Tycho Brahe

Danish astronomer

• Born: December 14, 1546
• Birthplace: Knudstrup Castle, Scania, Denmark (now in Sweden)
• Died: October 24, 1601
• Place of death: Prague, Bohemia (now in Czech Republic)

Brahe realized early that the existing means for observing and measuring celestial bodies and their motions were inaccurate. His great achievements led to significant improvements in existing instruments, the invention of new instruments, and amazingly accurate observations.

Early Life

Tycho Brahe (TI-koh BRAH-hee), born Tyge Brahe Ottos n, was the eldest of ten children born to Otto Brahe. The Brahes were an old and noble family with both Danish and Swedish branches. Tyge’s father was privy councillor to the king of Denmark at the time of Tyge’s birth and ended as governor of Helsingborg Castle in Scandia then part of Denmark. Tycho was not reared with his parents and younger siblings. His father’s brother J rgen, who was childless, stole him while he was still a baby. Initial turmoil in the family was stilled when Otto’s second son was born. It was therefore in the home of his uncle that Tyge was reared, showing so much early scholarly promise that, in addition to the requisite training for a young nobleman in horseback riding and swordsmanship, he was allowed to learn Latin in the hope that he would become a statesman and counselor to the king.

At thirteen, Tyge entered the University of Copenhagen, head held high above a piped collar and small rapiers by his side. Thirteen was not an unusual age for university entry at the time. He studied, as did most of his colleagues, philosophy, rhetoric, and law. The curriculum was in Latin. His academic career was planned for him: After finishing his studies in Denmark, he would go to one of the more famous German universities and study law, still in preparation for a career in government. The problem was that young Tyge (he took the name Tycho on graduation) was not interested in law. An event that took place on August 21, 1560, when he was nearly fourteen, came to fascinate him so deeply that it, in effect, determined his choice of career. He heard that an eclipse of the sun had been predicted for that day. That the prediction proved to be correct and that the sun was indeed eclipsed seemed to him divine.

It was not considered good form for one of Brahe’s social station to become a mere scientist, and his fascination with astronomy was greeted with far less than enthusiasm by his uncle and father. His astronomical studies were performed in secrecy and at night. When he went to Germany, a tutor accompanied him to ensure that he did not stray from his legal studies. The two arrived in Leipzig in 1562, when Brahe was not quite sixteen. Anders S rensen Vedel, the tutor, kept a rapt eye on his charge, and Brahe studied law by day and reserved his nights for gazing at the stars. He also managed to study mathematics, which would be necessary for him in his astronomical studies, and he met two of the more famous astronomers of his day, who happened to reside in Leipzig Bartholomaeus Scultetus and Valentin Thau. The instruments he used for his observations were quite crude: a globe, a compass, and a radius.

Life’s Work

The tutor eventually became aware of his charge’s illicit nightly activities, and the two of them were called home to be under J rgen Brahe’s intense scrutiny. Yet J rgen died not long afterward, leaving the nineteen-year-old Brahe wealthy and independent. Brahe could embark on his life’s work. For a while, out of a sense of duty, he performed his responsibilities as a nobleman and oversaw the Tostrup estate in Scandia that was part of his inheritance. In 1566, however, he decided to make his scientific studies the center of his life and activities.

To the accompaniment of his family’s scorn, Brahe moved to Wittenberg and worked with Kaspar Peucer, a then-famous astronomer, until an outbreak of the plague forced his return to Denmark. Later, he went to Augsburg because of its famous instrument makers; he wanted new, more precise, better designed instruments made for his observations. He had a new globe, sextant, and radius made. His fame in the scientific community began to grow.

Brahe concentrated his early studies on the apparent movements of the planets and the fixed stars. His father’s death and an appointment as cantor of the Roskilde Cathedral devoured much of his time, but he steadfastly continued his work. His growing fame changed the attitudes of his family and peers toward his work: His uncle Steen Brahe had a lab outfitted for him. His first major breakthrough was the observation of a new star, first seen on November 11, 1572. The star, which he appropriately called Stella Nova in a book entitled De nova et nullius aevi memoria prius visa stella (1573; about the new star), appeared in the Cassiopeia constellation. Large and bright, the new star remained visible until 1574. The accuracy of the observations, down to the minute details, caused a sensation in the scientific community, and Brahe was established as a great scholar.

Brahe, at this time a grown man, cut quite a striking figure. Bejeweled and flamboyantly dressed, he was stocky, with reddish-yellow hair combed forward to hide incipient baldness, and he sported a pointed beard and a flowing mustache. When he was young and while in Germany, Brahe had been in a duel, and his opponent sliced off a large piece of his nose, for which Brahe had a substitute made of gold and silver and painted to look natural. He always carried a box with glue and salve.

Brahe’s plan was to settle abroad and continue his studies, but the king changed his plans by donating to him the small island of Ven, in the channel between Denmark and Sweden. The position of the island was perfect for his purposes, and Brahe accepted the generous offer. On Ven, he built his famous observatory: the architecturally beautiful Uraniborg (after the muse of astronomy Urania), which contained a chemistry lab, his famous mural quadrant, and observatories in the attic. He also built the smaller, but equally famous, Stellaburg, which, except for a cupola, was built underground. This building contained many observational instruments, including his renowned revolving quadrant. It also had portraits, in the round, of the greats of astronomy: Timocharis, Hipparchus, Ptolemy, Nicolaus Copernicus, and himself.

On the official front, Brahe became royal mathematician and lecturer at the University of Copenhagen. Little is known about his private life. He married a bondwoman, Kirstine, by whom he had eight children, five girls and three boys. Brahe did not reveal this part of his life in his own writings, and his contemporaries restricted themselves to expressing disapproval of this alliance. In his observatories, he continued his work, making surprisingly accurate observations of celestial bodies. He always had a number of students living with him, who helped him in his observations.

