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

 Apr. 21: Improvements to glider syntheses mean that every 15bit still life has a recipe with at most 13 gliders. The upper limit is currently 12 gliders for 14bit 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 boundingbox 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 lowestcost syntheses.
 Apr. 67: 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 33bit 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.[1]

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 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 prime pairs or Fermat primes?
 ... that two completely different types of oblique spaceships, the waterbear and the halfbaked knightship, were constructed in 2014?
 ... that no Caterpillartype 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 spiralgrowth 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, currently 173,449 gliders — the runnerup being the Parallel HBK with a 38,380glider synthesis?
 ... that it was shown in 2014 that any salvo of gliders, no matter how tightly packed, can be constructed by crashing together gliders whose initial positions are farther apart than any chosen finite distance?
 ... that no spaceships with velocities other than c/4 diagonal (glider), c/2 orthogonal (*WSS variants), and c/12 diagonal (Corderships) had known glider syntheses until 2003, when a 2c/5 spaceship gun was constructed?
 ... that after ten years with no new small spaceship syntheses, a glider construction was found for the c/7 loafer in 2013?
 ... that glider constructions for three previously inconstructible spaceships (the dart, the crab, and the Parallel HBK) were discovered in 2014?

