Popular Science Monthly/Volume 39/June 1891/Sketch of Nicolaus Copernicus



MODERN astronomy may be said to have begun with Copernicus. Previous to his time the received theories of the structure and motions of the universe were incorrect, inconsistent, and incomprehensible, and did not explain the inexact observations that were referred to them. He gave to science a correct theory, in which exact observations have found clear and consistent explanations.

Nicolaus Kopernik was born in Thorn, now in Prussia, but at that time a part of Poland, February 18, 1473, and died May 24, 1543. The accounts vary concerning the station of his family. According to the one which seems best established, his father was a native of Cracow, the son of a man in good position there, and had settled as a wholesale trader in Thorn; his mother, Barbel von Wasselrode, was a sister of a Bishop of Ermeland. His earlier instruction, given him in the school at Thorn, included Greek and Latin letters. He then went, under the patronage of his uncle Lukas, who afterward became bishop, to the University of Cracow, where he applied himself to philosophy and medicine, but more ardently than to either of these branches, under the inspiration of the lessons of Albert Brudzewki, to mathematics and astronomy, in which he made himself familiar with the use of the instruments. He also, in his intervals of leisure, practiced in painting, with considerable success. When twenty-three years of age he proceeded to the University of Bologna, where he attended the lectures of Dominico Maria Novarra in astronomy, and formed a personal friendship with him; and then to Padua, where he studied mathematics and astronomy, and obtained the degree of Doctor of Medicine. In 1499 and 1500 he was in Rome, the associate of the astronomer Regiomontanus, and lecturing on the science to a numerous class. He then returned to his native land, where his reputation for learning and his gentle bearing gained him a cordial welcome. He became a priest, and, under the patronage of his episcopal uncle, a canon of Frauenburg, on the banks of the Vistula. Here, from 1503, he spent the remainder of his life, dividing his time between the duties of his profession, works of charity, and the study of astronomy. He visited the poor and sick, gave them medical attention, and relieved their wants at his own expense; devised a hydraulic system for the distribution of water through the city, remains of which are still to be seen; and composed a treatise on the coinage of money, which was preserved in the archives of the Diet of Grodno. The house which he occupied at Allenstein still stands there, or did very recently, with the holes which he made in the walls of his room in order to observe the passage of the stars across the meridian.

His position here was not, however, one of uninterrupted peace. It fell to him more than once to administer the affairs of the bishopric during a vacancy, and he was charged with the duty of defending the rights and privileges of the see against the Teutonic Knights, who were then very strong. These positions, says M. Biot in the Biographie Universelle, demanded probity and courage. "Copernicus let himself neither be dazzled by the authority of the Knights nor intimidated by their threats. If we repeat these details, which appear foreign to his glory, it is to show that in his character the taste for study and contemplation were united with firmness and constancy—qualities not less necessary than genius for attacking and overthrowing prejudices that had been consecrated by the faith of centuries."

Copernicus lived at the time of the awakening of knowledge, and was a part of it. The idea that the earth moved around the sun was not new; it had been uttered before, but, like many other thoughts that had been expressed among the ancients and then slumbered through the middle ages, it, being contrary to the received notions, was frowned on by authority and was refused a hearing. Copernicus saw, what an intelligent observer could not fail to see, that none of the systems then known could account for the motions of the stars. He had met the most distinguished astronomers of his own time. He was acquainted with all the systems of the ancients; and the more he examined them the more he was astonished at the want of harmony and inconsistency that marked them. "I then took pains," he says, "to read again all the books of philosophy that I could get, to assure myself whether I could find any different opinions from those which were taught in the schools concerning the motions of the spheres of the world. And I saw first in Cicero that Nicetas had expressed the opinion that the earth moves. Then I found in Plutarch that others had had the same idea... . Further, the leading Pythagoreans, Archytas of Tarentum, Heraclides of Pontus, Echrecrates, etc., taught the same doctrine, according to which the earth is not motionless in the center of the world, but turns in a circle, and is far from holding the first rank among the heavenly bodies." Pythagoras had learned the same doctrine; Timæus of Locris was very precise in announcing it, when he called the five planets the "organs of time on account of their revolutions," and added that we should have to suppose that the earth was not immovable in the same place, but that it turned around itself and was also carried along in space. Plutarch says that Plato, who had always taught that the sun turned around the earth, changed his opinion toward the end of his life, and regretted that he had not placed the sun at the center of the world, the only place that became it. Three centuries before Christ Aristarchus of Samos, according to Archimedes, composed a work, now lost, defending the doctrine of the movement of the earth against the opinions of philosophers to the contrary, in which he said that "the sun continues immovable and the earth moves around the sun, describing a circular course of which that star occupies the center." Passing to the Romans, this system of Aristarchus was modified into one like that of Tycho Brahe.

