Switch engine: Difference between revisions
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A '''switch engine''' (or '''Corder engine'''<ref>{{CiteLexicon|file=lex_c.htm#corderengine|name=Corder engine|accessdate=June 10, 2009}}</ref>) is a [[methuselah]] that was found by [[Charles Corderman]] in {{year|1971}}. It produces a copy of itself after 48 | A '''switch engine''' (or '''Corder engine'''<ref>{{CiteLexicon|file=lex_c.htm#corderengine|name=Corder engine|accessdate=June 10, 2009}}</ref>) is a [[methuselah]] that was found by [[Charles Corderman]] in {{year|1971}}.<ref>{{CiteLifeline|vol=4|pages=page 2|date=December 1971}}</ref> It produces a copy of itself after 48 generations, glide-reflected 4 cells northwest (starting in the form to the right), along with some active [[junk]]. If left unattended, the accumulating exhaust overtakes and destroys the engine after 24 cycles, but it can be stabilized to make [[c/12 diagonal]] [[puffer]]s and [[spaceship]]s. | ||
==History== | |||
In {{year|1971}}, Charles Corderman investigated the [[fate]] of all the small [[polyomino]]es exhaustively. Records indicate that he found the switch engine while investigating the decominoes (polyominoes having 10 cells). However, there do not appear to be{{citation needed}} decominoes which result in a clean switch engine. There is, on the other hand, a unique{{citation needed}} '''nonomino switch engine [[predecessor]]''' whose 2-tick descendant matches that of a switch engine: | |||
{{EmbedViewer | |||
|pname = nonominoswitchenginepredecessor | |||
|position = center | |||
|viewerconfig = #C [[ THUMBSIZE 2 Z 20 HEIGHT 480 GPS 1 AUTOSTART PAUSE 2 T 2 PAUSE 2 LOOP 3 ]] | |||
}} | |||
It is the smallest known polyomino to do so. If Corderman was examining polyominoes in order of size, then this smaller predecessor should have been found first in any case. | |||
==Stabilization== | ==Stabilization== | ||
There are two basic types of stabilized switch engine, both of which were also found by Charles Corderman: the [[period]] 288 [[block-laying switch engine]] (the more common of the two) and period 384 [[glider-producing switch engine]]. These two puffers are the most natural [[infinite growth]] patterns in [[Conway's Game of Life]], being by far the most common ones to occur from non-symmetric [[soup|random starting patterns]].<ref>{{cite web|url=http://catagolue.appspot.com/census/b3s23/C1 |title=Census - Catagolue |accessdate=September 28, 2015}}</ref> Switch engine-based puffers, and combinations thereof, are also the only infinite growth patterns observed to have emerged from asymmetric soups on [[Catagolue]]. | |||
In addition to the puffers based on a single switch engine, puffers such as [[Noah's ark]] can be created by combining two switch engines. Such puffers are generally quite [[dirty]]. However, it is also possible to create [[Cordership]]s made of switch engines that interact to remove their combined exhaust. These move at [[c/12 diagonal]]ly and are thus the slowest known spaceships in Life other than the [[ | Because the switch engine lends itself so naturally to infinitely-growing patterns, it appears in many of the smallest known superlinear growth patterns, including the [[mosquito]]es, [[catacryst]], [[metacatacryst]], [[Gotts dots]], and [[26-cell quadratic growth]]. | ||
In addition to the puffers based on a single switch engine, puffers such as [[Noah's ark]] can be created by combining two switch engines. Such puffers are generally quite [[dirty]]. However, it is also possible to create [[Cordership]]s made of switch engines that interact to remove their combined exhaust. These move at [[c/12 diagonal]]ly and are thus the slowest known spaceships in Life other than the [[adjustable ships]]. Such spaceships can be constructed by combining as few as [[2-engine Cordership|two]] switch engines. | |||
=='Swimmer' tracks== | =='Swimmer' tracks== | ||
{{main|Switch engine channel}} | |||
