History of cosmology from Plato to Einstein

Yesterday I gave an invited lecture in Lincoln at an international symposium of Robert Grosseteste (1175-1253) My topic was "Geometry and Cosmology in Antiquity and the Middle Ages", and the theme was that geometry is intertwined with cosmology in models of the universe. Anyone can download my ppt presentation and lecture script. Go to this webpage http://bit.ly/Ta1k5 and click through the links. It's free, no catch