This week's featured article
The grandfather problem is the following question, posed by John Conway in 1972 in Lifeline Volume 6:
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 great-grandfather, and another pattern with a great-grandfather but no great-great-grandfather.
- Is there a configuration which has a father but no grandfather?
In the news
- Mar. 7: A spider synthesis using 574 gliders and 9 LWSSes is found by Martin Grant. 
- Mar. 3: A period-120 oscillator, the highest period thus far, occurs from a natural soup on Catagolue.
- Mar. 2: Several symmetric-soup diehards with lifespans over 1500 ticks have been found by 'carybe', using apgsearch..
- Feb. 12: A lightweight Schick engine appears from a natural (C1) soup on Catagolue.
- Feb. 9: A 47,575-tick 16x16 methuselah found by Adam Goucher via apgsearch yields a 16-cell, 47,487-tick methuselah. This discovery skips over several empty 1000-tick bins in Catagolue above the previous record 16x16 methuselah, Homer.
- Feb. 4: A glider detection and removal upgrade in apgsearch version 4.91 gives a search speed boost of well over 50% compared to version 4.88.
- Feb. 4: Tanner Jacobi and Martin Grant find a recipe, subsequently reduced to 88 gliders, for the first-ever synthesizable c/4 spaceship, 46P4H1V0.
| The LifeWiki contains one of the most comprehensive catalogues of patterns available on the internet. Within it you will find:
Did you know...
- ...that there are currently known elementary spaceships with speeds c/7 and c/10 orthogonal, but none with c/8 or c/9?
- ...that there are currently known elementary spaceships with speeds c/7 and c/12 diagonal, but none with c/8, c/9, c/10 or c/11?
- ...that while the speed limit for orthogonal spaceships in rules using the Moore neighbourhood is c orthogonal, spaceships in Larger than Life rules are capable of breaking this barrier?
- ...that without the use of adjustable glider loops, there are no known oscillators with periods 43 or 53?
- ...that without the use of Herschel loops or adjustable glider loops, there are no known oscillators with periods 59 or 61?
- ... that small stable elementary period multipliers (also known as pulse dividers) have been found for multipliers of 2x, 3x, and 4x, but not for 5x or higher?
- ... that with reverse caber-tosser universal constructor technology, it is possible to build any possible glider-constructible pattern, no matter what size, using only 35 gliders?
- ... that there are at least four known ways to send information diagonally at a speed greater than the maximum spaceship speed through vacuum? (Complete mechanisms include speeds approaching c/2 via two perpendicular telegraphs, and 2c/3 via a 2c/3 wire.)
- ... that an oscillator with strict volatility 1 can be constructed for any period 3506909 or higher?
- ... that the original Gemini's "below-the-elbow" construction efficiency, roughly three gliders per still life, is about four times better than that of any subsequent self-constructing spaceship?