We were privileged to have a visit from Terry Tao today. He gave a nice talk on work with Ben Green on the orchard planting problem. For me even the Sylvester-Gallai theorem was news. His public lecture on the “Cosmic distance ladder” drew a huge crowd. I very much enjoyed the historical discussion of how astronomical distances were measured. It is interesting to think about why Aristarchus’s ideas were rejected by peer review. I have a renewed respect for Kepler and learned that Io orbits Jupiter every 42.5 hours.

He is touring the country as the 2013 Maclaurin Lecturer for the next several days. Definitely worth seeing!