This week's featured article

The kickback reaction is a collision of two gliders resulting in a single glider travelling in the opposite direction to one of the original gliders. This is important in the proof of the existence of a universal constructor, Bill Gosper's total aperiodic, and many other constructions.
Besides the 90degree collision shown here, one other twoglider collision with gliders meeting at 180 degrees also produces a clean output glider, and may also be called a "kickback reaction".

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 several candidate universal constructors have been demonstrated in Conway’s Life, but as of June 2015 none have been formally proven to be universal?
 ... 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 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?

