This is the weekly visible open thread. Odd-numbered open threads will be no-politics, even-numbered threads will be politics-allowed. This one is odd-numbered, so be careful. Otherwise, post about anything else you want. Also:

1: Comment of the week is Vosmyorka describing political polarization (or lack thereof) in the most recent Dutch election.

2: In my review of Antifragile , I repeated Nassim Taleb’s claim, sourced to history Guy Beaujouan, that “before the thirteenth century no more than five persons in the whole of Europe knew how to perform a division”. Here’s some discussion on whether that’s true.