Copernican System

   The heliocentric or sun-centered theory of the universe was postulated by a great Polish astronomer, Nicolaus Copernicus (1473-1543). For more than fourteen hundred years people had accepted the system of Ptolemy, namely, that the sun moved round the earth. That the opposite is true—that the planets revolved round the sun—had been considered many years before by the School of Pythagoras. Thanks to Copernicus, scientists have all come to agree that the sun is the center of the system of planets (the heliocentric theory), and that knowledge has become the foundation of modern astronomy.

   Although friends of Copernicus urged him to publish his masterwork Concerning the Revolution of the Celestial Spheres, he hid his publication for many years, for he knew that, although he was dedicating his work to Pope Paul III, a mind dominated by theology could not admit into its thinking scientific facts that might conflict with his beliefs. He was right, of course. The book was published when Copernicus was lying on his deathbed, and it was promptly placed on the Index of Forbidden Books.

   Copernicus was born in Thorn, Prussian Poland. He studied astronomy and mathematics at the University of Cracow, and then spent three years at the University of Bologna, where he also studied Greek and philosophy. He decided on a career with the church, becoming a canon at the Cathedral of Frauenburg, East Prussia. Although he remained at that post until his death, his chief interest was in astronomy.