Pure glider generator: Difference between revisions
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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. | 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. | ||
'''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> | '''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" /> | ||
{| | |||
|{{EmbedViewer | |||
{{EmbedViewer | |||
|pname = mirage | |pname = mirage | ||
|position = center | |position = center | ||
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|caption = Mirage<br/> | |caption = Mirage<br/> | ||
}} | }} | ||
{{EmbedViewer | |{{EmbedViewer | ||
|pname = mirage2 | |pname = mirage2 | ||
|position = center | |position = center | ||
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|caption = A sparse variant of mirage constructed by [[wwei23]] in 2017<br/> | |caption = A sparse variant of mirage constructed by [[wwei23]] in 2017<br/> | ||
}} | }} | ||
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Some other examples: | |||
{| | {| | ||
|- | |- | ||
|{{EmbedViewer | |{{EmbedViewer | ||
|pname = undecominotoglider | |pname = undecominotoglider | ||
|position = | |position = center | ||
|viewerconfig = #C [[ AUTOSTART THUMBSIZE 2 GPS 5 PAUSE 2 LOOP | |viewerconfig = #C [[ AUTOSTART THUMBSIZE 2 GPS 5 PAUSE 2 LOOP 25 ]] | ||
|caption = An undecomino that evolves into a single glider<br /> | |caption = An undecomino that evolves into a single glider<br /> | ||
}} | }} | ||
|{{EmbedViewer | |{{EmbedViewer | ||
|pname = 3polyominosto4gliders | |pname = 3polyominosto4gliders | ||
|position = | |position = center | ||
|viewerconfig = #C [[ AUTOSTART THUMBSIZE 2 GPS 5 PAUSE 2 LOOP 50 ]] | |viewerconfig = #C [[ AUTOSTART THUMBSIZE 2 GPS 5 PAUSE 2 LOOP 50 ]] | ||
|caption = Evolves into four gliders,<br/>one travelling in each direction<br /> | |caption = Evolves into four gliders,<br/>one travelling in each direction<br /> | ||
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==References== | ==References== | ||
<references /> | <references> | ||
<ref name="post12923">{{LinkForumThread | |||
|p = 12923 | |||
|format = ref | |||
|title = Re: Pure Glider Generators | |||
|author = Bob Shemyakin | |||
|date = August 17, 2014 | |||
}}</ref> | |||
</references> | |||
==External links== | ==External links== | ||
Revision as of 23:31, 26 December 2021
A pure glider generator (or simply glider generator) is a pattern that evolves into one or more gliders and nothing else. 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), but nowadays they are no longer considered important.
Examples
The 4-8-12 diamond and the bi-loaf[note 1] are two pure glider generators found by the Honeywell group in 1971.[1] 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.[2] It consists of two clocks, and evolves into two gliders in two generations.
Mirage (or Fata Morgana) is a pure glider generator in which many sparse cells quickly create 13 gliders. Eight of those gliders construct a Gosper glider gun at generation 34, but the remaining five destroy the gun by generation 73.[3] Similar patterns based on other glider syntheses can be constructed.[4]
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Some other examples:
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A pure glider generator is featured on xkcd as a tribute to John Conway.[5]
See also
Notes
- ↑ 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
- ↑ Robert Wainwright (March 1971). Lifeline, vol 1.
- ↑ Robert Wainwright (June 1971). Lifeline, vol 2.
- ↑ Alan Hensel's lifep.zip pattern collection.
- ↑ Bob Shemyakin (August 17, 2014). Re: Pure Glider Generators (discussion thread) at the ConwayLife.com forums
- ↑ "xkcd: RIP John Conway". Retrieved on December 18, 2020.
External links
- 4-8-12 diamond at the Life Lexicon
- Bi-loaf at the Life Lexicon
- Bi-clock at the Life Lexicon