(Pisa, 15.2.1564 – Arcetri, 8.1.1642)
Son of Vincenzo, a member of Florence’s small nobility and one of the greatest 16th century composers and writers of music, and Giulia Ammannati, Galileo grew up in Florence from the age of 10, where he began his studies.
For his university studies, his father chose the Pisa School of philosophy for him. Galileo only began to study mathematics in 1583 and was mainly self-taught.
He came to Padua in 1592 to take up the prestigious professorship of mathematics, after working as a professor in Pisa from 1589. He stayed here until 1610: later in his life, he remembered his time in Padua as being “the best eighteen years of my life”.
Galilei achieved his greatest successes in Padua: he wrote numerous works forming the basis of his mature concepts (above all in mechanics), he made instruments and elaborated theories that would go on to become revolutionary. He also established relationships with Gianfrancesco Sagredo, who played a leading role in dialogue at the time, and Paolo Sarpi, among others. A letter to Sarpi dated 1604 included Galileo’s formula for the law of falling bodies. In the same year, a former employee of the scientist reported him to the Inquisition of Padua for his poor religious zeal (he wrote horoscopes in order to sell them and had a non-marital relationship), but the charge was not taken any further. During this period, Galileo began observing the “Stella nova“(new star), about which he held public lectures.
His reputation, undisputed in the Serenissma Republic, spread abroad when he published his “Sidereus Nuncius” in 1610. This work was the result of Galileo’s astronomical observations using a new instrument, later called the “telescope“, which he himself had rebuilt based on indirect information. At the time, Galileo lived in Via dei Vignali, 17 (today’s “Via Galileo Galilei”): he probably observed the rings of Saturn that year from the courtyard of his home.
The affirmations reported on the Nuncius, initially contested by the academic Aristotelianism and by the followers of the astronomical tradition, were gradually assimilated, leading to the accentuation of the crisis of the Aristotelian cosmology and the geocentric model, and consolidating in Galileo the adhesion to the heliocentric model of Nicolaus Copernicus. In 1610 Galileo left Padua to move permanently to Florence, free from teaching commitments.