Neutronium, in the context of multi-state Life-like cellular automata, refers to an additional cell state that is permanently live. A cell in the "neutronium" state is also said to be neutronic. Informally, the term may also be used to refer to anti-neutronium: a cell that is permanently dead.
The Neutronium rule
Neutronium was first considered by Mike Turniansky for a rule of the same name. In this rule, cells can exist in three states, dead, live and neutronium, the last of which is considered "live"; evolution happens as in Conway's Game of Life, except that a live cell surrounded by eight live neighbors (including neutronic neighbors) will itself turn into neutronium.
More precisely, patterns in this CA evolve according to the following rules:
- A dead cell:
- is born if it has precisely 5 dead neighbors (i.e. precisely 3 neighbors each of which is either live or neutronic).
- A live cell:
- turns into neutronium if it has precisely 0 dead neighbors;
- survives (remains live) if it otherwise has has precisely 5 or 6 dead neighbors;
- dies otherwise.
- A neutronic cell:
- remains neutronic.
|“||But the oddest surprise was the r-pentonimo [sic], which after 76,398 generations had a population of 86,158,122, including an estimated 20,000 gliders flying out in four huge sparse triangular formations (and about 20 orthogonal spaceships), fleeing a central seething ball of neutronioum [sic] growing at a rate of about 2/11c[.]||”|
|— Mike Turniansky|
Generalizations and variants
- Mike Turniansky (March 10, 2014). R-pentomino neutronium (discussion thread) at the ConwayLife.com forums