BRAHE, TYCHO (1546–1601)

BRAHE, TYCHO (1546–1601), Danish astronomer and alchemist. Scion of the network of noble families that ruled Denmark in the sixteenth century, Tycho Brahe was heir to the lordship of the family seat, Knudstrup (in modern south Sweden). He entered the University of Copenhagen in 1559, but when it came time for him to travel and learn the ways and manners that would shape him into a noble warrior and statesman, he was sent abroad to Germany, where he studied at the universities of Leipzig, Wittenberg, Rostock, Basel (in Switzerland), and Augsburg. Mastering the fundamentals of mathematics and natural sciences, he was struck by the lack of precision in astronomy. While abroad he was also exposed to alchemy and the medical ideas of Paracelsus, the German religious enthusiast and physician whose ideas challenged the reigning academic medical establishment and were winning converts among members of Tycho's generation.

Tycho was recalled to Denmark when his father became mortally ill, in order to come into his inheritance and take his place among the feudal elite. Repelled by the life for which he had been bred, he sold his share of the family manor to his younger brother and moved in with his uncle at Herrevad manor, where he observed the stars and explored the nature of terrestrial matter in a small alchemical laboratory. He was walking to the main building from the laboratory in 1572 when he first spied a "new star" (nova stella) shining brightly in the constellation Cassiopeia, observation and consideration of which was to captivate his attention and change the course of his life. (It is now known as Tycho's star.)

According to the prevailing theory of the cosmos, drawn largely from Christian interpretations of the geocentric cosmology of Aristotle (384–322 B.C.E.), bodies in the heavens were permanent and incorruptible; whatever transitory objects appeared in the sky, such as comets, lightning, and hail, were regarded as terrestrial phenomena, occurring in the air or in the zone of fire imagined to surround it. Tycho, however, showed that the nova did not exhibit any parallax, the daily change of angular measurement that characterizes objects near the Earth, and must therefore be celestial, creating a problem for traditional cosmology. As a result of the treatise he published on the nova, he was asked to undertake a series of lectures on astrology and astronomy at the University of Copenhagen in 1574, and eventually King Frederick II (ruled 1559–1588) offered him lordship over the island of Hven, where, in the summer of 1576, he laid the foundation stone for his new manor house, which he named Uraniborg—castle of the heavens.

Uraniborg was modest in size, but elaborately designed and expensively crafted. In the basement Tycho created what at the time was one of Europe's most lavish alchemical laboratories, equipped with sixteen kinds of ovens for heating and distilling various plant, animal, and mineral substances in order to concentrate their virtues and obtain their spiritual essences. On the main floor were rooms for his family and guests, a kitchen, and a combination library and study. Each end of the second floor of the building housed an array of instruments located under removable roof sections. Tycho had ordered the first of his permanent instruments for measuring angles between celestial objects while in Augsburg and he added to his collection at Uraniborg, continuing to expand the sizes, designs, and materials of these instruments, building a special workshop nearby and employing trained craftsmen for this purpose. Finding that subtle movements of the instruments caused by the wind or by unsteady supports limited the accuracy of observations, Tycho built Stjærneborg ('castle of the stars'), an observatory comprising a central room surrounded by five pits dug into the ground, each of which was covered by a removable lid and housed a particular instrument that was set upon a stone foundation to reduce vibration. With large instruments of such quality, he attained unprecedented accuracy. Christian IV, however, succeeded Frederick II, assuming the throne in 1596, and began to cut Tycho's funding. In response, Tycho packed up his instruments and left Denmark in 1597, securing a position as imperial astronomer to the Holy Roman emperor Rudolf II, who provided him a castle near Prague in which to reestablish his research facilities, both astronomical and alchemical. At this point Tycho hired Johannes Kepler to assist him with the calculations necessary to establish a new astronomical theory on the basis of his accurate data—a theory that Tycho assumed would take a new form, with the Earth at the center of the movements of the Moon and Sun, but with the movements of the rest of the planets centered on the Sun. When Tycho died suddenly in the fall of 1601, Kepler was free to use the valuable data to create his own system, which laid the foundations for Newton's gravitational astronomy.

BRAHE, TYCHO (1546–1601)

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