Tychonic System Research Articles

How did a Lutheran astronomer get converted into a Catholic authority? The Jesuits and their reception of Tycho Brahe in Portugal.

This article explores the complex process of integrating Tycho Brahe's theories into the Jesuit intellectual framework through focusing on the international community of professors who taught mathematics at the College of Saint Anthony (Colégio de Santo Antão), Lisbon, during the first half of the seventeenth century. Historians have conceived the reception of the Tychonic system as a straightforward process motivated by the developments of early modern astronomy. Nevertheless, this paper argues that the cultural politics of the Counter-Reformation Church curbed the reception of Tycho Brahe within the Jesuit milieu. Despite supporting the Tychonic geo-heliocentric system, which they explicitly conceived of as a 'compromise' between the ancient Ptolemy and the modern Copernicus, and making recourse to some of the cosmological ideas produced in Tycho's Protestant milieu, the Jesuits strove to confine the authority of the Lutheran astronomer to the domain of mathematics. Philosophy was expected to remain the realm of Catholic orthodoxy. Thus, while Tycho Brahe entered the pantheon of 'Jesuit' authorities, he nonetheless was not granted the absolute status of intellectual authority. This case demonstrates how the impact of confessionalization reached well beyond the formal processes of science censorship.

Tycho Brahe’s Calculi ad Corrigenda Elementa Orbitae Saturni and the technical aspects of his planetary model of Saturn

Tycho Brahe was not just an observer; he was a skilled theoretical astronomer, as his lunar and solar models show. Still, even if he is recognized for proposing the Geoheliocentric system, little do we know of the technical details of his planetary models, probably because he died before publishing the last two volumes of his Astronomiae Instaurandae Progymnasmata, which he planned to devote to the planets. As it happens, however, there are some extant drafts of his calculations in Dreyer’s edition of Tycho’s Opera Omnia under the name Calculi ad Corrigenda Elementa orbitae Saturni, which, to the best of my knowledge, have not yet been analyzed before. In these manuscripts, Tycho starts with calculations based on the Prutenic Tables and makes a series of adjustments to the mean longitude, the longitude of the apogee, and the eccentricity to fit a series of observations of oppositions. In doing that, Tycho (1) describes and applies a new method for obtaining accurate values for the parameters of the superior planets, he (2) develops a divided eccentricity (not bisected) model of Saturn, similar to the one we know Longomontanus and Kepler applied to Mars, and finally (3) he realizes that the true position of the Sun somehow affects the motion of Saturn around the zodiac and develops a method to correct the position of Saturn as a function of solar equation of anomaly. So, a close analysis of the calculations reveals details of the Tychonic planetary models unknown until now. The present study analyzes these drafts.

STUDYING TYCHO’S STARS: A VIEW OF THE HEAVENS FROM THE PERSPECTIVE OF TYCHO BRAHE

During his life time, the famed 16th century astronomer Tycho Brahe made a convincing case for what came to be known as the Tychonic System. It was a picture of the heavens as he saw it from his observational complex Uraniborg. Yet despite the scientific prowess that marked everything Brahe did, the design of his system was powerfully influenced by a beliefs that had been in place since Ancient Greece.

La scienza e l’ipotesi assoluta. Metodologia e logica della ricerca nell’Almagestumnovumdi Giovanni Battista Riccioli

Astronomers before Newton in the 17th century attempted to find the best world system in the light of the new data and the novel observations that had been provided by the telescope but were not sufficient to prove that Copernicus was right. Using the new information, the Jesuit Giovanni Battista Riccioli developed a geo-heliocentric system that he considered a satisfactory alternative to heliocentrism. He argued that physical causes are difficult to generalize, but that nonetheless astronomers could formulate well-founded hypotheses. He skillfully combined the empirical data to articulate a deductive system, organized into elements such as definitions, arguments, theorems, corollaries, hypotheses, and so on. This system allowed him to avoid some of the errors of competing theories, and to obtain what he considered criteria to choose the best (hypothesis absoluta) using the so-called epic-epicycles. This article examines the conceptual and technical background of the Jesuit’s hypothesis and discusses how he was cautious yet bold in the way he formulated it.

