Nicolaus Copernicus (Mikolai Kopernik) was born February 19, 1473 in Torun, Poland. Copernicus was a proponent of the theory that the Sun, and not the Earth, is at rest in the center of the Universe.

Copernicus received his education, first at the University of Krakow, and then at various universities in Italy. While attending Padua University in Italy, Copernicus studied medicine, the Greek language, and mathematical sciences. He eventually received a degree in Canon Law at the University of Ferrara. When Copernicus returned to Poland he practiced medicine, though his official employment was as a canon in the cathedral chapter run by his uncle, the Bishop of Olsztyn.

Copernicus was never a professional Astronomer. The great work that made him famous was written in his spare time. It was for friends he met in Rome while pursuing his education that, in about 1513, Copernicus first wrote a short account his heliocentric (sun centered) cosmology. His heliocentric system states that the Sun (not the Earth) is at rest in the center of the Universe, with the other heavenly bodies (planets and stars) revolving around it in circular orbits. A full account of the theory titled, On the Revolutions of the Heavenly Spheres (De Revolutionibus Orbium Coelestium) was published in 1543, very near the end of Copernicus’s life. He is said to have received a copy of the printed book on his deathbed.

Copernicus’s heliocentric system was considered implausible by the vast majority of his contemporaries, and by most astronomers and natural philosophers until the middle of the seventeenth century. Its notable defenders included Johannes Kepler (1571 -1630) and Galileo Galilei (1564 - 1642). Strong theoretical underpinning for the Copernican theory was finally provided by Sir Isaac Newton's theory of universal gravitation (1687).

Copernicus died on May 24, 1543 in Frombork, Poland.