
I’ve just posted my latest YouTube video, in which I explain how to use binary numbers to jazz up your nail varnish: Alongside this video, I also have an associated puzzle for you to think about.

I’ve just posted my latest YouTube video, in which I explain how to use binary numbers to jazz up your nail varnish: Alongside this video, I also have an associated puzzle for you to think about.

Two months ago, I bought isthisprime.com and not only set up the internet’s fanciest primality-checking service, but also invented a rather addictive game. It quite quickly went viral, or as relatively viral as a maths game can get, with people tweeting their high scores and posting the link to reddit and Hacker News. I realised fairly…
Puzzlebomb is a monthly puzzle compendium. Issue 53 of Puzzlebomb, for May 2016, can be found here: Puzzlebomb – Issue 53 – May 2016 The solutions to Issue 53 can be found here: Puzzlebomb – Issue 53 – Solutions – May 2016 Previous issues of Puzzlebomb, and their solutions, can be found at Puzzlebomb.co.uk.
From Mark C. Wilson of the University of Auckland, a little public service announcement for anyone who’s ever been involved with a mathematical journal. Dear colleagues, There is much dissatisfaction with the current state of research publication, but little information on community attitudes and priorities. I have started a survey which I hope you will…
Here’s something fun you might want to spend some money on: a poster of the Mandelbrot set, in the style of an old-fashioned navigation chart. https://www.kickstarter.com/projects/billtavis/mandelmap-poster-a-vintage-style-map-of-the-mandel The Kickstarter has already racked up many multiples of the original funding goal with three weeks still to go, so it’s at the “effectively a pre-order” stage. The posters start at \$26. Kickstarter: Mandelmap…
Conjecture Every planar graph without 4-cycles and 5-cycles is 3-colourable. Nope! In a paper just uploaded to the arXiv, Vincent Cohen-Addad, Michael Hebdige, Daniel Kral, Zhentao Li and Esteban Salgado show the construction of a graph with no cycles of length 4 or 5 which isn’t 3-colourable: it isn’t possible to assign colours to its vertices so that no…

Warning: you could make a very strong argument I’ve thought far too much about something inconsequential. If that makes your stomach turn, look away now. This morning in the shower, I had an idle thought about my towel. It was, as always, folded neatly on the toilet seat. A problem that’s been bugging me for a few…