This week's featured article

A sawtooth is a finite pattern whose population grows without bound but does not tend to infinity. In other words, it is a pattern with population that reaches new heights infinitely often, but also infinitely often drops below some fixed value. Their name comes from the fact that their plot of population versus generation number looks roughly like an everincreasing sawtooth graph.
The first sawtooth was constructed by Dean Hickerson in April 1991 by using a loaf tractor beam (a technique that was also used in the construction of sawtooth 633). The least infinitely repeating population of any known sawtooth is 177, attained by Sawtooth 177; the smallest bounding box of any known sawtooth is 62x56, attained by a variant of the same pattern, Sawtooth 195

In the news


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 all still lifes up to 18 bits have a known glider synthesis, but it is 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 soupsearch 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 any gliderconstructible Life pattern can be constructed with a fixed maximum number of gliders N, probably less than 1000? It is only necessary to construct a slidingblock decoder, which selfdestructs after converting the position of a fardistant block into a slowsalvo recipe that constructs the required pattern.
 ... that Copperhead is not only the first c/10 orthogonal spaceship ever found, but also remarkably compact for a pattern not discovered until 2016?
 ... that loafer is the fifth smallest nonflotilla spaceship, but was discovered 43 years after the four spaceships smaller than it?
 ... that despite being the fourth smallest nonflotilla orthogonal spaceship, loafer has never appeared from a single randomly generated soup?
 ... that all known glider eaters take at least four ticks to recover to their original state after eating a glider?
 ... that the smallest 31c/240 spaceship does not make use of the 31c/240 reaction?
 ... that there is roughly one chance in 10^(N/3) that a still life appearing out of random soup will have a population of exactly N cells?

