Ill 



JOHTANN KEPLER 

 1571-1630 



Tycho Brake {i 546-1601), nobleman of Denmark, studied law at 

 the University of Copenhagen and became attracted to astronomical 

 studies by the occurrence of a predicted eclipse. Constructing his 

 own instruments, he made observations of the stars at Augsburg and 

 Wittenberg, and in 15/6 established the first observatory at Huen, 

 where he continued his work for twenty years. Banished from Ger- 

 many, he was invited by Emperor Rudolph to Prague, where he began 

 his compilation of the Rudolphin Tables which listed many of his 

 observations on the locations of the planets. Hearing of Kepler's 

 interest in astronomy, he secured the young German's assistance and 

 assigned to him the study of the planet Mars, which study Kepler con- 

 tinued after Tycho Brahe's death in 1601. 



Johann Kepler, the son of an innkeeper, was born December 2y, 

 1571, in IViirttemberg and sent to a local school, from which he was 

 removed when he was nine years old because of his father's impover- 

 ishment. After three years of work in the tavern, he was sent to a 

 monastic school and thence to the University of Tiibingen. Although 

 he was very frail in physique, he was a good student and attained 

 high scholarly standing. Becoming interested in the Copernican 

 theory, in i^pp he was invited by Tycho Brahe to become his assistant 

 at Prague. 



Kepler found his master's tables sufficiently accurate in his efforts 

 to discover some recognisable motion of the planet Mars which would 

 account for its apparent positions. In the course of this work he 

 corrected some of the Ptolemaic ideas which Copernicus had not com- 

 pletely abandoned. The latter retained the epicycle motion of the 

 planets within their larger revolutions in cycles. In comparing this 

 theory with his tables, Kepler found that it would not satisfactorily 

 account for the positions of Mars; and he was therefore led to the 

 long studies and mathematical computations which finally resulted in 



29 



