A Genius of Humanity, Kepler is considered to be "The Father of Celestial Mechanics"

Johannes Kepler was one of the key figures of the Scientific Revolution. True, he is not as well-known as Galileo or the reclusive genius Isaac Newton, who built on Kepler' work. But Kepler — Germany's mathematical genius — was a major player in astronomical history and set the stage for many subsequent important discoveries.

Great discoveries By describing the process of human vision, Kepler wrote the first modem book on optics: "Astronomiae Pars Optica". (1604). He discovered the inverse square law of light — the foundation (for measuring all modern stellar and galactic distances. His thoughts on the shapes of snowflakes resulted in the first book on crystallography. "Strena seu de nive sexangula". (1611).

After Galileo's telescopic discoveries in 1610. Kepler described how the revolutionary new instrument worked. He also introduced improvements, including one that increased the field of view. His design came into wide use by the middle of the 17th century. We know Kepler mostly for his three planetary laws, which he derived after a Herculean battle wish the data of the great Danish naked-eye observer. Tycho Braise. Kepler linked physics and astronomy by establishing the idea that the planets had to move due to unseen forces. He thus founded celestial mechanics and opened the door for Newton's work on gravitation.

Personal history Kepler was born December 27.1571 —28 years after the death of Copernicus and 7 years after Galileo's birth — in Weil der Stadt. a small. mostly Catholic town on the edge of the Black Forest in Southern Germany. Despite Demote being the oldest of four children (three siblings died in infancy). Kepler was always an underdog. His first chore in life was to overcome an unhappy childhood that was plagued by illnesses both real and imaginary. An early bout with smallpox left Kepler with defective vision, one reason he eventually pursued theoretical rather than observational astronomy. One notably happy event occurred when he was 5. Kepler's mother took him to a hilltop to view the Great Comet of I 577, whose tail arched across the entire sky.

Kepler's first job was as a math teacher in Graz, Austria. It was there that he embarked on his lifelong quest for harmony. In a flight of mathematical mysticism. he tried to link the known planets to Plato's five geometrical solids (the cube, tetrahedron, octahedron. icosahedron. and dodecahedron) By nesting each geometrical solid between the orbits of the planets. he thought he had the basis for the known number of the planets.

He was so pleased with this idea that he wrote it up as a sort of "theory of everything" called "Cosmographicon Mysterizon" ("The Cosmic Mystery"). The book impressed the most impressive astronomer of the day. Tycho Brahe. and the two men began what quickly became a tempestuous collaboration. Brahe had accumulated 20 years of precise observations and needed someone with Kepler's mathematical prowess to make sense of it. Kepler promised he could solve the orbit of Mars within 8 days. Mars was particularly difficult because the observations varied from Tycho's calculations more than any of the planets. Instead. the task took nearly 8 years!

the nightime motion of Mars!