Tycho Brahe and Kepler: AD 1600-1609
During 1600 two of Europe's leading astronomers are guests of the emperor Rudolf II in the castle of Benatky near Prague. Each is a refugee. The older man, Tycho Brahe, has spent twenty years making astronomical observations in Uranienborg, a custom-built observatory created for him on an island near Copenhagen by the Danish king Frederick II. But in 1596 his lavish funding is cut by Frederick's successor. Tycho moves, with his instruments, to the hospitality offered by Rudolf II in Bohemia.
The younger astronomer, Johannes Kepler, has had to leave his post in Graz, in Austria. He is expelled from the university in 1600 on religious grounds as a Protestant.
Tycho Brahe, after inviting Kepler to Prague in 1600, dies in the following year. Kepler inherits his instruments and the detailed results of a lifetime of observation. In 1602-3 Kepler edits and publishes Tycho's work (Astronomiae instauratae progymnasmata, 'Beginnings of a New Astronomy'), giving the precise position of 777 stars.
With Tycho's information on planetary movements over many years, together with his own continuing observations, Kepler is in a position to publish - in Prague in 1609 - his own most significant finding. His Astronomia nova puts forward the radical and correct proposition that the planets move in elliptical rather than circular orbits. |
