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  (46,10)c/158  
Heat  160959.2  
Kinetic symmetry  n  
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.
Waterbear was voted Pattern of the Year for 2014 in a belated vote held on the ConwayLife.com forums.^{[2]}
History
An early mention of such a spaceship came from Nicolay Beluchenko in his 2006 LifeCA post announcing the discovery of the (23,5)c/79 Herschel climber. The idea was later mentioned in an "open problem" list from Jason Summers in February 2008, which was reposted to the ConwayLife forums in June 2013.^{[3]} Further discussion below that eventually spawned a dedicated thread a month later.^{[4]} A thread announcing its completion came in December 2014.^{[1]}
Design
The base reaction consists of a crawler where a Herschel runs 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^{[5]} 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.^{[6]}
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
 ↑ ^{1.0} ^{1.1} Brett Berger (December 28, 2014). (23,5)c/79 knightship caterpillar complete! (discussion thread) at the ConwayLife.com forums
 ↑ 77topaz (March 7, 2018). Re: Belated Pattern of the Year 2014 competition: Voting (discussion thread) at the ConwayLife.com forums
 ↑ Dave Greene (June 18, 2013). Re: Incomplete search patterns  try to complete (discussion thread) at the ConwayLife.com forums
 ↑ Ivan Fomichev (July 8, 2013). (23,5)c/79 spaceship components (discussion thread) at the ConwayLife.com forums
 ↑ Brett Berger (October 6, 2014). Re: (23,5)c/79 spaceship components (discussion thread) at the ConwayLife.com forums
 ↑ Ivan Fomichev (July 9, 2013). Re: (23,5)c/79 spaceship components (discussion thread) at the ConwayLife.com forums
External links
 Waterbear at the Life Lexicon
 Brett Berger (December 3, 2021). Building the Waterbear spaceship. a blog by biggiemac42.
 Patterns
 Spaceships with between 100,000 and 999,999 cells
 Periodic objects with minimum population between 100,000 and 999,999
 Patterns with between 100,000 and 999,999 cells
 Patterns found by Brett Berger
 Patterns found by Ivan Fomichev
 Patterns found in 2014
 Outertotalistically endemic patterns
 Spaceships
 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 between 100,000 and 999,999
 Spaceships with mod 158
 Spaceships with n symmetry
 Pattern of the Year top contenders
 Pattern of the Year winners
 Engineered spaceships