DryLife/Snippet

Goldenhead, a c/10 spaceship in DryLife very similar to Life's Copperhead

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. The rule behaves in an explosive manner, as small patterns, such as the stairstep hexomino, may exhibit chaotic growth.

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, and it supports the pseudo-tagalong in fireship as well.

There is a proof sketch of DryLife's universality on ConwayLife.com forums. It is a proof-scheme covering all rules in the outer-totalistic rulespace between B3/S23 and B3678/S23678. In 2018, Peter Naszvadi constructed an explicit Rule 110 unit cell in DryLife, proving 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).