On the Revolutions of the Heavenly Spheres - Aftermath - A More Perfect Heaven: How Copernicus Revolutionized the Cosmos - Dava Sobel

A More Perfect Heaven: How Copernicus Revolutionized the Cosmos - Dava Sobel (2011)

Part III. Aftermath

Chapter 8. On the Revolutions of the Heavenly Spheres

I confess that I shall expound many things differently from my predecessors, although I shall do so thanks to them, and with their aid, for it was they who first opened the road of inquiry into these very questions.

On the Revolutions of the Heavenly Spheres, 1543

Alone again with his fears of ridicule after Rheticus left, Copernicus fussed over his original manuscript. He jotted notes in the margins regarding a few new thoughts and corrections. He felt grave misgivings about the Mercury sections in Books V and VI. Even the observations Rheticus had brought from Schöner proved largely useless in constraining Mercury’s orbit to his system, and Copernicus wound up with a clumsy adaptation of Ptolemy’s model for the innermost planet.

In mid-June 1542 Pope Paul III approved the choice of young Jan Loitz as Copernicus’s coadjutor. The news, in the form of a papal writ, did not reach Varmia for many months, however, and in the interim Copernicus drafted a long letter to His Holiness on a different matter. Although he clearly addressed this letter to Pope Paul at the Vatican, he sent the final draft to Rheticus, care of Petreius in Nuremberg, to serve as the dedication for On the Revolutions.

“I can readily imagine, Holy Father,” he began, “that as soon as some people hear how in this volume, which I have written about the revolutions of the spheres of the universe, I ascribe certain motions to the terrestrial globe, they will immediately shout to have me and my opinion hooted off the stage.” His reluctance to publish had never fully subsided. Even now, he avowed, he had agreed to publish his work only at the repeated urging of insistent friends.

“They exhorted me no longer to refuse, on account of the fear which I felt, to make my work available for the general use of students of astronomy. The crazier my doctrine of the Earth’s motion now appeared to most people, their argument ran, so much the more admiration and thanks would it gain after the publication of my writings dispelled the fog of absurdity by most luminous proofs.”

Copernicus nowhere recorded the circumstances of his decision to dedicate his book to Pope Paul. No notes from Giese, Dantiscus, or any other dignitaries so much as hint as to how the idea came about, or how they obtained permission from the papal curia. His Holiness Paul III, né Alessandro Farnese, possessed no personal knowledge of mathematics himself, but expressed his interest in the uses of that science through the employment of a full-time, high-profile astrologer, Luca Gaurico. In 1534, as thanks to Gaurico for predicting Paul’s ascent to the throne of St. Peter, the new pope invited the favored astrologer to Rome and made him a bishop.

Copernicus credited Paul with at least a partial understanding of the motions of the heavenly spheres. In the dedication letter, he walked the Holy Father quickly through the unsatisfying homocentrics, eccentrics, and epicycles that had failed to produce “the structure of the universe and the true symmetry of its parts.”

“After long reflection,” he continued, “I began to be annoyed that the movements of the world machine, created for our sake by the best and most systematic Artisan of all, were not understood with greater certainty by the philosophers.” Copernicus had circumvented the schools of astronomy, he said, to reread all of philosophy. In the pages of Cicero and Plutarch, he had found references to those few thinkers who dared to move the Earth “against the traditional opinion of astronomers and almost against common sense.” (He still knew nothing of the Earth-moving plan of Aristarchus, which had not yet been reported to Latin audiences.)


Alessandro Farnese, elected Pope Paul III in 1534, in a painting by Titian.

“Therefore I too began to consider the mobility of the Earth. And even though the idea seemed absurd, nevertheless I knew that others before me had been granted the freedom to imagine.”

Thus liberated, he had correlated all the heavenly motions, as confirmed in the present volume, the contents of which he summarized before laying the work at the pope’s feet.

“In order that the educated and uneducated alike may see that I do not run away from judgment, I have preferred dedicating these results of my nocturnal study to Your Holiness rather than to anyone else. For even in this very remote corner of the Earth where I live, you are considered the highest authority by virtue of the loftiness of your office and your love for all literature and even of mathematics.”

With that as preamble, he came to the real need for papal protection: “Perhaps there will be babblers who claim to be judges of astronomy although completely ignorant of the subject and, badly distorting some passage of Scripture to their purpose, will dare to find fault with my undertaking and censure it.” He and Rheticus had often discussed this possibility with Giese. They anticipated how Joshua’s command for the Sun to stand still might be hurled at Copernicus to prove the Sun’s motion and thereby destroy his whole theoretical edifice. Or criticism could wrap itself in Psalm 93’s proclamation that the foundations of the Earth remain forever unmoved—or Ecclesiastes’ account of how the Sun moves from sunrise to sunset and then hastens back to its rising place. Against the likelihood of such a biblical backlash, Rheticus had prepared a tract in which he rectified Holy Scripture with the Copernican ideal, but he had not yet published it. Even if Rheticus’s defense did appear in print, it could never approach the power of a single word from the pope.

