Unidimensional spaceship
A unidimensional spaceship is a spaceship which is one cell thick (unidimensional) in at least one of its phases.
History
Following a 9-year collaboration with several contributors which began in 2016[1], on December 1, 2025, the first unidimensional spaceship in Conway's Game of Life was completed by Hippo.69.[2] It works by using a line-of-six spark to start a blinker fuse, which burns through various different spacings of blinkers to produce spaceships. Those spaceships build a tape reader using slow salvo construction, which reads the long, sparse tape consisting of blinkers to build a universal constructor to rebuild the spaceship at a different location.
5 weeks after the first version, Hippo.69 constructed unidimensional spaceship 2, over 4 times smaller in bounding box length, period and population.[3] Much of the reduction was the result of a tape-reading mechanism that required only 3 slow glider pairs instead of 8, resulting in a much smaller initial fuse, combined with a more efficient mechanism of rebuilding the fuse.
On January 30, 2026, Hippo.69 went on to complete the third version with a better fuse arm[4], then built a fourth version on February 9.[5] On March 31, they completed unidimensional spaceship 5[6].
All currently known unidimensional spaceships in Life are glider constructible using 2 gliders per blinker and a simple pi-heptomino-based activation step.[7]
Below is a list of the statistics of each version of the unidimensional spaceship:
| Name | Length (thinnest phase) | Population (thinnest phase) | Period | Unsimplified velocity | Simplified velocity |
|---|---|---|---|---|---|
| Unidimensional spaceship 1 | 3,707,300,605 | 30,555,709 | 133,076,755,768 | 2c/133,076,755,768 | c/66,538,377,884 |
| Unidimensional spaceship 2 | 795,435,669 | 6,287,417 | 28,409,785,756 | 2c/28,409,785,756 | c/14,204,892,878 |
| Unidimensional spaceship 3 | 776,525,415 | 6,107,918 | 27,735,693,820 | 2c/27,735,693,820 | c/13,867,846,910 |
| Unidimensional spaceship 4 | 776,725,863 | 6,109,652 | 20,345,730,556 | 2c/20,345,730,556 | c/10,172,865,278 |
| Unidimensional spaceship 5 | 544,434,677 | 3,972,769 | 15,614,654,328 | 2c/15,614,654,328 | c/7,807,327,164 |
Because of the symmetry of unidimensional patterns, all unidimensional spaceships in Life can only travel orthogonally along its long axis.
References
- ↑ Adam P. Goucher (February 15, 2016). How about a unidimensional spaceship? (discussion thread) at the ConwayLife.com forums
- ↑ Hippo.69 (December 1, 2025). Re: How about a unidimensional spaceship? (discussion thread) at the ConwayLife.com forums
- ↑ Hippo.69 (January 4, 2026). Re: How about faster unidimensional spaceship (discussion thread) at the ConwayLife.com forums
- ↑ Hippo.69 (January 30, 2026). Re: How about faster unidimensional spaceship (discussion thread) at the ConwayLife.com forums
- ↑ Hippo.69 (February 9, 2026). Re: How about faster unidimensional spaceship (discussion thread) at the ConwayLife.com forums
- ↑ Hippo.69 (March 31, 2026). Re: How about faster unidimensional spaceship (discussion thread) at the ConwayLife.com forums
- ↑ I6_I6 (January 4, 2026). Re: How about a unidimensional spaceship? (discussion thread) at the ConwayLife.com forums