Other than my love of music and posting videos, what do you know about me?

[Lionel Mandrake]

53. That's approximately right.

Tybho Brahe was a member of the high Danish nobility, with ancesters named Rosenkranz and Guildenstern, among others. His principal duty was to cast horoscopes for the Royal brats. He believed that in order to cast accurate horoscopes, he needed more accurate tables of planetary positions than were then available. He got along well enough with the old king (Frederick II), who gave him the island of Hveen, where he would build his observatory (Uraniborg) and take measurements. He measured the positions of "fixed stars" (proper motions not having been discovered yet). He also measured the positions at various times of the planets relative to the stars. Tycho spent much of his life on Hveen. Uraniborg was the first large scientific laboratory. Students and other visitors would take measurements and do the tedious computations to translate angular measurements into astronomical coordinates. One of Tycho's accomplishments was the demonstration that comets lie above the Moon's orbit and are not atmospheric phenomena. Tycho also understood atmospheric refraction and corrected his measurements for it. He ordered craftsmen to build him the largest and most accurate instruments the world had ever seen. With these instruments installed at Uraniborg, Tycho and his assistants made measurements of unprecedented accuracy, which would not be improved upon until long after the invention of the telescope.

Tycho as a student (unusual enough in itself for a Danish nobleman) had fought a duel, with the result you mentioned. In those days, the proper activities of Danish noblemen were considered to be hunting, fighting, drinking, and being seen at court. Few of them could read. They interbred among a select group of families that constituted the high nobility. Tycho fell in love with a commoner and married her. This made things awkward at court. His wife would never have been welcome there. Even this would have been okay if the old king hadn't croaked. The new king (Christian IV) quarreled with Tycho Brahe and wouldn't support him. So Tycho, in middle age, was forced to go looking for another patron. He eventually landed in the court of the Holy Roman Emperor Rudolph II at Prague. There he took on a younger man (Kepler) as his assistant (not exactly an apprentice). Kepler's assignment was to compute the orbit of Mars according to the Tychonic system, a sort of compromise between Ptolemy and Copernicus, in which the Sun goes around the Earth, and the other planets go around the Sun. Kepler didn't believe in Tycho's system but kept his mouth shut until after Tycho's death (in 1601). Kepler tried to fit the observations of Mars with various combinations of circles (as Copernicus had done) but could not obtain agreement to within the observational errors. Then he tried other curves and succeeded with ellipses.