Because my voice recorder malfunctioned 15 minutes into my Lecture on
Copernicus on 2007 October 9, I've added this recording of my Copernicus
lecture from Autumn Quarter 2006. It is the same basic material, but
since I generally improvise on a basic outline, there will be some
differences. Personally, I liked this year's lecture better, but this
will at least cover most of the same material. Oh well.