ArgumentThe subject of the paper is the shift from an astrology-oriented astronomy towards an allegedly more objective, mathematically grounded approach to astronomy. This shift is illustrated through a close reading of Tycho Brahe's scientific development and the contemporaneous changes in his communicational strategies. Basing the argument on a substantial array of original sources it is claimed that the Danish astronomer developed a new astronomical discourse in pursuit of credibility, giving priority to observational astronomy and natural philosophical questions. The (...) abandonment of astrology in public discourse is primarily explained by Tycho's social position and greater sensibility to controversial issues. Tycho's example suggests that the changes in rhetorical strategies regarding astrology (which happened earlier than changes in astrological belief) should be given more recognition in the history of astronomy. (shrink)

(1984). Tycho brahe in china: the Jesuit mission to Peking and the iconography of European instrument-making processes. Annals of Science: Vol. 41, No. 5, pp. 417-443.

In the history of science the ‘Elixir Tychonis’ was rather neglected till today. This elixir consists of three prescriptions. The first was published in Cista medica by Thomas Bartholinus, the third in the biography of Brahe written by Gassendi . The famous edition of Opera omnia Brahei by Dreyer contains the three prescriptions in the Vol. IX; Dreyer used only the manuscript Langebekiana Nr. 179 under consideration of the printed texts differing from the manuscript. The discovery of the probable (...) unknown original text for the printed text in Cista medica was made by us in the University Library of Basle; by further inquiries were found two neglected manuscripts in the University Library of Erlangen. We restricted our examinations not only to palaeographical comparison of the three new manuscripts but we extended also the historical analysis to the interpretation of the underlying alchemical ideas of Tycho Brahe. In the history of chemistry the ‘chymist’ Brahe is rather unknown; therefore it seemed necessary to show by comparison with the original contemporary sources the position of our Danish astronomer towards Paracelsism in the sixteenth and seventeenth centuries. (shrink)

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 describes and applies a new method for obtaining accurate values for the parameters of the superior planets, he develops a divided eccentricity model of Saturn, similar to the one we know Longomontanus and Kepler applied to Mars, and finally 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. (shrink)

Summary Tycho Brahe's lunar theory, mostly the work of his assistant Christian Longomontanus, published in the Progymnasmata (1602), was the most advanced and accurate lunar theory yet developed. Its principal innovations are: the introduction of equant motion for the first inequality in order to separate the determination of direction and distance; a more accurate limit for the second inequality although requiring a more complex calculation; additional inequalities of the variation and, in place of the annual inequality in (...) class='Hi'>Tycho's earlier theory, a reduction in the equation of time; in the latitude theory a variation of the inclination of the orbital plane and an inequality of the motion of the nodes; a reduction in the range of variation of distance, parallax, and apparent diameter. Some of these were already present in Tycho's earlier lunar theory (1599), but all were changed in notable ways. Twenty years later Longomontanus published a modified version of the lunar theory in Astronomia Danica (1622), for the purpose of facilitating the calculation through new correction tables, and also explained his reasons for parts of the theory in the Progymnasmata. This paper is a technical study of both lunar theories. (shrink)

Two sextants constructed for Tycho Brahe are preserved in the National Technical Museum in Prague. One was constructed by Erasmus Habermel, the other by Jost Bürgi. Both were made in the year 1600. To overcome the observational errors, several improvements were made in the construction of these instruments, especially in the case of Bürgi's sextant. It would appear both from these instruments and from his tables of sines that Tycho wanted to reduce the errors to one minute (...) of arc. A replica of Bürgi's sextant, which is currently under construction, will allow the accuracy of the instrument to be tested. (shrink)

ABSTRACTIt is known that throughout the seventeenth century the world system proposed by Tycho Brahe assumed a preponderant position in the Iberian cosmological debate, according to many opinions the one showing the best agreement to empirical evidence. Moreover, the Tychonian model did not present the difficulties of apparent contradiction with scriptures, as the heliocentric system of Nicolaus Copernicus did, since it kept the earth fixed at the centre of the world. However, Tycho, as a Lutheran author, was (...) targeted by the Inquisition. Passages of various works of the Danish astronomer were included in the Spanish Indices of 1632, 1640 and 1707, although the formal condemnation of the Roman Inquisition never materialized. In the network of the Society of Jesus a seemingly informal censorship also circulated, apparently based on Tridentine determinations, published in 1651 in the influential work of Giambattista Riccioli Almagestum novum. In this paper I will discuss the scope, effects and limitations of the censorship of Tycho's scientific books in Portugal and Spain, through the analysis of several annotated copies, preserved manly in Iberian libraries, with a special attention to books with a well-established provenance in past Jesuit colleges. (shrink)

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.

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. (shrink)