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Waterbear image
Pattern type Spaceship
Number of cells 197896
Bounding box 13295×28010
Direction Oblique
Slope 23/5
Period 158
Mod 158
Speed (23,5)c/79
Heat 160959.2
Discovered by Brett Berger
Ivan Fomichev
Year of discovery 2014

Waterbear is an oblique spaceship constructed by Brett Berger on December 28, 2014.[1] It was the smallest (in terms of bounding box) known oblique spaceship, superseding parallel HBK, until the discovery of Sir Robin in March 2018. It was also the first "fast" oblique spaceship discovered in Conway's Game of Life.

The helix, fanout devices and syntheses for the helix were found by Ivan Fomichev.


The base reaction consists of a crawler consisting of a Herschel running on a track of gliders. The Herschel consumes a southwest glider and emits two gliders, one southwest and the other southeast, every 79 generations. Interactions between neighboring tracks[2] are used to create the necessary components to recreate the helix.

In July 2013, Ivan Fomichev proposed a very rough blueprint for the spaceship giving the shape below.[3]
The first outline of the shape a (23,5)c/79 spaceship would take.

Being made from gliders, the track gradually moves away from the helix, giving rise to the triangular bodies. This increasing distance means that each new *WSS added to the helix requires a proportionally larger addition to the length of the waterbear than the previous helix addition. A waterbear composed of a single large triangle would be somewhat easier to construct, but it would be unnecessarily large.

To avoid this problem, the same procedure used to build the helix can be used to "reset" the track. In the Waterbear design, this reset occurs at two points, resulting in three smaller triangles instead of one much larger one. The reset comes at the cost of a fair amount of output-suppressing cleanup, so the design balances the exponential size increase with the constant cleanup cost to achieve a reasonably small final area.


A demonstration of the spaceship in motion

See also


  1. Brett Berger (December 28, 2014). "(23,5)c/79 knightship caterpillar complete!". Retrieved on December 28, 2014.
  2. Brett Berger (October 6, 2014). "(23,5)c/79 spaceship components". Retrieved on December 29, 2014.
  3. Ivan Fomichev (July 9, 2013). "(23,5)c/79 spaceship components". Retrieved on December 29, 2014.