Pseudo-barberpole

Pseudo-barberpole
x = 12, y = 12, rule = B3/S23 10b2o$11bo$9bo$7bobo2$5bobo2$3bobo2$2b2o$o$2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART ]] #C [[ HEIGHT 500 THUMBSIZE 3 ZOOM 27 GPS 2 LOOP 5 ]]
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Pattern type	Oscillator
Family	Barberpole
Number of cells	15
Bounding box	12 × 12
Period	5 (mod: 5)
Heat	16.8
Volatility	0.82 | 0.82
Kinetic symmetry	/
Discovered by	Achim Flammenkamp
Year of discovery	1994
Rules Outer-totalistic rules B3/S23 – B378/S235678 # of rules 26 = 64 Isotropic rules B3-eiky/S2-c3jn – B2cn34-nqry5-aq6-n78/S234-jnz5678
Glider synthesis Fewest gliders 9 Catagolue-generated RLE synthesis Uploaded synthesis RLE pseudobarberpole_synth.rle
Pattern files Plaintext pseudobarberpole.cells RLE pseudobarberpole.rle
Identifiers apgcode xp5_y2g0k413zwo0a02z32 Pentadecathlon ID 15P5.1

The pseudo-barberpole (or Achim's p5) is a period-5 oscillator that was found by Achim Flammenkamp on August 22, 1994. With a minimum population of 15 cells, it is the smallest known period 5 oscillator, followed by octagon 2 with 16 cells.

Occurrence

See also: List of common oscillators

As of October 2024, this is one of two 15-cell oscillators, and one of three 15-cell periodic objects (still lifes and oscillators) which are yet to arise naturally from an asymmetric soup on Catagolue, with the other oscillator being the nonapole. On 2022-07-06, Charity Engine discovered a C4_1 symmetric soup from which four pseudo-barberpoles emerge. This is the only time a pseudo-barberpole has appeared in the final census of a non-diagonally-symmetric soup. However, the reaction in this soup evolves from fourfold rotational symmetry to eightfold symmetry, so this occurrence is not considered to be equivalent to a C1 occurrence.

x = 31, y = 31, rule = B3/S23 b3o2b2obobo2b2obo2bob2o2bo$2bobobo2bo2b2ob2ob2ob2o2b3o2bo$3bob3o2b4obo b7obobob2o$b2obobo4bob4o3bobob3obobo$2obo2bobob3obo4b4o2bobobo$b5o3b2o b2o3b3obob3o2bo$3bobo3bo2bob3o2b2o5b5o$obo2bobo5b2obobo3b2o4bobo$5o2bo 2b3ob4ob3o4bo$b2ob2o2b3o2bo4bo2bo2b2o3b2o$ob3obobo2b5o2bo2b2o2b2obo$b 2ob3obo3bo2b4obobo3b3obo$b2o2bobob3obo2b2ob2obob3ob2o$obo2bo2bo2b8ob2o bobob3o$bobo2b3o2b7o2bob3ob2o2bo$4o2bobob2ob2ob2ob2obobo2b4o$o2b2ob3ob o2b7o2b3o2bobo$b3obobob2ob8o2bo2bo2bobo$b2ob3obob2ob2o2bob3obobo2b2o$o b3o3bobob4o2bo3bob3ob2o$2bob2o2b2o2bo2b5o2bobob3obo$2o3b2o2bo2bo4bo2b 3o2b2ob2o$4bo4b3ob4ob3o2bo2b5o$obo4b2o3bobob2o5bobo2bobo$5o5b2o2b3obo 2bo3bobo$2bo2b3obob3o3b2ob2o3b5o$bobobo2b4o4bob3obobo2bob2o$obob3obobo 3b4obo4bobob2o$2obobob7obob4o2b3obo$o2b3o2b2ob2ob2ob2o2bo2bobobo$4bo2b 2obo2bob2o2bobob2o2b3o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ GPS 20 THUMBSIZE 2 PAUSE 1 AUTOSTART ]]

Charity Engine's C4_1 soup (click above to open LifeViewer)

Glider synthesis

Goldtiger997 found a 16-glider synthesis based on a sample soup from Adam P. Goucher's Catagolue on April 22, 2017. Martin Grant found an unrelated 13-glider synthesis that can also act as a synthesis component on June 20, 2018. On January 26, 2024, the cost was lowered to 10 gliders. On February 7, 2024, Martin Grant lowered the cost to 9 gliders.

Variants

x = 13, y = 13, rule = b3/s23 10b2ob$2o9bob$o8bo3b$2b2o3bobo3b2$3bobobo5b2$5bobobo3b2$3bobo3b2o2b$3b o8bo$bo9b2o$b2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ GPS 3 THUMBSIZE 2 ]]

A radially symmetric relative of the pseudo-barberpole (click above to open LifeViewer) RLE: here Plaintext: here Catagolue: here

On October 23, 2002 Gabriel Nivasch found a period-5 oscillator that consists of four radially symmetrically arranged halves of the pseudo-barberpole, somewhat akin to Quad. On 2022-04-20, Charity Engine found in a D4_x1 symmetric soup an oscillator that can be considered a tetramer of the pseudo-barberpole's ends.

x = 17, y = 17, rule = B3/S23 4b2o$4bobo2$6b2o$2o5b3o$o9bo$bobo2b3o2bo$3b2ob2o4bo$4bobo3bobo$4bo4b2ob2o$5bo2b3o2bobo$6bo9bo$7b3o5b2o$9b2o2$10bobo$11b2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ GPS 3 THUMBSIZE 2 ]] A D4_x1 symmetric variant (click above to open LifeViewer) Catagolue: here

x = 24, y = 24, rule = B3/S23 6b2o$6b2o2$7bo$6b3o$7b2o$2o2bo5b2o$2ob3o6bo$4b2o4bo$12bobo$6bobo$6bo7bobo$7bobo7bo$15bobo$9bobo$13bo4b2o$11bo6b3ob2o$12b2o5bo2b2o$15b2o$15b3o$16bo2$16b2o$16b2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ GPS 3 THUMBSIZE 2 ZOOM 10 ]] A volatility-0.95 D4_x4 symmetric oscillator comprised of two pseudo-barberpole rotors mutually stabilising block-perturbers (click above to open LifeViewer) Catagolue: here

See also

• Barberpole
• Smallest period 5 oscillators
• Highest volatility period-5 oscillators (containing also the volatility-0.95 variant)

External links

• Pseudo-barberpole at the Life Lexicon
• Pseudo-barberpole at Adam P. Goucher's Catagolue
• 15P5.1 at Heinrich Koenig's Game of Life Object Catalogs