Difference between revisions of "OCA:Pedestrian Life"

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'''Pedestrian Life''' is a [[cellular automaton#Well-known Life-like cellular automata|Life-like cellular automaton]] in which [[cell]]s survive from one generation to the next if they have 2 or 3 [[neighbours]], and are born if they have 3 or 8 neighbours.
'''Pedestrian Life''' is a [[cellular automaton#Well-known Life-like cellular automata|Life-like cellular automaton]] in which [[cell]]s survive from one generation to the next if they have 2 or 3 [[neighbours]], and are born if they have 3 or 8 neighbours.


==Patterns==
Many patterns from regular [[Conway's Game of Life|Life]] are compatible with this rule, since the rules differ only in one transition. However, [[traffic light]]s are much less common, as most predecessors tend to die, giving the rule its name.<ref name="tropylium20130409" />
Many patterns from regular [[Conway's Game of Life|Life]] are compatible with this rule. However, [[traffic light]]s are much less common, as most predecessors tend to die, giving the rule its name.<ref name="tropylium20130409" />


There are several [[natural]] patterns of interest. One is a [[stator]]less, rotating [[period]]-106 [[glider]] [[gun]]:
==Notable patterns==


[[File:Pedestrianlife p106gun.png|frame|center|The rotating p106 gun.<br />[[:File:Pedestrianlife p106gun.gif|View animated image]].<br />{{JavaRLE|pedestrianlife_p106gun|brief}}<br />{{LinkCatagolue|code=yl106_1_5_f4842a91ffb658737af39134e4680190|rule=b38s23|style=brief}}]]
The rule is particularly notable for its plurality of distinct [[natural]] linear growth mechanisms:
 
===Rotating gun===
 
The first is a [[stator]]less, rotating [[period]]-106 [[glider]] [[gun]]:
 
{{EmbedViewer
|pname = pedestrianlifep106gun
|position = center
|caption = The rotating p106 gun ({{LinkCatagolue|yl106_1_5_f4842a91ffb658737af39134e4680190|rule=b38s23|style=brief|format=linear growth}})<br>
}}
 
===(5,2)c/190 spaceships===


The second is a family of naturally occurring (5,2)c/190 [[oblique spaceship]]s, using mechanisms meshed together similarly to [[switch engine]]s:
The second is a family of naturally occurring (5,2)c/190 [[oblique spaceship]]s, using mechanisms meshed together similarly to [[switch engine]]s:


[[File:Pedestrianlife oblique spaceship.png|frame|center|The first (5,2)c/190 oblique spaceship found.<br />[[:File:Pedestrianlife oblique_spaceship.gif|View animated image.]]<br />{{JavaRLE|pedestrianlife_obliquespaceship|brief}}<br />{{LinkCatagolue|code=xq190_33y1g88gzy133433zyeskszzyjcmm8zyx352|rule=b38s23|style=brief}}]]
{{EmbedViewer
|pname = pedestrianlifeobliquespaceship
|position = center
|caption = The first (5,2)c/190 oblique spaceship found ({{LinkCatagolue|xq190_33y1g88gzy133433zyeskszzyjcmm8zyx352|rule=b38s23|style=brief}})<br>
|viewerconfig = [[ AUTOSTART GPS 10 TRACKLOOP 190 -1/95 -1/38 ]]
}}


There are at least 692 variants of these in the simplest form of two engines,<ref name="dsmiller20160624" /> and many more such as one which deletes and recreates a blinker, resulting in a period of 380.<ref name="applebottom20161027" /> Many similar technologies result in puffers, rakes and the like.
There are at least 692 variants of these in the simplest form of two engines,<ref name="dsmiller20160624" /> and many more such as one which deletes and recreates a blinker, resulting in a period of 380.<ref name="applebottom20161027" /> Many similar technologies result in puffers, rakes and the like.


