Gosper glider gun
| Gosper glider gun | |||||||||
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| Pattern type | Gun | ||||||||
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| Number of cells | 36 | ||||||||
| Bounding box | 36 × 9 | ||||||||
| Period | 30 | ||||||||
| Barrels | 1 | ||||||||
| Discovered by | Bill Gosper | ||||||||
| Year of discovery | 1970 | ||||||||
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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
| Glider destruction of the Gosper glider gun (click above to open LifeViewer) RLE: here Plaintext: here |
| An inline inverter inverting a glider stream (click above to open LifeViewer) RLE: here Plaintext: here |
| 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 |
| 'Five and Dime' reaction with two crossing p30 glider streams, producing a p150 glider stream. Found by Bill Gosper. A temporary blinker produced in the reaction can be used to switch the p300 stream, blocked by an eater 1 in the shown pattern[7] (click above to open LifeViewer) |
See also
References
- ↑ Dean Hickerson's oscillator stamp collection. Retrieved on March 14, 2020.
- ↑ Robert Wainwright (December 1971). Lifeline, vol 4, page 6.
- ↑ Mark Niemiec (September 11, 2013). Re: It´s not a Gosper Glider Gun ! (discussion thread) at the ConwayLife.com forums
- ↑ Tropylium (September 26, 2013). Re: It´s not a Gosper Glider Gun ! (discussion thread) at the ConwayLife.com forums
- ↑ Gardner, Martin (February 1971), "On cellular automata, self-reproduction, the Garden of Eden and the game 'life'", Scientific American 224 (2): 117
- ↑ dani (November 9, 2022). Re: Soup search results (discussion thread) at the ConwayLife.com forums
- ↑ Adam P. Goucher (December 8, 2020). Re: Thread For Your Useless Discoveries (discussion thread) at the ConwayLife.com forums
External links
- Gosper glider gun at the Life Lexicon
- Gosper glider gun at Adam P. Goucher's Catagolue (linear growth)