Various and Sundry

Some quick links:

  • Via my Columbia colleague at Mathematics Without Apologies, a documentary about Perelman that I was unaware of.
  • I learned something yesterday about another math department colleague, Mikhail Khovanov: he has games called Ringsanity and Ringiana available as apps.
  • Took a quick look at a Stephon Alexander’s new book The Jazz of Physics, which is now in bookstores. While I enjoyed reading some of his account of his career in theoretical physics, I’m afraid that his two main topics, jazz and models of the big bang, both are things that pretty much leave me cold. For those with more interest in either topic, you probably should take a closer look.
  • I’m sorry to see that there’s some sort of fight developing over Grothendieck’s papers. A shame.
  • Previous attempts to figure out what “ER=EPR” is supposed to mean have left me baffled. Trying to read Susskind’s write up of his IAS lectures on the topic hasn’t helped, I’m afraid.

: Mikhail Khovanov tells me that Ringiana for Android can be found here. It was developed jointly with Nikolay Gromov.

He also comments that “Thompson groups V and T act on the states of Ringiana and Ringsanity, correspondingly. These groups were the first two infinite, finitely-presented, simple groups discovered by mathematicians.”

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8 Responses to Various and Sundry

  1. Can Hatipoglu says:

    I am looking forward to see some content in English about the fight over Grothendieck’s papers.

  2. Yatima says:

    Reste à savoir quelle est la valeur de ces archives. “Difficile à dire, tant que l’université refuse tout échange avec nous”, poursuit l’avocate, “mais on peut imaginer que des grandes universités américaines avec beaucoup de moyens seraient prêtes à payer le prix fort.”

    The relatives’ lawyer says that the value of those documents (apparently hidden somewhere in Montpellier in a secret vault and being scanned to the tune of 45KEUR but with no intention of publishing them – indeed it seems Grothendieck did not want them published in the first place) is difficult to judge as the university refuses to engage but that big monied american universities would be willing to lay down large wads of cash.

    It sounds all pretty sordid.

    That article has a weird last paragraph saying that Einstein was a major factor of “The Bomb” (oh really?) and that no-one knows what might come out of Grothendieck’s stash of unpublished notes. Huh.

  3. ptmalloy says:

    Are there Android versions of the two games? Just looked for Ringsanity, but could not find it in the Google Play store.

  4. Anonymous says:

    “Ringiana is available for both iPhone and android, while Ringsanity you can get for iPhone, with android version in the works.”

    It can be downloaded from here:

  5. ptmalloy says:


    Thank you very much! I will look for it.


  6. Bill says:

    I am curious what was Mikhail motivation to create those apps…

  7. Abel Molina says:

    Wow, Ringsanity looks really cool. Thanks for posting the links, gonna get it for sure!

  8. What I find interesting about the documentary on Perelman is that there is no mention whatsoever of his Jewish heritage — or of the antisemitism he had to fight during his life as a student in St. Petersburg. Masha Gessen gives the full story in Perfect Rigor, her superb biography of the man.

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