Snark

Snark
14b2o$14bobo$16bo4b2o$12b4ob2o2bo2bo$12bo2bobobobob2o$15bobobobo$16b2o bobo$20bo2$6b2o$7bo7b2o$7bobo5b2o$8b2o7$18b2o$18bo$19b3o$21bo7$3o$2bo$ bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART ]] #C [[ WIDTH 600 HEIGHT 600 X 4 Y -4 THUMBSIZE 3 ZOOM 21 GPS 30 LOOP 128 ]]
View static image
Pattern type	Stable reflector
Number of cells	52
Bounding box	23 × 17
Angle	90°
Repeat time	43
Discovered by	Mike Playle
Year of discovery	2013
Rules Outer-totalistic rules B3/S23 – B38/S238 # of rules 22 = 4 Isotropic rules B3/S23 – B34c8/S234c5e6n8
Glider synthesis Fewest gliders 21† Catagolue-generated RLE synthesis Uploaded synthesis RLE snark_synth.rle †Can be constructed with 15 gliders using the reverse caber tosser universal constructor.
Pattern files Plaintext snark.cells RLE snark.rle
Identifiers apgcode xs49_wc9b88gy9o8zg88mlldxooy3321z11074zy5c453

The Snark is a 90° stable glider reflector discovered by Mike Playle on April 25, 2013. It is made up of two eater 1s, a block and a 31.4, the "heart" of the Snark. It is currently the fastest and the smallest 90° stable glider reflector, both in terms of the population and the bounding box. Another commonly-used stabilization of the catalyst is 34 bits, and many other variants are available. For a color-changing one, see the reflector in the stable reflector article, or a periodic bouncer.

#C four Snark catalyst variants #C Top: original variant by Mike Playle #C Left: Shannon Omick (better clearance on a diagonal) #C Right: Heinrich Koenig (better clearance on a different diagonal) #C Bottom: Simon Ekström (better clearance on two diagonals) x = 51, y = 52, rule = B3/S23 20b2o$20bobo$22bo4b2o$18b4ob2o2bo2bo$18bo2bobobobob2o$21bobobobo$22b2o bobo$26bo2$12b2o$13bo7b2o$13bobo5b2o$14b2o25bo$39b3o$38bo$38b2o3$46b2o $24b2o21bo$24bo22bob2o$14b3o8b3o11b2o4b3o2bo$4bo11bo10bo11b2o3bo3b2o$ 2b5o8bo5b2o21b4o$bo5bo13bo8b2o15bo$bo2b3o12bobo7bobo12b3o$2obo15b2o8bo 13bo$o2b4o21b2o14b5o$b2o3bo3b2o11bo22bo2bo$3b3o4b2o11b3o22b2o$3bo22bo$ 2obo21b2o$2ob2o3$11b2o$12bo$9b3o$9bo25b2o$28b2o5bobo$28b2o7bo$37b2o2$ 24bo$23bobob2o4b2o$23bobobobo2bo2bo$22b2obobobo3b2o$23bo2b2ob4o$23bo4b o3bo$24b3obo2bo$26bobobo$29bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBLAUNCH THUMBSIZE 2 ZOOM 8 HEIGHT 480 THEME Book GRID GRIDMAJOR 0 STARTFROM 232 ]]

Four Snark catalyst variants: top: Mike Playle (original variant); left: Shannon Omick (better clearance on a diagonal); right: Heinrich Koenig (better clearance on a different diagonal); bottom: Simon Ekström (better clearance on two diagonals) (click above to open LifeViewer) RLE: here Plaintext: here

The base reaction was discovered by Dietrich Leithner about 1998, but it consumed another block. A catalyst that could restore the block was found with Bellman, a program for searching catalytic reactions developed by Mike Playle. Prior to that, some attempts like p4 reflector were made with periodic sparkers.

Given its small repeat time, the Snark enabled adjustable glider loop oscillators of previously unknown periods of 43 and 53 to be constructed. It also made most large symmetrical Herschel loop guns obsolete, since it is now possible to make use of the Herschel gliders with a shorter path of the Herschel track itself.

The Snark was voted Pattern of the Year for 2013 in a belated vote held on the ConwayLife.com forums.

While the repeat time is 43, a continuous period-38 stream triples the period to 114, while a continuous period-41 stream quadruples the period to 164. A period-42 stream creates an extraneous honey farm, which can be deleted with a block, doubling the period to 84; this was used in a previous version of the smallest period-84 glider gun.

See also

• Boojum reflector
• Bandersnatch
• Semi-Snark
• Snarkmaker
• Snarkbreaker
• p43 Snark loop

External links

• Snark at the Life Lexicon
• Snark at Adam P. Goucher's Catagolue (pseudo-object)