De revolutionibus orbium coelestium

De revolutionibus orbium coelestium (English: On the Revolutions of the Heavenly Spheres), first printed in 1543 in Nuremberg, is the seminal work on heliocentric theory and the masterpiece of astronomer Nicolaus Copernicus (1473-1543). The book offers an alternative model of the universe to the Ptolemaic system.

History of the book

Copernicus initially wrote up an outline of his system in a short text called the Commentariolus. A physician's library list dating to 1514 includes a manuscript whose description matches the Commentariolus, so Copernicus must have begun work on his new system by that time. However, most historians believe that he wrote the Commentariolus after his return from Spain, and possibly only after 1510. At this time, Copernicus anticipated that he could reconcile the motion of the Earth to the perceived motions of the planets quite easily, with fewer motions than were necessary for the Alfonsine Tables, the version of Ptolemaic astronomy popular at that time.

Observations of Mercury by Bernhard Walther (1430-1504) of Nuremberg, a pupil of Regiomontanus, were made available to Nicolaus Copernicus by Johannes Schöner, 45 observations in total, 14 of them with longitude and latitude. Copernicus used three of them in De revolutionibus, giving only longitudes, and erroneously attributing them to Schöner. Copernicus's values differed slightly from the ones published by Schöner in 1544 in Observationes XXX annorum a I. Regiomontano et B. Walthero Norimbergae habitae, [4°, Norimb. 1544].

Remarkably the manuscript of De revolutionibus in Copernicus's own hand has survived. (Autograph manuscripts of published major scientific works from this time are rare.) Close examination of the manuscript, including the different types of paper used, has helped scholars to construct an approximate timetable for its composition. Apparently Copernicus began by making a few astronomical observations to provide new data to perfect his models. He may have begun writing the book while still engaged in observations. By the 1530s a substantial part of the book was completed. But he was still completing his work (even if he was not convinced that he wanted to publish it) when in 1539 Georg Joachim Rheticus, a great mathematician from Wittenberg, arrived in Frombork. In 1542, in Copernicus's name, Rheticus published a treatise on trigonometry (later included in the second book of De revolutionibus). Under strong pressure from Rheticus, and having seen that the first general reception of his work had not been unfavorable, Copernicus finally agreed to give the book to his close friend Tiedemann Giese, bishop of Chełmno (Kulm), to be delivered to Rheticus for printing by Johannes Petreius at Nürnberg (Nuremberg). It was published just before his death, in 1543.

The major work of Copernicus is the result of decades of labor. It rewrote Ptolemaic theory for a moving Earth, and incorporates over a thousand years of accounts of astronomical observations of varying accuracy. In its standard English edition, it contains 330 folio pages, 100 pages of tables, and over 20,000 tabulated numbers.

The book is dedicated to Pope Paul III (in a preface which attempts to articulate that mathematics, not physics, should be the basis for understanding and accepting his theory) and is divided into 6 parts ("books"):

* The first part contains a general vision of the heliocentric theory, and a summarized exposition of his idea on the World.

* The second part is mainly theoretical and describes the principles of spherical astronomy and a list of stars (as a basis for the arguments developed in the subsequent books).

* The third part is mainly dedicated to the apparent movements of the Sun and to related phenomena.

* The fourth part contains a similar description of the Moon and its orbital movements.

* The fifth and the sixth parts contain the concrete exposition of the new system.

De revolutionibus starts with an anonymous foreword stating that the whole work is only a simple hypothesis, implying that it might only be bold speculation. It is misleading to understand the word "hypothesis" in its modern sense, a proposed law or principle that is to be tested by experiment. Rather, the word should be understood as meaning a convenient bit of mathematics not necessarily related at all to reality. The foreword was at the time generally regarded as Copernicus's own idea, until Johannes Kepler showed that it was an addition by the Lutheran philosopher Andreas Osiander. That Osiander had written the preface was certainly common knowledge among astronomers well before Kepler. Johannes Praetorius (1537-1616) wrote on his copy of De Revolutionibus a comment that affirms Osiander as the author of the preface. [1]

