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{{Glossary}}
{{Glossary}}
A '''pure glider generator''' (or simply '''glider generator''') is a [[pattern]] that evolves into one or more [[glider]]s and nothing else. They are part of the [[Cosmology|cosmological]] classification of Life patterns. There was interest in this scheme early on, and within it on pure glider generators in particular (they were reported on quite frequently in the early issues of [[Lifeline]], for example), but nowadays they are no longer considered important.
A '''pure glider generator''' (or simply '''glider generator''') is a [[pattern]] that evolves into one or more [[glider]]s and nothing else.<ref name="lexicon_pureglidergenerator" /><ref name="t1327" /> They are part of the [[Cosmology|cosmological]] classification of Life patterns. There was interest in this scheme early on, and within it on pure glider generators in particular (they were reported on quite frequently in the early issues of [[Lifeline]], for example).
 
However, there are so many easy-to-find pure glider generators that it's impossible to catalogue them all, unless some extra constraints are added (for example being easily [[glider-constructible]], or being [[Blockic|made out of just blocks]], or being a [[one-cell-thick pattern]]).<ref name="post11185" /><ref name="t1065" /><ref name="t1332" />


==Examples==
==Examples==
{|
{{gallery top}}
|{{EmbedViewer
{{gallery item|{{EmbedViewer
|pname        = 4812diamond
|pname        = 4812diamond
|viewerconfig = #C [[ AUTOSTART THUMBSIZE 2 GPS 5 PAUSE 2 LOOP 50 ]]
|viewerconfig = #C [[ HEIGHT 500 THUMBSIZE 2 GPS 5 AUTOSTART T 0 PAUSE 2 LOOP 30 ]]
|caption = The '''4-8-12 diamond'''
|position    = center
}}
|caption     = The '''4-8-12 diamond'''
|{{EmbedViewer
|style        = width:300px;
}}}}
{{gallery item|{{EmbedViewer
|pname        = biloafpgg
|pname        = biloafpgg
|viewerconfig = #C [[ AUTOSTART THUMBSIZE 2 GPS 5 PAUSE 2 LOOP 50 ]]
|viewerconfig = #C [[ HEIGHT 500 THUMBSIZE 2 GPS 5 AUTOSTART T 0 PAUSE 2 LOOP 30 ]]
|caption = The '''bi-loaf'''
|position    = center
}}
|caption     = The '''bi-loaf'''
|{{EmbedViewer
|style        = width:300px;
}}}}
{{gallery item|{{EmbedViewer
|pname        = biclock
|pname        = biclock
|viewerconfig = #C [[ AUTOSTART THUMBSIZE 2 GPS 5 PAUSE 2 LOOP 50 ]]
|viewerconfig = #C [[ HEIGHT 500 THUMBSIZE 2 GPS 5 AUTOSTART T 0 PAUSE 2 LOOP 30 ]]
|caption = The '''bi-clock'''
|position    = center
}}
|caption     = The '''bi-clock'''
|}
|style        = width:300px;
 
}}}}
The '''4-8-12 diamond''' and the '''bi-loaf'''{{refn|group=note|The term "[[bi-loaf]]" is now a collective description of the [[still life]]s consisting of two [[loaves]], e.g. the [[half-bakery]] and the [[loaf back tie loaf]].}} are two pure glider generators found by the Honeywell group in {{year|1971}}.<ref>{{CiteLifeline|vol=1}}</ref> The former evolves into four gliders (one heading in each diagonal direction) in 15 [[generation]]s, while the latter yields two after four ticks. Gliders from the bi-loaf run in opposite ways along the diagonal that is closest to the great axis of the pattern. E.g. when the great axis is NNE-SSW, the gliders' directions are northeast & southwest. The '''bi-clock''' is a later example found by Dale Edwin Cole in the same year.<ref>{{CiteLifeline|vol=2}}</ref> It consists of two [[clock]]s, and evolves into two gliders in two [[generation]]s.
{{gallery bottom}}
 
'''Mirage''' (or '''Fata Morgana''') is a [[pure glider generator]] in which many sparse [[cell]]s quickly create 13 [[glider]]s. Eight of those gliders [[glider synthesis|construct]] a [[Gosper glider gun]] at [[generation]] 34, but the remaining five destroy the [[gun]] by generation 73.<ref>[[Alan Hensel]]'s [http://www.ibiblio.org/lifepatterns/ lifep.zip] pattern collection.</ref> Similar patterns based on other glider syntheses can be constructed.<ref name="post12923" />


