Period-20 glider gun

Period-20 glider gun
x = 68, y = 34, rule = B3/S23 2ob2o22b2o$o3bo4b4obo8b2obo2bo5b2o6b2o$b2obob2o4bo7b3obobob2o5bobob2o 3bo$2b3ob2obobobob2o2bo4bobobo8bobo2bo$o11b3ob2o6b2o4bo2b5obob3o$11o6b obo9b5o4b3o$11b2ob2obob2o4bo10b2o3b3o5b2ob2o$2b2o2b4obo3bo2bob4obo2b4o 4bo2bo3bo5b2ob2o3bobo4b2o$2b2o2bo2bo2b2obo3bo6b2o4bo3bobob3o13bob4o2bo $10bobo2bobobo2b6ob3o4bo3bo6b10o5bobo$2b2o4bobo3b2ob2o3bo5b2o4b2o3bo7b o3bo6b5o2b2o$3bo2b4obo11b5o6b2obo11bo3bob2obo4bobo$3bobo5b10o4b2o2bo5b o2bo9b2o2bo3b3o3bobo2bo$b2o2b2o2b2o9bo4b3obo6b3o8bo2b2o3bo3bo2bobob2o$ 2bobo2bobobo2b2o2bo10b2o3b3o10bo2b2o8bo3bo$o2bob3obobobo4b2o14bo9bo2bo 2bo3bo8b2o$2obo4bo5bo4bo18bo4bo3b2o2b2o2bo2bobo2bo$3bo10bo3bo18bo8bobo 4b3o2b2obobobo$3b2o10bob2o2b2o13bo2bo3bo3b2ob3o8bo2b2o$4bo2bobo2bo2b2o bo4bo13bo8bobo4b3o2b2obo$2bobobob2o2b3o2bobo3bo6bo7bo4bo3b2o2b2o2bo2bo bo$2b2o2bo8bo3bo3bo4b2ob2o2bo8bo2bo2bo3bo8b2o$6bob2o2b3o2bobo3bo6bo5bo 10bo2b2o8bo3bo$7bobo2bo2b2obo4bo10b3o10bo2b2o3bo3bo2bobob2o$3b2o10bob 2o2b2o25b2o2bo3b3o3bobo2bo$3bo10bo3bo30bo3bob2obo4bobo$2obo4bo5bo4bo 20bo6bo3bo6b5o2b2o$o2bob3obobobo4b2o8b4o9bo5b10o5bobo$2bobo2bobobo2b2o 2bo8b6o6b3o14bob4o2bo$b2o2b2o2b2o9bo6bo4bo16b2ob2o3bobo4b2o$3bobo5b10o 7bo2bo17b2ob2o$3bo2b4obo14bobo2bobo11bo$2b2o4bobo3b2ob2o7b2o4b2o12bo$ 14b2ob2o25b3o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART ]] #C [[ WIDTH 560 HEIGHT 320 ZOOM 8 GPS 10 AUTOSTART ]]
View static image
Pattern type	Gun
Number of cells	600
Bounding box	68 × 34
Period	20
Barrels	1
Discovered by	Matthias Merzenich Noam Elkies
Year of discovery	2013
Rules Outer-totalistic rules B3/S23 only # of rules 20 = 1 Isotropic rules B3/S23 only
Pattern files RLE period20glidergun.rle

Period-20 glider gun is a true period-20 glider gun that was discovered by Matthias Merzenich in 2013 and improved by Karel Suhajda, based on Elkies' true period 24 gun. Further improvements have been made since. This was the lowest-true-period gun known until the discovery of a period-16 glider gun in 2024.

Filtering the output of the gun with a blocker yields the smallest known period-40 glider gun, beating the eponymous period-40 glider gun at its own game. The further addition of Rich's p16 doubles the period again, resulting in the smallest known period-80 gun, and adding 68P32.1 on top of that doubles the period once more to 160.

