Difference between revisions of "Types of spaceships"

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{{Glossary}}
{{Glossary}}
There are many different '''types of [[spaceships]]''' in [[Conway's Game of Life]] and related [[cellular automaton|automata]]. The following are the terminology that are in common use. This page contains only very general terminology that applies to wide varieties of spaceships.
There are many different '''types of [[spaceships]]''' in [[Conway's Game of Life]] and related [[cellular automaton|automata]]. The following are the terminology that are in common use. This page contains only very general terminology that applies to wide varieties of spaceships.


==Universal classifications==
==Universal classifications==
 
Classifications that apply to both elementary and engineered (see below) spaceships.
Classifications that apply to both elementary and engineered spaceships.


===Flipper===
===Flipper===
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===Non-monotonic spaceship===
===Non-monotonic spaceship===
A spaceship is said to be '''non-monotonic''' if its [[bounding_box#Leading_edge|leading edge]] falls back in some [[generation]]s. The first non-monotonic spaceship to be found was the diagonal [[13-engine Cordership]], by [[Dean Hickerson]] in April [[:Category:Patterns found in 1991|1991]]. The [[non-monotonic spaceship 1|first orthogonal example]] was found by [[:Category:Patterns found by Hartmut Holzwart|Hartmut Holzwart]] in August [[:Category:Patterns found in 1992|1992]], which has period [[:Category:Spaceships with period 4|4]] and travels at speed [[:Category:Spaceships with speed c/4|c/4]]. In April [[:Category:Patterns found in 1994|1994]], Holzwart found examples of period [[:Category:Spaceships with period 3|3]] spaceships with this property, and this is clearly the smallest possible period. Another well-known non-monotonic spaceship is the [[weekender]]. [[114P6H1V0]]'s front part is non-monotonic, and so is the whole ship (unless its corresponding pushalong is introduced).
A spaceship is said to be '''non-monotonic''' if its [[bounding_box#Leading_edge|leading edge]] falls back in some [[generation]]s - i.e., the frontmost row doesn't always move forward or stay where it is. The first non-monotonic spaceship to be found was the diagonal [[13-engine Cordership]], by [[Dean Hickerson]] in April [[:Category:Patterns found in 1991|1991]]. The [[non-monotonic spaceship 1|first orthogonal example]] was found by [[:Category:Patterns found by Hartmut Holzwart|Hartmut Holzwart]] in August [[:Category:Patterns found in 1992|1992]], which has period [[:Category:Spaceships with period 4|4]] and travels at speed [[:Category:Spaceships with speed c/4|c/4]]. In April [[:Category:Patterns found in 1994|1994]], Holzwart found examples of period [[:Category:Spaceships with period 3|3]] spaceships with this property, and this is clearly the smallest possible period. Another well-known non-monotonic spaceship is the [[weekender]]. [[114P6H1V0]]'s front part is non-monotonic, and so is the whole ship (unless its corresponding pushalong is introduced).
 
===Oblique spaceship===
{{Main|Oblique spaceship}}
An '''oblique spaceship''' is a spaceship that moves neither orthogonally nor diagonally. Knightships (''infra'') are the simplest example of oblique spaceships; others include [[Andrew J. Wade]]'s [[ibisship]] [[Gemini]], and [[Brett Berger]]'s [[Waterbear]], with a [[displacement]] of (23,5) every 79 [[generation]]s.
 
===Knightship===
{{Main|Knightship}}
 
[[File:Sirrobin tiny.png|framed|right|[[Sir Robin]], the first elementary knightship to be found.<br />{{JavaRLE|sirrobin}}]]A '''knightship''' is a spaceship of type (2''m'',''m'')/''n'' (that is, a spaceship that moves two [[cell]]s horizontally for every one cell it moves vertically).
 
Various large [[knightship]]s have been constructed since {{year|2010}}; the first truly elementary knightship, [[Sir Robin]], was found by [[Adam P. Goucher]] on March 6, {{year|2018}}, based on a partial by [[Tomas Rokicki]].