“Astronomy is written for astronomers,” Copernicus asserted at the end of the dedication letter, for the simple reason that they alone could follow the mathematical proofs. That self-same audience of astronomers would recall the efforts of Leo X and the Lateran Council to reform the ecclesiastical calendar. They would remember how the attempt had failed for lack of adequate measurement of “the lengths of the year and month and the motions of the Sun and Moon.” Ever since that time, Copernicus said, “I have directed my attention to a more precise study of these topics. But what I have accomplished in this regard, I leave to the judgment of Your Holiness in particular and of all other learned astronomers. And lest I appear to promise more about the usefulness of this volume than I can fulfill, I now turn to the work itself.”

At the time Copernicus concluded this dedication, in June 1542, the first few sections of typeset text—chapters 1 through 6 of Book I—arrived in Frauenburg for his inspection. They looked quite good. Petreius had chosen an attractive roman font, with large, elegantly decorated initial capital letters by the distinguished Nuremberg artist Hans Sebald Beham to inaugurate each chapter. The lone geometrical figure in these introductory passages appeared crisp and clear—evidence that the printer had commissioned skilled carvers to cut woodblocks for the 142 required diagrams. Petreius had volunteered to absorb this and all other production costs, including more than a hundred reams of P-watermarked paper to run off the several hundred intended copies of the book. Still, Copernicus could not help finding a few infelicities he wished to correct, and which he pointed out by return mail. Although Petreius could not halt progress to reprint every page that Copernicus amended, he noted many of the author’s changes on an errata leaf printed later.


While drawing the several spheres of the planets with a pair of compasses, Copernicus inadvertently drilled a small hole in this page of his manuscript copy of On the Revolutions.

Rheticus hovered over the press, proofreading. This might not have been a truly full-time job, since he read so much faster than the type could be set and inked in the large flat plate, the paper positioned and impressed, and the double-spread printed sheets hung up to dry on both sides. The slow pace of perhaps two pages per day, further retarded by the wait for woodcuts or other delays, allowed Rheticus a few weeks off that summer. Two visits to family and friends in and around Feldkirch, once in early June and again in September, barely diverted him from his duty to On the Revolutions. Nor did he shirk his primary responsibility when he prepared two of his own recent commencement orations for publication by Petreius in August.

However, the time Rheticus devoted to negotiating a new teaching position—and his success on this score—abruptly ended his career as Copernicus’s proofreader. In mid-October, with less than half the book done, he left Nuremberg to accept the professorship of higher mathematics at the University of Leipzig, two hundred miles away from the print shop. Whereas before Rheticus had taught lower, or rudimentary, mathematics at Wittenberg, he would now lecture on advanced astronomy. He also realized a large financial gain over his former salary. Leipzig University’s records for 1542 state that when Rheticus refused the standard professorial pay of 100 florins per year, the authorities increased the offer to 140 in order to entice him.

Although no correspondence between Rheticus and Copernicus survives from this (or any other) juncture, it seems likely the disciple would have informed his teacher that he had moved on and turned over the proofreading responsibility to someone else—to Andreas Osiander, in fact.

Osiander had a history with Rheticus and Copernicus. His letters of the year before bespoke his great interest in their publishing venture, though his religious beliefs colored his opinion of all astronomical models and hypotheses. As he had told them, any number of competing sets of conjectures might account for the observed heavenly motions, but nothing short of divine revelation could determine which set, if any, truly corresponded to reality. And so, since it was impossible to know the truth, one astronomer should refrain from insulting another by insisting he had uncovered the actual workings of the celestial spheres.

Osiander also had ties to On the Revolutions through Petreius, who was an acquaintance of several years’ standing. Petreius had published some of Osiander’s sermons, and occasionally called on his services as an editor as well as a proofreader. It is unclear whether Rheticus or Petreius chose Osiander to fill the vacant slot, though they might well have shared the same good opinion of his qualifications.

Copernicus continued to receive batches of pages from the press all this while, although, after November 1542, he could no longer read and comment on them. In late autumn, at age sixty-nine, he suffered a stroke—a cerebral hemorrhage that raided his memory, robbed him of speech, and paralyzed the right side of his body. His friend Jerzy Donner, who had joined the chapter as a canon two years previously, alerted Giese.


Andreas Osiander, Minister of St. Lorenz Church in Nuremberg.

