JOHANNES KEPLER (: Done by: V. Ramya Nur Dayana Mimi Amira Hanin Insyirah

BIOGRAPHY  December 27, 1571  November 15, 1630  German mathematician, astronomer and astrologer, and key figure in the 17th century

CONTRIBUTIONS (:  known for his laws of planetary motions  Kepler published Astronomia nova (1609) 1. Elliptical Orbit  Each planet revolves around the Sun in an orbit  First to use focus in mathematical sense  The observations and theories proved that the theory of the circular orbits wrong 2. Speed  Kepler showed that a planet moves slower when it is farther away from the Sun

CONTRIBUTIONS  provided the basis for Newton’s theory of gravity  worked in the field of optics and invented an improved version of the refracting telescope called the Keplerian Telescope. This helped to legitimize the telescopic discoveries made by Galileo

CONTRIBUTIONS  Kepler analysed Brahe’s observations of Mars which made Brahe impressed of Keple’s theoretical ideas  Kepler wanted to test his theory based on Brahe’s data but realised that it would take up to 2 years to complete

CONTRIBUTIONS  When Brahe died, Kepler was appointed his successor  He had the responsibility of finishing Brahe’s uncompleted work  -Tycho died on October days later, Kepler was appointed as his successor and bore the responsibility of finishing Tycho’s uncompleted work

CONTRIBUTIONS  Kepler published astrological calendars  very popular  helped offset the costs of producing his other work.  forecast planetary positions and weather as well as political events which were accurate due to his keen grasp of contemporary political and theological tensions.  By 1624, however, the escalation of those tensions and the ambiguity of the prophecies meant political trouble for Kepler and his final calendar was publicly burned in Graz.

SIGNIFICANCE  His book Epitome of Copernican Astronomy was read widespread in Europe and continued to spread his ideas after his death  to support Copernicus with substantial evidence, and he consequently did much to help explain the great mystery of planetary orbits.  His work convinced people that the universe was heliocentric and he openly supported Copernicus’s theory.  Kepler's discoveries and intricate calculations were vital as a basis for Isaac Newton later work.

Significance of main contributions  Invention and improvement of the refracting telescope called the Keplerian Telescope, helped to legitimize the telescopic discoveries made by Galileo - > Galileo was then able to make very detailed observations of the stars that he could not have done with the naked eye alone  Integrated physics and astronomy together -> his book tried to explain planetary motions through physical causes -> introduced new ideas/new way of thinking  Spread of his ideas even after his death -> opened up new mindsets

REFERENCES  pler_m.htm pler_m.htm  OURSELVES ♥  I DON’T KNOW WHERE MIMI GOT THE INFO FROM. (: