Pi-heptomino
| Pi-heptomino | |||||||||
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| Pattern type | Methuselah | ||||||||
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| Number of cells | 7 | ||||||||
| Bounding box | 3 × 3 | ||||||||
| MCPS | 7 | ||||||||
| 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 | ||||||||
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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.
Generation 1 of pi-heptomino
A grandparent (a pentaplet) and parent (a hexomino) of pi
An alternative parent of generation 1
This pattern, which resembles the word Pi, evolves exactly like the pi-heptomino after two generations, stabilizing at generation 174
Gallery
| Another pi eater that uses a snake catalysis (fishhooks shown) (click above to open LifeViewer) RLE: here Plaintext: here |
| 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 (click above to open LifeViewer) RLE: here Plaintext: here |
See also
References
- ↑ "Blasting cap". The Life Lexicon. Stephen Silver. Retrieved on May 14, 2016.
External links
- Pi-heptomino at the Life Lexicon
- Pi-heptomino ash at Adam P. Goucher's Catagolue