Difference between revisions of "B-heptomino"

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|by          = 3
|by          = 3
|l            = 148
|l            = 148
|f            = 26
|f            = 28
|mcps        = 7
|mcps        = 7
|discoverer  = John Conway
|discoverer  = John Conway
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|synthesis    = 2
|synthesis    = 2
|synthesisRLE = true
|synthesisRLE = true
|life105      = true
|life106      = true
|plaintext    = true
|plaintext    = true
|rle          = true
|rle          = true
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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 [[block]]s, two [[glider]]s 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 [[:Category:Patterns found in 1996|1996]] due to [[:Category:Patterns found by David Buckingham|David Buckingham]]'s work on [[B track]]s.
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 [[block]]s, two [[glider]]s 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 [[:Category:Patterns found in 1996|1996]] due to [[:Category:Patterns found by David Buckingham|David Buckingham]]'s work on [[B track]]s.


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.  This alternate form is shown as the input for [[elementary]] [[converter]] patterns such as [[BFx59H]] and [[BRx46B]]. This is standard practice for elementary [[conduit]]s, since many of these conduits do in fact produce this alternate form as output.
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.  This alternate form is shown as the input for [[elementary]] [[converter]] patterns such as [[BFx59H]] and [[BRx46B]]. Many conduits produce this form of B, so it can be used when marking the position of an output B-heptaplet.


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]], and [[ecologist]].
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 ==
== In other rules ==
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==Image gallery==
==Image gallery==
<gallery>
<gallery>
Image:BheptominoGen20.png|Generation 20 of the B-heptomino
Image:BheptominoGen20.png|Generation 20 of the B-heptomino, showing its [[Herschel]] offspring
Image:BheptominoFinal.png|Generation 148 of the B-heptomino
Image:BheptominoFinal.png|Generation 148 of the B-heptomino
Image:Bparent.png|A 6-cell parent of the B-heptomino
Image:Bparent.png|A 6-cell parent of the B-heptomino
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==See also==
==See also==
*[[Herschel]]
*[[C-heptomino]]
*[[C-heptomino]]
*[[Conduit 1]]
*[[Conduit 1]]

Revision as of 04:39, 23 June 2019

B-heptomino
x = 4, y = 3, rule = B3/S23 ob2o$3o$bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]]
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

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. This alternate form is shown as the input for elementary converter patterns such as BFx59H and BRx46B. Many conduits produce this form of B, so it can be used when marking the position of an output B-heptaplet.

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 in many rules.

  • 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

See also

External links

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