1633 Using the newly invented telescope, the Italian astronomer Galileo Gal ilei (1564-1642) started recording his observations of the moon and other celestial bodies around 1600. This led him to believe that the sun was at the center of the solar system, as Nicolaus Copernicus had theorized more than 50 years earlier.
As it had been in Copernicus's time, the notion of a heliocentric universe went against the Catholic Church's teachings. Galileo knew his findings would upset Church leaders, but he still went ahead with the Italian publication of his Dialogue Concerning the Two Chief World Systems, the Ptolemaic and the Copernican in 1632.
Galileo considered science to be distinct from religion, but the Church did not. Pope Urban VIII banned the book, seeing it as a personal insult after supporting Galileo in the past.
Even Galileo's renowned debating skills couldn't save him from being called to Rome to answer the Inquisition in 1633. Threatened with torture, he renounced the Copernican system. Still, he spent the rest of his life under house arrest. The trial remains one of the world's most celebrated examples of the battle between science and religion. The works of Galileo and Copernicus would remain on the Catholic Church's Index of Forbidden Books until 1835, despite the fact that scientists accepted their ideas in the 17th century.