8.9. Glossary¶
Beehive: A stable pattern in which every cell in the beehive has 2 or 3 neighbors, so they all survive, and none of the dead cells adjacent to the beehive has 3 neighbors, so no new cells are born.
Glider: After a period of 4 steps, the glider is back in the starting configuration, shifted one unit down and to the right.
Gosper’s Gun: Is a stable pattern that periodically produces a spaceship — as the stream of spaceships moves out from the source, the number of live cells grows indefinitely.
Instrumentalism: Instrumentalism is the view that theories are instruments that we use for our purposes.
Methuselahs: Long-lived patterns that yield a surprising number of live cells.
Puffer Train: A translating pattern that leaves live cells in its wake.
Scientific Realism: Scientific realism pertains to scientific theories and the entities they postulate. A theory postulates an entity if it is expressed in terms of the properties and behavior of the entity.
Spaceships: Called this because as some patterns oscillate and return to the starting configuration, but shifted in space.
Stable Pattern: Pattern that does not change from generation to generation.
Toad: They change over time but eventually return to their starting configuration, which is an oscillator that alternates between two states. The “period” of this oscillator is 2.
Unstable Pattern: Pattern that changes from generation to generation.