Backrake 2

Backrake 2
x = 19, y = 26, rule = B3/S23 3bo$2b3o$b2obo5bo$b3o5b3o$2b2o4bo2b2o3b3o$8b3o4bo2bo$18bo$18bo$18bo$2b 3o12bo$2bo2bo$2bo$2bo$3bo7$3o$o2bo11bo$o13b3o$o12b2obo$o12b3o$bo12b2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART ]] #C [[ ZOOM 10 AUTOSTART OFF ]]
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Pattern type	Rake Puffer
Number of cells	65
Bounding box	19 × 26
Direction	Orthogonal
Period	12
Speed	c/2
Discovered by	David Buckingham
Year of discovery	Unknown
Rules Outer-totalistic rules B3/S23 – B38/S238 # of rules 22 = 4 Isotropic rules B3/S23-y – B34e6c8/S234ct5ek6ei7e8
Glider synthesis Fewest gliders 17† Uploaded synthesis RLE backrake2_synth.rle †Can be constructed with 15 gliders using the reverse caber tosser universal constructor.
Pattern files Plaintext backrake2.cells RLE backrake2.rle

Backrake 2 is a period-12 backrake that was created by David Buckingham. It works by having a front puffer made up of two lightweight spaceships, a middleweight spaceship, and a B-heptomino (much like puffer 2) send debris back to another lightweight and middleweight spaceship, which turn the debris into a backward-moving glider.

Three copies of this backrake feature in total aperiodic.

Reduction

On April 28, 2022, wwei23 discovered a 39-cell period-12 backrake that works as a reduced version of Backrake 2 using the apgsearch custom symmetry WSS_test, that had also found 35P12H6V0.

x = 20, y = 6, rule = B3/S23 9bo7bo$b3o4b3o5b3o$o2bo3bo2b2o4bob2o$3bo3bo3bo5b3o$3bo4b2o2bo4b2o$obo 8bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ ZOOM 20 Y 6 HEIGHT 480 TRACKLOOP 12288 0 -1/2 THUMBSIZE 2 GPS 4 AUTOSTART ]]

(click above to open LifeViewer) RLE: here Plaintext: here

See also

• Backrake 1
• Backrake 3