OCA:DryLife
| DryLife | ||
|
||
| Rulestring | 23/37 B37/S23 |
|
|---|---|---|
| Rule integer | 6280 | |
| Character | Explosive | |
| Black/white reversal | B0123478/S0234678 | |
DryLife is a Life-like cellular automaton in which cells survive from one generation to the next if they have 2 or 3 neighbours, and are born if they have 3 or 7 neighbours.
Patterns
DryLife is so named because the standard spaceships from normal life; lightweight spaceship, middleweight spaceship, and heavyweight spaceship — also known as "fishes" — do not work, though the glider does. Some other spaceships, such as the weekender and loafer, work in this rule. The copperhead evolves into the closely related c/10 goldenhead, differing from copperhead by two cells in one phase.
Two correctly spaced B-heptominoes (as in the twin bees shuttle) act as a c/2 orthogonal puffer.
A new speed allowed by DryLife is 9c/28 orthogonal. Technology travelling at this speed relies on the R-pentomino. There is a small 9c/28 orthogonal pond puffer, and a 9c/28 spaceship. Guns and breeders have been constructed that fire spaceships and rakes of this speed respectively.
The "flower garden", a common constellation which evolves from honey farm predecessors, composed of two bi-boats and two cis-mirrored R-bees, is shown to the right.
Universality
There is a proof sketch of this rule's universality as well as an explicit Rule 110 unit cell.[1] In the same topic on ConwayLife forums,[2] there is a proof-scheme covering all rules in the outer-totalistic rulespace between B3/S23 and B3678/S23678.
An explicit Rule 110 unit cell construction[3] proves its Turing-completeness; the pattern itself is basically a meta-polyglot, covering some related cellular automata in which the pattern only differs in some parts (in this case, the guns).
References
- ↑ Peter Naszvadi (August 7, 2018). "List of the Turing-complete totalistic life-like CA". ConwayLife.com forums. Retrieved on May 17, 2019.
- ↑ Peter Naszvadi (December 12, 2016). "List of the Turing-complete totalistic life-like CA". ConwayLife.com forums. Retrieved on May 17, 2019.
- ↑ "Explicit Rule-110 Unit Cell Construction for DryLife".
External links
- DryLife at David Eppstein's Glider Database
- DryLife at Adam P. Goucher's Catagolue
- Taming B37/S23 (discussion thread) at the ConwayLife.com forums
