P. Goucher, and Dave Greene | [202] |

Sawtooth 177 is currently the smallest known sawtooth. | ||||

11 | 29 | Single-lane construction arm toolkit | Simon Ekström | [203] |

The Single-Lane Construction Arm Toolkit is an important result for simplifying self-constructing circuitry, especially those where a recipe needs to be duplicated, as in the linear propagator, not just interpreted as in the Demonoid and Gemini. | ||||

12 | 28 | Elementary conduits collection | Matthias Merzenich, Dave Greene, and thunk | [204] |

The Elementary Conduits Collection, recently significantly expanded with new discoveries, is a one-stop shop for the building blocks of stable tracks. It was organized to catalogue all converters between likely active reactions, not just from Herschel to Herschel. | ||||

13 | 26 | (L|M)WSS-to-glider | Ivan Fomichev and Dongook Lee | [205] |

(L|M)WSS-to-G is the second known small conduit that turns standard spaceships into gliders, and the first that accepts LWSSs. | ||||

14 | 23 | Collection of guns | Chris Cain, Simon Ekström, Scot Ellison, and Dave Greene | [206] |

The Collection of Guns is an ambitious project to collect new smaller glider guns using the syringe and other recent discoveries. All guns in the range 78-999 were eventually reduced to bounding boxes less than 8000 cells. | ||||

15 | 19 | Dragon lightsaber | Martin Grant | [207] |

Dragon Lightsaber is a mysterious pattern that seems to calculate some sequence. It is this type of a lightsaber. | ||||

16 | 14 | Quadratic sawtooth | Martin Grant, Aidan F. Pierce, Dongook Lee, and Alexey Nigin | [208] |

Quadratic sawtooth is a sawtooth whose population peaks grow quadratically. | ||||

17 | 13 | t*log(log(t)) growth | Alexey Nigin and Michael Simkin | [209] |

t*log(log(t)) growth is pattern with an exotic growth rate. That growth rate has long been achievable via exponential filters, but this pattern utilizes a completely different design. |

### 2014

Initial entries • Belated entries • Belated voting • Results

The following patterns were submitted as competition entries by users in early 2016. Patterns were not voted on at the time, but a belated vote was held in early 2018, featuring three further submissions in addition to the original nine. Kiran Linsuain organized the 2016 competition; 77topaz organized the 2018 vote.

Final rank | Stars | Pattern | Author | Link(s) |
---|---|---|---|---|

Description | ||||

1 | 30 | Waterbear | Brett Berger and Ivan Fomichev | [210] |

The first fast oblique spaceship, moving at speed (23,5)c/79. | ||||

2 | 23 | Centipede | Chris Cain | [211] |

A large, engineered spaceship that moves at 31c/240, using a unique reaction. | ||||

3 | 21 | Half-baked knightship | Adam P. Goucher, Chris Cain, Dave Greene, and Ivan Fomichev | [212] |

An oblique spaceship that moves with displacement (6,3), using the half-bakery reaction. | ||||

=4 | 17 | Switch engine ping-pong | Michael Simkin | [213] |

A 23-cell quadratic growth pattern, the smallest known. | ||||

=4 | 17 | Syntheses for all 17- and 18-bit still lifes | Martin Grant, Mark Niemiec, and Matthias Merzenich | [214] [215] |

Note: Some of the 18-bit syntheses were later found to be invalid, and the project was not completed for real until 2019.^{[2]}
| ||||

=6 | 13 | Pufferfish | Richard Schank | [216] |

A period 12 c/2 puffer that was used to make the first wholly high-period c/2 spaceship. | ||||

=6 | 13 | Spiral growth | Dave Greene | [217] |

A self-constructing pattern that grows in an outward spiral. | ||||

=8 | 12 | Dart and crab syntheses | Martin Grant, Mark Niemiec, Michael Simkin, Ivan Fomichev, Tanner Jacobi, and Brett Berger | [218] [219] |

Glider syntheses for small spaceships that did not previously have any. | ||||

=8 | 12 | Weekender distaff | Ivan Fomichev | [220] |

The first 2c/7 orthogonal rake, consisting of a long chain of weekenders perturbing debris. | ||||

10 | 8 | Honey thieves^{†} |
Matthias Merzenich | [221] |

The smallest known period-17 oscillator, and the first one with a known glider synthesis. | ||||

11 | 7 | p27 billiard table oscillator^{†} |
Matthias Merzenich | [222] |

An oscillator in which period 5, period 8 and period 3 rotors phase shift each other. | ||||

12 | 6 | LCM oscillators^{†} |
Noam Elkies | [223] |

Oscillators featuring multiple rotors that interact in complicated ways. |

^{†}not originally submitted in 2014.