==Elementary classifications==
==Elementary classifications==
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===Smoking ship===
===Smoking ship===
A '''smoking ship''' is a spaceship that produces [[smoke]]. If the smoke extends past the edge of the rest of the spaceship, then it can be used to perturb other objects as the spaceship passes by. Running [[glider]]s into the smoke is often a good way to turn or duplicate them, or convert them into other objects. Sometimes the smoke from a smoking ship may itself be perturbed by accompanying spaceships in order to form a puffer. Simple examples of a smoking ship are [[Schick engine]] and [[Coe ship]]. Sometimes combinations of smoking tagalongs are puffers - such as a P48 blinker puffer produced by attaching two Coe engines to LWSS's pulling the Schick engine.
A '''smoking ship''' (or '''smoky ship''') is a spaceship that produces [[smoke]]. If the smoke extends past the edge of the rest of the spaceship, then it can be used to perturb other objects as the spaceship passes by. Running [[glider]]s into the smoke is often a good way to turn or duplicate them, or convert them into other objects. Sometimes the smoke from a smoking ship may itself be perturbed by accompanying spaceships in order to form a puffer. Simple examples of a smoking ship are [[Schick engine]], [[Ecologist]], [[Pufferfish spaceship]] and [[Coe ship]]. Sometimes combinations of smoking tagalongs are puffers - such as a P48 blinker puffer produced by attaching two Coe engines to LWSS's pulling the Schick engine.
 
===Spaceship made of spaceships===
A '''[[SMOS|spaceship made of spaceships]] (SMOS)''' is a spaceship consisting of multiple other spaceships colliding with one another and eventually regenerating themselves in a different position.


==Engineered classifications==
==Engineered classifications==


Classifications that apply only to [[Spaceship#Engineered spaceships|engineered]] and [[Spaceship#Engineerable spaceships|engineerable spaceships]].
Classifications that apply only to [[Spaceship#Engineered spaceships|engineered]] and [[Spaceship#Adjustable_spaceships|adjustable spaceships]].


===Self-constructing spaceship===
===Self-constructing spaceship===
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A similar "Geminoid" construction mechanism has been shown to be workable in the Conway's Life [[replicator]].  Geminoids may use either a pair of (much smaller) universal constructors, or just a single constructor for both ends of the spaceship.
A similar "Geminoid" construction mechanism has been shown to be workable in the Conway's Life [[replicator]].  Geminoids may use either a pair of (much smaller) universal constructors, or just a single constructor for both ends of the spaceship.
Several designs have been proposed for Geminoid spaceships<ref>{{cite web|url=http://conwaylife.com/forums/viewtopic.php?f=2&t=1006/|title=Geminoid Challenge forum discussion|accessdate=July 23, 2014}}</ref>, and some theoretical work has been done resulting in a completed Geminoid spaceship pattern in a model rule.<ref>{{cite web|url=http://conwaylife.com/forums/viewtopic.php?f=11&t=1353|title=Geminoid Particles rule forum discussion|accessdate=July 23, 2014}}</ref>.  As of November 2015, the only Geminoid spaceship completed for any Lifelike rule is the diagonally traveling "[[Demonoid]]".
Several designs have been proposed for Geminoid spaceships<ref>{{cite web|url=http://conwaylife.com/forums/viewtopic.php?f=2&t=1006/|title=Geminoid Challenge forum discussion|accessdate=July 23, 2014}}</ref>, and some theoretical work has been done resulting in a completed Geminoid spaceship pattern in a model rule.<ref>{{cite web|url=http://conwaylife.com/forums/viewtopic.php?f=11&t=1353|title=Geminoid Particles rule forum discussion|accessdate=July 23, 2014}}</ref>.  As of August 2017, the only Geminoid spaceships completed for any Lifelike rule are the diagonally traveling "[[Demonoid]]"s and the rookwise "[[Orthogonoid]]".
 