Like [[Herschel]]s, switch engines can be supported by [[conduit]]s made out of well-separated still lifes.<ref>{{cite web|url=http://pentadecathlon.com/lifenews/2005/09/bobsled_run_update.html|title=Bobsled run update|author=Dave Greene|publisher=Game of Life News|date=September 6, 2005|accessdate=September 21, 2014}}</ref> These 'swimmer tracks' were discovered by [[David Bell]] in 2005, and can be any length. Stable converters have been constructed that convert Herschels to switch engines and back<ref>{{cite web|url=http://b3s23life.blogspot.com/2007/06/new-kind-of-signal-though-not-useful.html|title=A New Kind of Signal|author=Dave Greene|publisher=Work in Progress blog|date=June 17, 2007|accessdate=September 21, 2014}}</ref>. Much faster, smaller and more efficient Herschel-to-swimmer converters can now be constructed with new technology, particularly [[Snark|Snark reflectors]].<ref>{{cite web|url=http://www.conwaylife.com/forums/viewtopic.php?f=2&t=2799&p=42033#p42069|title=Re: Implications of a Three-Glider Switch Engine|author=Dave Greene|date=March 25, 2017|accessdate=February 13, 2018}}</ref> | Like [[Herschel]]s, switch engines can be supported by [[conduit]]s made out of well-separated still lifes.<ref>{{cite web|url=http://pentadecathlon.com/lifenews/2005/09/bobsled_run_update.html|title=Bobsled run update|author=Dave Greene|publisher=Game of Life News|date=September 6, 2005|accessdate=September 21, 2014}}</ref> These 'swimmer tracks' were discovered by [[David Bell]] in 2005, and can be any length. Stable converters have been constructed that convert Herschels to switch engines and back<ref>{{cite web|url=http://b3s23life.blogspot.com/2007/06/new-kind-of-signal-though-not-useful.html|title=A New Kind of Signal|author=Dave Greene|publisher=Work in Progress blog|date=June 17, 2007|accessdate=September 21, 2014}}</ref>. Much faster, smaller and more efficient Herschel-to-swimmer converters can now be constructed with new technology, particularly [[Snark|Snark reflectors]].<ref>{{cite web|url=http://www.conwaylife.com/forums/viewtopic.php?f=2&t=2799&p=42033#p42069|title=Re: Implications of a Three-Glider Switch Engine|author=Dave Greene|date=March 25, 2017|accessdate=February 13, 2018}}</ref> | ||
==Stable pattern== | ==Stable pattern== | ||
The stable pattern that results from the switch engine has 842 [[cell]]s. It consists of 60 [[block]]s, 33 [[beehive]]s (including one [[honey farm]]), 50 [[blinker]]s (including eight [[traffic light]]s), 12 [[glider]]s, 11 [[boat]]s, 11 [[loaf|loaves]], four [[ship]]s, two [[long boat]]s, two [[pond]]s, and two [[tub]]s. | The stable pattern that results from the switch engine has 842 [[cell]]s. It consists of 60 [[block]]s, 33 [[beehive]]s (including one [[honey farm]]), 50 [[blinker]]s (including eight [[traffic light]]s), 12 [[glider]]s, 11 [[boat]]s, 11 [[loaf|loaves]], four [[ship]]s, two [[long boat]]s, two [[pond]]s, and two [[tub]]s. | ||
{| | {| | ||
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|[[Image:Switchengine_final.png|thumb|left|Generation 3911]] | |[[Image:Switchengine_final.png|thumb|left|Generation 3911]] | ||
|} | |} | ||
==Synthesis== | |||
In {{year|1973}}, Douglas G. Petrie employed a {{gliders|4}} recipe of a switch engine in his [[synthesis]] for a block-laying switch engine.<ref>{{CiteLifeline|vol=10|pages=page 5|date=June 1973}}</ref> Decades later, [[Luka Okanishi]] discovered a surprisingly small {{gliders|3}} synthesis for a clean switch engine on March 12, {{year|2017}}.<ref name="post41557" /> | |||
==See also== | ==See also== | ||
*[[Ark]] | *[[Ark]] | ||
*[[Cordership]] | *[[Cordership]] | ||
==References== | ==References== | ||
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{{LinkLexicon|lex_s.htm#switchengine}} | {{LinkLexicon|lex_s.htm#switchengine}} | ||
<!-- *[http://www.calcyman.co.uk/life/corder.htm Corderships and Switch Engines] at [http://www.calcyman.co.uk/ www.calcyman.co.uk] --> | <!-- *[http://www.calcyman.co.uk/life/corder.htm Corderships and Switch Engines] at [http://www.calcyman.co.uk/ www.calcyman.co.uk] --> | ||
{{LinkLexicon|filename=lex_n.htm#nonominoswitchenginepredecessor|patternname=Nonomino switch engine predecessor}} | |||
[[Category:Puffer engines]] | [[Category:Puffer engines]] | ||
__NOTOC__ | __NOTOC__ | ||
Revision as of 03:18, 1 November 2020
| Switch engine | |||||||
| View static image | |||||||
| Pattern type | Methuselah | ||||||
|---|---|---|---|---|---|---|---|
| Number of cells | 8 | ||||||
| Bounding box | 6 × 4 | ||||||
| MCPS | 10 | ||||||
| Lifespan | 3911 generations | ||||||
| Final population | 842 | ||||||
| L/I | 488.9 | ||||||
| F/I | 105.3 | ||||||
| F/L | 0.215 | ||||||
| L/MCPS | 391.1 | ||||||
| Static symmetry | Unspecified | ||||||
| Discovered by | Charles Corderman | ||||||
| Year of discovery | 1971 | ||||||
| |||||||
| |||||||
A switch engine (or Corder engine[1]) is a methuselah that was found by Charles Corderman in 1971.[2] It produces a copy of itself after 48 generations, glide-reflected 4 cells northwest (starting in the form to the right), along with some active junk. If left unattended, the accumulating exhaust overtakes and destroys the engine after 24 cycles, but it can be stabilized to make c/12 diagonal puffers and spaceships.
