# Period

http://www.urbandictionary.com/define.php?term=appletart%20game&defid=5956600 2. appletart game 15 up, 2 down A game invented in October 2009 at First Flight High School where participants use the word appletart or some of its variants. Originally it was focused on who could say it the loudest but has evolved over time. The ways to play include: 1. Who can say appletart the loudest? 2. Who can say appletart the most in a game? 3. Who will say appletart last? 4. Who will day appletart in the funniest or most awkward situations? 5. What word will be matched when someone says appletart? Will it be appletart, applepie, poptart, or something else?1. kid 1: Appletart. kid 2: Appletart! kid 1: APPLETART! Kid 1:APPLETART!!! kid 3: AAAPPLETAAARRT!!!!! kid 4: There goes another appletart game.2. I love playing the appletart game. Appletart! appletart game mugs & shirtsapple tart game appletart apple tart appletard appleturd applefart applefuckingtart applepie poptart by appletartkid Jul 16, 2011 share this add a video The period of a pattern is the smallest number of generations it takes for it to reappear in its original form, possibly with some slight modification of interest. The term is used most commonly for oscillators and spaceships, but can also be used for puffers, wicks, fuses, superstrings, factories and guns. In the last case there is a distinction between true period and pseudo period. There is also a somewhat different concept of period for wicktrailers.

## Oscillators

In the case of oscillators, the period refers simply to the minimum number of generations it takes for the pattern to reappear exactly as it started. The period is equal to the number of distinct phases of the pattern. For example, the blinker is a period 2 oscillator because it has two distinct phases: one in which the three alive cells are arranged horizontally, and one in which the three alive cells are arranged vertically.

The period of an oscillator takes orientation into account. That is, even though the two phases of the blinker look the same from different orientations, they are considered two distinct phases and thus its period is 2. Also consider mold, which has period 4 even though its mirror image appears after only 2 generations.

## Spaceships

A glider (period 4)

For spaceships, the period refers to the minimum number of generations it takes for the pattern to reappear as it started, but at a different location. The period of a spaceship has nothing to do with how much the spaceship is displaced; only how long it takes for it to reappear. For example, the glider is a period 4 spaceship as can be seen to the right.

The period of a spaceship takes orientation into account. That is, even though the the glider appears mirrored after only 2 generations, its period is 4.