seeds/README.md

   1 Seeds
   2 =====
   3
   4 https://en.wikipedia.org/wiki/Seeds_(cellular_automaton)
   5
   6 > Seeds is a cellular automaton in the same family as the Game of Life,
   7 > initially investigated by Brian Silverman[1][2] and named by Mirek
   8 > Wójtowicz.[1][3] It consists of infinite two-dimensional grid of cells, each
   9 > of which may be in one of two states: on or off. Each cell is considered to
  10 > have eight neighbors (Moore neighborhood), as in Life. In each time step, a
  11 > cell turns on or is "born" if it was off or "dead" but had exactly two
  12 > neighbors that were on; all other cells turn off. Thus, in the notation
  13 > describing the family of cellular automata containing Life, it is described
  14 > by the rule B2/S.[1]
  15 >
  16 > In Game of Life terminology, a pattern in which all cells that were on turn
  17 > off at each step is called a phoenix. All patterns in Seeds have this form.
  18 > Even though all live cells are constantly dying, the small birth requirement
  19 > of two cells means that nearly every pattern in Seeds explodes into a chaotic
  20 > mess that grows to cover the entire universe. Thus, in Wolfram's
  21 > classification of cellular automata, it is a Class III automaton, in which
  22 > nearly all patterns evolve chaotically.[1]
  23 >
  24 > However, some patterns are known to behave in a more controlled fashion,
  25 > repeating the same shape either in the same position of the grid (an
  26 > oscillator) or translated some number of grid units after several steps (a
  27 > spaceship). More complex rake and puffer patterns are known which move like
  28 > spaceships leaving trails of oscillators or other spaceships behind them.
  29 > Most of these patterns move at a speed of 1 cell per time step (the so-called
  30 > speed of light, or c/1)[4] including three commonly seen spaceships with four
  31 > on cells each, but slower-moving patterns are also known. A collection of
  32 > patterns for the Seeds rule collected by Jason Summers includes patterns
  33 > found by Stephen Wright, Mirek Wójtowicz, Noam Elkies, Mark Niemiec, Peter
  34 > Naszvadi, and David Eppstein.[5]