Changes

Scientists of that time were often opinionated and prone to risk-taking in their theories, and Kepler was no exception. He sacrificed his religious reputation by questioning the "science" of the time, which later forced him to be cut off from orthodox [[Lutheranism]]. Although the loss was great, Kepler was able to become a mathematician and teacher in Graz, [[Austria]], in 1594.<ref name=dao/><ref name=rice/> While at Graz, Kepler wrote his famous ''Mysterium Cosmographicum'', the first forthright and public defense of Copernican [[heliocentrism]].<ref name=nasa/>

Scientists of that time were often opinionated and prone to risk-taking in their theories, and Kepler was no exception. He sacrificed his religious reputation by questioning the "science" of the time, which later forced him to be cut off from orthodox [[Lutheranism]]. Although the loss was great, Kepler was able to become a mathematician and teacher in Graz, [[Austria]], in 1594.<ref name=dao/><ref name=rice/> While at Graz, Kepler wrote his famous ''Mysterium Cosmographicum'', the first forthright and public defense of Copernican [[heliocentrism]].<ref name=nasa/>

In 1600, Kepler left his job at Graz on account of the [[Counter Reformation]]. Unwilling either to convert to Catholicism or to sign the Lutheran Formula of Concord, he decided to leave Graz and travel to Prague.<ref name=nasa/><ref name=rice/> There he became the assistant to [[Tycho Brahe]], court mathematician to Emperor Rudolf II.<ref name=dao/>. Tycho was also makng observations on the orbit of the planets. In 1601, Tycho died, and Kepler was named Imperial Mathematician in his place,<ref name=nasa/> the highest ranking in Europe at the time.<ref name=rice/> After reading and studying the data that Tycho had developed and researched, Kepler was able to resolve a nagging problem concerning the motion of [[Mars]], and in particular its apparent [[retrograde motion]] in relation to the [[Earth]]. Kepler went on to calculate Mars' orbit--as an [[ellipse]], not a [[circle]].

In 1600, Kepler left his job at Graz on account of the [[Counter Reformation]]. Unwilling either to convert to Catholicism or to sign the Lutheran Formula of Concord, he decided to leave Graz and travel to Prague.<ref name=nasa/><ref name=rice/> There he became the assistant to [[Tycho Brahe]], court mathematician to Emperor Rudolf II.<ref name=dao/>. Tycho was also making observations on the orbit of the planets. In 1601, Tycho died, and Kepler was named Imperial Mathematician in his place,<ref name=nasa/> the highest ranking in Europe at the time.<ref name=rice/> After reading and studying the data that Tycho had developed and researched, Kepler was able to resolve a nagging problem concerning the motion of [[Mars]], and in particular its apparent [[retrograde motion]] in relation to the [[Earth]]. Kepler went on to calculate Mars' orbit--as an [[ellipse]], not a [[circle]].

Kepler remained as Imperial Mathematician until 1612, when Rudolf II was deposed.<ref name=rice/> In the next year (1613) he accepted a teaching position in Linz, the last semi-permanent position he ever held. He held this job until 1626, when the pressures of the [[Thirty Years' War]] forced him to leave. Now out of a job and with no salary, he tried in vain to seek employment and to sue for back payment of his salary as Imperial Mathematician.<ref name=rice/> He died in 1630, at Regensburg.<ref name=rice/><ref name=nasa/>

Kepler remained as Imperial Mathematician until 1612, when Rudolf II was deposed.<ref name=rice/> In the next year (1613) he accepted a teaching position in Linz, the last semi-permanent position he ever held. He held this job until 1626, when the pressures of the [[Thirty Years' War]] forced him to leave. Now out of a job and with no salary, he tried in vain to seek employment and to sue for back payment of his salary as Imperial Mathematician.<ref name=rice/> He died in 1630, at Regensburg.<ref name=rice/><ref name=nasa/>