Galileo Galilei, Italian astronomer and physicist, 1623.
© Science Museum / Science & Society Picture Library
Frontispiece portrait engraved by Francesco Villamena, from Galileo's (1564-1642) masterpiece 'Il Saggiatore' (The Asayer) published by the Lincean Academy in 1623. The book was considered one of the greatest polemics in science. It was addresed to Virginio Cesarini who wrote to Galileo in 1619 praising him for showing him the road of truth. In 'Il Saggiatore', Galileo suggested a general scientific approach for investigating celestial phenomena. Galileo is one of the greatest scientists and his achievements include the discovery of Jupiter's moons.