Half-baked knightship

Half-baked knightship
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Pattern type	Spaceship
Family	Half-baked knightship
Number of cells	1049395
Bounding box	450801 × 461227
Direction	Oblique
Slope	2
Period	2621440
Mod	Unknown
Speed	(6,3)c/2621440 | (6,3)c/2621440
Heat	Unknown
Discovered by	Adam P. Goucher Chris Cain Dave Greene Ivan Fomichev
Year of discovery	2014
Rules Outer-totalistic rules B3/S23 only # of rules 20 = 1
Pattern files Macrocell halfbakedknightship.mc

Half-baked knightship is a class of knightship based on the well-known half-bakery reaction with a glider. It is a self-supporting macro-spaceship, as contrasted with the elementary Sir Robin. Half-baked knightships were the smallest known oblique spaceships in Conway's Game of Life both in terms of the bounding box and minimum population until December 2014 when the waterbear was discovered with a smaller bounding box. The Gemini and its derivatives, the only formerly known oblique spaceships, step farther in each period in spite of their larger size and population, so they travel much faster than half-bakery knightships.

In May 2014 Ivan Fomichev found the key reactions, which allow long chains of half-bakeries to regenerate themselves at (6, 3), and also to regenerate seed constellations at one end of the ship. When triggered, the seeds produce the small glider salvos that mediate the (6, 3) offset reaction. Components and slow salvo syntheses for the ship were found by the combined efforts of Chris Cain, Ivan Fomichev and Dave Greene.

Adam P. Goucher proposed the base design for the ship, and in July 2014 wrote a Golly script that assembled the components into an unoptimised but working half-baked knightship of any sufficiently large period. An example was posted for period 2621440.

Several days later, Chris Cain wrote an alternative assembly script that built a parallel HBK an order of magnitude smaller, using a more sophisticated design with the most efficient known components.

Half-baked knightships are the first family of patterns to demonstrate universal construction capability using monochromatic slow salvos -- all gliders the same color. They are also the first known spaceship family with adjustable velocity but fixed slope.

The half-baked knightships ranked third place in the Pattern of the Year 2014 competition in a belated vote held in 2018 on the ConwayLife.com forums, behind the centipede and the waterbear.

See also

• Parallel HBK
• Caterpillar
• Gemini
• Slow salvo

External links

• Half-baked knightship at the Life Lexicon