The Sun in the Church: Cathedrals as Solar Observatories

Through much of the Scientific Revolution, between 1650 and 1750, Catholic churches were the best solar observatories in the world. Constructed initially to solve the pressing problem of providing an unquestionable date for Easter, the instruments that made the churches' observatories also threw light on the disputed geometry of the solar system. Within sight of the altar, they subverted Church doctrine about mankind's place in the universe. Measurements made in the oldest cathedral observatory, San Petronio in Bologna, in the heart of the Papal States, supported Kepler's revolutionary discovery that neither the sun's orbit, nor the earth's, can be a circle, and thus indirectly favored ideas condemned at the trial of Galileo. A tale of politically canny astronomers and cardinals with a taste for mathematics, The Sun in the Church explains the unlikely accomplishments of the Church-sponsored observers. It engagingly describes Galileo's political overreaching, his subsequent trial for he