Johannes Kepler

It's fact
Kepler is famous now an astronomer although in his life time he earned money by practicing astrology. It is said that he was at home calculating orbits of planets as well as casting horoscope for the nobility. In December 1998, Anthony Misch, an astronomer at the Lick Observatory at UC Santa Cruz, came across a 400 year old horoscope manuscript, by chance, while leafing through old documents purchased by the observatory over a century ago. Misch had the document authenticated, by a European firm, which penned by was Johannes Kepler, considered to be one of the fathers of modern astronomy along with Copernicus and Galileo.




Johannes Kepler
```````(1571-1630)
~~~~~~~The first Astrophysicist in the Western World 

Born: December 27, 1571, Well der Stadt near Stuttgart, Germany 
Died: November 15, 1630 (aged 58), Regensburg, Bavaria, Germany 
Residence: Baden-WOrttemberg; Styria; Bohemia; Upper Austria 
Field: Astronomy, astrology, mathematics and natural philosophy 
Institutions: University of Linz (Alma mater University of Tubingen) 
Known for:1<epler's laws of planetary motion, Kepler Conjecture 
Religion: Lutheran

Before Kepler, path of planets 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 represpnted mathematically as an ellipse. 


Johannes Kepler was a German astronomer and astrologer who was considered to be the most illustrious theoretical astronomer of all time by Nobel Laureate Shelly Glashow. Carl Sagan described him as the " The first astrophysicist and last scientific astrologer". Kepler was the student of Tycho Brahe and used Brahe's observational records to come up with the 3 laws of planetary motion eponymously known as Kepler's laws of planetary motion.


Kepler's laws also provided one of the foundations for Isaac Newton's theory of universal gravitation and helped get support for Galileo's work in observational astronomy. Later the derivation of Kepter's laws from Newton's theories was an exercise for advanced students of natural science in Europe. 


Kepler analyzed the vast amount of data he received upon Brahe's death. From this data, he prepared new planetary tables (called the Rudolphine Tables). At first, he determined the shape of planetary orbits to be ovoid, but rejected this result for aesthetic reasons. Going back over his calculations, he found and corrected an error. The new shape turned out to be an ellipse, which fit well into Kepler's views on nature. Kepler later sent his theories to the Danish astronomer Tycho Brahe. Brahe was impressed with Kepler and employed Kepler as an assistant. Upon Brahe's death, Kepler inherited the vast data collection of Brahe's.


Kepler tried all sorts of mystical notions to describe planetary orbits, using the Platonic solids and musical analogies. Spread out through his voluminous calculations in "Astronomia Nova", however, were three gems: Kepler's laws of planetary motion. For the formulation of these taws, Kepler is considered the founder of physical astronomy. 


The first law states that the planets move in elliptical orbits with the Sun at one focus. The second law states that the planets sweep out equal areas in equal times (which is equivalent to the statement of conservation of angular momentum.) The third law states that the period squared in proportional to the semimajor axis cubed. Kepler believed that the planets were kept in their orbits by a  "anima matrix" (motive soul), but later modified it to "vis matrix" (life force). He also studied optics as an aspect of astronomy in "Astronomiae Pars Optica"(1604), and developed the concept of a ray. 


Kepler was a brilliant thinker and a lucid writer, but he was a disaster as a classroom teacher. "He mumbled. He digressed. He was at times utterly incomprehensible... He was distracted by an incessant interior clamor of associations and speculations vying for his attention. And one pleasant summer afternoon... he was visited by a revelation that was to alter radically the future of astronomy..." Carl Sagan commented. 

Posted in: Greatest Astronomers