Bi-block

Bi-block
x = 5, y = 2, rule = B3/S23 2ob2o$2ob2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBSIZE 3 ZOOM 21 HEIGHT 400 SUPPRESS ]]
View static image
Pattern type	Pseudo still life
Number of cells	8
Bounding box	5 × 2
Static symmetry	Unspecified
Discovered by	Unknown
Year of discovery	1970
Rules Outer-totalistic rules B/S3 – B35678/S012345678 # of rules 213 = 8192 Isotropic rules B/S3a – B1e2-ac34-i5678/S012345678
Glider synthesis Fewest gliders 2 Catagolue-generated RLE synthesis Uploaded synthesis RLE biblock_synth.rle
Pattern files Plaintext biblock.cells RLE biblock.rle
Identifiers apgcode xs8_rr

The bi-block is a common formation of two blocks and the smallest and most common pseudo still life. Similar pseudo still lifes can be formed by considering any rectangular array of blocks, some of which are shown below.

Bi-blocks can be hassled by sparks to create oscillators, such as the p18 bi-block hassler and four molds hassling eight blocks.

Commonness

The bi-block is about ¼ as common as the pond, the most common 8-bit strict still life. Compared to other strict still lifes, it is more common than the ship-tie but less common than the long boat. In odd orthogonal symmetries, bi-blocks are more common, as gliders in the same phase that collide in odd symmetry form a bi-block.

Counting both strict and pseudo still lifes, the tri-block is the 9th most common 12-bit still life, and it would rank third behind the ship-tie and mirrored table but ahead of the block on cap if it were strict. Unlike the bi-block, tri-blocks must form by chance.

Gallery

[[:RLE:Triblock]] #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ GPS 8 THUMBSIZE 2 ]] Triblock (click above to open LifeViewer) RLE: here Plaintext: here Catagolue: here	x = 5, y = 5, rule = B3/S23 2ob2o$2ob2o2$2ob2o$2ob2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ GPS 8 THUMBSIZE 2 ]] 2 × 2 group of blocks (click above to open LifeViewer) RLE: here Plaintext: here Catagolue: here	[[:RLE:2by3groupofblocks]] #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ GPS 8 THUMBSIZE 2 ]] 2 × 3 group of blocks (click above to open LifeViewer) RLE: here Plaintext: here Catagolue: here
x = 5, y = 4, rule = B3/S23 2bo$2obo$o3bo$b3o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ GPS 8 THUMBSIZE 2 ]] Common predecessor of bi-block plus one other unrelated block Ash on Catagolue: here (click above to open LifeViewer) RLE: here Plaintext: here	x = 5, y = 3, rule = B3/S23 obo$2ob2o$2bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ GPS 8 THUMBSIZE 2 ]] About ⅓ as common as the previous pattern, and creates just a bi-block and nothing else (click above to open LifeViewer) RLE: here Plaintext: here	x = 6, y = 4, rule = B3/S23 2bo$bo$o$2ob3o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ GPS 8 THUMBSIZE 2 ]] another small predecessor of a clean bi-block, whose great-great-grandchild is fairly common (click above to open LifeViewer) RLE: here Plaintext: here

See also

• Bi-block hassler

External links

• Bi-block at the Life Lexicon
• Bi-block at Adam P. Goucher's Catagolue (pseudo-object)