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3b2o3b$2b2o4b$4bo3b$6b2o$5bo2b2$4bo2bo$b2obo3b$2o4bob$2bobo2bo$7bo$4bo 2bo$5bobo$5bobo$6b2o$6bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART ]] #C [[ HEIGHT 500 THUMBSIZE 3 ZOOM 21 GPS 4 TRACKLOOP 4 -1/4 -1/4 ]]
Pattern type Tagalong
Number of cells 29
Bounding box 10 × 17
Direction Diagonal
Period 4
Mod 4
Speed c/4 | c/4
Heat 30
Discovered by Hartmut Holzwart
Year of discovery 2004

B29 is a c/4 diagonal spaceship discovered by Hartmut Holzwart in September 2004.[1] In generation 2 it produces an isolated domino spark that can be used to perturb reactions. In terms of its 29 cells, it is the fourth smallest c/4 diagonal spaceship, as well as the smallest c/4 spaceship to not exhibit glide symmetry.

Two gliders can be seen at the front of the ship, one of these being temporary and the other permanent, making this a tagalong. The other glider does not stay as a glider but still moves like one.

Glider synthesis

B29 is one of relatively few elementary diagonal spaceships with a known glider synthesis, due to a synthesis completed by Tanner Jacobi in April 2015.[2][3][4]


There are three ways in which a glider can non-trivially follow a B29. All three such spaceships have been synthesized, with two of them having a glider cost lower than their minimum population.

x = 54, y = 16, rule = B3/S23 3b2o18b2o18b2o$2b2o18b2o18b2o$4bo19bo19bo$6b2o18b2o18b2o$5bo19bo19bo2$ 4bo2bo16bo2bo16bo2bo$b2obo16b2obo16b2obo$2o4bo13b2o4bo13b2o4bo$2bobo2b o14bobo2bo14bobo2bo$7bo19bo19bo$4bo2bo16bo2bo16bo2bo$5bobo3b2o12bobo2b 3o12bobo$5bobo2b2o13bobo2bo14bobo4bo$6b2o4bo13b2o3bo14b2o3b2o$6bo19bo 19bo4bobo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBSIZE 2 ZOOM 10 TRACKLOOP 4 -1/4 -1/4 GPS 4 ]]
Three ways in which gliders can non-trivially follow a B29
(click above to open LifeViewer)
RLE: here Plaintext: here

In addition, there are two ways to attach Wainwright's tagalong to the back of a B29 to create two distinct 36-cell spaceships. Neither of these appear to have been synthesized so far.

x = 33, y = 16, rule = B3/S23 3b2o18b2o$2b2o18b2o$4bo19bo$6b2o18b2o$5bo19bo2$4bo2bo16bo2bo$b2obo16b 2obo$2o4bo13b2o4bo$2bobo2bo14bobo2bo$7bo19bo$4bo2bo4b2o10bo2bo$5bobo3b 2o12bobo2b3o$5bobo4bo12bobo2bo$6b2o3b2o13b2o4bo$6bo19bo3b2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBSIZE 2 ZOOM 10 TRACKLOOP 4 -1/4 -1/4 GPS 4 ]]
Two ways in which Wainwright's tagalong can be supported by B29
(click above to open LifeViewer)
RLE: here Plaintext: here

See also


  1. "B29". The Life Lexicon. Stephen Silver.
  2. Tanner Jacobi (April 5, 2015). Re: Small Spaceship Syntheses (discussion thread) at the ConwayLife.com forums
  3. Matthias Merzenich (June 12, 2015). Re: 4 glider syntheses (discussion thread) at the ConwayLife.com forums
  4. Matthias Merzenich (January 22, 2016). Re: Soup search results (discussion thread) at the ConwayLife.com forums

External links