Johannes Kepler was a German Lutheran mathematician, astronomer and astrologer, and a key figure in the 17th century astronomical revolution. He is best known for his eponymous laws of planetary motion, codified by later astronomers based on his works Astronomia nova, Harmonices Mundi, and Epitome of Copernican Astronomy. Before Kepler, planets' paths were computed by combinations of the circular motions of the celestial orbs. After Kepler, astronomers shifted their attention from orbs to orbits—paths that could be represented mathematically as an ellipse. Kepler's laws also provided one of the foundations for Isaac Newton's theory of universal gravitation. During his career Kepler was a mathematics teacher at a Graz seminary school, an assistant to Tycho Brahe, the court mathematician to Emperor Rudolf II, a mathematics teacher in Linz, Austria, and an adviser to General Wallenstein. He also did fundamental work in the field of optics and helped to legitimize the telescopic discoveries of his contemporary Galileo Galilei.

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_______________________________ Today's selected anniversaries:

1410: The Kingdom of Poland and the Grand Duchy of Lithuania defeated the Monastic State of the Teutonic Knights in the Battle of Grunwald, the decisive engagement of the Polish-Lithuanian-Teutonic War. (http://en.wikipedia.org/wiki/Battle_of_Grunwald)

1685: James Scott, Duke of Monmouth, was executed for his role in the Monmouth Rebellion, an attempt to overthrow the King James II of England. (http://en.wikipedia.org/wiki/James_Scott%2C_1st_Duke_of_Monmouth)

1799: French soldiers uncovered the Rosetta Stone in the Egyptian port city of Rashid. (http://en.wikipedia.org/wiki/Rosetta_Stone)

1823: A fire destroyed the ancient Basilica of Saint Paul Outside the Walls in Rome. The church would later be restored by 1840. (http://en.wikipedia.org/wiki/Basilica_of_Saint_Paul_Outside_the_Walls)

1974: Greek-sponsored nationalists overthrew Archbishop Makarios, President of Cyprus, in a coup d'état and replaced him with Nikos Sampson. (http://en.wikipedia.org/wiki/Makarios_III)

_____________________ Wiktionary's Word of the day:

coy: Pretending shyness or modesty. (http://en.wiktionary.org/wiki/coy)

_____________________ Wikiquote of the day:

Love is the extremely difficult realisation that something other than oneself is real. Love, and so art and morals, is the discovery of reality. -- Iris Murdoch (http://en.wikiquote.org/wiki/Iris_Murdoch)