A World Lit Only by Fire

by William Manchester

Nicolaus Copernicus. After years of observing the skies and consulting mathematical tables which he had copied at the University of Kraków, Copernicus had reached the conclusion—which at first seemed absurd, even to him—that the earth was actually moving. In 1514 he showed friends a short manuscript, De hypothesibus motuum coelestium a se constitutis commentariolus (Little Commentary), challenging the ancient Ptolemaic assumptions, and this was followed by the fuller De revolutionibus orbium coelestium (On the Revolutions of the Celestial Orbs), in which he concluded that the earth, far from being the center of the universe, merely rotated on its own axis and orbited around a stationary sun once a year.