Lecture
This lecture explores the concept of epicyclic curves, which have been a fundamental tool in astronomy since ancient times. It delves into the historical development of epicyclic models, from the Greeks to Kepler, and the complexities astronomers faced in modeling planetary motions. The lecture also discusses Ptolemy's Almagest, Copernicus' heliocentric system, and the significance of commensurability in periodicity. The presentation focuses on the basic mechanism of epicyclic curves composed of a single deferent circle and a single epicycle, as seen in Dürer's 'spider' instrument.