Tycho's System and the Decline of the Traditional Cosmos

The paper discusses Tycho Brahe’s geo-heliocentric system, arguing that it represents a good instance of a failed synthesis. First, the Author analyzes the physical and metaphysical principles grounding this system, relying on Brahe’s correspondence with Christoph Rothmann. The popular anti-Copernican arguments of the tower and of the cannon, which Galileo would try to refute in his Dialogue Concerning the Two Chief World Systems, find here their first formulation. Secondly, some theoretical problems of Tycho’s system are discussed, intending also to clarify Galileo’s ambiguous attitude towards him. Indeed, although Brahe is surely the major polemical reference of Galileo’s Dialogue, he is never explicitly mentioned therein. This is because, as Galileo says, Tycho was never able to provide a thorough description of a system of the world comparable to those of Ptolemy and of Copernicus. Brahe’s system may thus be characterized as the last great attempt to synthetize the old and the new, before the risk of the collapse of the traditional cosmos: attempt which, considering the growing success of the heliocentric model, was inevitably doomed to failure.

From the Jesuits’ treatises to the imperial compendium : The appropriation of the Tychonic system in seventeenth and eighteenth-century China

La réception du système tychonique en Chine à la fin de la dynastie Ming et au début de la dynastie Qing est une question importante à la fois dans l’histoire de l’astronomie chinoise et dans celle des échanges scientifiques entre l’Est et l’Ouest. Dans cet article, une nouvelle exploration complète de ce processus historique est présentée. Les Traités d’astronomie calendaire de l’ère Chongzhen ( Chongzhen lishu ), qui présentent les méthodes de Tycho Brahe, ont été révisés à plusieurs reprises lors de la réforme astronomique de la fin de la dynastie Ming. L’examen attentif de ces traités révèle qu’ils contiennent différents types d’erreurs et d’incohérences. Les astronomes du début des Qing se sont efforcés de résoudre ces problèmes et d’améliorer la théorie tychonique quand ils ont étudié les Traités d’astronomie calendaire de l’ère Chongzhen , et certains d’entre eux ont réussi à proposer des procédures améliorées. Plus tard, dans le but de mettre fin à la dépendance à l’égard des Jésuites en matière scientifique, l’empereur Kangxi a ordonné la compilation d’un nouveau traité d’astronomie. De nombreux résultats obtenus par les savants chinois ont finalement été incorporés dans ce nouveau traité, l’ Examen complet des phénomènes astronomique composé par l’empereur ( Yuzhi lixiang kaocheng ).

Pietro Daniel Omodeo (Editor). Duncan Liddel (1561–1613): Networks of Polymathy and the Northern European Renaissance. With Karin Friedrich. (Scientific and Learned Cultures and Their Institutions, 17.) xii + 322 pp., figs., bibl., index. Leiden/Boston: Brill, 2016. €135 (cloth).

Pietro Daniel Omodeo (Editor). <i>Duncan Liddel (1561–1613): Networks of Polymathy and the Northern European Renaissance</i>. With Karin Friedrich. (Scientific and Learned Cultures and Their Institutions, 17.) xii + 322 pp., figs., bibl., index. Leiden/Boston: Brill, 2016. €135 (cloth).

