OCA:DryLife
DryLife  


Rulestring  23/37 B37/S23 


Rule integer  6280  
Character  Explosive  
Black/white reversal  B0123478/S0234678 
DryLife is a Lifelike 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 x66, 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 Bheptominoes (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 Rpentomino. 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 composed of two biboats and two cismirrored Rbees which evolves from honey farm predecessors, is shown to the right.
Universality
There is a proof sketch of DryLife's universality on ConwayLife.com forums. It is a proofscheme covering all rules in the outertotalistic rulespace between B3/S23 and B3678/S23678.^{[1]}
In 2018, Peter Naszvadi constructed an explicit Rule 110 unit cell in DryLife, proving its Turingcompleteness.^{[2]} The pattern itself is basically a metapolyglot, covering some related cellular automata in which the pattern only differs in some parts (in this case, the guns).
References
 ↑ Peter Naszvadi (December 12, 2016). Re: List of the Turingcomplete totalistic lifelike CA (discussion thread) at the ConwayLife.com forums
 ↑ Peter Naszvadi (March 29, 2018). Re: List of the Turingcomplete totalistic lifelike CA (discussion thread) at the ConwayLife.com forums
External links
 DryLife at David Eppstein's Glider Database
 DryLife at Adam P. Goucher's Catagolue
 Puffer with unstable trail (B37/S23) (discussion thread) at the ConwayLife.com forums
 Taming B37/S23 (discussion thread) at the ConwayLife.com forums