Brian's Brain
| Brian's Brain | ||
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| View animated image | ||
| Rulestring | /2/3 B2/S/C3 B2/S/G3 |
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| Character | Chaotic | |
Brian's Brain (also called BB, or simply Brain) is a cellular automaton and one of the best-known Generations rules. It is similar to Seeds, but with an additional state; dead cells get born if they have exactly two live neighbors, and live cells never survive, but instead of dying immediately, they advance to a third state, not considered "live" for the purpose of cell birth, before dying. The rule was first considered by Brian Silverman in the mid-1990s.
Brian's Brain can be thought of as emulating a neural network, with state 0 representing "ready", state 1 representing "firing", and state 2 representing "refractory"; the rule can then be stated as "only a cell in the ready state may fire and it will only do so if exactly 2 of its neighbors are firing. After firing for one step, a cell spends a step in the refractory state before regaining readiness".
Patterns
Most patterns in Brian's Brain are spaceships; the first oscillators were discovered by Michael Sweney in December 1999. No period-2 oscillators exist (as in any Generations rule with more than two states); an example of a period-3 oscillator is shown to the right. Rakes, breeders, puffers, periodic agars and wicks have been constructed in Brian's Brain.
External links
- Brian's Brain (discussion thread) at the ConwayLife.com forums
- Brian's Brain at Adam P. Goucher's Catagolue
- Brian's Brain at Wikipedia
