Galileo Galilei of her life. Vincenzo was later legitimised as the legal heir of Galileo and married Sestilia Bocchineri. Although Galileo seriously considered the priesthood as a young man, at his father's urging he instead enrolled in 1580 at the University of Pisa for a medical degree. In 1581, when he was studying medicine, he noticed a swinging chandelier, which air currents shifted about to swing in larger and smaller arcs. To him, it seemed, by comparison with his heartbeat, that the chandelier took the same amount of time to swing back and forth, no matter how far it was swinging. When
Galileo Galilei letter to Cardinal Orsini. In 1619, Mario Guiducci, a pupil of Galileo's, published a lecture written largely by Galileo under the title "Discourse on the Comets" ("Discorso Delle Comete"), arguing against the Jesuit interpretation of comets. In 1623, Galileo published "The Assayer—Il Saggiatore", which attacked theories based on Aristotle's authority and promoted experimentation and the mathematical formulation of scientific ideas. The book was highly successful and even found support among the higher echelons of the Christian church. Following the success of "The Assayer", Galileo published the "Dialogue Concerning the Two Chief World Systems" (Dialogo sopra i due massimi sistemi del