OCA:Stains
| Stains | |
| View static image | |
| Rulestring | 235678/3678 B3678/S235678 |
|---|---|
| Rule integer | 252360 |
| Character | Stable |
| Black/white reversal | B478/S34678 |
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Stains is a Life-like cellular automaton with the following rules:
- a dead cell gets born when it has 3, 6, 7 or 8 alive neighbours,
- an alive cell survives when it has 2, 3, 5, 6, 7 or 8 alive neighbours.
Almost all random patterns in Stains grow up to a certain point and then turn into one or more irregular-shaped oscillators or still lifes.
On August 7, 2021, Peter Naszvadi proved that Stains is Turing-complete on an infinite, periodically-tiled grid by constructing a Rule 110 "unit stripe".[1]
Spaceships
A variety of spaceships are known to exist in Stains, including the glider as well as several larger ships:
| Eppstein's glider 3640 (c/2 orthogonal) (click above to open LifeViewer) RLE: here Plaintext: here Catagolue: here |
| Eppstein's glider 5900 (c/6 orthogonal) (click above to open LifeViewer) RLE: here Plaintext: here Catagolue: here |
| Eppstein's glider 13695 (2c/5 orthogonal) (click above to open LifeViewer) RLE: here Plaintext: here Catagolue: here |
| Eppstein's glider 13965 (c/3 orthogonal) (click above to open LifeViewer) RLE: here Plaintext: here Catagolue: here |
| Eppstein's glider 18511 (c/4 orthogonal) (click above to open LifeViewer) RLE: here Plaintext: here Catagolue: here |
| Eppstein's glider 20317 (c/5 orthogonal) (click above to open LifeViewer) RLE: here Plaintext: here Catagolue: here |
| More c/3 orthogonal ships (click above to open LifeViewer) RLE: here Plaintext: here |
Infinite growth
The question of whether infinite growth existed in Stains remained open until 1999, when a variety of 2c/5 orthogonal linear growth patterns were published.[2] Linear growth patterns with speeds of 3c/7 orthogonal were later discovered in 2016,[3] followed by c/3 and c/4 orthogonal in 2017.[4][5] However, the existence of nonlinear infinite growth as well as sawtooths in this rule remains an open question.
References
- ↑ Peter Naszvadi (August 7, 2021). Re: List of the Turing-complete totalistic life-like CA (discussion thread) at the ConwayLife.com forums
- ↑ Peter Naszvadi (May 7, 2016). B3678/S235678 (Stains) found patterns - infinite growth (discussion thread) at the ConwayLife.com forums
- ↑ Josh Ball (July 30, 2016). Re: Thread for Your Accidental Discoveries that Aren't in CGOL (discussion thread) at the ConwayLife.com forums
- ↑ Peter Naszvadi (January 15, 2017). Re: B3678/S235678 (Stains) found patterns - infinite growth (discussion thread) at the ConwayLife.com forums
- ↑ Josh Ball (January 22, 2017). Re: B3678/S235678 (Stains) found patterns - infinite growth (discussion thread) at the ConwayLife.com forums
External links
- Stains: a World of Enormous Oscillators
- Stains at Adam P. Goucher's Catagolue
- Stains at David Eppstein's Glider Database
- B3678/S235678 (Stains) found patterns - infinite growth (discussion thread) at the ConwayLife.com forums
- MCell built-in Life rules: Stains at Mirek Wójtowicz's Cellebration page