x = 78, y = 43, rule = B3/S23 25bo14bo$24bobo12bobob2o$23bo2bo2b2o7bo2bobobob2o$23bob2obobo8b3o3bobo $22b2o2bobo14bobobo2bo$24b2obo2bo8b3o3bobobobo$24bo2bo10bo2b3o3bobobo$ 21b2obo2bo3bo6b2o2bo2b3ob2o$22bob2obo3bo10bobo$22bo4bo14bo$23b3o2bobo 13b3ob2o$25bo2bobo14b2obo2bo$29b3o12bo3bob2o$28b2o2b2o6b2o2bo2bobo$30b ob2o6bobob4obo4bo6b2o$31b2o11bo3bo4bobo4bo2bo2bo4b2o$26b2o5b2o6bobob3o 4bo2bo4bobo3b3o2bobo2b2o$15b2o5b2obobo4b3o6bo3bo6b4ob2obo2b3o3bobo2bo 2bo$5b2o4bo2bo2bo3bobobobob2o8b2o3bo12bobobobo2bo2bob2obobo$2o2bobo2b 3o3bobo3bo3bo2b2ob2o6b2obo11b2o3bob2o3bo3b2o2bob2o$o2bo2bobo3b3o2bob2o b4o4b2o2bo5bo2bo9bo3bo4bo2bo3bo3b2o$bobob2obo2bo2bobobobo9bobobo6b3o9b 2o7bob2obobo2bobo$2obo4bo2bo4b2o3b3o7bo2b2o3b3o8bob3obobo3bobob2ob5o$ 3bob2o3bo3bo2bo6bo14bo12bobobobob2o2bo3bo$3bo4bobobo2b2o2bobo2b3o16bo 4bo4b2obobobo3bo3bo2bo$4b5ob2obobo2b2obobob2o15bo8b2o3b2obo2bob2o3b3o$ 9bo3bo2b2o4bo4bo13bo2bo3bo2b3obo3bob2o$6bo2bo3bo3bobobob2o3bo13bo8b2o 3b2obo2bob2o3b3o$6b3o3b2obo2bob2o2bo3bo6bo7bo4bo4b2obobobo3bo3bo2bo$ 15b2obo4bo4bo4b2ob2o2bo11bobobobob2o2bo3bo$6b3o3b2obo2bob2o2bo3bo6bo5b o8bob3obobo3bobob2ob5o$6bo2bo3bo3bobobob2o3bo10b3o11b2o7bob2obobo2bobo $9bo3bo2b2o4bo4bo25bo3bo4bo2bo3bo3b2o$4b5ob2obobo2b2obobob2o27b2o3bob 2o3bo3b2o2bob2o$3bo4bobobo2b2o2bobo2b3o18bo11bobobobo2bo2bob2obobo$3bo b2o3bo3bo2bo6bo8b4o9bo5b4ob2obo2b3o3bobo2bo2bo$2obo4bo2bo4b2o3b3o8b6o 6b3o5bo2bo4bobo3b3o2bobo2b2o$bobob2obo2bo2bobobobo11bo4bo15bobo4bo2bo 2bo4b2o$o2bo2bobo3b3o2bob2ob4o7bo2bo17bo6b2o$2o2bobo2b3o3bobo4bo2bo5bo bo2bobo11bo$5b2o4bo2bo2bo4bobo6b2o4b2o12bo$15b2o6bo25b3o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ MAXGRIDSIZE 9 AUTOSTART GPS 10 THUMBSIZE 2 ZOOM 8 WIDTH 680 HEIGHT 400 ]]

The original form of the gun discovered by Matthias Merzenich in 2013 and improved by Karel Suhajda (click above to open LifeViewer) RLE: here Plaintext: here

Gallery

x = 78, y = 38, rule = B3/S23 46bo12b2ob2o$44b3o12b2ob2o3bobo4b2o$43bo22bob4o2bo$14b2ob2o24b2o12b10o 5bobo$2b2o4bobo3b2ob2o38bo10b2ob2o2b2o$3bo2b4obo28b3o16bo3bob2obobo2bo bo$3bobo5b10o18bo3bo14b2o2bob2o2bob3obo2bo$b2o2b2ob2o10bo19bo17bo4b2o 4b3o2bob2o$2bobo2bobob2obo3bo26bo12b3ob2o10bo$o2bob3obo2b2obo2b2o26bo 8bo2b2o2b2o9b2o$2obo2b3o4b2o4bo20b2o3bo4b2o2bo3bo3bo2bo2bobo2bo$3bo10b 2ob3o20bo8bobob3o2bobo2b3o2b2obobobo$3b2o9b2o2b2o2bo18b3o5bo3b3ob2o2b 2o8bo2b2o$4bo2bobo2bo2bo3bo3bo2b2o21bobob3o2bobo2b3o2b2obo$2bobobob2o 2b3o2bobo2b3obobo21b2o2bo3bo3bo2bo2bobo$2b2o2bo8b2o2b2ob3o3bo5b3o18bo 2b2o2b2o9b2o$6bob2o2b3o2bobo2b3obobo8bo20b3ob2o10bo$7bobo2bo2bo3bo3bo 2b2o4bo3b2o20bo4b2o4b3o2bob2o$3b2o9b2o2b2o2bo8bo26b2o2bob2o2bob3obo2bo $3bo10b2ob3o12bo26bo3bob2obobo2bobo$2obo2b3o4b2o4bo17bo19bo10b2ob2o2b 2o$o2bob3obo2b2obo2b2o7b3o4bo3bo18b10o5bobo$2bobo2bobob2obo3bo4b2o10b 3o28bob4o2bo$b2o2b2ob2o10bo2bo2bob2ob3o25b2ob2o3bobo4b2o$3bobo5b10o4b 2obo2bobo25b2ob2o$3bo2b4obo14bobo2bob2o6bo$2b2o4bobo3b2ob2o7bob2o3b2o 7bo$14b2ob2o8bo2bo9b3o$28b3o$32bo$30b2ob2o11bo$29bobo15bo$29bo2bo2bo9b 3o$30bobo4bo$31b2ob4o$33bo17bo$33bobo16bo$34b2o14b3o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ GPS 10 THUMBSIZE 2 ZOOM 10 WIDTH 900 HEIGHT 500 ]]

