Caterloopillar

Caterloopillar
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Pattern type	Spaceship
Number of cells	232815
Bounding box	734 × 514927
Direction	Orthogonal
Period	2000
Mod	Unknown
Speed	c/8 | Unknown
Heat	Unknown
Discovered by	Michael Simkin
Year of discovery	2016
Rules Outer-totalistic rules B3/S23 only # of rules 20 = 1

Caterloopillar is the name given to a family of spaceships containing two major parts - the front and the back. In Caterloopillar each part has the properties of universal construction, and thus each part is constructing the building blocks of the other part, while also reading and moving a construction tape. As the name suggests, this creates somewhat paradoxical design, similar to the Strange loop concept.

The general design was proposed by David Bell in October 2006 in LifeCA mailing list and allegedly earlier and independently by Jason Summers. The first Caterloopillar was constructed by Michael Simkin and completed on April 9, 2016. This Caterloopillar has a speed of c/8.

Caterloopillars with many other speeds can be constructed using a slightly modified design. The major limitation of this design is upper bound of speed c/4, as the signal transferring is done by converting a still life into a glider and back, thus limiting the moving speed of the tape to c/4 (the speed of the glider).

See also

• Caterpillar

External links

• Michael Simkin (April 9, 2016). "Caterloopillar WIP (all speeds < c/4)".
• Hartmut Holzwart (September 11, 2014). "David Bell's engineless caterpillar idea revisited".
• Caterloopillar GitHub repository
• Caterloopillar c/8 RLE file