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x = 3, y = 3, rule = B3/S23 3o$obo$obo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ HEIGHT 600 WIDTH 600 THUMBSIZE 3 ZOOM 60 ]]
Pattern type Methuselah
Number of cells 7
Bounding box 3 × 3
Lifespan 173 generations
Final population 55
L/I 24.7
F/I 7.9
F/L 0.318
L/MCPS 24.7
Discovered by John Conway
Year of discovery 1970

Pi-heptomino (or pi; sometimes called blasting cap at MIT after its shape at generation 1[1]) is a common heptomino that stabilizes at generation 173, leaving behind six blocks, five blinkers and two ponds. The name "pi" is also applied to some slight variations of this object that follow that same evolutionary sequence – in a pi ship, for example, the pi-heptomino itself never actually arises. Forms that are synonymous with the pi-heptomino are displayed below.

In April 1992, Bill Gosper discovered that two blocks can be used to eat a pi, as shown below. The eating reaction takes 65 generations to complete. Gosper also discovered in the same month that a pi, along with two blocks and two blinkers, can be used to create a queen bee shuttle.

It is the most common methuselah to occur naturally in a specific orientation; while less common than the R-pentomino, the R-pentomino has eight orientations, while the pi-heptomino only has four, and more common sequences like the traffic light and honey farm are not methuselahs.

The Pi-heptomino can be considered a failed puffer or failed spaceship, since on its own it travels at 3c/10 for only a short time before being stopped by its own trailing debris. However, it can be stabilized into a 3c/10 wave.


x = 9, y = 12, rule = B3/S23 2o5b2o$2o5b2o8$3b3o$3bobo$3bobo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ HEIGHT 360 WIDTH 600 THUMBSIZE 2 ]]
A Blockic pi eater
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RLE: here Plaintext: here
2o19b2o$bo8b3o8bob$bobo6bobo6bobob$2b2o6bobo6b2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ HEIGHT 360 WIDTH 600 THUMBSIZE 2 ]]
Another pi eater that uses a snake catalysis (fishhooks shown)
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RLE: here Plaintext: here
x = 135, y = 106, rule = B3/S23 71b3o$70bo3bo$70b2ob2o8$62bo9bo58b2o$60b2ob2o6b3o56bob2o$60b2ob2o5b2ob 2o55b2ob2o8$62bo9bo29bo28b2o$b3o57bobo7bobo27bobo7b3o7b3o6bo2bo$2ob2o 55b2ob2o5bo3bo25bo3bo6bo2bo6bo2bo5bo3bo$71bobo26bo3bo6bo3bo4bo4bo5bo2b o7$12bo9bo$b2obo6bobo7bobo37b3o7b3o$bobo7bobo7bo2bo36bobo7b3o$bobo7bob o7bo2bo36bobo7bobo7$o3bo$4bo6b3o18bo19bo9bo9bo19bo$b3o7b2o18b3o17b3o7b 3o7b3o17b3o$b2o30bo17bo2bo6bobo$12b2o18bo39bo18bobo7$11bo2bo$11b2obo 16b3o7b3o7b3o7b3o7b3o7b3o$12bo17bo2bo6bo3bo6bo2bo6bo2bo7bo9bo$12b2o15b 4o10bo10bo16bobo6bobo$29b2o50bo7$31b2o49b2o$32b2o46bobo$28bob2o50bo$ 29bo50b2o7$31b2o$29bo2bo$28bo3bo$29b2o7$31bo$29b4o$29bo2bo$29b2o8$30b 3o$28b2obo$30bo8$29bob2o$28bo2bo$29bobo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ HEIGHT 720 WIDTH 960 THUMBSIZE 2 ZOOM 6 GPS 1 ]]
Common formations equivalent to the pi-heptomino. Patterns in the same row are in the same generation. To follow an evolutionary sequence, start from the bottom and move up; if there is nothing above a pattern, its evolutionary sequence converges with the closest column inward that has a pattern until they all reach the top. Ignore dying sparks
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RLE: here Plaintext: here

See also


  1. "Blasting cap". The Life Lexicon. Stephen Silver. Retrieved on May 14, 2016.

External links