The Ptolemaic system of the universe, with the earth at the center, had held sway since antiquity as authoritative in philosophy, science, and church teaching. Following his observations of the heavenly bodies, Nicolaus Copernicus (1473-1543) abandoned the geocentric system for a heliocentric model, with the sun at the center. His remarkable work, On the Revolutions of Heavenly Spheres, stands as one of the greatest intellectual revolutions of all time, and profoundly influenced, among others, Galileo and Sir Isaac Newton.

"Commentariolus," from Nicolaus Copernicus. Nicolaus Copernicus, Renaissance mathematician and astronomer who formulated a model of the universe that placed the Sun rather than the Earth at its center (1473-1543)