Galileo Galilei  (1564-1642) is considered the father of modern science and made important contributions in the fields of physics, astronomy, cosmology, mathematics and philosophy. Galileo invented an improved telescope that allowed him to observe and describe Jupiter's moons, Saturn's rings, Venus' phases, sunspots and the steep lunar surface. His talent for self-promotion won him powerful friends among the ruling elite of Italy and enemies among the leaders of the Catholic Church. Galileo's defense of a heliocentric universe brought him before religious authorities in 1616 and again in 1633, when he was forced to recant and was placed under house arrest for the rest of his life.

Galileo's early life, education and experiments

Galileo Galilei was born in Pisa in 1564, the first of six children of Vincenzo Galilei, a musician and scholar. In 1581 he entered the University of Pisa at the age of 16 to study medicine, but soon turned to mathematics. He left without finishing his degree (yes, Galileo did leave the university!). In 1583 he made his first important discovery, describing the rules governing the movement of pendulums.