### 2013

No competition was initially held in 2013. However, it was mentioned in various places that the winner for 2013 was clearly Mike Playle's Snark^{[3]}^{[4]}, with no particular need for a formal vote. A belated vote was organized in early 2018 by 77topaz. The following patterns were submitted as competition entries by users.

Final rank | Stars | Pattern | Author | Link(s) |
---|---|---|---|---|

Description | ||||

1 | 34 | Snark | Mike Playle | [224] |

A stable 90˚ glider reflector which, with 52 cells and a repeat time of 43, is both far smaller and far faster than previous such patterns. | ||||

2 | 31 | Loafer | Josh Ball | [225] |

The first c/7 orthogonal spaceship and, with just 20 cells, the smallest spaceship other than the glider and xWSSes. | ||||

=3 | 22 | CC semi-Snark | Sergey Petrov | [226] |

A small, Spartan 90˚ glider reflector which functions as a period doubler. | ||||

=3 | 22 | Linear propagator | Dave Greene | [227] |

A large, engineered pattern which is arguably the first example of a replicator in Conway's Game of Life, depending on the exact definition used. | ||||

5 | 17 | Original 16-bit still life synthesis project | Martin Grant, Mark Niemiec, Matthias Merzenich, Dave Greene | [228] |

A project to synthesize all 16-bit still lifes. | ||||

6 | 15 | Period-20 glider gun | Matthias Merzenich | [229] |

A true period-20 glider gun, the smallest true period known for a gun. | ||||

7 | 14 | 135-degree MWSS-to-G | Matthias Merzenich | [230] |

The first fast elementary MWSS-to-glider converter. | ||||

8 | 11 | Period-40 glider gun | Adam P. Goucher, Matthias Merzenich, Jason Summers | [231] |

A true period-40 glider gun based on complicated reactions involving honey farm predecessors, period-5 and period-8 oscillators. | ||||

=9 | 9 | AK-94 and Pre-pulsar shuttle 22 | Mike Playle, Matthias Merzenich | [232] [233] |

Two constructions based on a new catalyst found by Mike Playle. | ||||

=9 | 9 | Standard spaceship eater | Matthias Merzenich | [234] |

A still life capable of eating every type of standard spaceship. | ||||

=11 | 8 | p29 reflector | Matthias Merzenich, Noam Elkies, David Buckingham | [235] |

A reflector based on a Pre-pulsar shuttle 29 variant. | ||||

=11 | 8 | c/4 diagonal wickstretcher | Matthias Merzenich, Jason Summers, Paul Tooke | [236] |

A fencepost for a partial c/4 diagonal wickstretcher found by Paul Tooke in 2004. | ||||

13 | 7 | c/5 orthogonal wickstretcher | Matthias Merzenich, Hartmut Holzwart, Jason Summers | [237] |

The first c/5 orthogonal wickstretcher to be found. | ||||

14 | 5 | French kiss synthesis | Martin Grant | [238] |

A 23-glider synthesis for a period-3 oscillator which, despite its size, previously had no known synthesis. | ||||

=15 | 4 | 41P4H1V0 | Jason Summers | [239] |

At the time of its discovery, the second smallest known c/4 orthogonal spaceship. | ||||

=15 | 4 | 138P7 | Karel Suhajda | [240] |

A fairly strong period-7 sparker, at a time when few were known. It was used to create a period-14 traffic light hassler. |

### 2012

No vote was held for 2012, but the following patterns were submitted as competition entries by users. 137ben organized the competition.

Pattern | Author | Link(s) |
---|---|---|

Description | ||

37P4H1V0 | Josh Ball | [241] |

A 37-cell c/4 orthogonal spaceship by Josh Ball. In terms of minimum population, it is the smallest known c/4 orthogonal spaceship. | ||

Statorless p3 | Jason Summers | [242] |

The first statorless period-3 oscillator. | ||

444-tick glider-to-Herschel converter | Sergey Petrov | [243] |

This is the fastest known stable glider-to-Herschel converter/90-degree glider reflector currently known. | ||

G4 Herschel merge circuit | Sergey Petrov | [244] [245] [246] |

Ambidextrous G5 Herschel transceiver | Sergey Petrov | [247] [248] |

Period-4 90-degree reflector | Karel Suhajda, Matthias Merzenich | [249] |

### 2011

The following patterns were voted on for the 2011 competition. Users were able to vote for up to three patterns, but not their own patterns; all votes were weighted equally. Adam P. Goucher organized the competition.

