Galileo Galilei (1564–1642)
- Italian astronomer who was one of the first people to look at the sky through a telescope. He concluded from sights like the craters of the Moon, the satellites of Jupiter and the phases of Venus that the heavens contain as much imperfection and movement as the Earth and that the Earth moves like other astronomical objects, a conclusion which led him to a showdown with the Church of Rome in which he was forced to retract. His last book was published in the protestant Netherlands, away from the influence of Rome, in 1638. He also applied mathematical analysis to movement of bodies in a way which was a precursor to Newton’s work on motion, and was an inventor whose devices ranged from clocks to artillery. He observed Neptune without recognising it as an unknown planet.