In 1543, Nicolaus Copernicus re-introduced the Heliocentric idea of

Aristarchus of Samos in an attempt to purge Ptolemy's geocentric system

of the un-Aristotelian idea of the Equant. His goal was to derive a

model that, in his words, pleased the mind as well as preserved

appearances. What he started, without intending, was a profound

revolution in thought that was to overturn both Ptolemy and Aristotle

within two centuries, and help give birth the the modern world. This

lecture looks at the Copernican system, and sets the stage for the

scientific revolution of the following generations. Recorded 2006 Oct

10 in 100 Stillman Hall on the Columbus campus of The Ohio State

University.