Final rank | Votes | Pattern | Author | Link(s) |
---|---|---|---|---|

Description | ||||

=1 | 10 | Fully universal Turing machine | Paul Rendell | [250] |

An extension of the Universal Turing machine and Turing machine, also by Paul Rendell. | ||||

=1 | 10 | Lobster | Matthias Merzenich | [251] |

A c/7 diagonal spaceship found using WinLifeSearch. | ||||

3 | 7 | Garden of Eden 6 | Marijn Heule, Christiaan Hartman, Kees Kwekkeboom, and Alain Noels | [252] |

A small (10×10), rotationally symmetric garden of Eden whose orphan requires only 92 cells to specify. | ||||

=4 | 6 | Collection of new stable technology | Sergey Petrov | [253] [254] |

=4 | 6 | Oblique antstretcher | Matthias Merzenich | [255] |

An antstretcher combining a c/5 orthogonal component with a c/4 diagonal component previously found by Hartmut Holzwart in 2006. | ||||

=6 | 5 | 1×N quadratic growth | Stephen Silver | [256] |

The first pattern exhibiting quadratic growth that starts with the thickness of a single cell, using the breeder from Nick Gotts' 26-cell quadratic growth. | ||||

=6 | 5 | Pulsar Pixel Display | Mark Walsh | [257] |

8 | 4 | Stable HWSS Heisenburp | Sergey Petrov, Richard Schank, Martin Grant | [258] |

9 | 2 | 77P6H1V1 | Josh Ball | [259] |

The smallest known spaceship of this speed in terms of its minimum population, found using WinLifeSearch. | ||||

10 | 1 | Small moving sawtooth | cloudy197 | [260] |

### 2010

The following patterns were voted on for the 2010 competition. Users were able to vote for up to three patterns, but not their own patterns; all votes were weighted equally. Adam P. Goucher organized the competition.

Final rank | Votes | Pattern | Author | Link(s) |
---|---|---|---|---|

Description | ||||

1 | 14 | Gemini | Andrew J. Wade | [261] |

The first oblique spaceship to be constructed, with a speed of (5120,1024)c/33699586. | ||||

2 | 9 | Phi calculator | Adam P. Goucher | [262] |

A modification of Goucher's similar pi calculator to instead calculate the digits of the golden ratio. | ||||

3 | 6 | c/5 diagonal rake | Matthias Merzenich | [263] |

=4 | 5 | Pianola breeders | Paul Tooke | [264] |

A series of Gemini-inspired patterns with a growth rate in between linear and quadratic growth. | ||||

=4 | 5 | Merzenich's p31 | Matthias Merzenich | [265] |

The first known period 31 oscillator, which also has the ability to reflect gliders 90 degrees. | ||||

6 | 4 | Gemini guns | Dave Greene | [266] [267] |

=7 | 2 | Sawtooth 260 | David Bell | [268] |

Formerly the smallest known sawtooth in terms of minimum repeating population. | ||||

=7 | 2 | c/5 orthogonal greyships | Hartmut Holzwart | [269] |

9 | 1 | Period-45 glider gun | Matthias Merzenich | [270] |

The first true-period-45 glider gun to be discovered. | ||||

=10 | 0 | MWSS Heisenburp device | Martin Grant | [271] |

=10 | 0 | Beluchenko's other p37 | Nicolay Beluchenko | [272] |

The second known period 37 oscillator, and the first one with the ability to reflect gliders 90 degrees. | ||||

=10 | 0 | Flying wing spaceship | Emerson J. Perkins | [273] |

A growing spaceship which grows in both dimensions. |

## Also see

## References

- ↑ Alexey Nigin (February 11, 2016). "Re: Pattern of the Year 2015 (Votes)".
*ConwayLife.com forums*. Retrieved on July 20, 2017. - ↑ Ian07 (October 9, 2019). Re: 18-bit SL Syntheses (100% Complete!) (discussion thread) at the ConwayLife.com forums
- ↑ Emerson J. Perkins (April 26, 2013). "Re: Just the place for a Snark!". Retrieved on February 5, 2018.
- ↑ Dave Greene (January 1, 2016). "Re: Pattern of the Year 2015 (Entries)". Retrieved on February 5, 2018.