Gosper glider gun

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Gosper glider gun
24bo11b$22bobo11b$12b2o6b2o12b2o$11bo3bo4b2o12b2o$2o8bo5bo3b2o14b$2o8b o3bob2o4bobo11b$10bo5bo7bo11b$11bo3bo20b$12b2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART ]] #C [[ THUMBSIZE 2 GPS 10 ZOOM 16 ]]
Pattern type Gun
Number of cells 36
Bounding box 36 × 9
Period 30
Barrels 1
Discovered by Bill Gosper
Year of discovery 1970

The Gosper glider gun is the first known gun, and indeed the first known finite pattern with unbounded growth, found by Bill Gosper in November 1970.[1] It consists of two queen bee shuttles stabilized by two blocks.

Its 36 cells remained the smallest population of any known gun until the discovery of the double-barreled Simkin glider gun in 2015 which overtook this record with only 29 cells. But in terms of bounding box Gosper glider gun is outright the smallest. In 1971, Charles Corderman found a small predecessor of Gosper glider gun that has only 21 cells.[2]

There are two other ways in which queen bees can interact to form gliders,[3] and a third queen bee can be used to reflect a glider and make a "pseudo-Gosper gun".[4] See period-30 glider gun for more information.

A 13-glider synthesis of the Gosper glider gun was found no later than February 1971, and was featured in Martin Gardner's second column on Conway's Game of Life after being submitted by Robert Wainwright.[5] An 8-glider synthesis was later found, which remains the smallest known glider synthesis of any gun. It can be destroyed completely by 2 gliders, as shown below.

The first known semi-natural occurrence of this glider gun is a tetramer variant, which appeared on November 9, 2022, in a symmetric soup by Open Science Grid.[6]

Gallery

x = 47, y = 26, rule = B3/S23 bo$2bo$3o6$15bo$15b4o$16b4o10b2o$5b2o9bo2bo9bobo$5b2o9b4o8b3o8b2o$15b 4o8b3o9b2o$15bo12b3o$29bobo$30b2o7$45b2o$44b2o$46bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBSIZE 2 ZOOM 8 AUTOSTART GPS 10 LOOP 100 ]]
Glider destruction of the Gosper glider gun (click above to open LifeViewer)
RLE: here Plaintext: here
x = 36, y = 20, rule = B3/S23 9bo$7bobo$8b2o5$16bo$17bo$15b3o2$23bobo$21bo3bo$13bo7bo$12b4o4bo4bo8b 2o$11b2obobo4bo12b2o$2o8b3obo2bo3bo3bo$2o9b2obobo6bobo$12b4o$13bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBSIZE 2 ZOOM 8 AUTOSTART GPS 10 LOOP 120 ]]
An inline inverter inverting a glider stream (click above to open LifeViewer)
RLE: here Plaintext: here
x = 39, y = 27, rule = B3/S23 27bo$27b4o$11bo16b4o$10bobo5b2o8bo2bo5b2o$3b2o3b2o3bo14b4o5b2o$3b2o3b 2o3bo4bobob2o3b4o$8b2o3bo5b2o3bo2bo$10bobo10bo$11bo8bo2bo2$26bobo$28bo $24bo$26bo$25bo2$11b2o$11b2o4bo$2o6b2o6b5ob2o$2o5b3o5bo2b2o4bo$8b2o5b 2o8bo12bo$11b2o4bo7bo10bobo$11b2o12bo11b2o$24bo8b2o$22b2o9bobo$35bo$ 35b2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBSIZE 2 ZOOM 8 AUTOSTART GPS 10 ]]
Period-60 glider gun, or twogun, composed of two Gosper glider guns. Found by Bill Gosper (click above to open LifeViewer)
RLE: here Plaintext: here

See also

References

  1. Dean Hickerson's oscillator stamp collection. Retrieved on March 14, 2020.
  2. Robert Wainwright (December 1971). Lifeline, vol 4, page 6.
  3. Mark Niemiec (September 11, 2013). Re: It´s not a Gosper Glider Gun ! (discussion thread) at the ConwayLife.com forums
  4. Tropylium (September 26, 2013). Re: It´s not a Gosper Glider Gun ! (discussion thread) at the ConwayLife.com forums
  5. Gardner, Martin (February 1971), "On cellular automata, self-reproduction, the Garden of Eden and the game 'life'", Scientific American 224 (2): 117
  6. dani (November 9, 2022). Re: Soup search results (discussion thread) at the ConwayLife.com forums

External links