In his system Copernicus argued that the universe is made up of eight spheres. The outer, eighth sphere consisted of motionless, fixed stars with the sun motionless at the centre. The planets revolved around the Sun in the order of Mercury, Venus, Earth, Mars, Jupiter, and Saturn. The moon however, revolved around the Earth. Moreover, according to him, what seemed to be the movement of the Sun and fixed stars around the Earth was really explained by the daily rotation of the Earth around its own axis. Even with all of his advances, he retained the circular orbits, because of which he was forced to also retain the epicycles of the Ptolemaic system to prove his calculations correct. Nevertheless, the shift from an Earth-centered, to a sun-centered system was very important and raised serious questions about Aristotle's astronomy and physics, despite Copernicus's adherence to Aristotle.

Reception among scholars

The book caused only mild controversy at the time, and provoked no fierce sermons about contradicting holy scripture; Osiander's preface, therefore, may have had some success. In 1546, however, a Dominican, Giovanni Maria Tolosani, wrote a treatise denouncing the theory and defending the absolute truth of scripture. Tolosani also claimed that Bartolomeo Spina, the Master of the Sacred Palace, had intended to condemn the theory but had been unable to press the issue because of ill health.

According to Olivier Thill's 2002 update of a biography written in 1654 by Pierre Gassendi, many persons, astronomers, theologians and others, knew about Copernicus's theory before 1615. Their stance is given as follows:[2]

Identification of "Copernicans" or "anti-Copernicans" will vary depending on the criteria used. For instance, Gassendi apparently considered Tycho Brahe to be a supporter of Copernicus, even though Tycho plainly believed that the Earth did not move. Tycho performed many of the essential measurements which Johannes Kepler used to advance Copernicus's position.

It has been much debated why sixty years would pass before Copernicus's work would come under serious attack. The alleged reasons range from the personality of Galileo Galilei to the availability of actual evidence (such as observations with the telescope) which could make it practical for the first time to settle the truth or falsity of the theory. Whatever the reason, in 1616 Cardinal Bellarmine gave Galileo an order from the Pope to take the position that the system was purely hypothesis. After that, De revolutionibus was placed on the Index of Forbidden Books along with two less important works (but none of Galileo's, at that time). It was not formally banned but merely withdrawn from circulation pending "corrections" which would clarify the status of the theory as hypothesis (nine sentences, by which the heliocentric system was represented as certain, had to be either omitted or changed). Such corrections were prepared by Francesco Ingoli and others, and were formally approved in 1620; the reading of the book was then allowed.[3] But the book was never reprinted with these changes, and was available in Catholic jurisdictions only by special request of suitably qualified scholars.[citation needed] It remained on the Index until 1758, when Pope Benedict XIV (1740-58) removed the uncorrected book from his revised Index.[4]

A few years after the death of Copernicus, Erasmus Reinhold developed the Prutenic Tables (Prussian Tables, Latin: Tabulae prutenicae, German: Preußische Tafeln), based on Copernicus's observations. Reinhold's Prutenic Tables were used as a basis for the calendar reform instituted under Pope Gregory XIII. The tables were also used by sailors and sea explorers, who during the fourteenth and fifteenth centuries had used the Table of the Stars by Regiomontanus.

Copernicus's mocking of Lactantius

Nicolaus Copernicus mocked Lactantius, who was an early Christian author (ca. 240 - ca. 320), in De revolutionibus:

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. I disregard them even to the extent of despising their criticism as unfounded. For it is not unknown that Lactantius, otherwise an illustrious writer but hardly an astronomer, speaks quite childishly about the Earth's shape, when he mocks those who declared that the Earth has the form of a globe. Hence scholars need not be surprised if any such persons will likewise ridicule me. Astronomy is written for astronomers.

A German TV documentary on "The world's 7 greatest lies" [1] states that medieval scholars knew very well that the Earth was a sphere. Copernicus is blamed for omitting that Lactantius was the exception rather than the rule, thus he contributed to the flat Earth mythology.

