Hacksaw
| Hacksaw | |||||||||
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| Pattern type | Sawtooth | ||||||||
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| Number of cells | 687 | ||||||||
| Bounding box | 199 × 102 | ||||||||
| Expansion factor | 9 | ||||||||
| Discovered by | Dean Hickerson | ||||||||
| Year of discovery | 1992 | ||||||||
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Hacksaw is an orthogonal sawtooth with expansion factor equal to 9 that was found by Dean Hickerson on August 7, 1992. The population in generation t = 385 (9n) − 189 (n ≥ 1) is t/4 + 1079, but the population in generation 1155 (9n) − 179 (n ≥ 0) is only 977.
The hacksaw can be seen below. The pattern consists of two parts, a stationary shotgun and a set of puffers moving east. The shotgun produces, and usually destroys, a salvo consisting of a middleweight spaceship and two lightweight spaceships. The moving part consists of a blinker puffer 1 and two period 24 glider puffers whose output gliders destroy each other (with help from an accompanying middleweight spaceship). In generation 385 (9n − 189) (n ≥ 1) (and 228 for n = 0), a salvo hits the back end of the row of blinkers, causing it to form a blinker fuse that decays at 2c/3. When the row is completely gone, a new row starts to form and a spark is produced. The spark is turned into a glider by an accompanying heavyweight spaceship; the glider is turned into a westward lightweight spaceship in generation 1155 (9n − 127) (n ≥ 0) by interacting with the glider puffers. The 3-glider synthesis of the lightweight spaceship is due to David Buckingham. When the lightweight spaceship hits the shotgun in generation 2310 (9n − 184) (n ≥ 0), another salvo is released, starting the cycle again.
The idea for this sawtooth pattern was suggested by Bill Gosper.
Hacksaw
| (click above to open LifeViewer) RLE: here Plaintext: here |
Image gallery
The number of alive cells plotted versus the number of elapsed generations roughly forms an ever-increasing sawtooth graph.
Videos
See also
External links
- Dean Hickerson. "Hacksaw". Dean Hickerson's Game of Life page. Retrieved on April 30, 2022.
- Hacksaw at Paul Callahan's Page of Conway's Life Miscellany