Poncelet's Porism

In this talk, Prof. Matt Bainbridge will talk about the Poncelet’s Porism. More specifically, suppose E and F are ellipses in the plane with E inside F. Poncelet’s Porism says that if there is a single polygon which is inscribed in F and circumscribed around E, then there are infinitely many such polygons. In this talk, I’ll give a beautiful proof of this theorem using some basic (but deep) properties of elliptic curves.