From LifeWiki
Jump to: navigation, search
2bo$2o$o2b3o2bo$o4b3o$b3o2b2o2$b3o2b2o$o4b3o$o2b3o2bo$2o$2bo! #C [[ THEME 6 GRID GRIDMAJOR 0 THUMBLAUNCH AUTOSTART ]] #C [[ TRACKLOOP 4 -1/2 0 THUMBSIZE 2 GPS 4 ]]
Pattern type Spaceship
Number of cells 34
Bounding box 9×11
Direction Orthogonal
Period 4
Mod 4
Speed c/2
Heat 31
Discovered by Hartmut Holzwart
Year of discovery 1992

x66 is a period 4 spaceship with speed c/2 that was found by Hartmut Holzwart in July 1992. One of the symmetric halves can alternatively be escorted by a heavyweight spaceship. Its name refers to the fact that every cell (alive or dead) has at most 6 live neighbours (in contrast to spaceships based on lightweight spaceships, middleweight spaceships, or heavyweight spaceships). In fact, this spaceship was found via a search with this restriction. From this follows that the spaceship is stable also in Life-like rules allowing birth or survival for a cell with 7 or 8 neighbors.

x66 was first synthesized on January 11, 2015, requiring 166 gliders. After the emergence of this spaceship in a symmetrical soup on March 8, 2015,[1] this was drastically reduced to 13 gliders.

Half of x66 can be supported by a heavyweight spaceship. Since the heavyweight spaceship is glide symmetric, it can support two halves at once, or one half alongside a sidecar.

Image gallery

Half of x66 supported by a heavyweight spaceship
RLE: here

See also


  1. flipper77 (March 8, 2015). "Re: Soup search results". Retrieved on March 18, 2016.

External links

  • x66 at the Life Lexicon