EightLife

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EightLife
EightLife rule
Rulestring 238/3
B3/S238
Rule integer 137224
Character Chaotic
Black/white reversal B123478/S01234678

EightLife (or Pulsar Life) is a Life-like cellular automaton in which cells survive from one generation to the next if they have 2, 3 or 8 neighbours, and are born if they have 3 neighbours.

Patterns

Many patterns from regular Life are compatible with this rule. This is because EightLife is the most similar rule to Life, because cells are more likely to be off than on, and this rule requires a 3 by 3 square of on cells for an evolution difference, the least likely arrangement. Some patterns, like the heavyweight spaceship, do not survive this. Pulsars are common, as the name "Pulsar Life" suggests, evolving from the pi heptomino. Honeycombs are also common, because a common spark in Life (specifically that of a lone table, the one hassled in worker bee) evolves into this pattern instead. The pentadecathlon evolves differently in a few phases but is still period 15 and retains its domino spark.

Universality

It was mentioned in a poor quality article[1], but the first true proof was published on conwaylife forums[2] - basically it is a Rule-110[3] cellular automata unit cell, which was inherited from Conway's Game of Life and constructed by Jason Summers[4]

References

  1. http://repositorio.uam.es/bitstream/handle/10486/664759/fine_soler_JGPS_2013_ampl.pdf?sequence=2
  2. "List of the Turing-complete totalistic life-like CA". Peter Naszvadi. Retrieved on December 12, 2016.
  3. https://en.wikipedia.org/wiki/Rule_110
  4. http://pentadecathlon.com/lifenews/2005/12/rule_110_unit_cell.html

External links