Copernicus, Nicolaus (1473–1543)

Nicolaus Copernicus

1580 portrait (artist unknown) in the Old Town City Hall, Torun.

Model of the solar system according to Copernicus

Copernicus pictured the planets as revolving around the sun in a complicated pattern or circular motions, the basis of which is shown here. His theory did not give more accurate planetary predictions than Ptolemy's of AD 140, but it was a triumph of ideas that showed man in his true place in nature. Proof that the planets revolve in ellipses came in 1609 from the German astronomer Johannes Kepler (1571-1630).

Nicolaus Copernicus was a Polish astronomer (born Mikolaj Kopernik) who was the first in Renaissance Europe to advance the heliocentric theory, namely, that Earth and other planets revolve around the Sun.


The son of a wealthy merchant, Copernicus was born at Torun and educated at Cracow University and at various Italian universities where he studied medicine and law. On his return to Poland in 1506 he served as physician and secretary to his uncle Lucas, Bishop of Ermland. On his uncle's death in 1512, Copernicus took up the post of canon of Frauenburg Cathedral to which he had been appointed in 1499. By this time he had already abandoned the Ptolemaic system and had begun to formulate the revolutionary system with which his name has been associated (see Copernican system and Copernican Revolution). The new system was first described in his Commentariolus, a brief tract completed sometime before 1514 and circulated in manuscript form to interested scholars. Thereafter he worked out the details of the new system in his De revolutionibus orbium coelestium (On the Revolution of the Celestial Sphere). Although it was complete in manuscript by 1530 Copernicus seemed, for reasons that are unclear, reluctant to publish it. In fact, it was not until Rheticus arrived in Frauenburg in 1539 and intervened that Copernicus reluctantly allowed its publication. The work finally appeared in 1543 just in time, according to popular legend, for it to be shown to Copernicus on his deathbed.