A different period-20 gun constructed on May 17, 2021 by Matthias Merzenich based on a period-20 oscillator by wwei23 and David Raucci. The dependent p20 on the right can be replaced with a p20 T-nose if the fishhook is replaced with a boat (click above to open LifeViewer) RLE: here Plaintext: here

x = 65, y = 28, rule = B3/S23 31bo8b2o3b2o12b2o$6b2o6b2o15b3o5bo2bo2bo12bobo$5bo2bo5b2o18bo4bobo5bo 3b2ob2o2bo$o2bo2bobo24b2o3b2ob6obobobobobob2o$5obob2o27bo2bo7bobo5bobo $6bo3bo7bo4b2o8bob4o2bo2b2ob2ob2o4bobo$2b2obo4bo6b10o5bo4bo2bo2bo4b2o 5b2o2bo$bo3b2o3bo5b2ob3o10bo3bo6b2o8bo2bo3bo$bobobo4bo6b4o4bob2o3bo5bo 3bobob3o3b5o2bobob2o$2bo3bo3bo7bo3bob2o2bo3bo2bo2bo2b2o3bo2bo2bo3bobo 2b2obo$3b2obob2o18bo4b2o3b2o2b3obob2o2b4o2b2o$4bobobo13b2o3bo11bobo2bo bo2bobo4b2o$3bo2bobo5b2o10bo10bobob3o3bobo2b3o2bo$3b2o2bo6b2o6bo2bo6b 2o3b2obo7b2o4b2o$22bo9bobo5bob2o$29bo4bo5b2obo$4bob2ob2o5b3obob2o6bo3b 2o$4b2obobo8b3o7b3o$9bo2b2o4bo4bo$8bo3b4o2bo4b2o$5b2o3bo4b2o2b2o3b2o8b o$4bo3bob2o3b2o3bo3bo10bo$4bobobo6bo4b2o3b3o5b3o$3b2obob2o3bo2bo3b2o5b o$2bo2b2obo2bo2bob3o3b2o$3bo5b2obobo4b2obo16bo$4b4obo2bo2b3o2bobo17bo$ 6bobo2b2o4b2o2bo16b3o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ GPS 10 THUMBSIZE 2 ZOOM 8 ]] An even smaller period-20 glider gun by David Raucci, Martin Grant, Tanner Jacobi and Matthias Merzenich (click above to open LifeViewer) RLE: here Plaintext: here

x = 44, y = 27, rule = B3/S23 6b2o6b2o$5bo2bo5b2o$o2bo2bobo25b2o$5obob2o24b2o$6bo3bo7bo4b2o$2b2obo4b o6b10o5b4o$bo3b2o3bo5b2ob3o10bo3bo3bobo$bobobo4bo6b4o4bob2o5b2obobob2o $2bo3bo3bo7bo3bob2o2bo4bo3bobo$3b2obob2o18bo3b2o3bobob2o$4bobobo13b2o 3bo4bo4bobob2o$3bo2bobo5b2o10bo7b2o3bo$3b2o2bo6b2o6bo2bo10bobo$22bo11b 3obobo$29bo3bo3b2ob3o$4bob2ob2o5b3obob2o6bo3b2o3bo3bo$4b2obobo8b3o7b3o 5b2obo2b2o$9bo2b2o4bo4bo12bobo$8bo3b4o2bo4b2o$5b2o3bo4b2o2b2o3b2o8bo$ 4bo3bob2o3b2o3bo3bo10bo$4bobobo6bo4b2o3b3o5b3o$3b2obob2o3bo2bo3b2o5bo$ 2bo2b2obo2bo2bob3o3b2o$3bo5b2obobo4b2obo16bo$4b4obo2bo2b3o2bobo17bo$6b obo2b2o4b2o2bo16b3o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ GPS 10 THUMBSIZE 2 ZOOM 8 ]] The current smallest period-20 glider gun, by Martin Grant (click above to open LifeViewer) RLE: here Plaintext: here

External links

• Recent Discoveries, part II at Game of Life News. Posted by Adam P. Goucher on May 29, 2013.