On Sunspots

Galileo's telescopic discoveries, and especially his observation of sunspots, caused great debate in an age when the heavens were thought by most to be perfect and unchanging. Christoph Schemer, a Jesuit mathematician, argued that sunspots were satellites of the Sun crossing in front of it. Galileo, on the other hand, countered that the spots were on or near the surface of the Sun itself, and he supported his position with a series of meticulous observations and mathematical demonstrations that eventually convinced even his rival.

On Sunspots collects the correspondence that constituted the public debate, including the first English translation of Schemer's two tracts as well as Galileo's three letters, which previously have been published in English only in abridged form. In addition, Eileen Reeves and Albert Van Helden have supplemented the correspondence with informative introductions, extensive notes, and a bibliographv. Ibis book will be the standard work on the subject, essential for students and historians of astronomy, the telescope, and early modern religion.

"This translation is both timely and commendable, Until now, English-speaking students of Galileo and Scheiner have been poorly served. For the first time, readers have access to both sides of this important debate in the same language. This will be an essential text."-Nick Wilding, Georgia State University

"This is an excellent addition to the literature on Galileo and, more generally, on the Copernican Revolution. It makes available important works that are relatively inaccessible in their original edition and have never been fully translated into English."-Maurice Finocchiaro, University of Nevada, Las Vegas

Eileen Reeves is professor of comparative literature at Princeton University. Albert Van Helden is professor emeritus of the history of science at Rice University and the University of Urecht