Galileo's years in Padua

Son of Vincenzo, a member of the minor Florentine nobility, a composer and music theorist among the greatest of the sixteenth century, and of Giulia Ammannati, Galileo Galilei was born in Pisa on 15 February 1564 and from the age of 10 grew up in Firenze, where he completed his early studies.
For his proper university education, his father chose for him the Pisan school of philosophy. Galileo began to devote himself to mathematics only from 1583 onwards, and chiefly as a self-taught scholar.

He arrived in Padua in 1592 to take up the prestigious chair of mathematics, after working as a lecturer in Pisa from 1589. He remained here until 1610: later he would recall the Paduan period as “the best eighteen years of all my life”. It was precisely in this city that Galilei spent the most productive years of his studies: he wrote numerous texts that lay at the origin of his mature ideas (especially in mechanics),  produced instruments, and developed theories that would prove revolutionary. He established relationships, among others, with Gianfrancesco Sagredo, later one of the protagonists of the Dialogue, and with Paolo Sarpi. It is in a letter of 1604 to the latter that Galileo’s formulation of the law of falling bodies appears. In that same year, a former employee of the scientist denounced him to the Paduan Inquisition for a lack of religious zeal (he drew up horoscopes to sell them and maintained a non-marital relationship), but the accusation did not proceed. It was also during that period that he began the observation of the “new star”, on which he gave public lectures.

His fame, unquestioned in the Serenissima, spread beyond its borders when he published the Sidereus nuncius, in 1610. The treatise is the result of Galileo’s astronomical observations made with a new instrument, later called the “telescope”, which he himself had reconstructed from indirect information. Galileo was living at that time at via dei Vignali 17 (today via Galileo Galilei): it was probably from the courtyard of his house that he also observed the rings of Saturn that year.

The claims reported in the Nuncius, initially challenged by academic Aristotelianism and by followers of the astronomical tradition, were progressively accepted, leading to the intensification of the crisis of Aristotelian cosmology and the geocentric model, and strengthening Galileo’s adherence to the heliocentric one of Nicolò Copernico. The fame resulting from the Nuncius brought Galilei appointment as ‘mathematician and philosopher’ to the Grand Duke of Tuscany, Cosimo II, and increased remuneration: in 1610 he therefore left Padua to move permanently to Firenze, free from teaching duties.