On Tycho's Island: Tycho Brahe and His Assistants, 1570-1601 (review)

On Tycho's Island: Tycho Brahe and His Assistants, 1570--1601. By John Robert Christianson (New York: Cambridge University Press, 1999) 451 pp. $34.95

Although Tycho Brahe (1546--1601) is less famous than Copernicus, Johannes Kepler, and Galileo, his importance to the development of modern science rivals theirs. In 1576, Tycho persuaded King Frederick II of Denmark to grant him governance of the island Hven and to support the construction of a research facility devoted primarily to observational astronomy. Tycho moved into Uraniborg in 1580, before the facility was finished, and remained there until 1597, when conflicts with King Christian, Frederick's newly crowned son, led him to leave Denmark, ultimately settling in Prague (where Kepler joined his entourage).

The years at Uraniborg provided the world with recorded observations of the locations of the planets (and stars) that remained the primary database for all theoretical work on orbital motion until well into the eighteenth century, when systematic telescopic observations, begun in the 1660s, finally replaced them. Even though the observations at Uraniborg were naked-eye, they were accurate to within a few minutes of arc, thanks, first, to the special instruments Tycho had built for observing and, second, to his training of those who joined him in making them. Equally important, these were the first data of uniformly high quality that covered an extended period of time. To support this effort and to promulgate his research in other areas, Tycho turned Uraniborg into the first self-contained modern research center, with facilities for making instruments and other equipment, producing publications, and even making paper for them. He drew talent from all over Europe, and although few remained at Hven for more than a few years, they spread his ideas and approach widely.

The late Victor Thoren published an outstanding intellectual biography of Tycho, The Lord of Uraniborg: A Biography of Tycho Brahe (New York) in 1990. Christianson's book complements Thoren's by delving into the social and political forces involved in establishing and maintaining Uraniborg, and then in causing its ultimate demise. To mention a few, because Tycho's wife was a commoner, their children were barred from receiving his titles and privileges without an edict from the throne, which was rarely granted, making his efforts to this end controversial. In addition to the usual political conflicts within the royal court, competition and resentment between Uraniborg and the University of Copenhagen over funds introduced the nastiness of academic politics. Complicating all of these matters was a conflict within Lutheranism in Denmark, between the Philippist and the Gnesio-Lutheran schools of theology, with Tycho tied to the former and the latter gaining ascendancy under King Christian. Exacerbating all of this turmoil was Tycho's difficult personality, which put him into constant conflict with many of those working with him, as well as with the original inhabitants of Hven--not to mention a scandalous jilting of Tycho's daughter Magdalene in the early 1690s and the redress that he sought for it.

The first 248 pages of Christianson's book offer a social and political history of Uraniborg and its aftermath, chronicling Tycho's initial success in keeping all these forces from undermining his efforts and his subsequent loss of control. This portion of the book is a joy to read; the scholarly treatment is almost as engaging as a romance novel. The remaining 131 pages give biographical sketches of each of the individuals associated with Uraniborg about whom Christianson managed to acquire information during the years he worked on this project. These sketches will be a starting point for future research on Uraniborg and the dissemination of the work carried out there. One need not have interest in the history of science to find this book a pleasure.

George E. Smith
Tufts University

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