A third is a (101,3)c/1884 puffer.<ref name="calcyman20161109" /> Due to its massive ash trails no spaceships have been derived from it.
===Symmetric puffers===
 
The third is a natural 31c/589 diagonally-symmetric [[ark]], which has arisen several times in asymmetric soups. It emits two backward streams of gliders, which can lead to high-[[novelty]] interactions. One such example is a 750000-generation [[methuselah]] in which an ark is born and eventually destroyed by a retrograde glider produced from the chaos [[hassle]]d by the glider streams.
 
There is a similar 57c/488 orthogonally-symmetric puffer, but that has only arisen in soups with even orthogonal symmetry.
 
===(101,3)c/1884 oblique puffer===
 
The fourth is a (101,3)c/1884 puffer.<ref name="calcyman20161109" /> Due to its massive ash trails no spaceships have been derived from it.


==Universality==
==Universality==
The Turing-completeness of EightLife was mentioned in a poor quality article,<ref>{{cite web|url=http://repositorio.uam.es/bitstream/handle/10486/664759/fine_soler_JGPS_2013_ampl.pdf?sequence=2|title=Fine tuning explained? Multiverses and cellular automata|work=Journal for General Philosophy of Science|author=Francisco José Soler Gil, Manuel Alfonesca|date=July 2013|accessdate=January 21, 2017}}</ref> but the article failed to list the necessary patterns and reactions inherited from [[Conway's Game of Life]] for creating any kind of pattern that proves universality. The same applies to [[HoneyLife]] and [[EightLife]]; the latter rule has a constructive proof for its Turing-completeness.


Its Turing-completeness was mentioned in a poor quality article<ref>http://repositorio.uam.es/bitstream/handle/10486/664759/fine_soler_JGPS_2013_ampl.pdf?sequence=2</ref>, but it is baloney in this aspect, because didn't list the necessary patterns and reactions inherited from [[Conway's Game of Life]] for creating any kind of patterns that proves universality, just mentioning their existence. The same applies to [[HoneyLife]] and [[EightLife]]; the latter rule has a constructive proof for its Turing-completeness.
There is a proof sketch of Pedestrian Life's universality. It is on ConwayLife forums,<ref name="post38167" /> which contains a proof-scheme covering all rules in the [[outer-totalistic]] [[rulespace]] between [[B3/S23]] and B3678/S23678.
 
There is a proof sketch of Pedestrian Life's universality. It is on conwaylife forums<ref>{{cite web|url=http://conwaylife.com/forums/viewtopic.php?f=11&t=2597#p38167|title=List of the Turing-complete totalistic life-like CA}}</ref>, which contains a proof-scheme covering all rules that support [[glider]] and their [[rulestring]] matches B3[678]*/S23[678]*.


==References==
==References==
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|accessdate = November 19, 2016
|accessdate = November 19, 2016
|work      = ConwayLife.com forums
|work      = ConwayLife.com forums
}}</ref>
<ref name="post38167">{{LinkForumThread
|format = ref
|title  = Re: List of the Turing-complete totalistic life-like CA
|p      = 38167
|author = Peter Naszvadi
|date  = December 12, 2016
}}</ref>
}}</ref>
</references>
</references>

Revision as of 14:55, 9 August 2019

Pedestrian Life
x=0, y = 0, rule = B38/S23 ! #C [[ THEME Inverse ]] #C [[ RANDOMIZE2 RANDSEED 1729 THUMBLAUNCH THUMBNAIL THUMBSIZE 2 GRID ZOOM 6 WIDTH 600 HEIGHT 600 LABEL 90 -20 2 "#G" AUTOSTART PAUSE 2 GPS 8 LOOP 256 ]]
LifeViewer-generated pseudorandom soup
View static image
View animated image
Rulestring 23/38
B38/S23
Rule integer 6408
Character Chaotic
Black/white reversal B0123478/S1234678

Pedestrian Life is a Life-like cellular automaton in which cells survive from one generation to the next if they have 2 or 3 neighbours, and are born if they have 3 or 8 neighbours.