{|
The '''4-8-12 diamond''' and the '''bi-loaf'''{{refn|group=note|The term "[[bi-loaf]]" is now a collective description of the [[still life]]s consisting of two [[loaves]], e.g. the [[half-bakery]] and the [[loaf back tie loaf]].}} are two pure glider generators found by the [[Honeywell group]] in {{year|1971}}.<ref>{{CiteLifeline|vol=1|pages=page 3}}</ref> The former evolves into four gliders (one heading in each diagonal direction) in 15 [[generation]]s, while the latter yields two after four ticks. Gliders from the bi-loaf run in opposite ways along the diagonal that is closest to the great axis of the pattern. E.g. when the great axis is NNE-SSW, the gliders' directions are northeast & southwest. The '''bi-clock''' is a later example found by Dale Edwin Cole in the same year.<ref>{{CiteLifeline|vol=2|pages=page 5}}</ref> It consists of two closely placed [[clock]]s, and evolves into two gliders in two [[generation]]s.
|{{EmbedViewer
{{gallery top}}
|pname = mirage
{{gallery item|{{EmbedViewer
|position    = center
|pname       = undecominotoglider
|viewerconfig = #C [[ THUMBSIZE 2 LOOP 90 AUTOSTART PAUSE 5 GPS 15 ]]
|viewerconfig = #C [[ HEIGHT 500 THUMBSIZE 2 GPS 5 AUTOSTART T 0 PAUSE 2 LOOP 30 ]]
|caption      = Mirage<br/>
}}
|{{EmbedViewer
|pname = mirage2
|position    = center
|position    = center
|viewerconfig = #C [[ THUMBSIZE 2 LOOP 90 AUTOSTART PAUSE 5 GPS 15 ]]
|caption      = An undecomino that evolves into a single glider
|caption      = A sparse variant of mirage constructed by  [[wwei23]] in 2017<br/>
|style        = width:300px;
}}
}}}}
|}
{{gallery item|{{EmbedViewer
Some other examples:
|pname       = 3polyominosto4gliders
{|
|viewerconfig = #C [[ HEIGHT 500 THUMBSIZE 2 GPS 5 AUTOSTART T 0 PAUSE 2 LOOP 40 ]]
|-
|{{EmbedViewer
|pname = undecominotoglider
|position    = center
|position    = center
|viewerconfig = #C [[ AUTOSTART THUMBSIZE 2 GPS 5 PAUSE 2 LOOP 25 ]]
|caption      = Evolves into four gliders, one travelling in each direction
|caption      = An undecomino that evolves into a single glider<br />
|style        = width:300px;
}}
}}}}
|{{EmbedViewer
{{gallery bottom}}
|pname = 3polyominosto4gliders
|position    = center
|viewerconfig = #C [[ AUTOSTART THUMBSIZE 2 GPS 5 PAUSE 2 LOOP 50 ]]
|caption      = Evolves into four gliders,<br/>one travelling in each direction<br />
}}
|}


A pure glider generator is featured on xkcd as a tribute to [[John Conway]].<ref>{{cite web|url=https://xkcd.com/2293/ |title=xkcd: RIP John Conway|accessdate=December 18, 2020}}</ref>
A pure glider generator was featured on Randall Munroe's webcomic xkcd as a tribute to [[John Conway]], the inventor of [[Game of Life]].<ref>{{cite web|url=https://xkcd.com/2293/ |title=2293: RIP John Conway|author=Randall Munroe|date=April 13, 2020|accessdate=December 18, 2020}}</ref>


==See also==
==See also==
*[[Mirage]]
* [[Mirage]]
*[[Spark]]
* [[Spark]]
*[[Splitter]]
* [[Splitter]]
*[[Turner]]
* [[Turner]]
*[[Over-unity reaction]]
* [[Over-unity reaction]]
*[[Glider gun]]
* [[Glider gun]]


==Notes==
==Notes==
Line 71: Line 62:
==References==
==References==
<references>
<references>
<ref name="post12923">{{LinkForumThread
<ref name="lexicon_pureglidergenerator">{{LinkLexicon|lex_p.htm#pureglidergenerator|name=Pure glider generator|style=raw}} at the [[Life Lexicon]]</ref>
|p          = 12923
<ref name="t1065">{{LinkForumThread
|format    = ref
|format    = ref
|f          = 2
|t          = 1065
|title      = Blockic splitters
|author    = knightlife
|date      = April 4th, 2013
}}</ref>
<ref name="t1327">{{LinkForumThread
|format    = ref
|f          = 2
|t          = 1327
|title      = Pure Glider Generators
|author    = twinb7
|date      = March 2nd, 2014
}}</ref>
<ref name="t1332">{{LinkForumThread
|format    = ref
|f          = 2
|t          = 1332
|title      = 1-Dimensional Patterns
|author    = twinb7
|date      = March 5th, 2014
}}</ref>
<ref name="post11185">{{LinkForumThread
|format    = ref
|p          = 11185
|title      = Re: Pure Glider Generators
|title      = Re: Pure Glider Generators
|author    = Bob Shemyakin
|author    = Dave Greene
|date      = August 17, 2014
|date      = March 8th, 2014
}}</ref>
}}</ref>
</references>
</references>