In his review of the ancient systems, Copernicus was most drawn, according to M. Biot, "to that of the Egyptians, which made Mercury and Venus revolve round the sun, and put Mars, Jupiter, Saturn, and the sun in motion round the earth; and to that of Apollonius of Perga, which made the sun the common center of all the planetary motions, while the sun itself revolved around the earth—an arrangement that became the system of Tycho Brahe. Copernicus was impressed with these systems because he found that they represented well the limited excursions of Mars and Venus around the sun, explaining their movements, direct, stationary, and retrograde, an advantage which the system of Apollonius extended to the superior planets. The astronomical planets were thus no longer simple sports of the imagination to him. He had studied them experimentally, and had found the conditions which they must satisfy. The hardest part of his discovery was made. On the other hand, he perceived that the Pythagoreans had taken away the earth from the center of the world and put the sun there. It seemed to him that Apollonius's system would be simpler and more symmetrical if it was modified in this sense, so as to suppose the sun fixed in the center, and the earth revolving round it. He had seen also that Nicetas, Heraclides, and other philosophers, while they placed the earth in the center of the world, had ventured to give it a movement of rotation upon itself, producing the phenomena of the rising and setting of the stars and the alternations of day and night. He still more approved the theory of Philolaus, who, taking the earth away from the center of the world, had given it a rotation on its axis and another motion of annual revolution around the sun. And, although it might seem difficult and even absurd to take the earth from the center and make a simple planet of it, yet, as other astronomers before him had taken the liberty of imagining circles in the sky to explain phenomena, he thought he might be permitted to look for some other arrangement, with a moving earth, which would establish a more simple order in the motions of the stars. Thus, taking what is true from each system and rejecting all in them that was false and complicated, he composed that admirable whole which we call the system of Copernicus, and which is really only the correct arrangement of the planetary system to which we belong." "After long researches" Copernicus himself said, "I am convinced that if we refer the—motions of—the other planets to the revolution of the earth, calculation will agree well with observation. . . . I do not doubt that mathematicians will be of my opinion, if they will take the pains to make themselves acquainted,—not superficially but profoundly, with the demonstration which I shall present in this book."

He reasoned that "every displacement manifest to our view proceeds either from the object perceived or from the subject which perceives, or from the unequal motions of the two, for an equal and simultaneous motion of the object and the subject could cause no semblance of displacement. The earth is the place whence the movement of the sky is presented to our view. Every motion starting from the earth is reflected in the sky, which will appear to move in the opposite direction. Such is the diurnal revolution, which appears to involve the whole universe except the earth. If now we suppose that-the sky has none of this motion, but that the earth turns around itself from west to east (in a contrary direction from the apparent motion of the sky), we shall find that it is really-so." Among the chief arguments in support of this view, the astronomer insisted especially on the immensity of the sky—as compared with the size of the earth: "The whole mass of the earth," he said, "vanishes before the grandeur of the sky; the horizon divides the celestial sphere into halves, which could not be if the earth bore any proportion to the extent of the sky, or if its distance from the center—of—the—universe was perceptible! Compared to the sky, the earth is only a point; it is as a finite quantity compared with an infinite quantity. It is no more admissible to suppose the earth resting in the center of the universe. What! to believe that immensity turns every twenty-four hours around an insignificancy!" So the inequalities in the movements of the planets their forward and backward—movements and stationary positions were referred to two causes: the movement of translation of the earth and the proper motions of the planets; correctly, as modern astronomers explain them, only Copernicus was not able to give details and exact figures?

