December 17, 1998 CfA Colloquium

Title: Sleepwalking or argument? The truth behind Kepler's Astronomia nova

Speaker: James Voelkel

Abstract: Kepler's Astronomia nova (1609), in which he discloses what later became known as his first two laws of planetary motion, is an unusual and engaging book. In great--sometimes stultifying--detail, he describes his five years of work on the orbit of Mars, including any number of false starts and missteps along the way. His narrative is so personal, with its self-deprecating and even comic asides, that it has long been taken to be a true account of his work, and it has been the basis for almost everything that has been written about the actual course of his research. So artful and technically brilliant is his account that we have believed he was a "sleepwalker" who compulsively described his experience. He was not. The Astronomia nova is not a true historical account; it is a pseudo-history, a purposely-constructed rhetorical argument. This colloquium will provide the context for understanding why such a stratagem was necessary.

Reference for students: For examples of the unusual style of Kepler's (Astronomia nova), read the Introduction; the introduction to the Summaries of the Individual Chapters (pp. 78-79 of Donahue's translation); and Chapter 7, "The circumstances under which I happened upon the theory of Mars." The first page of Chapter 45 (p. 455 and the top of 456 in Donahue's translation) is also charming. Students may pick up copies of these materials from Prof. Gingerich. More references
Lunch on Thursday at 1pm in the classroom