Top all-time · #7496
Nathaniel Johnston
Personal blog · njohnston.camathscience
Nathaniel Johnston's personal blog at njohnston.ca covers math and science. Since 2012, 11 different Hacker News readers have linked it 13 times, most often “Generating Sequences of Primes in Conway's Game of Life (2009)”. It is still writing: the last post was on 2024-11-22, and you can follow it by feed.
Too few sampled comments (7) to say how often HN recommends it.?
Why HN links it
HN readers link Nathaniel Johnston's blog for proofs about Game of Life spaceship speed limits, and for posts on superpermutations and number puzzles like the smallest uninteresting number.
Summarised by Claude from a sample of 7 HN comments that link here. Each comment is marked recommending, critical or neutral (citing without judging); how this works.
Most-linked posts?
- /2009/10/spaceship-speed-limits-in-life-like-cellular-automata/2 people · 3 mentions · first linked 2016-03-10
- /2009/06/11630-is-the-first-uninteresting-number/2 people · 2 mentions · first linked 2013-01-01
- Generating Sequences of Primes in Conway's Game of Life (2009)2 people · 2 mentions · first linked 2014-01-08
What Hacker News says?
This blog post has a explanation of the proof. http://www.njohnston.ca/2009/10/spaceship-speed-limits-in-li...
Comment linking /2009/10/spaceship-speed-limits-in-life-like-cellular-automata/
on “Elementary Knightship found in Conway's Game of Life”Submitted The Minimal Superpermutation Problem as a story · 3 points
HN discussion>3 cells forward, 3 reset steps Yes, you've got the right idea. It's actually more like "3 preperation steps, 3 steps forward" There's a proof ( http://www.njohnston.ca/2009/10/spaceship-speed-limits-in-li... ) that a spaceship that travels n cells vertically and m cells horizontally must take at least 2*(n+m) generations to do so.
Comment linking /2009/10/spaceship-speed-limits-in-life-like-cellular-automata/
on “Elementary Knightship found in Conway's Game of Life”Submitted A Derivation of Conway’s Degree-71 “Look-and-Say” Polynomial (2010) as a story · 2 points
HN discussionYou will like this: http://www.njohnston.ca/2009/06/11630-is-the-first-uninteres...
Comment linking /2009/06/11630-is-the-first-uninteresting-number/
on “I Am Releasing Ten Million Passwords”Submitted Generating Sequences of Primes in Conway's Game of Life (2009) as a story · 2 points
HN discussionc/3 diagonal is actually impossible as well - the limit is c/4, proved by Conway himself in Life's early years. His proof can be found here: http://www.njohnston.ca/2009/10/spaceship-speed-limits-in-li...
Comment linking /2009/10/spaceship-speed-limits-in-life-like-cellular-automata/
on “Is this c/10 spaceship known?”Submitted Conway’s Game of Life: Mathematics and Construction as a story · 1 points
HN discussionI know you’re joking, but apparently it was given as a programming problem in a contest on at least one occasion. See here: http://www.njohnston.ca/2014/08/obvious-does-not-imply-true-...
Comment linking /2014/08/obvious-does-not-imply-true-the-minimal-superpermutation-conjecture-is-false/
on “Mystery Math Whiz and Novelist Advance Permutation Problem”Submitted Generating Sequences of Primes in Conway's Game of Life (2009) as a story · 1 points
HN discussionThe technique may be different, but the results seem to be identical to what you get from the standard method e.g. described in Section 2 of http://www.njohnston.ca/wp-content/uploads/2013/03/minimal_s... or section 1 of https://arxiv.org/pdf/1408.5108.pdf; or as implemented by https://github.com/superpermutators/superperm/blob/master/bi... This method produces superpermutations of length 1! + 2! + ... + n!, which w…
Comment linking /wp-content/uploads/2013/03/minimal_superpermutations.pdf;
on “Superpermutations”Submitted Counting and Solving Final Fantasy XIII-2′s Clock Puzzles as a story · 1 points
HN discussionrelevant: http://www.njohnston.ca/2009/06/11630-is-the-first-uninteres...
Comment linking /2009/06/11630-is-the-first-uninteresting-number/
on “The smallest uninteresting number”
