Galileo Galilei

(1564–1642)

   Scientist.

   Galileo was born in Pisa, Italy. He was educated at the university there and in 1589 he was appointed Professor of Mathematics. Two years later he moved first to Florence and then to the University of Padua where he remained until 1610. It was during this period that he discovered the four moons orbiting the planet Jupiter, which led him to support the Copernican theory of the solar system.

   In 1610 he was appointed philosopher and mathematician to the Duke of Tuscany. Galileo is remembered in Christian history for his conflict with the Church authorities. At this period, largely for theological reasons, the Church was still insisting on the Ptolemaic explanation of the universe, that all the heavenly bodies circled the earth. In 1616 Copernicus’s theory – that the sun was at the centre of the solar system – was condemned and Galileo was forbidden to teach it. Nevertheless in 1632 he published his Dialogo dei Due Massimi Sistemi del Mondo, showing the inadequacies of the Ptolemaic view. He was brought to trial before the Inquisition and, under threat of torture, was forced to recant. According to legend, even at this point, he is said to have whispered that none the less the earth does move. He was sentenced to life imprisonment under suspicion of heresy and died while under house arrest.

   M.A. Finocchiaro (ed. and transl.), The Galileo Affair: A Documentary History (1989);

   J.J. Langford, Galileo, Science and the Church (1966);

   M. Sharratt, Galileo: Decisive Innovator (1994).