| 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] |