We want your best #proofinatoot on mathstodon.xyz

Mastodon is a new social network, heavily inspired by Twitter but with a few differences: tweets are called toots, it’s populated by tusksome mammals instead of little birds, and it’s designed to run in a decentralised manner – anyone can set up their own ‘instance’ and connect to everyone else using the GNU Social protocol.

Colin Wright and I both jumped on the bandwagon fairly early on, and realised it might be just the thing for mathematicians who want to be social: the 500 character limit leaves plenty of room for good thinkin’, and the open-source software means you can finally achieve the ultimate dream of maths on the web: LaTeX rendering!

Alexandre Grothendieck’s notes archive to be released online

News from France, where the family of the late Alexandre Grothendieck, legend of basically all maths, have finally reached an agreement with the academic community about his huge archive of written notes. Discussions have been ongoing for a while but it’s finally been agreed that the notes can be released online for the community at large to take advantage of.

The notes comprise over 100,000 pages of mathematics, diagrams and letters to collaborators, and an initial chunk of over 18,000 pages will be online from 10th May on the University of Montpellier’s website. It’s expected that many undiscovered mathematical treasures might be found within, although the challenge of reading through and deciphering it all may take a Polymath-style mass effort.

More information

The notes of the mathematician Alexandre Grothendieck arrive on the net, at Libération (in French)

via Jordan Ellenberg on Twitter

Carnival of Mathematics 145

 

Carnival of Mathematics LogoWelcome to the 145th Carnival of Mathematics, hosted here at The Aperiodical.

If you’re not familiar with the Carnival of Mathematics, it’s a monthly blog post, hosted on some kind volunteer’s maths blog, rounding up their favourite mathematical blog posts (and submissions they’ve received through our form) from the past month, ish. If you think you’d like to host one on your blog, simply drop an email to katie@aperiodical.com and we can find an upcoming month you can do. On to the Carnival!

Review: The Mathematics of Secrets by Joshua Holden

Any book on cryptography written for a more-or-less lay audience must inevitably face comparisons to The Code Book, written in 1999 by Simon Singh, the king of distilling complex subjects to a few hundred pages of understandable writing. While Singh’s book is a pretty thorough history of codes and codebreaking through the centuries with plenty of the maths thrown in, The Mathematics of Secrets is tilted (and indeed titled) more towards a fuller explanation of the mathematical techniques underlying the various ciphers. Although Holden’s book follows a basically chronological path, you won’t find too much interest in pre-computer ciphers here: Enigma is cracked on page seventy, and the name Alan Turing does not appear in the book.

Video: How to draw an egg

Katie’s done another video! This time it’s a neat method for constructing an egg-shape, using arcs of circles.

Bonus challenge: See if you can count how many times Katie accidentally says ‘compass’ instead of ‘pair of compasses’ during the video.

Timetabling choreography with maths

Earlier this week my sister-in-law (“SIL” from now on) sent me an email asking for help. She’s a dance teacher, and her class need to rehearse their group pieces before their exam. She’d been trying to work out how to timetable the groups’ rehearsals, and couldn’t make it all fit together. So of course, she asked her friendly neighbourhood mathmo for help.

My initial reply was cheery and optimistic. It’s always good to let people think you know what you’re doing: much like one of Evel Knievel’s stunts, it makes you look even better on the occasions you succeed.

I’d half-remembered Katie’s friend’s Dad’s golf tournament problem and made a guess about the root of the difficulty she was having, but on closer inspection it wasn’t quite the same. I’m going to try to recount the process of coming up with an answer as it happened, with wrong turns and half-baked ideas included.