State of the Tau 2024

Michael Hartl • Jun 28, 2024

It’s that time of year again: the summer (or winter!) solstice, high school graduations, college commencements, and of course Tau Day!

Michael Hartl here, founder of Tau Day and author of The Tau Manifesto. Thanks for joining me for another year of celebrating the true circle constant—the ratio of a circle’s circumference, not to its diameter, but to its radius:

\[ \tau = \frac{C}{r} = 6.283185\ldots \]

First publicly proposed in 2010 by The Tau Manifesto (now available both online and as a print edition at Amazon), tau has seen adoption by thousands (millions?) of math enthusiasts around the world, including the official Google calculator, the Python programming language, and (new this year!) iOS, Apple’s ubiquitous mobile operating system.

The State of the Tau 2024 is published jointly on the Tau Day website, on Substack, and on my personal website. In addition to tau topics, my posts chronicle my current math learning project, including lots of recommendations for math learning resources. Subscribe to my Substack for free post notifications, join as a paid subscriber to support my work financially, or join as a Founding Member to get a personal video chat with me on any subject of your choosing!

Without further ado, here are some highlights from the world of tau since Tau Day last year:

  • The Simons Laufer Mathematical Sciences Institute (SLMath, formerly MSRI) is running their third annual Tau Day fundraiser, with generous matching gifts to double the impact of donations. (details)

  • SLMath is also sponsoring not one but two puzzle contests (one featuring an Official Tau Shirt as a top prize), both available on the SLMath Tau Day page. (details)

  • I have received reports of continued adoption of tau in various corners of computing, including the Nim systems programming language and an amazing appearance in iOS, the operating system powering iPhone and iPad. (details)

  • There were lots of great tau happenings on Twitter (sometimes, though rarely, called 𝕏), including supportive tweets from MIT, Vitalik Buterin, and Elon Musk! (details)

  • An alert tauist passed along a vintage Vi Hart video I somehow missed all these years, featuring a wonderful song about tau. (details)

You can find the full State of the Tau 2024 on the Tau Day website. Happy Tau Day!