Now blogging on Bluesky
I haven t been actively blogging for several years at this point, but have instead been posting on other social media. These days I m on Bluesky (@njohnston.ca), so here s my Bluesky feed come talk to me there:
Nathaniel Johnston
Quantum information theory, cellular automata, and recreational mathematics
Latest posts
Minimal injective superstrings: A simpler generalization of superpermutations
It seems that I write about superpermutations way too frequently, and today I m going to continue the trend. Recall that a superpermutation is a string on n symbols that contains all n! permutations of those n symbols as contiguous substrings. For example, when n = 3, the 3! = 6 permutations of the symbols 1 , [ ]
Herschel tracks in Conway’s Game of Life – Part 1 – Making oscillators and glider guns of any period 61 or larger
Back in September 1995, David Buckingham showed how to construct oscillators and glider guns of any period at least 61 in Conway s Game of Life. His method was based on a tool called a Herschel conduit ; a configuration of still lifes that can be used to move a Herschel from one location to another. By [ ]
Solving the “Lights Out” Puzzle via Linear Algebra
Lights Out is a puzzle that sits in a very interesting place mathematically: while many puzzles can be solved with the help of math, Lights Out is solved exactly and completely by math (linear algebra in particular). Linear algebra doesn t just make it easier to solve: it finds an exact solution, and does it so [ ]
First true period 15 and 16 glider guns found in Conway’s Game of Life
I ve been meaning to make a series of videos on Conway s Game of Life for a few years now, and I finally decided that rather than rehashing topics that are already covered in the textbook, I ll make videos explaining particularly notable new discoveries as they re made. Unfortunately, the news that Life is omniperiodic is somewhat [ ]
What is the Maximum Possible Area of 3 Circles in a Triangle?
After a 3-year hiatus, I m back making math videos, not least of all thanks to my new fancy-schmancy basement studio: This time I m trying this crazy technique called editing , rather than just recording myself and dumping raw video footage online (which, believe it or not, is what I did for my previous videos – those [ ]