### Six announcements

Monday, September 21st, 2015- I did a podcast interview with Julia Galef for her series “Rationally Speaking.” See also here for the transcript (which I read rather than having to listen to myself stutter). The interview is all about Aumann’s Theorem, and whether rational people can agree to disagree. It covers a lot of the same ground as my recent post on the same topic, except with less technical detail about agreement theory and more … well,
*agreement*. At Julia’s suggestion, we’re planning to do a follow-up podcast about the particular intractability of*online*disagreements. I feel confident that we’ll solve that problem once and for all. (**Update:**Also check out this YouTube video, where Julia offers additional thoughts about what we discussed.) - When Julia asked me to recommend a book at the end of the interview, I picked probably my favorite contemporary novel: The Mind-Body Problem by Rebecca Newberger Goldstein. Embarrassingly, I hadn’t realized that Rebecca had already been on Julia’s show twice as a guest! Anyway, one of the thrills of my life over the last year has been to get to know Rebecca a little, as well as her husband, who’s some guy named Steve Pinker. Like, they both live right here in Boston! You can talk to them! I was especially pleased two weeks ago to learn that Rebecca won the National Humanities Medal—as I told Julia, Rebecca Goldstein getting a medal at the White House is the sort of thing I imagine happening in my ideal fantasy world, making it a pleasant surprise that it happened in this one. Huge congratulations to Rebecca!
- The NSA has released probably its most explicit public statement so far about its plans to move to quantum-resistant cryptography. For more see Bruce Schneier’s Crypto-Gram. Hat tip for this item goes to reader Ole Aamot, one of the only people I’ve ever encountered whose name alphabetically precedes mine.
- Last Tuesday, I got to hear Ayaan Hirsi Ali speak at MIT about her new book,
*Heretic*, and then spend almost an hour talking to students who had come to argue with her. I found her clear, articulate, and courageous (as I guess one has to be in her line of work, even with armed cops on either side of the lecture hall). After the shameful decision of Brandeis in caving in to pressure and cancelling Hirsi Ali’s commencement speech, I thought it spoke well of MIT that they let her speak at all. The bar shouldn’t be that low, but it is. - From far away on the political spectrum, I also heard Noam Chomsky talk last week (my first time hearing him live), about the current state of linguistics. Much of the talk, it struck me, could have been given in the 1950s with essentially zero change (and I suspect Chomsky would agree), though a few parts of it were newer, such as the speculation that human languages have many of the features they do in order to minimize the amount of computation that the speaker needs to perform. The talk was full of declarations that there had been
*no useful work whatsoever*on various questions (e.g., about the evolutionary function of language), that they were total mysteries and would perhaps remain total mysteries forever. - Many of you have surely heard by now that Terry Tao solved the Erdös Discrepancy Problem, by showing that for every infinite sequence of heads and tails and every positive integer C, there’s a positive integer k such that, if you look at the subsequence formed by every k
^{th}flip, there comes a point where the heads outnumber tails or vice versa by at least C. This resolves a problem that’s been open for more than 80 years. For more details, see this post by Timothy Gowers. Notably, Tao’s proof builds, in part, on a recent Polymath collaborative online effort. It was a big deal last year when Konev and Lisitsa used a SAT-solver to prove that there’s always a subsequence with discrepancy at least 3; Tao’s result now improves on that bound by ∞.