Recent research

For a long time, historians believed that the book was not widely read at the time of its first publication. Owen Gingerich, a widely recognized authority on both Nicolaus Copernicus and Johannes Kepler, disproved that belief after a 35-year-long project to examine every surviving copy of the first two editions. His efforts and conclusions are recounted in The Book Nobody Read, published in 2004 by Walker & Co. That book and the research behind it earned the Polish government's Order of Merit in 1981. Due largely to Dr. Gingerich's scholarship, De revolutionibus has been researched and catalogued better than any first-edition historical text except for the original Gutenberg Bible.[5]


* 1543, Nuremberg, by Johannes Petreius

* 1566, Basel, by Henricus Petrus

* 1617, Amsterdam, by Müller of Göttingen [2]

* 1854, Warsaw, with Polish translation and the real preface of Copernicus

* 1873, Thorn (Torun), by the local Copernicus Society, with all the corrections of the text, made by Copernicus, given as foot-notes.

English translations

* On the revolutions of the heavenly spheres [translated] with an introd. and notes by A. M. Duncan. Newton Abbot : David & Charles; New York : Barnes and Noble, 1976 ISBN 0-7153-6927-X (David & Charles) ISBN 0-06-491279-5 (Barnes and Noble)

* On the revolutions ; translation and commentary by Edward Rosen. Baltimore : Johns Hopkins University Press, 1992 ISBN 0-8018-4515-7 (Foundations of natural history) (originally published Warsaw, 1978)

* On the revolutions of the heavenly spheres ... transl. by C. G. Wallis. First published Annapolis : St John's College Bookstore, 1939. Later republished in v. 16 of the set Great Books of the Western World (Chicago : Encyclopædia Britannica, 1952); in the series of the same name published by the Franklin Library, Franklin Center, Philadelphia, 1985; in v. 15 of the second edition of Great Books (Encyclopædia Britannica, 1990); and in 1995 by Prometheus Books (Amherst, NY.) in its Great minds series - Science (ISBN 1-57392-035-5).


  1. ^ Robert Westman, Three Responses to Copernican Theory in The Copernican Achievement - Robert Westman (ed) (1975)
  2. ^ Gassendi 2002.
  3. ^ "Nicolaus Copernicus," Catholic Encyclopedia.
  4. ^ "Benedict XIV." Catholic Encyclopedia.
  5. ^ Peter DeMarco. "Book quest took him around the globe". Boston Globe. April 13, 2004


* Gassendi, Pierre: The Life of Copernicus, biography (1654), with notes by Olivier Thill (2002), ISBN 1-59160-193-2 [3]

* Gingerich, Owen: An annotated census of Copernicus' De revolutionibus (Nuremberg, 1543 and Basel, 1566). Leiden : Brill, 2002 ISBN 90-04-11466-1 (Studia copernicana. Brill's series; v. 2)

* Gingerich, Owen: The Book Nobody Read : Chasing the Revolutions of Nicolaus Copernicus. New York : Walker, 2004 ISBN 0-8027-1415-3

* Hannam, James (2007). Deconstructing Copernicus. Medieval Science and Philosophy. Retrieved on 2007-08-17. Analyses the varieties of argument used by Copernicus.

* Heilbron, J.L.: The Sun in the Church: Cathedrals as Solar Observatories. Cambridge, Massachusetts, Harvard University Press, 1999 ISBN 0-674-85433-0

* Swerdlow, N.M., O. Neugebauer: Mathematical astronomy in Copernicus's De revolutionibus. New York : Springer, 1984 ISBN 0-387-90939-7 (Studies in the history of mathematics and physical sciences ; 10)

* Vermij, R.H.: The Calvinist Copernicans: The Reception of the New Astronomy in the Dutch Republic, 1575-1750. Amsterdam : Koninklijke Nederlandse Akademie van Wetenschappen, 2002 ISBN 90-6984-340-4 [4]

* Westman, R.S., ed.: The Copernican achievement. Berkeley : University of California Press, 1975 ISBN 0-520-02877-5

* Zinner, E.: Entstehung und Ausbreitung der coppernicanischen Lehre. 2. Aufl. durchgesehen und erg. von Heribert M. Nobis und Felix Schmeidler. München : C.H. Beck, 1988 ISBN 3-406-32049-X


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