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a5bb74bc SK |
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] |