==External links==
==External links==
{{LinkLexicon|lex_p.htm#pureglidergenerator}}
* {{LinkLexicon|lex_p.htm#pureglidergenerator}}
{{LinkLexicon|filename=lex_1.htm#a-4812diamond|patternname=4-8-12 diamond}}
* {{LinkLexicon|filename=lex_1.htm#a-4812diamond|patternname=4-8-12 diamond}}
{{LinkLexicon|filename=lex_b.htm#biloaf|patternname=Bi-loaf}}
* {{LinkLexicon|filename=lex_b.htm#biloaf|patternname=Bi-loaf}}
{{LinkLexicon|filename=lex_b.htm#biclock|patternname=Bi-clock}}
* {{LinkLexicon|filename=lex_b.htm#biclock|patternname=Bi-clock}}
 
__NOTOC__
__NOTOC__

Latest revision as of 21:37, 22 May 2023

A pure glider generator (or simply glider generator) is a pattern that evolves into one or more gliders and nothing else.[1][2] They are part of the cosmological classification of Life patterns. There was interest in this scheme early on, and within it on pure glider generators in particular (they were reported on quite frequently in the early issues of Lifeline, for example).

However, there are so many easy-to-find pure glider generators that it's impossible to catalogue them all, unless some extra constraints are added (for example being easily glider-constructible, or being made out of just blocks, or being a one-cell-thick pattern).[3][4][5]

Examples

x = 12, y = 9, rule = B3/S23 4b4o2$2b8o2$12o2$2b8o2$4b4o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ HEIGHT 500 THUMBSIZE 2 GPS 5 AUTOSTART T 0 PAUSE 2 LOOP 30 ]]
The 4-8-12 diamond
(click above to open LifeViewer)
RLE: here Plaintext: here
x = 4, y = 7, rule = B3/S23 2bo$bobo$o2bo$b2o$o2bo$obo$bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ HEIGHT 500 THUMBSIZE 2 GPS 5 AUTOSTART T 0 PAUSE 2 LOOP 30 ]]
The bi-loaf
(click above to open LifeViewer)
RLE: here Plaintext: here
x = 7, y = 7, rule = B3/S23 2bo$2o$2b2o$bo3bo$3b2o$5b2o$4bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ HEIGHT 500 THUMBSIZE 2 GPS 5 AUTOSTART T 0 PAUSE 2 LOOP 30 ]]
The bi-clock
(click above to open LifeViewer)
RLE: here Plaintext: here


The 4-8-12 diamond and the bi-loaf[note 1] are two pure glider generators found by the Honeywell group in 1971.[6] The former evolves into four gliders (one heading in each diagonal direction) in 15 generations, while the latter yields two after four ticks. Gliders from the bi-loaf run in opposite ways along the diagonal that is closest to the great axis of the pattern. E.g. when the great axis is NNE-SSW, the gliders' directions are northeast & southwest. The bi-clock is a later example found by Dale Edwin Cole in the same year.[7] It consists of two closely placed clocks, and evolves into two gliders in two generations.

x = 6, y = 2, rule = B3/S23 6o$5o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ HEIGHT 500 THUMBSIZE 2 GPS 5 AUTOSTART T 0 PAUSE 2 LOOP 30 ]]
An undecomino that evolves into a single glider
(click above to open LifeViewer)
RLE: here Plaintext: here
x = 15, y=9, rule = B3/S23 2bo$2bo$3o2$6b3o$7bo$12b3o$12bo$12bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ HEIGHT 500 THUMBSIZE 2 GPS 5 AUTOSTART T 0 PAUSE 2 LOOP 40 ]]
Evolves into four gliders, one travelling in each direction
(click above to open LifeViewer)
RLE: here Plaintext: here


A pure glider generator was featured on Randall Munroe's webcomic xkcd as a tribute to John Conway, the inventor of Game of Life.[8]

See also

Notes

  1. ↑ The term "bi-loaf" is now a collective description of the still lifes consisting of two loaves, e.g. the half-bakery and the loaf back tie loaf.

References

  1. ↑ Pure glider generator at the Life Lexicon
  2. ↑ twinb7 (March 2nd, 2014). Pure Glider Generators (discussion thread) at the ConwayLife.com forums
  3. ↑ Dave Greene (March 8th, 2014). Re: Pure Glider Generators (discussion thread) at the ConwayLife.com forums
  4. ↑ knightlife (April 4th, 2013). Blockic splitters (discussion thread) at the ConwayLife.com forums
  5. ↑ twinb7 (March 5th, 2014). 1-Dimensional Patterns (discussion thread) at the ConwayLife.com forums
  6. ↑ Robert Wainwright (March 1971). Lifeline, vol 1, page 3.
  7. ↑ Robert Wainwright (June 1971). Lifeline, vol 2, page 5.
  8. ↑ Randall Munroe (April 13, 2020). "2293: RIP John Conway". Retrieved on December 18, 2020.


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