Biography
(Pisa 1564-Arcetri, Florence 1642) Son of the musicologist Vincenzo, Galileo was educated by the friars of Vallombrosa. He dropped out of the faculty of medicine at the University of Pisa to focus on philosophy and mathematics which he later taught first at Pisa and then, in 1592, at Padua where he stayed for eighteen years. There Galileo invented a pair of “compasses” to calculate the solution of ballistic problems, he studied the motion of the pendulum, and carried out numerous experiments which led him to the discovery of the laws that govern gravity. In the astronomical field Galileo invented the telescope in 1609 which allowed him to see for the first time the mountains and craters on the moon, the Milky way and four satellites of Jupiter. In 1610 he published his discoveries in “Sidereus Nuncius”.

His observations on the phases of Venus represented a convincing confirmation of the Copernican theory, considered to be heretic by the theologians of the time for its contradiction with the contents of the Bible. Also his criticism on Aristotle’s theory on the perfection of the heavens was opposed to the point that at the beginning of 1616 the Jesuit priests ordered him to retreat his theory on the motion of the Earth. Galileo remained silent for years, once more turning to the study of falling bodies. He expressed his findings in a treatise “Il Saggiatore” (1623) and began to write a book on the examination of the Ptolemaic and Copernicans theory under the light of tidal physics. In 1630 the book received the approval of the censors of the church of Rome and was published under the title “ Dialogo Sopra i Due Massimi Sistemi del Mondo”.

Suddenly however Galileo was summoned to Rome by the Inquisition which tried him for “serious suspected heresy”. He was forced to abjure and was convicted to home arrest in his house at Arcetri. The “Dialogo” was burned and the sentence read publicly in all the universities. The last of Galileo’s essays, “Discorsi e dimostrazioni Matematiche Intorno a Due Nuove Scienze Attinenti alla Meccanica”, published in Holland in 1638 included all his studies on movement. His general principles on mechanics helped Newton to formulate his law on gravity which linked Kepler’s laws on the planets with Galileo’s physics and mathematics. In 1979 Pope John Paul II asked for an investigation on Galileo’s trial and the astronomer’s innocence was approved in 1992.