Trying Ursus: A Reappraisal of the Tycho-Ursus Priority Dispute

1. INTRODUCTIONThe late sixteenth century is one of the most interesting and exciting periods in the history of astronomy. It is a period of both and transition, as Richard Jarrell has appropriately described it: consolidation of the mathematical techniques of Copernicus and transition from the purely mathematical account of planetary motions to a wider discussion of the actual nature of the universe.1 During the years following the publication of Copernicus's De revolutionibus in 1543, the most important developments in astronomy and cosmology took place in Northern Europe, particularly in Protestant Germany and Bohemia. Jarrell further classifies the serious practitioners of astronomy at the end of the century into three categories: loyal to the Ptolemaic order of the universe but willing to introduce Copernican mathematical techniques; those who had adopted some variation of the geo-heliocentric framework; and those who were confirmed Copernicans.2The humanistic educational reform initiated by Philip Melanchthon encouraged the study of mathematics and astronomy, and the University of Wittenberg became a sort of Mecca for the mathematical astronomers of the time. It was the place where Georg Rheticus, Copernicus's only direct disciple, had taught, and it became the place where Copernican astronomy was most seriously and thoroughly studied. Among those young astronomers who undertook the pilgrimage to Wittenberg was Tycho Brahe (1546-1601). But it was in Bohemia where the latter's encounter and subsequent brief period of collaboration with Johannes Kepler (1571-1630) took place. This was certainly one of the most significant events in the history of astronomy, for it involved an unprecedented fusion of theory and observation: Kepler was one of the ablest mathematicians in Europe and Tycho certainly the best observational astronomer.For our present purposes, what interests us is that both Tycho and Kepler came to work together under the patronage of Emperor Rudolph ? in Prague and, at the same time, both men worked under the shadow of a third character: Nicolaus Reimers Baer (1551-1600), also known by his Latin nickname of Ursus ('The Bear), who had been the former Imperial Mathematician, a post in which first Tycho and then Kepler were to succeed him. During the last decade of the sixteenth century, Tycho and Ursus became engaged in a fierce and bitter priority dispute over the invention of the geo-heliocentric system of the world, a compromise between Ptolemaic geocentrism and Copernican heliocentrism, and Kepler, who worked for Tycho, was also reluctantly drawn into it.Shortly after Tycho's first diagram of the geo-heliocentric system appeared in print, Ursus published a book of his own, containing a very similar cosmological arrangement. When Tycho learned about it, he accused Ursus of having stolen the system from him in a visit the latter made to Uraniborg, his observatory on the island of Hven. Tycho initially aired his accusation only in private correspondence, but when he decided to publish a selection of his letters, the matter went public. When Ursus in turn found himself labelled a plagiarist in print, he decided to respond, and he did so by publishing a second book attacking Tycho's claims to priority and originality in the discovery of the geo-hehocentric system, and also attacking him personally. As a result, Tycho decided to take legal action against Ursus, on the grounds of plagiarism and defamation. When arrangements were being made for the upcoming trial, and relevant circumstantial evidence was being gathered by Tycho, Ursus died, so the trial never took place. Nonetheless, Tycho persevered in his pursuit of Ursus beyond the grave. Now that the author was gone, the enemy was his book, so Tycho launched a campaign against Ursus's book and also planned to publish a volume of his own containing all the relevant documents, with the aim of settling matters forever: establishing his priority, restoring his honour and reputation, and refuting Ursus's claims. …

The great Martian catastrophe and how Kepler fixed it

For a few weeks every 32 years, both the Ptolemaic and Copernican predictions for the position of Mars are off by close to 5 degrees—a problem first noticed by Tycho Brahe.

Gassendi's Reinterpretation of the Galilean Theory of Tides

In the concluding pages of his Epistolae duae de motu impresso a motore translato (1642), Pierre Gassendi provides a brief summary of the explanation of the tides found in Galileo's Dialogue over the Two Chief World Systems (1632). A comparison between the two texts reveals, however, that Gassendi surreptitiously modifies Galileo's theory in some crucial points in the vain hope of rendering it more compatible with the observed phenomena. But why did Gassendi not acknowledge his departures from the Galilean model? The present article argues that cautiousness was just one of the reasons that stopped the French priest from turning Galileo's theory into his own theory. He was probably also aware of the fact that Kepler's model of planetary motion, which he endorsed in the Epistolae, could not be reconciled with Galileo's explanation of the tides. In the postumously published Syntagma philosophicum (1658), Gassendi tried to mend this major inconsistency by arguing that Galileo's theory of the tides not only remained valid, but became even more coherent, if one attributed to the Earth an elliptic orbit. But given that in the Syntagma Gassendi officially adhered to the Tychonic system, his effort to reconcile Kepler and Galileo, while already unconvincing by itself, appears completely futile.

