72P21
Jump to navigation
Jump to search
| 72P21 | |||||||||
| View static image | |||||||||
| Pattern type | Oscillator | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Number of cells | 72 | ||||||||
| Bounding box | 34 × 34 | ||||||||
| Period | 21 (mod: 21) | ||||||||
| Heat | 39.2 | ||||||||
| Volatility | 0.86 | 0.86 | ||||||||
| Kinetic symmetry | rk | ||||||||
| Discovered by | David Raucci Nora Brown | ||||||||
| Year of discovery | 2021 | ||||||||
| |||||||||
| |||||||||
| |||||||||
| |||||||||
72P21 is a period-21 oscillator discovered by David Raucci on May 21, 2021.[1] The oscillator has undergone several changes:
- May 21, 2021: Initial discovery, using four 754P7s.
- November 20, 2021: 62P7 is discovered. The sparker can be made 62P7, massively reducing the size.
- September 24, 2022: Nora Brown reduces the sparker to a stable catalyst consisting of a ship and fishhook.
- February 10, 2023: Charity Engine finds the oscillator in stable catalyst form semi-naturally (in the C4_4 census).
The active region contains four I-heptominoes in one phase, but since the I-heptomino evolutionary sequence does not occur at all, calling it an I-heptomino hassler is a bit misleading.
On May 22, 2024, Chris857 found a 52-glider synthesis based on the C4_4 soup.[2][3] On May 24, 2024, he reduced the cost to 40 gliders.[2][4]
Gallery
| The one known random symmetric soup that creates this oscillator (click above to open LifeViewer) |
References
- ↑ David Raucci (May 21, 2021). Re: Oscillator Discussion Thread (discussion thread) at the ConwayLife.com forums
- ↑ 2.0 2.1 Chris857 (May 22, 2024). Re: Synthesising Oscillators (discussion thread) at the ConwayLife.com forums
- ↑ shinjuku (#6916457570) (May 22, 2024). Job triggered by Adam P. Goucher at GitLab Catagolue project.
- ↑ shinjuku (#6928304159) (May 24, 2024). Job triggered by Adam P. Goucher at GitLab Catagolue project.
External links
Categories:
- Patterns
- Oscillators with 72 cells
- Periodic objects with minimum population 72
- Patterns with 72 cells
- Patterns found by David Raucci
- Patterns found by Nora Brown
- Patterns found in 2021
- Patterns that can be constructed with 39 gliders
- Oscillators
- Oscillators with period 21
- Oscillators with mod 21
- Oscillators with heat 39
- Oscillators with volatility 0.86
- Oscillators with strict volatility 0.86
- Oscillators with rk symmetry
- Semi-natural periodic objects