Nicolaus Copernicus Is Born

Nicolaus Copernicus (19 February 1473 – 24 May 1543) was the first astronomer to formulate a comprehensive heliocentric cosmology, which displaced the Earth from the center of the universe.

His epochal book, De revolutionibus orbium coelestium (On the Revolutions of the Celestial Spheres), published in 1543 just before he died, is often regarded as the starting point of modern astronomy and the defining epiphany that began the Scientific Revolution. His heliocentric model, with the sun at the center of the universe, demonstrated that the observed motions of celestial objects can be explained without putting the Earth at rest in the center of the universe. His work stimulated further scientific investigations, becoming a landmark in the history of modern science that is now often referred to as the Copernican Revolution.

Among the great polymaths of the Renaissance, Copernicus was a mathematician, astronomer, physician, quadrilingual polyglot, classical scholar, translator, artist, Catholic cleric, jurist, governor, military leader, diplomat and economist. Among his many responsibilities, astronomy figured as little more than an avocation — yet it was in that field that he made his mark upon the world.

In astronomy, heliocentrism is the theory that the Sun is at the center of the Universe. The word came from the Greek (ήλιος Helios = sun and κέντρον kentron = center). Historically, heliocentrism was opposed to geocentrism, which placed the Earth at the center. Though discussions on the possibility of heliocentrism date to classical antiquity, it was not until 1,800 years later, however, in the 16th century, that the Polish mathematician and astronomer Nicolaus Copernicus presented a fully predictive mathematical model of a heliocentric system, which was later elaborated and expanded by Johannes Kepler.

Copernicus is said to be the founder of modern astronomy. He was born in Poland,1 and eventually was sent off to Cracow University, there to study mathematics and optics; at Bologna, canon law. Returning from his studies in Italy, Copernicus, through the influence of his uncle, was appointed as a canon in the cathedral of Frauenburg where he spent a sheltered and academic life for the rest of his days. Because of his clerical position, Copernicus moved in the highest circles of power; but a student he remained. For relaxation Copernicus painted and translated Greek poetry into Latin. His interest in astronomy gradually grew to be one in which he had a primary interest. His investigations were carried on quietly and alone, without help or consultation. He made his celestial observations from a turret situated on the protective wall around the cathedral, observations were made "bare eyeball," so to speak, as a hundred more years were to pass before the invention of the telescope. In 1530, Copernicus completed and gave to the world his great work De Revolutionibus, which asserted that the earth rotated on its axis once daily and traveled around the sun once yearly: a fantastic concept for the times. Up to the time of Copernicus the thinkers of the western world believed in the Ptolemiac theory that the universe was a closed space bounded by a spherical envelope beyond which there was nothing. Claudius Ptolemy, an Egyptian living in Alexandria, at about 150 A.D., gathered and organized the thoughts of the earlier thinkers. (It is to be noted that one of the ancient Greek astronomers, Aristarchus, did have ideas similar to those more fully developed by Copernicus but they were rejected in favour of the geocentric or earth-centered scheme as was espoused by Aristotle.) Ptolemy's findings were that the earth was a fixed, inert, immovable mass, located at the center of the universe, and all celestial bodies, including the sun and the fixed stars, revolved around it. It was a theory that appealed to human nature. It fit with the casual observations that a person might want to make in the field; and second, it fed man's ego.