This week's featured article
| 2×2 is a Life-like 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 As a result, patterns that are originally made up of 2×2 blocks will forever be made up of 2×2 blocks, but the block partition will be offset by one cell in the odd generations from the even generations.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 212 = 4096 such Life-like automata, of which 2×2 is the most well-known.
| The LifeWiki contains one of the most comprehensive catalogues of patterns available on the internet. Within it you will find:
Did you know...
- ... that the first self-constructing Conway's Life pattern was built in 2010?
- ... that the first glider synthesis for a c/3 spaceship was completed in 2014?
- ... that the first "macro-spaceship" gun (a Gemini spaceship gun) was constructed in 2010, followed by the HBK gun in January 2015?
- ... that the waterbear is the single known high-speed oblique spaceship, many orders of magnitude faster than Gemini spaceships and half-baked knightships?
- ... that there are no known direct reflectors for lightspeed wire signals, or for signals in 2c/3 wires?
- ... that 24 ten-cell patterns exhibit infinite growth, with 17 unique pattern types, but that it has been proven that no nine-cell pattern exhibits infinite growth?
- ... that all still lifes up to 18 bits have a known glider synthesis, but it's still not known whether all still lifes are synthesizable.
- ...that the French kiss remained without a glider synthesis until 2013?
- ... that Adam P. Goucher's distributed Catagolue soup-search project, started in February 2015, has already tested more random soups than any previous such project, and has contributed to the reduction of many glider construction recipes?
- ...that the largest interesting pattern constructed, the caterpillar, contains over 11 million cells?