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'''Period-24 glider gun''' is a [[Gun#True-period_guns|true period]] 24 [[gun]] discovered by [[Noam Elkies|Noam D. Elkies]] in [[:Category:Patterns found in 1997|1997]].<ref name="callahan">{{cite web|url=http://www.radicaleye.com/lifepage/patterns/p24gun/p24gun.html|title=p24 "true" gun (mail digest)|author=Paul Callahan|date=February 11, 2001|accessdate=March 17, 2016}}</ref> It uses four large [[period]] [[:Category:oscillators with period 4|4]] [[oscillator]]s (two of them variants of [[fountain]], the other two adjoined by common [[casing]]) to hassle two [[T-tetromino]]s, which react together to produce gliders. The form on the right is a reduced variant found by Karel Suhajda.<ref name="jslife">{{cite web|url=http://entropymine.com/jason/life/|title=Pattern Collections, jslife/osc |author=Jason Summers|date=December 30, 2012|accessdate=March 17, 2016}}</ref> The eater 1 can be replaced with a [[unix]] for compacting purposes, such as in the [[period-48 glider gun]].
A '''period-24 glider gun''' is any [[true]] period 24 [[glider gun]].
No more than five days after the initial discovery, Elkies found a method to double the period of the gun, resulting in the first known period 48 glider gun.<ref name="callahan" /> A smaller version was found in 2016 by Tanner Jacobi, using [[Rich's p16]] to double the period.<ref name="jacobi">{{cite web|title=Re: Soup search results|author=Tanner Jacobi|date=2016-07-05|accessdate=2016-07-05|work=ConwayLife.com forums|url=http://www.conwaylife.com/forums/viewtopic.php?f=2&t=1452&start=1075#p32769}}</ref>
The first true period 24 glider gun was discovered by [[Noam D. Elkies]] in {{year|1997}}.<ref name="callahan" /> It uses four large {{period|4}} [[oscillator]]s (two of them variants of [[fountain]], the other two adjoined by common [[casing]]) to hassle two [[T-tetromino]]es, which react together to produce gliders. The form on the right is a reduced variant found by Karel Suhajda.<ref>{{CiteSummersPattern|name=jslife|accessdate=March 17, 2016}}</ref> The eater 1 can be replaced with a [[unix]] for compacting purposes, such as in earlier versions of the [[period-48 glider gun]].
==Gallery==
No more than five days after the initial discovery, Elkies found a method to double the period of the gun, resulting in the first known period 48 glider gun.<ref name="callahan" /> A smaller version was found in 2016 by Tanner Jacobi, using [[Rich's p16]] to double the period.<ref name="post32769" />
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|[[Image:Period24glidergun(original).png|framed|left|Original period 24 glider gun.]]
In January {{year|2019}}, a smaller period-24 gun was assembled by [[Tanner Jacobi]] and [[Matthias Merzenich]], based on the [[dueling banjos]] oscillator<ref name="post67805" /> (see animation below). It was further reduced in November of that same year due to the discovery of a new p6 [[domino]] [[sparker]] by [[Dongook Lee]].<ref name="post85150" /><ref name="post85220" /> Both of these variants have been used to create period-48 [[LWSS]] guns,<ref name="post67916" /><ref name="post85162" /> and the former gun was in turn used to create a [[pseudo-period]] 16 glider gun.<ref name="post67942" />
|caption = A p48 [[LWSS]] gun, using [[Rich's p16]].<br>
|caption = A p48 [[LWSS]] gun, using [[Rich's p16]] and [[Eye of Sauron]]
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}}
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On October 2, {{year|2022}}, [[cvojan]] and [[vivi]] discovered<ref name="post151670" /> a period-24 [[glider gun]] with a {{times|21|20}} [[bounding box]], making it the second smallest known glider gun with a unique period. This was reduced to {{times|20|20}} by [[James Pascua]] the next day.<ref name="post151697" />
A period-24 glider gun is any true period 24 glider gun.
The first true period 24 glider gun was discovered by Noam D. Elkies in 1997.[1] It uses four large period-4oscillators (two of them variants of fountain, the other two adjoined by common casing) to hassle two T-tetrominoes, which react together to produce gliders. The form on the right is a reduced variant found by Karel Suhajda.[2] The eater 1 can be replaced with a unix for compacting purposes, such as in earlier versions of the period-48 glider gun.
No more than five days after the initial discovery, Elkies found a method to double the period of the gun, resulting in the first known period 48 glider gun.[1] A smaller version was found in 2016 by Tanner Jacobi, using Rich's p16 to double the period.[3]
In January 2019, a smaller period-24 gun was assembled by Tanner Jacobi and Matthias Merzenich, based on the dueling banjos oscillator[4] (see animation below). It was further reduced in November of that same year due to the discovery of a new p6 dominosparker by Dongook Lee.[5][6] Both of these variants have been used to create period-48 LWSS guns,[7][8] and the former gun was in turn used to create a pseudo-period 16 glider gun.[9]
On October 2, 2022, cvojan and vivi discovered[10] a period-24 glider gun with a 21 × 20bounding box, making it the second smallest known glider gun with a unique period. This was reduced to 20 × 20 by James Pascua the next day.[11]
