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

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 in 2016, patterns were found that have greatgreatgrandparents but no greatgreatgreatgrandparents?
 ... that no way is known for a 3x3 pattern to be tiled into an MxN rectangle to produce a Garden of Eden, but that there are 4x3, 4x4 and larger tiles that can be repeated in this way to produce GoEs?
 ... that there are spaceship stabilizations of agars?
 ...that there are 9,971,377 strict still lifes with population 25?
 ...that there are 24,619,307 strict still lifes with population 26?
 ...that there are 60,823,008 strict still lifes with population 27?
 ...that there are 150,613,157 strict still lifes with population 28?
 ... that the largest interesting pattern constructed, the caterpillar, contains over 11 million cells?
 ... that the Gosper glider gun was the first pattern to be discovered that exhibits infinite growth?
 ... that the blocklaying switch engine and the gliderproducing switch engine (and various combinations of two switch engines) are the only two infinitelygrowing patterns that are known to have ever occurred naturally from a nonsymmetric random starting configuration?

