Gemini

Gemini
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Pattern type	Spaceship
Number of cells	846278
Bounding box	4217807 × 4220191
Direction	Oblique
Slope	5
Period	33699586 (mod: 33699586)
Speed	(2560,512)c/16849793 | (5120,1024)c/33699586
Heat	Unknown
Kinetic symmetry	n
Discovered by	Andrew J. Wade
Year of discovery	2010
Rules Outer-totalistic rules B3/S23 only # of rules 20 = 1
Glider synthesis Fewest gliders 173449† Uploaded synthesis RLE gemini_synth.rle †Can be constructed with 15 gliders using the reverse caber tosser universal constructor.
Pattern files Macrocell gemini.mc Zip archive gemini.zip

Gemini is the first oblique spaceship to be constructed, and was created by Andrew J. Wade in 2010. It displaces itself by 5,120 cells vertically and 1,024 cells horizontally every 33,699,586 generations, and is therefore an ibisship. It derives its name from the latin, gemini, meaning twins, describing its 2 identical halves, each of which contains three Chapman-Greene construction arms. A tape of gliders continually relays between the two halves, instructing each to delete its parent and construct a daughter configuration.

It is the largest spaceship in terms of its diameter and bounding box, but has a much smaller population than the Caterpillar.

The pattern marks the thirteenth explicitly-constructed spaceship velocity, but facilitates an infinite range of related velocities. For example, Dave Greene has reduced its period by eight generations, whilst maintaining its displacement. Theoretically speaking, a Gemini-esque spaceship could be constructed with any velocity slower than (but not equal to) (1,1)c/580. In June 2010, Greene also constructed slope-2 and slope-3 versions of the spaceship.

Gemini was voted Pattern of the Year for 2010 on the ConwayLife.com forums.

Videos

Click to load content Various zoom levels of gemini demonstrating its size

Click to load content Some of Gemini's features (with CA music)

Pattern files

• Gemini
• Gemini 2
• Gemini 3

See also

• Geminoid
• Replicator
• Half-baked knightship

External links

• Gemini at the Life Lexicon
• New Scientist: First replicating creature spawned in life simulator
• Gemini guns at Game of Life News. Posted by Adam P. Goucher on July 30, 2010.
• downloadable zip of the Gemini RLE file (Google is not allowing to download the file, but you can Share->Email as attachment to yourself)
• Gemini RLE file with programs used to construct it (on Google docs so download quota may be exceeded by the time you attempt download.)
• Gemini RLE file with programs used to construct it (alternate download on drop.io)