Ptolemy had argued against the idea of these motions of the earth, because if the earth were translated through space it would leave all the loose things on it behind; and, if it turned on its axis from west to east, it would be impossible for bodies to make any headway to the eastward, for, whatever the rate of their motion, the earth would always reach a given point in that direction first. Hence the former idea was the most ridiculous of all (πάντων γελοιότατα) and the latter altogether ridiculous (πάνυ γλοΙόταον). These arguments seemed unanswerable, and had been received, with Ptolemy's theory, till they had become almost an article of faith. It required a courage which we can only weakly comprehend at this day for a student to fly in the face of the world, of science and religion, and take the solar system to pieces, to put it together again, and to say, after all, that it is the earth which moves and not the sun. Copernicus was slow in venturing before the public with his theory. He began the formulation of his system in 1507; but he wisely determined to make thorough work of the matter, and publish nothing that he could not support with carefully considered argument and evidence. He would not be satisfied with reconciling general appearances with his theory; he would go into details and show how it fitted individual phenomena. He would show how all the movements of the heavenly bodies could be accounted for and predicted by it; even how those phenomena which had hitherto proved unaccountable, the stationary positions and retrograde motions of the planets, and the precession of the equinoxes, found explanation in it. In the mean time reports had got into circulation respecting his new theory, and the public wanted to know what it was. Astronomers were waiting for it, and he was urged to publish it. But he delayed, revising his sheets daily for the insertion of corrected data, and adding new results; and he shrank from the inevitable conflict with the prejudices of the day. These prejudices were already beginning to make their mark. Men of science could accept his views or give them utterance, so far as they had been made acquainted with them, but the general public was against them. He was ridiculed in a comedy; but his gravity and self-restraint carried him safely through all these trials. At last he permitted his friends to publish the work, which he dedicated, in deprecation of clerical censure, to Pope Paul III, in order, as he said in the dedication, that no one should accuse him of running away from the judgment of enlightened men, and that the authority of his Holiness, if he should approve the work, might secure him against the stings of calumny. "I believe," he also said, "that as soon as what I have written in this book concerning the motions of the earth is known, a cry of shame will be raised against me. I am, further, not so much in love with my ideas as to be careless of what others might think about them. And, although the thoughts of the philosopher differ from the aims of the crowd, because he proposes to seek for the truth, so far as God has given it to human wisdom to do, I am not yet ready to reject entirely opinions which seem to be at variance with mine... . All these motives, together with the fear of becoming—on account of novelty and apparent absurdity—an object of ridicule, had nearly caused me to renounce the enterprise. But some friends—among them Cardinal Schomberg and Tidium Gisius, Bishop of Kulm—succeeded in overcoming my repugnance. The last, especially, insisted most earnestly on my publishing this book, which I had kept on the shelf, not nine years, but nearly thirty-six."

The book (De Revolutionibus Orbium Cælestium) was printed at Nuremberg, under the care of Rheticus, one of Copernicus's pupils, in 1543. Although Copernicus had till that time been enjoying excellent health, he had then been attacked by a dysentery; and this had passed into a paralysis, with loss of his mental faculties, when the first copy of the book was given to him only a few hours before his death. He saw it and handled it, but was too far gone to exhibit any signs of appreciation of it, or for his friends to be able to know how he was affected by it, or whether he realized what it was. The first edition of the De Revolutionibus, which is now very rare, was followed by a second edition in 1566, and a third in 1617. Seventy-three years after the death of its author, on the 5th of March, 1616, it was condemned by the Congregation of the Index "for containing ideas set forth as true on the positions and motions of the earth entirely contrary to the Holy Scripture."

The first work recording the labors of the astronomer was the letter published by Rheticus under the title Ad Clar. V. de Jo. Schonerum de Libris Revolutionum eruditiss, Viri et Mathematici excellentiss. Rev. Doctoris Nicolai Copernici Torunnæi, Canonici Varmiensis, per quemdam juvenem Mathematicæ studiosum, Narratio prima, Dantzic, 1540; reprinted, with a eulogium, at Basle, 1541. The works of Copernicus are De Revolutionibus Orbium Cælestium Libri VI, Nuremberg, 1543; reprinted at Basle in 1566, with the letter of Rheticus, and also included in the Astronomia Instaurataol Nicolas Muller, Amsterdam, 1617 and 1640; a treatise on Trigonometry, with tables of sines, entitled De Lateribus et Angulis Triangulorum, Wittenberg; Theophylacti Scholastici Simocattæ Epistolæ morales, rurales, et amatoriæ, cum Versione Latina. There are also the treatise on money, already mentioned, and several manuscript treatises in the library of the bishopric of Wiarmia.

The tomb of Copernicus, which was exactly like those of the other canons of Frauenburg, was adorned with a Latin epitaph by the Polish Bishop Cromer, in 1581. It was repaired by Napoleon I in 1807, and so placed that it could be seen from all parts of the church. A statue of Copernicus by Thorwaldsen was erected by subscriptions from the Polish people, in 1829, in the Casimir Palace at Warsaw. The Polish clergy, invited to attend the ceremonies, refused, because his. book had been condemned by the Holy Office in 1616. Another monument to him, by Tieck, was erected at Thorn in 1853.