Many patterns from regular Life are compatible with this rule, since the rules differ only in one transition. However, traffic lights are much less common, as most predecessors tend to die, giving the rule its name.[1]

Notable patterns

The rule is particularly notable for its plurality of distinct natural linear growth mechanisms:

Rotating gun

The first is a statorless, rotating period-106 glider gun:

x = 8, y = 6, rule = B38/S23 o2bo$5bo$o3bob2o$o3bo$ob2o$obo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]]
The rotating p106 gun (Catagolue: here)

(click above to open LifeViewer)
RLE: here Plaintext: here

(5,2)c/190 spaceships

The second is a family of naturally occurring (5,2)c/190 oblique spaceships, using mechanisms meshed together similarly to switch engines:

x = 40, y = 28, rule = B38/S23 2o$2o2$8b2o$7bo2bo$5b2ob2o$5b2ob2o$7bo5$18b3o$18bobo$18b3o7$24b2o$23b 3o$23bo2bo$24b2o$37b2o$37bobo$38bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] [[ AUTOSTART GPS 10 TRACKLOOP 190 -1/95 -1/38 ]]
The first (5,2)c/190 oblique spaceship found (Catagolue: here)

(click above to open LifeViewer)
RLE: here Plaintext: here

There are at least 692 variants of these in the simplest form of two engines,[2] and many more such as one which deletes and recreates a blinker, resulting in a period of 380.[3] Many similar technologies result in puffers, rakes and the like.

Symmetric puffers

The third is a natural 31c/589 diagonally-symmetric ark, which has arisen several times in asymmetric soups. It emits two backward streams of gliders, which can lead to high-novelty interactions. One such example is a 750000-generation methuselah in which an ark is born and eventually destroyed by a retrograde glider produced from the chaos hassled by the glider streams.

There is a similar 57c/488 orthogonally-symmetric puffer, but that has only arisen in soups with even orthogonal symmetry.

(101,3)c/1884 oblique puffer

The fourth is a (101,3)c/1884 puffer.[4] Due to its massive ash trails no spaceships have been derived from it.

Universality

The Turing-completeness of EightLife was mentioned in a poor quality article,[5] but the article failed to list the necessary patterns and reactions inherited from Conway's Game of Life for creating any kind of pattern that proves universality. The same applies to HoneyLife and EightLife; the latter rule has a constructive proof for its Turing-completeness.

There is a proof sketch of Pedestrian Life's universality. It is on ConwayLife forums,[6] which contains a proof-scheme covering all rules in the outer-totalistic rulespace between B3/S23 and B3678/S23678.

References

  1. ↑ Tropylium (April 9, 2013). "Re: What do you want out of (conway's) life this year?". ConwayLife.com forums. Retrieved on June 24, 2016.
  2. ↑ David S. Miller (June 24, 2016). "Re: B38/S23". ConwayLife.com forums. Retrieved on October 31, 2016.
  3. ↑ Apple Bottom (October 27, 2016). "Re: Soup search results in rules other than Conway's Life". ConwayLife.com forums. Retrieved on October 31, 2016.
  4. ↑ Adam P. Goucher (November 9, 2016). "Re: Soup search results in rules other than Conway's Life". ConwayLife.com forums. Retrieved on November 19, 2016.
  5. ↑ Francisco José Soler Gil, Manuel Alfonesca (July 2013). "Fine tuning explained? Multiverses and cellular automata". Journal for General Philosophy of Science. Retrieved on January 21, 2017.
  6. ↑ Peter Naszvadi (December 12, 2016). Re: List of the Turing-complete totalistic life-like CA (discussion thread) at the ConwayLife.com forums

External links

Pedestrian Life at Adam P. Goucher's Catagolue Pedestrian Life at David Eppstein's Glider Database

Retrieved from "https://conwaylife.com/w/index.php?title=OCA:Pedestrian_Life&oldid=63222"