Galileo Galilei was born on 15 February 1565, in Pisa. He was the first of six children of Vincenzo Galilei, a famous lutenist, composer and music theorist, and Giulia Galilei. Galileo became an accomplished lutenist himself and learned early from his father a scepticism for established authority, the value of quantified experimentation, as well as the results expected from a combination of mathematics and experiment. When Galileo was 8, the family moved to Florence, but he was left with Jacopo Borghini for two years. He was educated in the Vallombrosa Abbey. Despite being a genuinely pious Catholic, Galileo fathered three children out of wedlock: Virginia (born in 1600), Livia (born 1601) and Vincenzo (born in 1606). Because of their illegitimate birth, Galileo considered his daughters unmarriageable: they were accepted by the convent of San Matteo in Arcetri, where they became nuns. Vincenzo was later legitimised as the legal heir. Although Galileo considered being a pri...