===Knightship===
[[Image:AlmostKnightship.png|framed|right|An "almost knightship"<br />{{JavaRLE|almostknightship}}]]A '''knightship''' is a spaceship of type (2m,m)/n (that is, a spaceship that moves two [[cell]]s horizontally for every one cell it moves vertically). Knightships must be asymmetric and their period must be at least 6, which makes searching for them using programs like [[lifesrc]] very difficult. An elementary would-be knightship, dubbed "[[almost knightship]]" was found by [[Eugene Langvagen]] on March 23, [[:Category:Patterns found in 2004|2004]], which would be a period-6 knightship if it weren't for two cells that are incorrect in its sixth generation.<ref>{{cite web|url=http://plife.sourceforge.net/|title=PLife Home Page|accessdate=May 22, 2009}}</ref>
 
By analogy with the corresponding fairy chess pieces, spaceships of types (3m,m)/n, (3m,2m)/n and (4m,m)/n would presumably be called camelships, zebraships and giraffeships, respectively.
 
Alternatively, 'knightship' may refer to any spaceship that travels in an oblique direction (not diagonally or orthogonally). In June, 2010 [[Dave Greene]] constructed the first true knightship in Life, which is based on Gemini and travels at a velocity of (4096,8192)/c35567490.<ref>[http://www.conwaylife.com/forums/viewtopic.php?f=2&t=406&start=25a#p2578 post] on the conwaylife.com forums</ref>.
 
In July 2014, a knightship, based on a different principle and dubbed [[half-baked knightship]], was built in a joint effort.
Very slow self-constructing knightships with the minimum step size of (2,1) -- or spaceships with any other (x,y) step size -- can now be created using known Geminoid technology.  The general method involves programming a universal constructor to build large constellations of objects.  These "seed" constellations are designed to be triggered by a single glider collision, to produce a [[slow salvo]] capable of destroying and rebuilding the universal constructor at the correct offset.  No examples have been completed as of December 2014.
 
In December 2014, Brett Berger constructed a [[waterbear|(23,5)c/79 knightship]], the first "fast" knightship in Conway's Game of Life.
 
Many automata extremely similar to Life have Knightship sand related technology. One notable example is [[Pedestrian Life]], possessing families of [[(5,2)c/190]] natural engineered ships paralleling the [[Cordership]]s ([[Corderoid]] technology), and an extremely messy [[(101,3)c/1884]] puffer has been found to occur naturally. [[tdrylife]] possesses a slope 3 ship puffer which can also be stabilised.


==See also==
==See also==
* [[List of spaceships]]
* [[:Category:Glide symmetric spaceships|List of glide symmetric spaceships]]
* [[:Category:Glide symmetric spaceships|List of glide symmetric spaceships]]
* [[:Category:Non-monotonic spaceships|List of non-monotonic spaceships]]
* [[:Category:Non-monotonic spaceships|List of non-monotonic spaceships]]
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==External links==
==External links==
*[http://www.argentum.freeserve.co.uk/lex.htm The Life Lexicon]
{{LinkLexicon|lex.htm|name=Introduction}}
{{LinkEppstein|page=gliders/knightships.html|name=The off-slope gliders}}
 
[[Category:Everything else]]
[[Category:Everything else]]

Revision as of 18:33, 6 December 2018

There are many different types of spaceships in Conway's Game of Life and related automata. The following are the terminology that are in common use. This page contains only very general terminology that applies to wide varieties of spaceships.

Universal classifications

Classifications that apply to both elementary and engineered (see below) spaceships.

Flipper

A flipper is a spaceship (or oscillator) that forms its mirror image halfway through its period. All flipper spaceships are glide symmetric and conversely all glide symmetric spaceships are flippers. All of the functional standard spaceships are flippers.

Glide symmetric spaceship

A spaceship is said to be glide symmetric if it undergoes reflection and translation simultaneously. It is not difficult to show that a spaceship is glide symmetric if and only if it is a flipper.

Non-monotonic spaceship

A spaceship is said to be non-monotonic if its leading edge falls back in some generations - i.e., the frontmost row doesn't always move forward or stay where it is. The first non-monotonic spaceship to be found was the diagonal 13-engine Cordership, by Dean Hickerson in April 1991. The first orthogonal example was found by Hartmut Holzwart in August 1992, which has period 4 and travels at speed c/4. In April 1994, Holzwart found examples of period 3 spaceships with this property, and this is clearly the smallest possible period. Another well-known non-monotonic spaceship is the weekender. 114P6H1V0's front part is non-monotonic, and so is the whole ship (unless its corresponding pushalong is introduced).

