1822: The College of Cardinals finally caves in to the hard facts of science, saying that the "publication of works treating of the motion of the Earth and the stability of the sun, in accordance with the opinion of modern astronomers, is permitted."

It represented a major shift in dogma for the Catholic Church, a concession that the Earth, in fact, might revolve around the sun. Unfortunately, it came 189 years too late to do Galileo Galilei any good.

Still, it would take another 13 years, until 1835, before Galileo's Dialogue Concerning the Two Chief World Systems -- the work in which he defends the heliocentric theory -- would be removed from the Vatican's list of banned books.

As a theory, heliocentrism had existed since the ancient Greeks, who were the first to determine that the Earth is a sphere in a sky full of spheres. It remained an unproven theory directly opposed to the geocentric view held by Ptolemy and Aristotle, and embraced by Rome, that the Earth is the center of the universe.