This week's featured article

2×2 is a Lifelike cellular automaton in which cells survive from one generation to the next if they have 1, 2 or 5 neighbours, and are born if they have 3 or 6 neighbours. That is, it is governed by the rulestring "B36/S125". Patterns under the rule have a chaotic evolution similar to those under the standard Life rules, but the chaos tends to die out much more quickly.
The 2×2 rule gets its name from the fact that it can emulate a simpler cellular automaton that acts on each 2×2 block. The emulated automaton is a block cellular automaton that makes use of the Margolus neighbourhood. As a result, patterns that are originally made up of 2×2 blocks will forever be made up of 2×2 blocks, but the block partition will be offset by one cell in the odd generations from the even generations. There are 2^{12} = 4096 such Lifelike automata, of which 2×2 is the most wellknown.

Pattern collection

The LifeWiki contains one of the most comprehensive catalogues of patterns available on the internet. Within it you will find:


Did you know...

 ... that quadraticallygrowing patterns have been found with as few as 23 initial cells?
 ... that the blinker is the only known oscillator that is one cell thick?
 ... that the first spaceship found in Conway's Game of Life that travels in an oblique direction was discovered in 2010?
 ... that there are still lifes that can be split into four stable islands, but not two or three?
 ... that no new spaceships were discovered after 1970 until 1989?
 ... that the first stable reflector was found in October 1996, and the first fast stable reflector appeared in 2013, allowing the construction of oscillators of all periods ≥43 ticks?
 ... that twentyfour spaceship velocities have been constructed, including five infinitely adjustable families of ships?
 ... that there are 71 distinct ways for two gliders to collide, but it is unknown how many distinct 3glider collisions there are?
 ... that to display the smallest known gun pattern for a Gemini spaceship at 1 cell = 1 pixel, on a standarddensity video monitor, a screen over one mile square would be needed?
 ... that no oddperiod glider guns were known before 1995, when a period 565 p5sparkassisted Bheptomino loop was constructed by David Buckingham?