Oblique spaceship

Main article: Oblique spaceship

An oblique spaceship is a spaceship that moves neither orthogonally nor diagonally. Knightships (infra) are the simplest example of oblique spaceships; others include Andrew J. Wade's ibisship Gemini, and Brett Berger's Waterbear, with a displacement of (23,5) every 79 generations.

Knightship

Main article: Knightship
Sir Robin, the first elementary knightship to be found.
Download RLE: click here

A knightship is a spaceship of type (2m,m)/n (that is, a spaceship that moves two cells horizontally for every one cell it moves vertically).

Various large knightships have been constructed since 2010; the first truly elementary knightship, Sir Robin, was found by Adam P. Goucher on March 6, 2018, based on a partial by Tomas Rokicki.

Elementary classifications

Classifications that only apply to elementary spaceships.

Standard spaceship

A standard spaceship is a glider, lightweight spaceship, middleweight spaceship, or heavyweight spaceship. That is, it is one of the original spaceships that have been known since 1970. Many failed standard spaceships like the overweight spaceship and the b-heptomino as well as the hassled object in the roteightor also display standard-like behavior and can be hassled. Nontrivial flotillae of interacting elementary spaceships do not count as standard spaceships. A non-standard spaceship is any other spaceship.

Edge-repair spaceship

An edge-repair spaceship is a spaceship that has an edge that possesses no spark and yet is able to perturb things because of its ability to repair certain types of damage to itself. The most useful example is edge-repair spaceship 1, which can destroy Herschels as it travels. Another well-known example is edge-repair spaceship 2, which can destroy beehives.

Flotilla

A flotilla is a spaceship composed of a number of smaller interacting spaceships. Often one or more of these is not a true spaceship and could not survive without the support of the others. Flotilla 1 is the most common example, and it contains an overweight spaceship escorted by two heavyweight spaceships.

Frothing spaceship

A frothing spaceship is a spaceship whose back end appears to be unstable and breaking apart, but which nonetheless survives (compare with frothing puffer). The exhaust festers and clings to the back of the spaceship before breaking off.

Smoking ship

A smoking ship (or smoky ship) is a spaceship that produces smoke. If the smoke extends past the edge of the rest of the spaceship, then it can be used to perturb other objects as the spaceship passes by. Running gliders into the smoke is often a good way to turn or duplicate them, or convert them into other objects. Sometimes the smoke from a smoking ship may itself be perturbed by accompanying spaceships in order to form a puffer. Simple examples of a smoking ship are Schick engine, Ecologist, Pufferfish spaceship and Coe ship. Sometimes combinations of smoking tagalongs are puffers - such as a P48 blinker puffer produced by attaching two Coe engines to LWSS's pulling the Schick engine.

Spaceship made of spaceships

A spaceship made of spaceships (SMOS) is a spaceship consisting of multiple other spaceships colliding with one another and eventually regenerating themselves in a different position.

Engineered classifications

Classifications that apply only to engineered and adjustable spaceships.

Self-constructing spaceship

The first oblique spaceship to be discovered, Gemini, was found in May, 2010 with a velocity of (5120,1024)c/33699586. It uses twin universal constructor mechanisms sharing a single construction recipe in the form of long streams of gliders. Each universal constructor builds a copy of itself at a fixed offset, while simultaneously disassembling the previous copy of itself and reflecting the construction recipe 180 degrees to feed into the new copy of its twin.

A similar "Geminoid" construction mechanism has been shown to be workable in the Conway's Life replicator. Geminoids may use either a pair of (much smaller) universal constructors, or just a single constructor for both ends of the spaceship. Several designs have been proposed for Geminoid spaceships[1], and some theoretical work has been done resulting in a completed Geminoid spaceship pattern in a model rule.[2]. As of August 2017, the only Geminoid spaceships completed for any Lifelike rule are the diagonally traveling "Demonoid"s and the rookwise "Orthogonoid".

See also

References

  1. "Geminoid Challenge forum discussion". Retrieved on July 23, 2014.
  2. "Geminoid Particles rule forum discussion". Retrieved on July 23, 2014.

External links