Galileo, an illustrious Italian mathematician, physicist, and astronomer, born at Pisa, demonstrated the isochronism of the pendulum, invented the thermometer and the hydrostatic balance, propounded the law of falling bodies, constructed the first astronomical telescope, and by means of it satisfied himself of, and proved, the truth of the Copernican doctrine, that the sun and not the earth is the centre of the planetary system, and that the earth revolves round it like the other planets which reflect its light; his insistence on this truth provoked the hostility of the Church, and an ecclesiastical decree which pronounced the Copernican theory heresy; for the profession of it he was brought to the bar of the Inquisition, where he was compelled to forswear it by oath, concluding his recantation, it is said, with the exclamation, "still, it moves"; before his end he became blind, and died in Florence at 78, the year Newton was born (1564-1642).