Gil Kalai: "Puzzles about trees, high dimensions, elections and noise"

In the lecture I will talk about some mathematical puzzles that have preoccupied me over the years, and I will also reveal to you some of the secrets of our trade.
I will first discuss trees, their numbers, and how to extend the notion of trees to two dimensional objects, next, I will talk about high dimensional geometric bodies,
and the last topic will be about election rules that are immune to errors in counting the votes.