The role of Rothmann in the dissolution of the celestial spheres

At the end of the sixteenth century astronomers and others felt compelled to choose among different cosmologies. For Tycho Brahe, who played a central role in these debates, the intersection of the spheres of Mars and the Sun was an outstanding problem that had to be resolved before he made his choice. His ultimate solution was to eliminate celestial spheres in favour of fluid heavens, a crucial step in the abandonment of the Ptolemaic system and the demise of Aristotelian celestial physics. These debates involved issues that had not previously been part of astronomy, and had the effect of undermining the traditional hierarchy of the sciences. While this complicated story involves many scientific personalities of the sixteenth and seventeenth centuries, in the present paper we will concentrate on one figure who has been assigned an unnecessarily minor role in most histories of science: Christoph Rothmann. In the present paper we show that ‘the dissolution of the celestial spheres’ depends on arguments about the substance of the heavens, following a mistaken argument of Gemma Frisius, elaborated by Joannes Pena and appropriated by Rothmann. We next consider the status and origin of the doctrine, as presented by Brahe, that the heavenly spheres are solid, and the impact on Brahe of Rothmann's treatise on the comet of 1585. Rothmann provided several key ideas that enabled Brahe to develop his system, and we suggest in passing that Rothmann may also have precipitated Brahe's re-evaluation of his attempt to detect the parallax of Mars during the opposition of 1582–83. We offer a new account of this central piece of evidence for the Tychonic system.

The Lord of Uraniborg: a biography of Tycho Brahe

Preface 1. A noble humanist 2. The new star 3. Becoming a professional 4. The first years on Hven: 1576-1579 5. Urania's castle 6. The flowering of Uraniborg 7. First renovations: the solar theory 8. The tychonic system of the world 9. High tide: 1586-1591 10. The theory of the motion of the moon 11. The last years at Uraniborg 12. Exile 13. A home away from home? Epilogue Appendices Author index Subject index.

The Lord of Uraniborg: A Biography of Tycho Brahe

Preface 1. A noble humanist 2. The new star 3. Becoming a professional 4. The first years on Hven: 1576-1579 5. Urania's castle 6. The flowering of Uraniborg 7. First renovations: the solar theory 8. The tychonic system of the world 9. High tide: 1586-1591 10. The theory of the motion of the moon 11. The last years at Uraniborg 12. Exile 13. A home away from home? Epilogue Appendices Author index Subject index.

The Rationality of the Copernican Revolution

Given the central importance of the Copernican theory to the birth of modern science, it is somewhat surprising to learn that there were remarkably few committed Copernicans prior to 1600. In a recent study, Westman (1980) finds only ten, of whom fewer than five were major scientific figures. The vast majority of scientists in this period continued to accept the Earth-centered astronomy of Ptolemy or later switched to the geoheliocentric system of Tychp Brahe. This widespread reluctance to adopt the heliocentric theory suggests the following questions about the Copernican Revolution: When and why did it become rational to reject the Ptolemaic theory as false? When and why did it become rational to accept the Copernican theory as true? Or, to put these questions in the more familiar language of the epistemologist: When and why did the beliefs that the Ptolemaic theory is false and that the Copernican theory is true become justified beliefs?

Galileo's contribution to astronomy

The chief aim of the present paper is to destroy the (not even pious) legend of Galileo's early Copernican convictions. This legend is based above all on his letter to Kepler of 4th August 1597, in which he claims to have subscribed “for many years past” to the teaching of Copernicus. On the evidence of his writings and lecture notes, however, it cannot be doubted that Galileo became a convinced Copernican only after the telescopic discoveries. It is shown that Galileo's repugnance to Tycho Brahe and his system is based not on a careful study of Tycho's work, but rather on psychological imponderables such as the circumstance that Christopher Scheiner and others of his adversaries had adopted the Tychonic system in order to avoid the necessity of accepting the Copernican. It is shown, finally, that Galileo's merits in the field of theoretical astronomy are by far inferior to his achievements in the realm of physics.