Burloaferimeter

Burloaferimeter
4b2o4b$5bo4b$4bo5b$3bob3o2b$3bobo2bob$2obo3bobo$2obo4bob$4b4o2b2$4b2o 4b$4b2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART ]] #C [[ HEIGHT 600 THUMBSIZE 3 ZOOM 36 GPS 3 ]]
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Pattern type	Oscillator
Oscillator type	Billiard table
Number of cells	28
Bounding box	10 × 11
Period	7
Mod	7
Heat	1.4
Volatility	0.16
Strict volatility	0.16
Discovered by	David Buckingham
Year of discovery	1972
Rules Outer-totalistic rules B3/S23 – B38/S0235678 # of rules 26 = 64 Isotropic rules B3einy/S2-n3-j – B2n34ackqyz5acin6-ik7c8/S01c234-in5678
Glider synthesis Fewest gliders (canonical) 22† Catagolue-generated RLE (canonical) synthesis Fewest gliders (cheapest variant) 9 Catagolue-generated RLE (cheapest variant) synthesis Uploaded synthesis RLE burloaferimeter_synth.rle †Can be constructed with 15 gliders using the reverse caber tosser universal constructor.
Pattern files Plaintext burloaferimeter.cells RLE burloaferimeter.rle
Identifiers apgcode (canonical) xp7_0g88b5oz1255kk3033zy011 apgcode (cheapest variant) xp7_gg0g88baa4oz1pgf0c9311

Burloaferimeter is a period-7 oscillator that was found by David Buckingham in 1972. In terms of its 28 cells, it is tied with the three unnamed oscillators 28P7.1, 28P7.2, and 28P7.3 as the smallest known period 7 oscillator. In terms of bounding box, the outright winner is an 11 × 9 burloaferimeter stator variant (Catagolue: here). It is the only known oscillator with a heat below 2.

Etymology

According to Mark D. Niemiec, a loaf was called a Bread Loaf by his group, which then was abbreviated to Br'loaf, then became burloaf. "Burloaf" has a population of 7, which "measures" burloaferimeter's period. While Burloaf has been shortened to Loaf, this change has not affected the name of the "Burloaferimeter".

Variants

x = 16, y = 16, rule = B3/S23 6bo2bo6b$6b4o6b$16b$4b8o4b$3bo8bo3b$3bo3b3o2bo3b$2obobo2bo3bob2o$bobob 2o3bobobob$bobobo3b2obobob$2obo3bo2bobob2o$3bo2b3o3bo3b$3bo8bo3b$4b8o4b$ 16b$6b4o6b$6bo2bo6b! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ HEIGHT 500 THUMBSIZE 2 ZOOM 18 ]]

C4_4-symmetric quadruple burloaferimeter variant found by Park Shinhwan on Catagolue in November 2016 (click above to open LifeViewer) RLE: here Plaintext: here Catagolue: here

x = 16, y = 16, rule = B3/S23 6b2o2b2o4b$6b2o2b2o4b$16b$4b8o4b$2obo8bo3b$2obo3b3o2bo3b$3bobobo4bob2o$ 3bobo3b2obob2o$2obob2o3bobo3b$2obo4bobobo3b$3bo2b3o3bob2o$3bo8bob2o$4b 8o4b$16b$4b2o2b2o6b$4b2o2b2o6b! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ HEIGHT 500 THUMBSIZE 2 ZOOM 18 ]]

C4_4-symmetric quadruple burloaferimeter variant found by Apple Bottom on Catagolue on June 16, 2017 (click above to open LifeViewer) RLE: here Plaintext: here Catagolue: here

A 28-glider synthesis for the first variant was discovered by Luka Okanishi shortly after, and was improved to 24 gliders by Jeremy Tan on January 5, 2020.

On September 27, 2020, a burloaferimeter stator variant appeared in an asymmetric soup found by Rob Liston, becoming the first period-7 oscillator to occur naturally. A 12-glider synthesis based on this soup was found soon afterwards due to contributions by various users on Discord. A second burloaferimeter variant occurred on January 9, 2021, in a soup found by Adam P. Goucher. Many stator variants have been found since, mostly by Charity Engine.

On September 3, 2022, an asymmetric 32-cell burloaferimeter variant appeared in a symmetric soup found by the Open Science Grid. A soup-based 9-glider synthesis of this variant was later found by Carson Cheng.

See also

• 69P48
• Airforce

External links

• Burloaferimeter at the Life Lexicon
• Burloaferimeter at Adam P. Goucher's Catagolue
• Mark D. Niemiec. Re: Soup search results (discussion thread) at the ConwayLife.com forums (burloaferimeter variants)