COPERNICUS, NICCOLÒ. – Astronomer and canon, born on 19 Feb. 1473 at Thorn (Toruń) in western Prussia to Niccolò and Barbara Watzelrode; he died at Frauenburg on 24 May 1543. After classical studies, he devoted himself also to philosophy and astronomy at the University of Cracow, where he is recorded in 1491. He followed his uncle Luca Watzelrode to Ermland when the latter was appointed bishop there.
At this time he translated the letters of Theophylactus Simocatta: the first Greek work translated into Latin in the land watered by the Vistula. In 1497, having received minor orders, he was appointed canon of Frauenburg (diocese of Ermland), but meanwhile he had gone to Italy (1496); he studied theology and canon law at Bologna and Ferrara, also attending the lectures of Domenico Maria Novara, a distinguished astronomer. In 1500 he gave lectures on astronomy at the Sapienza in Rome; finally, on 31 May 1503, he obtained the degree in law at Padua. He also applied himself to medicine and indeed practiced this art in his homeland, where he is found in 1505. With a few modest instruments he set up an observatory at Frauenburg on a tower near the Cathedral, and alternated his astronomical observations with the various duties incumbent upon him as canon. From his study of the precession of the equinoxes, to which Novara had introduced him, and from the question of Easter, he was led to revise all the doctrines concerning celestial motions. Around 1530 he began to draft his principal work: De revolutionibus orbium coelestium libri sex, preceded by an explanatory commentary. News of this reached Cardinal Niccolò Schönberg, a Dominican, in 1536, who approved it, and Giovanni Gioachino Retico in 1539, who published a summary of it; but the printing done at Nuremberg was not ready until 1543, and Copernicus barely had time to see the first copies when he was overtaken by death. Copernicus, who remained a faithful Catholic, wished to dedicate his work to Paul III, an enthusiastic patron of astronomical science; yet it appears with a preface by the Lutheran Andreas Osiander intended to suggest that Copernicus had proposed his system merely as a hypothesis. The Lutherans indeed immediately thought it to be in conflict with the Bible.
As is well known, Copernicus, in opposition to the Ptolemaic astronomical system then universally accepted in the schools, which placed the earth at the center of the universe, upheld the heliocentric system that placed the sun at the center, around which the earth with its satellite revolved together with the other planets. Since Kepler had not yet discovered that the orbits of the planets were ellipses rather than circles, the Copernican system presented certain difficulties, but it was far simpler and more persuasive than the exceedingly complicated Ptolemaic system. Yet the Copernican system at first met with only limited favor; his work was printed at Nuremberg in 1543 by his faithful pupil Retico and at Amsterdam by Niccolò Müller in 1614 and 1630, and then not again until 1854 and 1873 (at Leipzig from the original manuscript). In Italy it was almost ignored until Galileo became its advocate, giving the system new support and clarification with his discoveries. – See pl. XVIII.