Difference between revisions of "Oblique spaceship"

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(I kinda doubt whether this extra column is really necessary, but-- as long as it exists the figures should at least be right.)
(note about 0E0P metacell)
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! Movement
! Movement
! Maximum speed<br> (Life)
! Maximum speed<br> (Life)
! Absolute maximum<br>([[Non-totalistic Life-like cellular automaton|all range-1 rules]])
! Example
! Example
|-
| (0''m'',''m'')/''n''
| orthogonal ship
| orthogonal<br>(rookwise)
| c/2
| c
| [[Lightweight spaceship]]*
|-
| (1''m'',''m'')/''n''
| diagonal ship
| diagonal<br>(bishopwise)
| c/4
| c/2
| [[glider]]*
|-
|-
| (2''m'',''m'')/''n''
| (2''m'',''m'')/''n''
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| knightwise
| knightwise
| (2,1)c/6
| (2,1)c/6
| (2,1)c/3
| [[Sir Robin]]*
| [[Sir Robin]]*
|-
|-
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| camelwise
| camelwise
| (3,1)c/8
| (3,1)c/8
| (3,1)c/4
| [[Camelship]]
| [[Gemini 3]]
|-
|-
| (4''m'',''m'')/''n''
| (4''m'',''m'')/''n''
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| giraffewise
| giraffewise
| (4,1)c/10
| (4,1)c/10
| (4,1)c/5
| ''none found''
| ''none found''
|-
|-
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| ibiswise
| ibiswise
| (5,1)c/12
| (5,1)c/12
| (5,1)c/6
| [[Gemini]]
| [[Gemini]]
|-
|-
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| flamingowise
| flamingowise
| (6,1)c/14
| (6,1)c/14
| (6,1)c/7
| ''none found''
| ''none found''
|-
|-
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| zebrawise
| zebrawise
| (3,2)c/10
| (3,2)c/10
| (3,2)c/5
| ''none found''
| ''none found''
|-
|-
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| antelopewise
| antelopewise
| (4,3)c/14
| (4,3)c/14
| (4,3)c/7
| ''none found''
| ''none found''
|-
|-
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|  
|  
| (23,5)c/56
| (23,5)c/56
| (23,5)c/28
| [[waterbear]]
| [[waterbear]]
|-
|-
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<nowiki>*</nowiki>''Spaceship is elementary''
<nowiki>*</nowiki>''Spaceship is elementary''


A full list of spaceships in Life can be seen at [[List of spaceships]]; further spaceships in arbitrary isotropic non-totalistic rules are catalogued at [[LifeWiki:Smallest Spaceships Supporting Specific Speeds|the 5s project]].
A full list of spaceships in Life can be seen at [[List of spaceships]]. Further spaceships in arbitrary isotropic non-totalistic rules are catalogued at [[LifeWiki:Smallest Spaceships Supporting Specific Speeds|the 5s project]]; these can be emulated to produce a spaceship with equivalent [[slope]] in Life using the [[0E0P metacell]], but no examples have been explicitly constructed yet.


==History==
==History==
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In March 2018, [[Adam P. Goucher]] and [[Tomas Rokicki]] discovered [[Sir Robin]], the first elementary oblique ship. It is the fastest knightship and lowest-period oblique ship possible, and also the smallest known oblique ship.
In March 2018, [[Adam P. Goucher]] and [[Tomas Rokicki]] discovered [[Sir Robin]], the first elementary oblique ship. It is the fastest knightship and lowest-period oblique ship possible, and also the smallest known oblique ship.
In December 2018, [[Chris Cain]] completed a new diagonal loop design for a small-step oblique spaceship, a true [[camelship]] with a (3,1) step size in each cycle instead of the (3072,1024) step distance of the [[Gemini 3|adjusted Gemini]] spaceship.


==Other rules==
==Other rules==
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These natural spaceships and puffers are qualitatively different from any in Life, which are either large engineered constructions or, in the case of [[Sir Robin]], the result of extensive computer search.
These natural spaceships and puffers are qualitatively different from any in Life, which are either large engineered constructions or, in the case of [[Sir Robin]], the result of extensive computer search.


==Also see==
==See also==
* [[Knightship]]
* [[Knightship]]
* [[Types of spaceships]]
* [[Types of spaceships]]
==External links==
{{LinkLexicon|lex_o.htm#oblique|name=Oblique}}

Revision as of 00:59, 6 January 2020

An oblique spaceship is a spaceship which moves neither orthogonally nor diagonally.

The simplest type is a knightship, so called because it moves parallel to a knight in chess. By analogy with the corresponding fairy chess pieces, the following other terms may be used to designate spaceships with different slopes:

Type Ship Movement Maximum speed
(Life)
Example
(2m,m)/n knightship knightwise (2,1)c/6 Sir Robin*
(3m,m)/n camelship camelwise (3,1)c/8 Camelship
(4m,m)/n giraffeship giraffewise (4,1)c/10 none found
(5m,m)/n ibisship ibiswise (5,1)c/12 Gemini
(6m,m)/n flamingoship flamingowise (6,1)c/14 none found
(3m,2m)/n zebraship zebrawise (3,2)c/10 none found
(4m,3m)/n antelopeship antelopewise (4,3)c/14 none found
...
(23m,5m)/n (23,5)c/56 waterbear

*Spaceship is elementary

A full list of spaceships in Life can be seen at List of spaceships. Further spaceships in arbitrary isotropic non-totalistic rules are catalogued at the 5s project; these can be emulated to produce a spaceship with equivalent slope in Life using the 0E0P metacell, but no examples have been explicitly constructed yet.

History

The first oblique spaceship was Andrew Wade's ibisship Gemini, based on the Chapman-Greene universal constructor. Dave Greene proceeded to build variants, called Geminoids, travelling in a variety of directions.

In early 2014, a collaborative effort was launched to build a half-baked knightship, which translates itself by (6, 3) each period and is therefore a knightship. Chris Cain optimised the construction to yield a smaller and faster parallel HBK.

In December 2014, Brett Berger constructed the first fast oblique spaceship in Conway's Game of Life, the waterbear, moving at a velocity of (23,5)c/79. It has a bounding box very slightly smaller than the parallel HBK. With a period of 158, it is the lowest-period oblique spaceship other than Sir Robin.

In March 2018, Adam P. Goucher and Tomas Rokicki discovered Sir Robin, the first elementary oblique ship. It is the fastest knightship and lowest-period oblique ship possible, and also the smallest known oblique ship.

In December 2018, Chris Cain completed a new diagonal loop design for a small-step oblique spaceship, a true camelship with a (3,1) step size in each cycle instead of the (3072,1024) step distance of the adjusted Gemini spaceship.

Other rules

(5,2)c/190 oblique spaceship in Pedestrian Life (B38/S23)

Many automata extremely similar to Life have oblique ships and related technology. For example, Pedestrian Life has a naturally-occuring family of (5,2)c/190 ships, as well as a natural (101,3)c/1884 puffer; tDryLife has a slope 3 ship puffer that can be stabilized into a spaceship.

These natural spaceships and puffers are qualitatively different from any in Life, which are either large engineered constructions or, in the case of Sir Robin, the result of extensive computer search.

See also

External links