Johannes Kepler 1571 – 1630
As attested to on my birth certificate to the left, I was born in a hospital on Keplerstraße (Kepler street) in Linz, Austria, where Johannes Kepler lived and worked from 1612 to 1626. The name may not be familiar to you, but he was among the key men who revolutionized astronomical thinking and could be counted among the first astrophysicists. His contemporaries included Galileo Galilei, Tycho Brahe, and later Isaac Newton. Johannes Kepler was most famous for elucidating the motion of planets and adding to the theory of Copernicus, a Polish mathematician and scientist, that the sun is the center of the solar system and the earth revolves around it. Unfortunately, none of Kepler’s astronomical genius rubbed off on me despite my proximity to his spirit, undoubtedly still haunting Kepler Street.
Kepler came up with his three laws of planetary motion, although described by him with very complex mathematical formulations, they can be simply stated:
1. The orbits of the planets are not circles but ellipses
2. Planets move proportionally faster when they are nearer the sun.
3. The more distant planets take proportionally longer to orbit the sun. This third of Kepler’s laws inspired Newton to elucidate the nature of gravity, not the apple that supposedly fell on his head. Kepler also gave us the word “satellite.” Kepler worked for Tycho Brahe, the Danish astronomer, although it was a contentious relationship. Brahe was very secretive and would not share his astronomical observations that Kepler needed to finish his theories of planetary motion. When Brahe died under peculiar circumstances, even the possibility of murder, among other things, he had a secret dalliance with the Danish King’s mother. Eventually, Kepler did get access to all the data he needed. He was able to explain why Mars appeared to be reversing its revolutions around the sun and the mathematical relationships of the other planetary orbits.
Kepler discovered the optics that operate in our eyes, that binocular vision is dependent on two eyes, and the mechanism that makes us near or farsighted, which he could correct with different ground glass lenses. How the telescope works and magnifies was also one of his academic interests. Although Isaac Newton is credited with inventing Calculus, Kepler preceded him with Integral Calculus by almost fifty years. Kepler had the belief that the world was in harmony in all aspects, astronomy, nature, music, mathematics, and even snowflakes. He wrote a pamphlet, Strena Seu de Nive Sexanula (A New Year’s Gift of Hexagonal Snow), and he was the first human to observe that phenomenon. At the time, discussion of heliocentrism was heretical and almost caused Galileo to be burned at the stake. Kepler and his wife, if they were separated, communicated in code to avoid any accusations of heresy. Kepler’s mother was, in fact, accused of witchcraft. He defended her and was able to save her life by getting her sentence commuted to exile. It was Kepler who wrote the first science fiction book entitled Somnium (The Dream), where he envisioned non-human intelligent life on the moon, with large animals resembling dinosaurs roaming about. He also described what was a supernova, named for him in his book, De Stella Nova.
Johannes Kepler was a true Renaissance man before that term existed.