Copernicus, NICOLAS, founder of the modern astronomy, was born 19th February 1473, at Thorn, in West Prussia, lately belonging to the order of the Teutonic Knights (q.v.), but then a part of Poland. His father, a Polish subject, was apparently a Germanised Slav, and his mother of pure German extraction. Copernicus seems to have spoken German as his mother-tongue; but Poland and Germany still dispute with each other the honour of producing him. Brought up under the guardianship of his uncle Lucas, prince-bishop of the great Prussian diocese of Ermland, he matriculated at Cracow 1491, and there studied mathematics, optics, and perspective. Leaving without taking a degree, he enrolled himself in 1496 in the 'Natio-Germanorum' of Bologna University as a student of canon law, and was next year appointed canon of Frauenburg, the cathedral city of the diocese of Ermland, standing on the shores of the Frisches Haff. The year 1500 he spent at Rome, where he lectured on astronomy, and (6th November) 'observed an eclipse of the moon.' The following year he began the study of medicine at Padua, medicine in that age being essentially dependent on astronomy, and was at Ferrara, in 1503, invested with the doctorship of canon law. In 1505 he left Italy never to return to it, and settled in his native Prussia. 'Scholasticus' of Breslau till 1538, and canon of Frauenburg, yet Copernicus never became a priest. Appointed permanent medical attendant on his uncle, he lived with him from 1507 till 1512 in the princely castle of Heilsberg, 46 miles from the town of Frauenburg, where, besides thinking out his new astronomy, he had toilsome administrative and other duties to perform, involving him in frequent journeys. After his uncle's death in 1512, he lived at Frauenburg with an income as canon calculated at about £450 of present money, not merely to study the stars in his tower Curia Copernicana, but to execute difficult and multifarious offices as bailiff, military governor, judge, tax-collector, vicar-general, and physician. These offices he fulfilled with vigour and success, even while his difficulties were increased by the intrigues and wars which ultimately led to the restoration of West Prussia to the Teutonic Knights, and its incorporation with the Protestant state of Brandenburg. The coinage having been grossly debased by the Teutonic Knights and the three leading commercial towns of Prussia, Copernicus set himself strenuously to the task of its reform, and advocated the establishment of a single mint for the whole of Prussia. In 1523 he was appointed administrator-general of the diocese. The De Revolutionibus he completed in 1530, but could not be prevailed on to give it to the press till just before the end of his life. In 1542 he was seized with apoplexy, accompanied by paralysis on the right side. On the 24th May 1543 the first printed copy of the work arrived at Frauenburg, and was touched by his dying hands only a few hours before he expired. His memory gone, and his faculties all obscured, it could only be said he seemed to know what it was he touched.
Besides the De Revolutionibus, Copernicus wrote and published at Cracow a Latin translation of the Epistles of the Byzantine author Theophylactus Simocatta, and a treatise on trigonometry. His life was written by Gassendi; more recently by Von Hippler (1873), and Polkovski (Warsaw, 1873). By far the most complete account of Copernicus's life and labours is, however, the great biography by Dr Prowe (2 vols. Berlin, 1883; volume of documents, 1884). Copernicus's family name of Koppernigk is derived from a village so called in Silesia, and was Latinised by himself as Copernicus, and indeed by him generally so spelt.
THE COPERNICAN SYSTEM is that which represents the sun to be at rest in the centre of the universe, and the earth and planets to move round it as a centre. It got its name from Copernicus, who (although some vague general notion of the system seems to be due to Pythagoras) first distinctly drew the attention of philosophers to it, and devoted his life to its demonstration. For the rest, the glory of developing on the lines he broadly laid down, belongs to Kepler, Galileo, and others, and to Newton, who finally marked out the form of modern theoretical astronomy. Many who reverence the name of Copernicus in connection with this system, would be surprised to find, on perusing his work, how much of error, unsound reasoning, and happy conjecture combined to secure for him in all times the association of the system with his name; yet, with all its faults, that work marks one of the greatest steps ever taken in science.
Entitled De Revolutionibus Orbium, and dedicated to Pope Paul III., it consists of six books. The first contains the following propositions: 1. That the universe is spherical. This is established by such arguments as that the sphere is the most perfect figure, &c. 2. That the earth is spherical, which flows from the same kind of considerations. 3. That the earth and sea make one globe. 4. That the motions of all the heavenly bodies must be uniform and circular, or compounded of uniform and circular motions. Here, again, we meet with singular reasons. A simple body must move circularly, and nothing but circular motion could give periodicity to phenomena. 5. That, supposing the distance of the stars to be immense, there is no reason why the earth should not have a motion round its axis as well as a motion in its orbit. 6. That the sphere of the stars is immensely distant. The proof is fanciful, and shows he had no notion of a universe of stars pervading space. 7 and 8. The ancients were wrong in placing the earth at the centre of the universe. The arguments under this head are as fanciful as those which they were designed to refute. The falling of a body to the earth he deduces from the assumption, that it is only given to wholes to move circularly, while it is of the nature of parts, separated from their wholes, to move in right lines. That there must be a centrum mundi, an entity unknown to modern science, is admitted, the question being as to its position. 9. It is possible for the earth to have several motions. 10. He establishes the order of the planets, and draws a diagram of the system much as it is now represented. Following the old systems, such as the Ptolemaic, he lays down a sphere for the fixed stars. It is clear, also, that he had no idea of the motions of the planets other than that they were such as would be caused by their being fixed in immense crystal spheres revolving round the sun.
The sum of Copernicus's astronomical achievements is, mainly, the shifting of the centre of the solar system from the earth to the sun, and the consequent explanation of the alternation of day and night by the earth's rotation round itself, and of the vicissitude of the seasons by the earth's revolution round the sun. This complete transformation in astronomy was due in the first instance to the sense of order in Copernicus's own mind, which, ever more clearly, protested against the inverse conception of a much smaller body at the centre, and a far greater at the circumference, and all the repugnant notions regarding the movements of the planets which such a conception involved. Discriminating motion as an attribute of matter, and space as the scene but not the subject of motion, Copernicus explained how the celestial sphere was but a limitation of space, and its movement only apparent; and how the 'backward loopings' of the paths pursued by the planets were only the perspective result of their real movements in conjunction with the real movements of the earth. Such was the comprehensive scheme of astronomy conceived by Copernicus; but it was impossible for him, with the instruments and ascertained facts then at his disposal, to master all the details. Instead of grasping the idea of elliptic orbits, he still abode by that of uniform circular motion, and had therefore to retain the 'epicycles' to account for 'irregularities,' though he reduced this apparatus of checks and balances to the number of thirty-four. It was reserved for Kepler to dispense with the epicycles (see PTOLEMAIC SYSTEM, ASTRONOMY, KEPLER). Catholic churchmen received Copernicus's work with much favour; the only theological objections came from the Protestants. Luther denounced Copernicus as an arrogant fool who wrote in defiance of Scripture, and Melanchthon urged the suppression of such mischievous doctrines by the secular power. The conduct of the De Revolutionibus through the press having been delegated by Copernicus's friend, George Joachim von Lauchen (Rheticus) to Osander (q.v.), the latter, by way of conciliating existing prejudices, foisted on the work a preface (Præfatiuncula) quite foreign from Copernicus's intentions, in which the doctrine of the earth's rotation is represented as a mere hypothesis, which has been attributed wrongly to Copernicus himself.