Regular polygon surfaces:
Ian Alevy answers Problem 72 of The Open Problems Project ( every topological sphere made of regular pentagons can be constructed by gluing regular dodecahedra together.

You can also glue dodecahedra to get higher-genus surfaces, as in this image from, but Alevy's theorem doesn't apply, so we don't know whether all higher-genus regular-pentagon surfaces are formed that way.

Another one of my domain coloring stuff from my archives: an iterated rational function with icosahedral symmetry, plotted over the Riemann sphere

Mathematical sign language:

Hearing-impaired eletrical engineering researcher Jess Boland discovered that weren't enough technical terms in British Sign Language to cover the mathematics she uses in her work, so she's been creating new ones as well as promoting the ones BSL already had. Katie Steckles interviews her for The Aperiodical.

(@aperiodical has a Mathstodon account but they're letting it go stale instead of promoting their new posts...)

We've blogged about #Halcyon 2.3.0,what we did especially in this release and also a few things before.You can read it here:
Additionally new strings of Halcyon 2.3.0 are now ready for translation at .We need your help for offering Halcyon in even more languages and to update existing languages.Thank you very much for your help!

自動Google日本語翻訳で「使いやすい」に変換されてて正反対ビックリ Show more

misskey.ioでnotestockの登録ができなかった問題を修正しました。専門的な原因: Show more

I've just updated to Mastodon v2.8.0.
Release notes:
It's got polls, an interface to manage your follow lists, and lets us change signups from open access to "ask for an invitation". We'll do that if spam becomes a problem again (it currently isn't)

from Show more



#quesdon 本家の未回答質問をQuesdon(にインポートできるようになりました。

Regardless of the Reply's Context, Show more

Sorry, I can't look Show more

We're proud to announce that #Halcyon has been bought by @facebook .We're looking forward to a cooperation which will bring advantages for both platforms.Let's make federated social media for the masses together!We thank everyone who went the long way with us.Nothing will change for you as a user except that we will abuse every action you do for advertising.Oh by the way ads will be introduced with the next release!Find out more here:

Problem of Twitter's"#数学デー" etc Show more


I'm looking for identities like this one that I've already found:

I can't think of a better way of distributing the code we use to add to, so I've made a GitHub gist containing a patch file:
It also includes a patch to add the automatic replacement of some LaTeX commands with equivalents inside the toot compose box, which is more convenient when you don't need "proper" LaTeX typesetting.

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A Mastodon instance for maths people. The kind of people who make \(\pi z^2 \times a\) jokes.

Use \( and \) for inline LaTeX, and \[ and \] for display mode.