This week's featured article
| A spaceship (much less commonly referred to as a glider or a fish) is a finite pattern that returns to its initial state after a number of generations (known as its period) but in a different location. The speed of a spaceship is the number of cells that the pattern moves during its period. This is expressed in terms of c (the metaphorical "speed of light") which is one cell per generation; thus, a spaceship with a period of five that moves two cells to the left during its period travels at the speed of 2c/5. Most known spaceships in Life travel either orthogonally (only horizontal or vertical displacement) or diagonally (equal horizontal and vertical displacement). However, several large Conway's Life spaceships have been engineered that travel in various oblique directions, and it is known that Life has spaceships that travel in all rational directions at arbitrarily slow speeds.
In the news
- Apr. 21: Improvements to glider syntheses mean that every 15-bit still life has a recipe with at most 13 gliders. The upper limit is currently 12 gliders for 14-bit still lifes, 10 gliders for 13 bits, 8 gliders for 12 bits, and 7 gliders for 11 bits.
- Apr. 17: Tanner Jacobi and Matthias Merzenich set several new bounding-box records with a new glider gun mechanism based on filtered MWSSes.
- Apr. 10: Jeremy Tan releases a new glider recipe database, Shinjuku, specifically for tracking lowest-cost syntheses.
- Apr. 6-7: LifeViewer standardizes support for triangular neighbourhoods starting with Build 320.
- Apr. 5: An exhaustive computer search run by Nathaniel Johnston reveals that there are 14,223,867,298 strict and 15,851,861,075 pseudo 33-bit still lifes, including eleven pseudo still lifes that can be partitioned into three stable pieces but not two, and none that can be partitioned into four stable pieces but not two or three.
| 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 number of still lifes with N+1 bits is roughly 2.48 times larger than the number of N-bit still lifes?
- ... that the odds of a randomly-chosen 20x20 soup pattern being a methuselah that lasts between 1000N and 1000(N+1) ticks, is roughly the same as the odds that it will last any amount of time longer than 1000x(N+1) ticks?
- ... that all still lifes up to 16 cells can be synthesized at a cost of less than one glider per cell?
- ... that the first elementary knightship, Sir Robin, was discovered only in 2018, with there having been a very close call in 2004?
- ... that there is a 6x2 counterexample to the Coolout Conjecture, proving that patterns that are internally compatible with stability can not always be made part of a larger still life, no matter what cells are added around the edges?
- ... that a Conway's Life pattern representing a complete programmable 8-bit computer, consisting only of buckaroos, p60 glider guns, and glider duplicators, was completed in November 2016?
- ... that whilst no elementary oblique spaceships were found in B3/S23 until 2018, and none have occurred naturally, at least two naturally occurring reactions have been discovered in B38/S23 that travel in an oblique direction?
- ... that not all 1.00 volatility oscillators are phoenixes, but volatility 1.00 period 2 oscillators must be phoenixes?
- ... that no pattern inside a 6x6 bounding box is a Garden of Eden?
- ... that Garden of Eden patterns with only 45 ON cells have been found?