This week's featured article

The grandfather problem is the following question, posed by John Conway in 1972 in Lifeline Volume 6:
 Is there a configuration which has a father but no grandfather?
Conway offered a $50 cash prize to "the first person to settle the grandfather problem either way". But the problem remained open until May 2016, when mtve presented such a pattern  and, soon after that, a pattern with a grandfather but no greatgrandfather, and another pattern with a greatgrandfather but no greatgreatgrandfather.

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 the smallest known sawtooth pattern in Conway's Life consists of only 177 ON cells?
 ... that there are now over a hundred and twenty known Herschel conduits, counting stable conduits only, and a much larger number if oscillatorsupported conduits are included?
 ... that Demonoids, Caterloopillars, Orthogonoids, halfbakery knightships are the only known types of spaceships with fixed slope but adjustable speed  not counting 0E0P metacellbased patterns?
 ... that a pattern exists in which no cell in the unbounded Life plane ever becomes periodic?
 ... 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?