By 1582, Brahe had reached a point at which he could propose his own astronomical system. He rejected both the static Ptolemaic system with the sun and planets moving around Earth in individual orbits and the Copernican system, which has Earth and the other planets moving around the sun. Brahe’s system is an amalgam. For reasons involving both the laws of physics and the Bible, he could not accept a system that makes Earth simply one of the planets that revolve around the sun. In Brahe’s system, Earth is static and the moon and the sun revolve around it, with the other planets revolving around the sun. It remained for Brahe’s student Johannes Kepler to reinstate the correct Copernican system reinforced by Brahe’s minutely correct measurements and observations.

On Ven, Brahe had his own printing press and published, besides his own works, calendars and horoscopes for the king and other high dignitaries. Like many of his contemporaries, Brahe did not distinguish sharply between astronomy and astrology, but he apparently did not think highly of horoscopes and made them only under duress. Many kings and dignitaries from around Europe visited the island to see the famous observatories.

On the island, Brahe did the bulk of his scientific work. He made accurate observations of the sun, moon, and planets. Many scholars find that his greatest achievement, besides his introduction of the use of transversals on the graduated arcs of astronomical instruments and his improvements of existing instruments (such as the equatorial armillae, which are spheres used to establish differences in longitude and latitude), was his catalog of fixed stars, which stood until such improved instruments as telescopes and clocks of precision came into use.

Unfortunately, Brahe did not adhere to his scientific studies. As he grew older, his idiosyncrasies became more obvious and he became involved in some petty suits that alienated the king, who had been one of his staunchest supporters. Brahe’s intransigence finally caused the king to confiscate land that had been bequeathed to him, leaving Brahe without an adequate source of income.

Finally, in July, 1597, Brahe left native shores and moved to Rostock, Germany. He sent a submissive letter to King Christian IV , in which he asked the king to take him back into his good graces. The letter elicited a direct and angry response from the king, who said that until Brahe came to his senses, admitted his faults, and promised to do as he was told, he should not return.

Brahe, determined not to give in, decided to find a new mentor. He approached Emperor Rudolf II in Prague. Rudolf had a reputation as a patron of the sciences and indeed took Brahe and his collaborator Kepler under his wing. The two famous astronomers had, at times, a stormy relationship, and, after several years, Kepler had a nervous breakdown and left Prague. Brahe died on October 24, 1601, in Prague.

Significance

Tycho Brahe was a transitional figure in the history of astronomy. His theoretical work was flawed and actually a step back from the work of Copernicus. His great achievements were in the areas of practical and spherical astronomy. He devised new and more sophisticated instruments for observations and recorded an astounding body of observations that represented a quantum leap forward in knowledge about the movements and relative positions of celestial bodies.

Brahe’s observatories represented the state of the art in sixteenth century astronomy. Here he gazed at and recorded the stars, made mathematical computations, and had his most famous instruments built and installed: three equatorial armillae; a mural quadrant, which he used to determine time; and sextants with transversals on the graduated arc and improved sights that allowed for pointing the instrument with great precision to measure distances and angles.

Brahe’s legacy, which has made him, in one biographer’s somewhat hyperbolic phrase, “a king among astronomers,” is his large body of accurate observations and measurements performed by means of instruments and methods devised by him.

Bibliography

Christianson, John Robert. On Tycho’s Island: Tycho Brahe and His Assistants, 1570-1601. New York: Cambridge University Press, 2000. Extensive study of Brahe’s life and accomplishments in many fields, including philosophy, chemistry, poetry, and reform. The book focuses especially on the vital intellectual community he created, and it provides short biographies of more than twenty members of that community. Includes illustrations, maps, bibliographic references, and index.

Christianson, John Robert. Tycho Brahe: A Picture of Scientific Life and Work in the Sixteenth Century. Reprint. New York: Dover, 1963. The most detailed work on Brahe in terms of his work and studies. Early in the book, Dreyer sets the general scientific and astronomical stage Brahe was to enter. While somewhat technical, the book gives a thorough and minute description of Brahe’s instruments and observations.

Ferguson, Kitty. Tycho and Kepler: The Unlikely Partnership That Forever Changed Our Understanding of the Heavens. New York: Walker, 2002. Tells the story of the relationship between Brahe’s work and Kepler’s, as well as the relationship between the two men. Argues that neither would have achieved fame or lasting effects on science without each other’s aid. Includes eight pages of photographic plates, illustrations, maps, bibliographic references, and index.

Gade, John Allyne. The Life and Times of Tycho Brahe. Princeton, N.J.: Princeton University Press, 1947. Reprint. New York: Greenwood Press, 1969. Gade gives the social and political backdrop to Brahe’s life and work. His emphasis is not so much on technical descriptions as on Brahe the person and the community member. Gade writes amusingly of Brahe’s childhood and youth and gives a fairly complex psychological profile of the adult scientist and nobleman. The most personal portrait of Brahe extant.

Gray, R. A. “Life and Work of Tycho Brahe.” Royal Astronomical Society of Canada Journal 17 (1923). Starts with a careful statement of the Ptolemaic and other theories current before the advent of Brahe. Lists among Brahe’s achievements his statement that comets are not, as previously believed, within Earth’s atmosphere. Also mentions Brahe’s improvements on existing instruments.

Thoren, Victor E., with John R. Christianson. The Lord of Uraniborg: A Biography of Tycho Brahe. New York: Cambridge University Press, 1990. Massive and comprehensive biography that attempts to reevaluate and reinterpret nearly every aspect of Brahe’s career and contribution to science. Includes illustrations, bibliographic references, index.