Johannes Kepler (LoPresti)

Johannes Kepler was born in Württemberg in 1571. His promising academic life was rewarded with a scholarship to the University of Tübingen, where he was first introduced to the ideas of Copernicus. Kepler’s fortuitous partnership with Tycho Brahe was in many ways a product of chance. As a Lutheran, Kepler was forced to leave his teaching post in Graz as a result of the counter reformation and move to Prague where Brahe was serving as the Imperial Mathematician. He later inherited this position after Brahe’s death in 1601. In this post, Kepler was finally able to access Brahe’s wealth of incredibly accurate planetary measurements and data. From this data he was able to create a model of planetary motion that showed orbits as elliptical and not circular as previously thought. Published in 1609, Astronomia Nova outlined Kepler’s first two laws of planetary motion. These laws of elliptical orbits and equal areas in equal times were some of the first applications of the scientific method were accurate models were drawn from incomplete data. Despite great personal tragedy and religious persecution Kepler was able to produce bodies of work that cemented his legacy. His most influential work is often considered to be Epitome Astronomiae published in 1621. This seminole work cataloged all of heliocentric astronomy in a clear and logical way. This combined with his developmental work on logarithms, allowed him to produce tables that could predict the locations of planets both in the past and future. Sadly Kepler passed away in 1630 before he could witness his predicted passing of Mercury and Venus in front of the Sun. In addition to his groundbreaking work in astronomy, Kepler also published widely on the topic of optics. With works explaining pinhole cameras, refraction within the eyes, how telescopes work, and total internal refraction, Kepler was a man of great intellectual prowess. It is the ideas of Kepler and not an apple, that laid the groundwork for Isaac Newton’s discovery of gravity. By having a framework with which to understand the planetary motion, Newton was able to explain Johannes Kepler's noted relation between periodic times and mean distances. Kepler was a clear step forward from conjecture and speculation to the enlightenment of Newton. Shaped by religious persecution and his own personal setbacks Kepler was able to stand tall as a pillar of scientific integrity who stayed true to the data and brought about a planetary scale revolution in his own right.



“Johannes Kepler: His Life, His Laws and Times.” Edited by Alan Gould, NASA, NASA, 24 Sept. 2016,