Difference between revisions of "B-heptomino"
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== In other rules == | == In other rules == | ||
The B-heptomino is a stable puffer in many rules. | The B-heptomino is a stable puffer, spaceship, replicator, or oscillator in many [[Isotropic non-totalistic Life-like cellular automaton | non-totalistic]] rules. | ||
For example: | |||
* In B3/S23-e4e, it evolves into a (16,5)c/74 [[oblique spaceship]]. | * In B3/S23-e4e, it evolves into a (16,5)c/74 [[oblique spaceship]]. | ||
* In B3/S23-a, it is a glide-symmetric 10c/20 spaceship. | * In B3/S23-a, it is a glide-symmetric 10c/20 spaceship. | ||
Revision as of 12:15, 26 April 2020
| B-heptomino | |||||||
| View static image | |||||||
| Pattern type | Methuselah | ||||||
|---|---|---|---|---|---|---|---|
| Number of cells | 7 | ||||||
| Bounding box | 4 × 3 | ||||||
| MCPS | 7 | ||||||
| Lifespan | 148 generations | ||||||
| Final population | 28 | ||||||
| L/I | 21.1 | ||||||
| F/I | 4 | ||||||
| F/L | 0.189 | ||||||
| L/MCPS | 21.1 | ||||||
| Discovered by | John Conway | ||||||
| Year of discovery | 1970 | ||||||
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The B-heptomino (or B-heptaplet, if the top-left cell is shifted one cell left) is a very common methuselah that evolves into three blocks, two gliders and a ship after 148 generations. Compare with Herschel, which appears at generation 20 of the B-heptomino's evolution. B-heptominoes acquired particular importance in 1996 due to David Buckingham's work on B tracks.
This pattern often arises with the cell at top left shifted one space to the left, producing a seven-bit polyplet that shares the same eight-bit descendant but is not technically a heptomino at all. Many conduits produce this form of B via the R-pentomino, so these two forms of B can be used interchangeably when marking in conduits.
The B-heptomino is considered a failed puffer or failed spaceship, since on its own it travels at c/2 for only a short time before being affected by its own trailing debris. However, it can be stabilized into a c/2 puffer or into a clean c/2 rake or spaceship. See, e.g., puffer 2, backrake 2, ecologist, or pufferfish.
In other rules
The B-heptomino is a stable puffer, spaceship, replicator, or oscillator in many non-totalistic rules. For example:
- In B3/S23-e4e, it evolves into a (16,5)c/74 oblique spaceship.
- In B3/S23-a, it is a glide-symmetric 10c/20 spaceship.
- In B34ej5y6n/S23, it is an oblique quadratic replicator, one of only a few known.
- In B36n/S2-i36c7c, it evolves into a glide-symmetric 9c/70 diagonal spaceship.
Image gallery
Generation 20 of the B-heptomino, showing its Herschel offspring
Generation 148 of the B-heptomino
A 6-cell parent of the B-heptomino
See also
External links
- B-heptomino at the Life Lexicon