Today's featured article
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| A still life is a pattern that does not change from one generation to the next, and thus may be thought of as an oscillator with period 1. Still lifes are sometimes assumed to be finite and non-empty. The two main subgroups of still lifes are strict still lifes and pseudo still lifes. In some contexts, the term "still life" may refer to strict still lifes.
A strict still life is a still life that is either connected (i.e., has no islands), or is such that removing one or more its islands destroys the stability of the pattern. For example, beehive with tail is a strict still life because it is connected, and mirrored table is a strict still life because neither of the tables are stable by themselves.
A pseudo still life consists of two or more islands which can be partitioned (either individually or as sets) into non-interacting subpatterns which are by themselves each still lifes. Furthermore, there must be at least one dead cell that has more than three alive neighbours in the overall pattern but has less than three alive neighbours in the subpatterns. This final restriction removes patterns such as bakery, blockade and fleet from consideration, as the islands are not "almost touching".
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In the news
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- December 5: Matthias Merzenich completes the first true period-35 glider gun based on a partial result by iNoMed and hotcrystal0.
- November 18: AlbertArmStain discovers a small, direct H-to-MWSS conduit with a repeat time of 141 ticks. Period1GliderGun and Lucy D'Agostino subsequently find variants that reduce the repeat time to 120 ticks.
- November 3: Lucy D'Agostino discovers a new set of connectable Spartan converters with E-heptomino inputs, further expanding the set of known E-heptomino conduits.
- November 2: iNoMed finds a way to use stable catalysts to make a p2 traffic jam wire turn a 90-degree corner with no help from sparkers.
- October 28-30: Entity Valkyrie builds the first known true period-47 glider gun based on a partial result by iNoMed, after which the bounding box is reduced by more than a factor of four by several contributors over the next two days, from 311 × 289 down to Luka Okanishi's greatly simplified design at 147 × 144.
- October 20: FWKnightship completes a redesigned (34,7)c/156 spaceship with a bounding box of (52514, 158980) and minimum population of 655,594; this is less than 1/38th of the population and less than 1/6000th of the area of the previous version of this spaceship constructed by Luka Okanishi last year.
- October 10: AlbertArmstain rebuilds an initial stage from Mitchell Riley's H-to-Gs into a Herschel-to-B-heptomino converter; Lucy D'Agostino notices that this is actually a known E-heptomino converter appended to a previously unknown Herschel-to-E converter, HRx93E -- which enables completely new Spartan Herschel conduits Rx155 and R194, among other things.
- October 10: Mitchell Riley's "LightCone" search program finds several new Spartan Herschel-to-glider converters.
- October 9: Tanner Jacobi reduces the cost of the synthesis for B29 from 25 to 16 gliders, using QuFince to avoid scaffolding.
- October 9: Chris857 finds a synthesis for popover.
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Did you know...
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- ... that several different universal constructors in Conway’s Life have been shown to be capable of constructing their own circuitry?
- ... that there are dozens of known Cordership variants, including puffers, rakes and wickstretchers, with periods of any multiple of 96?
- ... that greyships have been constructed with speeds of c/2, c/3, c/4, c/5, and 2c/5?
- ... that most greyships travel parallel to the stripes in their included agars, but a few travel perpendicular to the stripes, or "against the grain"?
- ... that a pattern has been constructed that calculates and prints out the digits of pi in decimal, and a similar one prints out the decimal digits of the Golden Ratio?
- ... that several different patterns have been constructed to calculate and display the sequence of prime numbers, and some have been adapted to display only twin primes or Fermat primes?
- ... that two completely different types of oblique spaceships, the waterbear and the half-baked knightship, were constructed in 2014?
- ... that no Caterpillar-type spaceships were completed for almost ten years after the original Caterpillar was constructed in 2004, but that two different designs, the waterbear and the centipede, were finished in 2014?
- ... that the first spiral-growth pattern in Conway's Life was constructed in 2014?
- ... that among known glider recipes for irreducible objects, the Gemini spaceship has the largest known minimal recipe not counting encoded RCT recipes, currently 173,449 gliders — the runner-up being the self-synthesizing oblique loopship which is its own 144,221-glider synthesis?
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Pattern collection
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| The LifeWiki contains one of the most comprehensive catalogues of patterns available on the internet. Within it you will find:
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