The Caterpillar is the first 17c/45 spaceship that was constructed, and is the first engineered spaceship, making use of the 17c/45 reaction. It was created via a combination of manually-constructed parts put together by David Bell, Jason Summers and Gabriel Nivasch and a computer-aided construction coded by Nivasch. The Caterpillar's construction took place over a long period of time, but it was completed on December 31, 2004.
Caterpillar is, in terms of its minimum 11,880,063 alive cells, by far the largest interesting pattern that has been constructed in Life. By comparison, the Spartan universal computer-constructor has a larger bounding box, but only half a million live cells. The image to the right is zoomed out to a scale of 32 cells per pixel and still only shows the top 3% of it. Encoded as an RLE file, it is over 29MB in size. Despite this, it moves at the speed of 17c/45, which is the fourth fastest orthogonal speed with a known spaceship.
The whole spaceship (512 cells/pixel)
Full view of caterpillar (click to view)
- "The 17c/45 Caterpillar spaceship". Gabriel Nivasch's Life page (January 2005). A "brief overview" of how the Caterpillar works (with illustrations and RLE files of parts), the pattern in RLE format, plus complete C++ & RLE sources for assembling it.
- "17c/45 "Caterpillar" spaceship". Jason Summer's Life page. A short summary of what the Caterpillar is with a few pictures, plus the pattern in RLE and .mc (macrocell) formats. Golly loads the macrocell file much more quickly than the RLE.
- The Caterpillar (glider 1) at David Eppstein's Glider Database