“I was shocked by what you wrote about the impaired health of the venerable old man, our Copernicus,” Giese replied on December 8, 1542. “Just as he loved privacy while his constitution was sound, so, I think, now that he is sick, there are few friends who are affected by his condition. I therefore ask you … please to watch over him and take care of the man whom you cherished at all times together with me. Let him not be deprived of brotherly help in this emergency.”

At the end of December, when the news of Copernicus’s infirmity reached his relatives in Danzig, Jan Loitz’s father reminded Bishop Dantiscus that the boy stood ready to take possession of the fourteenth Varmia canonry—Copernicus’s canonry—as soon as Rome approved.

Canon Fabian Emerich, the chapter’s replacement physician, judged the medical situation hopeless. Copernicus could do little but lie in bed, and he ate hardly anything. Attended by Donner through the winter and spring, Copernicus gradually declined, drifting in and out of consciousness until early May, when he no longer woke and slept but stayed asleep continuously. On May 24, 1543, the final pages of his book arrived from Nuremberg. Donner took them to the invalid’s bedside, put them in his hands, and the next moment saw the life go out of him—as though Copernicus had held on all those months just to see the thing complete, and now he could let go.

They buried him, as was customary, in the sandy soil under the floor of the cathedral, somewhere near his own altar. No marker or epitaph designated his exact resting place, but that, too, was the custom.

His will divided his cash reserve of five hundred marks among the children of his nieces—Katyryna’s daughters, long since married and mothers several times over. If he accumulated greater wealth through the years, he must have given it away before he fell ill. He left his medical texts to Emerich, and his other books to the chapter library. His own book, his only lasting legacy, was now an orphan.

The final signatures of On the Revolutions to reach Copernicus contained the first few pages, including the title page, which identified the author without fanfare as “Nicolaus Copernicus of Torun.” After a lifetime spent in Varmia, he still belonged to his native city, while his work, Six Books on the Revolutions of the Heavenly Spheres, entered the world (as the bottom of the page attests) through the press of Johannes Petreius, Nuremberg, 1543. Above his own name the printer had placed a welcome—and a warning—to the potential audience.

“You have in this recent work, studious reader,” Petreius announced, “the motion of both the fixed stars and the planets, restored on the basis of ancient as well as recent observations, and also outfitted with new and marvelous hypotheses. You also have most expeditious tables, from which you can compute those motions with the utmost ease for any time whatever. Therefore buy, read, profit.”

The very next line sounded a caution in Greek: “Let no one untrained in geometry enter here.” This maxim, which reputedly appeared over the gate to Plato’s Academy, reiterated Copernicus’s own contention that mathematics was written for mathematicians.

Turning over the title page, brave readers encountered yet another caveat, under the heading “To the Reader Concerning the Hypotheses of this Work.” This note anonymously acknowledged the clamor surrounding the publication of the book in hand:

“There have already been widespread reports about the novel hypotheses of this work, which declares that the Earth moves whereas the Sun is at rest in the center of the universe. Hence certain scholars, I have no doubt, are deeply offended and believe that the liberal arts, which were established long ago on a sound basis, should not be thrown into confusion. But if these men are willing to examine the matter closely, they will find that the author of this work has done nothing blameworthy. For it is the duty of an astronomer to compose the history of the celestial motions through careful and expert study. Then he must conceive and devise the causes of these motions or hypotheses about them. Since he cannot in any way attain to the true causes, he will adopt whatever suppositions enable the motions to be computed correctly from the principles of geometry for the future as well as for the past. The present author has performed both these duties excellently. For these hypotheses need not be true nor even probable. On the contrary, if they provide a calculus consistent with the observations, that alone is enough.”

There followed a familiar trope: “And if any causes are devised by the imagination, as indeed very many are, they are not put forward to convince anyone that they are true, but merely to provide a reliable basis for computation. However, since different hypotheses are sometimes offered for one and the same motion … the astronomer will take as his first choice that hypothesis which is the easiest to grasp. The philosopher will perhaps rather seek the semblance of the truth. But neither of them will understand or state anything certain, unless it has been divinely revealed to him.”

Some readers assumed these words to be Copernicus’s own. Others recognized them as the voice of another, but were left to guess at its identity as they continued reading.

“Therefore alongside the ancient hypotheses, which are no more probable, let us permit these new hypotheses also to become known, especially since they are admirable as well as simple and bring with them a huge treasure of very skillful observations. So far as hypotheses are concerned, let no one expect anything certain from astronomy, which cannot furnish it, lest he accept as the truth ideas conceived for another purpose, and depart from this study a greater fool than when he entered it. Farewell.”

Although Copernicus himself had at last loosed his vision of “the composition of movements of the spheres of the world,” this anonymous preamble reduced his effort to the status of an interesting and worthy aid to calculation, wholly unrelated to reality.