Galilei Against the Aristotelians

Scientists with different conceptions of the Universe tried to explain the nature and origin of the new star observed in 1604; among them, Galilei and Kepler, but also Arab, Chinese, and Korean astronomers. A month after Galilei’s lectures, in January 1605, the otherwise unknown Aristotelian Antonio Lorenzini published in Padua a pamphlet claiming that the new object could not be a star. His main argument was that measurement techniques used by astronomers, Galilei in particular, could not be applied to celestial objects: physics is not valid outside the Earth and the circumterrestrial medium. In February 1605, the Dialogo de Cecco di Ronchitti da Bruzene in perpuosito de la stella nuova (Dialogue by Cecco di Ronchitti from Bruzene about the new star), a pseudonymous booklet in Paduan dialect, was published in Padua, at the same publisher who had printed the book by Lorenzini. According to most critics, this book was written by Galilei together with his student and Girolamo Spinelli. Galilei received several replies, notably by Baldassarre Capra and Lodovico Delle Colombe, and counterreplied. The main documents related to the discussion in Italy are translated in this chapter.