History
In 1971, Charles Corderman investigated the fate of all the small polyominoes exhaustively. Records indicate that he found the switch engine while investigating the decominoes (polyominoes having 10 cells). However, there do not appear to be[citation needed] decominoes which result in a clean switch engine. There is, on the other hand, a unique[citation needed] nonomino switch engine predecessor whose 2-tick descendant matches that of a switch engine:
| (click above to open LifeViewer) RLE: here Plaintext: here |
It is the smallest known polyomino to do so. If Corderman was examining polyominoes in order of size, then this smaller predecessor should have been found first in any case.
Stabilization
There are two basic types of stabilized switch engine, both of which were also found by Charles Corderman: the period 288 block-laying switch engine (the more common of the two) and period 384 glider-producing switch engine. These two puffers are the most natural infinite growth patterns in Conway's Game of Life, being by far the most common ones to occur from non-symmetric random starting patterns.[3] Switch engine-based puffers, and combinations thereof, are also the only infinite growth patterns observed to have emerged from asymmetric soups on Catagolue.
Because the switch engine lends itself so naturally to infinitely-growing patterns, it appears in many of the smallest known superlinear growth patterns, including the mosquitoes, catacryst, metacatacryst, Gotts dots, and 26-cell quadratic growth.
In addition to the puffers based on a single switch engine, puffers such as Noah's ark can be created by combining two switch engines. Such puffers are generally quite dirty. However, it is also possible to create Corderships made of switch engines that interact to remove their combined exhaust. These move at c/12 diagonally and are thus the slowest known spaceships in Life other than the adjustable ships. Such spaceships can be constructed by combining as few as two switch engines.
'Swimmer' tracks
- Main article: Switch engine channel
Like Herschels, switch engines can be supported by conduits made out of well-separated still lifes.[4] These 'swimmer tracks' were discovered by David Bell in 2005, and can be any length. Stable converters have been constructed that convert Herschels to switch engines and back[5]. Much faster, smaller and more efficient Herschel-to-swimmer converters can now be constructed with new technology, particularly Snark reflectors.[6]
Stable pattern
The stable pattern that results from the switch engine has 842 cells. It consists of 60 blocks, 33 beehives (including one honey farm), 50 blinkers (including eight traffic lights), 12 gliders, 11 boats, 11 loaves, four ships, two long boats, two ponds, and two tubs.
 |
Synthesis
In 1973, Douglas G. Petrie employed a 4-glider recipe of a switch engine in his synthesis for a block-laying switch engine.[7] Decades later, Luka Okanishi discovered a surprisingly small 3-glider synthesis for a clean switch engine on March 12, 2017.[8]
See also
References
- ↑ "Corder engine". The Life Lexicon. Stephen Silver. Retrieved on June 10, 2009.
- ↑ Robert Wainwright (December 1971). Lifeline, vol 4, page 2.
- ↑ "Census - Catagolue". Retrieved on September 28, 2015.
- ↑ Dave Greene (September 6, 2005). "Bobsled run update". Game of Life News. Retrieved on September 21, 2014.
- ↑ Dave Greene (June 17, 2007). "A New Kind of Signal". Work in Progress blog. Retrieved on September 21, 2014.
- ↑ Dave Greene (March 25, 2017). "Re: Implications of a Three-Glider Switch Engine". Retrieved on February 13, 2018.
- ↑ Robert Wainwright (June 1973). Lifeline, vol 10, page 5.
- ↑ Luka Okanishi (March 12, 2017). Re: Thread For Your Accidental Discoveries (discussion thread) at the ConwayLife.com forums
External links
- Switch engine at the Life Lexicon