Copernicus’ birthday was February 19th. He was born in 1473.
Polish astronomer and mathematician who, as a student, studied canon law, mathematics, and medicine at Cracow, Bologna, Rome, Padua, and Ferrara. Copernicus became interested in astronomy and published an early description of his “heliocentric” model of the solar system in Commentariolus (1512). In this model, the sun was actually not exactly the center of the solar system, but was slightly offset from the center using a device invented by Ptolemy known as the equant point. The idea that the Sun was the center of the solar system was not new (similar theories had been proposed by Aristarchus and Nicholas of Cusa), but Copernicus also worked out his system in full mathematical detail. Even though the mathematics in his description was not any simpler than Ptolemy’s, it required fewer basic assumptions. By postulating only the rotation of the Earth, revolution about the sun, and tilt of Earth’s rotational axis, Copernicus could explain the observed motion of the heavens. However, because Copernicus retained circular orbits, his system required the inclusion of epicycles. Unfortunately, out of fear that his ideas might get him into trouble with the church, Copernicus delayed publication of them.
Copernicus proposed his theory as a true description, not just a theory to save appearances. Unlike Buridan and Oresme, he did not think that any theory which saved appearances was valid, instead believing that there could only be a single true theory. When the work was published, however, Andreas Osiander added an unauthorized preface stating that the contents was merely a device to simplify calculations.
Copernicus adapted physics to the demands of astronomy, believing that the principles of Ptolemy’s system were incorrect, not the math or observations. He was the first person in history to create a complete and general system, combining mathematics, physics, and cosmology. (Ptolemy, for instance, had treated each planet separately.)
© 1996-2007 Eric W. Weisstein
Weisstein, Eric W. “Copernicus, Nicholaus (1473-1543).” Eric Weisstein’s World of Physics. http://scienceworld.wolfram.com/biography/Copernicus.html