Waterbear
Waterbear  
View static 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  
Speed (unsimplified)  (46,10)c/158  
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.
Design
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]}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 outputsuppressing cleanup, so the design balances the exponential size increase with the constant cleanup cost to achieve a reasonably small final area.
Video
See also
References
 ↑ Brett Berger (December 28, 2014). "(23,5)c/79 knightship caterpillar complete!". Retrieved on December 28, 2014.
 ↑ Brett Berger (October 6, 2014). "(23,5)c/79 spaceship components". Retrieved on December 29, 2014.
 ↑ Ivan Fomichev (July 9, 2013). "(23,5)c/79 spaceship components". Retrieved on December 29, 2014.
External links
 Waterbear at the Life Lexicon
 Patterns
 Patterns with 1000 or more cells
 Patterns found by Brett Berger
 Patterns found by Ivan Fomichev
 Patterns found in 2014
 Spaceships
 Periodic objects with minimum population 197896
 Spaceships with period 158
 Oblique spaceships
 Spaceships with slope 23/5
 Spaceships with speed (23,5)c/79
 Spaceships with unsimplified speed (46,10)c/158
 Spaceships with heat 160959
 Spaceships with mod 158
 Engineered spaceships