Pre-pulsar spaceship
| Pre-pulsar spaceship | |||||||||
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| Pattern type | Spaceship | ||||||||
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| Number of cells | 128 | ||||||||
| Bounding box | 73 × 14 | ||||||||
| Direction | Orthogonal | ||||||||
| Period | 30 (mod: 30) | ||||||||
| Speed | c/5 | 6c/30 | ||||||||
| Heat | 131.5 | ||||||||
| Kinetic symmetry | -c | ||||||||
| Discovered by | David Bell | ||||||||
| Year of discovery | 1998 | ||||||||
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Pre-pulsar spaceship (or PPS for short) is any of three different period-30 c/5 orthogonal spaceships in which a pre-pulsar is pushed by a pair of spiders. The back sparks of these spaceships can be used to perturb gliders in many different ways, allowing the easy construction of c/5 puffers.
The first pre-pulsar spaceship, the symmetric pre-pulsar spaceship (or SPPS for short, shown below) was found by David Bell in May 1998[1] and was based on the p15 pre-pulsar spaceship found by Noam Elkies in December 1997.
| The symmetric pre-pulsar spaceship (click above to open LifeViewer) RLE: here Plaintext: here |
The asymmetric pre-pulsar spaceship (or APPS, shown in the gallery below) was found by Alan Hensel, also in May 1998, based on a skewed version of the pre-pulsar.
The glide symmetric pre-pulsar spaceship (or GPPS, shown in the gallery below) was also found by David Bell in May 1998. It is similar to the symmetric pre-pulsar spaceship but contains an extra T-tetromino between the spiders and is glide symmetric.
Martin Grant's 601-glider spider synthesis resulted in a 1212-glider synthesis for the symmetric pre-pulsar spaceship on March 8, 2019.[2]
In June 1998, David Bell found reactions using a lightweight spaceship to convert between the symmetric and glide-symmetric forms of the p30 pre-pulsar spaceship. This means that a PPS can be used to store a moving bit of information.[3]
Gallery
| The asymmetric pre-pulsar spaceship (click above to open LifeViewer) RLE: here Plaintext: here |
| The glide symmetric pre-pulsar spaceship (click above to open LifeViewer) RLE: here Plaintext: here |
References
- ↑ Jason Summers' jslife pattern collection. Retrieved on October 28, 2020.
- ↑ Adam P. Goucher (March 8, 2019). Re: Small Spaceship Syntheses (discussion thread) at the ConwayLife.com forums
- ↑ Dave Greene (May 27, 2022). Re: Can we substantiate this claim? (discussion thread) at the ConwayLife.com forums
External links
- Pre-pulsar spaceship at the Life Lexicon
- Symmetric pre-pulsar spaceship at Adam P. Goucher's Catagolue
- Asymmetric pre-pulsar spaceship at Adam P. Goucher's Catagolue (extended)
- Glide symmetric pre-pulsar spaceship at Adam P. Goucher's Catagolue
- 128P30H6V0.1 at Heinrich Koenig's Game of Life Object Catalogs
- Patterns
- Spaceships with between 120 and 129 cells
- Periodic objects with minimum population between 120 and 129
- Patterns with between 120 and 129 cells
- Patterns found by David Bell
- Patterns found in 1998
- Patterns that can be constructed with between 400 and 499 gliders
- Spaceships
- Spaceships with period 30
- Orthogonal spaceships
- Spaceships with speed c/5
- Spaceships with unsimplified speed 6c/30
- Spaceships with heat between 130 and 139
- Spaceships with mod 30
- Spaceships with -c symmetry
- Patterns found by Alan Hensel
- Non-monotonic spaceships