Online Astronomy eText: Orbital Motions
Biography of Tyge (Tycho) Brahe
(also see Tycho Brahe's Astronomical Accomplishments)
      Tyge (Latinized as Tycho) Brahe is one of the great names in astronomical history, a man who made many contributions, some of them quite brilliant, in advancing our knowledge of the Universe, but was overshadowed after his death by his failure to accept some of the consequences of his discoveries.


A 1946 Danish stamp honoring the 400th anniversary of Tycho Brahe's birth

      Tycho was born on December 14, 1546 in Skane, which is part of a small peninsula on the very southwestern part of Sweden. At the time that area and several other parts of what is now southwestern Sweden were part of Denmark, and it wasn't until 1658 that Sweden took permanent possession of the territories. As a result, Tycho is considered to have been a Dane, even though his birthplace is now in Sweden (the Danish stamp shown above can be viewed as both a way of honoring his birth, and of protesting the loss of former possessions).
      Tycho's career was greatly influenced by the fact that his parents, Otte Brahe and Beate Billie, were among the highest-ranking members of the Danish nobility. At that time a twenty-member oligarchy, the Rigsraad, ruled Denmark. Otte was one of the members of the Rigsraad, and several members of his mother's family were also members of that body, so he was born into one of the most powerful families of his day. Rather oddly, however, he was not raised by his parents. One of his uncles, Jörgen Brahe, a very wealthy man in his own right, was childless, and prior to Tycho's birth his parents had promised that they would allow Jörgen to adopt the boy, but after he was born they refused to keep their word. Later, however, they had another son, and Jörgen kidnapped Tycho, apparently feeling that his brother should be content with the other son. Although Otte was furious and threatened to kill Jörgen, he never did so, and eventually became reconciled to the fact that at least Tycho would have a fabulous inheritance.
      Originally Jörgen intended that Tycho should become a lawyer, and among other things had him start to study Latin. Since by this time all things Roman were anathema to members of the Protestant religion, his parents objected, but were put off by the explanation that Latin was absolutely necessary for a study of the law. On August 21, 1560 an astronomical event occurred, one of many that would influence Tycho's life, and would lead him to use his knowledge of Latin in a completely different way. On that date the 13-year-old youngster was attending the University of Copenhagen when the Moon partially covered the Sun, producing a partial eclipse. The fact that the event had been predicted in advance made a powerful impression on Tycho, and he immediately purchased a Latin copy of Ptolemy's great work on astronomy, the "Almagest", and a set of astronomical tables based upon Copernicus' then relatively new theory of the motions of the heavens. By the time he was 16, Tycho had completely lost interest in the law, and although he was sent to Leipzig to continue his legal studies, he managed to find numerous ways to ditch a private tutor, Anders Vedel, who was hired to keep an eye on him, and concentrate on astronomical studies instead. (It probably didn't hurt Tycho's reputation that he and Vedel remained good friends throughout their lives, especially when Vedel became Denmark's first historian.)
      Tycho's family was not keen on his astronomical observations, and he spent as much of his early life outside Denmark, at various foreign universities, as possible. In 1565 his uncle saved the life of the King of Denmark, preventing him from drowning, but in the process Jörgen contracted pneumonia and soon died. This provided Tycho with a fabulous fortune, which he did a great deal to enhance throughout his life. At one point late in his life his personal fortune and the monies that he controlled in other ways were estimated to amount to 1% of the entire worth of Denmark, and he never felt it necessary to stint in any way on how he spent his money, or better yet the monies of his patrons.
      One thing that Tycho spent lavishly on was astronomical instruments. Prior to his efforts the best equipment available for estimating the positions of stars and planets were crude pointers which were only capable of estimating angles of about 1 degree or so. By the end of his career he had supervised the construction of dozens of instruments, some of enormous size and complexity, which were capable of measuring angles over a hundred times smaller than that. As a result of the high quality of his instruments and a dogged determination to use them to their fullest accuracy, he made tens of thousands of observations of more than 1000 stars and of all the naked eye planets, over a period of decades, with an average accuracy of 1/50th of a degree, which is as good or better than the smallest angle that most people of excellent vision can perceive, and many of his observations were twice as accurate as that. It was the incredible accuracy of his observations (incredible because they were all done with the unaided eye, before the invention of the telescope) which made it possible for Johannes Kepler to discover the true nature of the planetary orbits after Tycho's death.
      Another thing he lavished his money on was the observatory, the Uraniborg, which he had constructed on the island of Ven (nowadays, usually spelled Hven or Hveen). It took eight years of hard work by virtually the entire population of the island to build the castle-like structure, work which was not entirely appreciated by the populace, many of whom sought to leave the island, but were prevented from doing so by a law which Tycho arranged to have passed, forbidding anyone from doing so without the express permission of Tycho himself, or of the King of Denmark. Needless to say this did not endear him to the local population, and a number of interesting slanders about Tycho were invented by various enemies, many of which persist to this day; but on the whole it is thought that he was no more villainous, ruthless, or overbearing than any other nobleman of his day.
      Even with Tycho's enormous fortune and the essentially free labor of the inhabitants of his private fiefdom, the construction of the Uraniborg and the carrying out of extensive astronomical and other investigations, not to mention lavish parties replete with fireworks, drink, and other frivolities common to those of great wealth and unlimited power, the cost of his lifestyle was staggering, and he found it necessary to augment his own wealth with the patronage of others. The chief of these was the King of Denmark, who gave him huge sums of money for the best part of two decades. As already mentioned, much of that money was spent on various frivolities, but the largest portion was spent constructing the finest observing equipment (albeit naked-eye equipment) of the day, and to pay a small army of assistants to help him make his observations, and Tycho did succeed in producing a series of observations of the positions of heavenly objects which were unsurpassed in accuracy for nearly a century and a half after his death (which, considering the fact that the telescope was invented not long after his death, is truly amazing). If not for the exceptional accuracy of Tycho's measurements, Kepler probably would have failed to discover the elliptical motion of Mars, which was the basis of his Laws of Planetary Motion.