“I much prefer the sharpest criticism of a single intelligent man to the thoughtless approval of the masses.”

Johannes Kepler

Johannes Kepler, the German mathematician, may not be as well-remembered as Nicolas Copernicus, but he was one of the key reasons why the Polish astronomer’s theories ultimately became widely recognized and accepted. Copernicus argued that the planets rotate around the sun.  Johannes Kepler validated this theory by providing the arithmetical and observational evidence.

Johannes Kepler, as many stargazers before him, faced strong resistance, particularly from his mentor Tycho Brahe, imperial mathematician to Rudolph II, ruler of the Holy Roman Empire.  Brahe was considered to be the most famous astronomer of the second half of the sixteenth century.  While Kepler held the Copernican view of the universe in high esteem, Brahe rejected it completely. When Brahe died in 1601, Kepler inherited his position in Rudolph’s court, which allowed him access to Brahe’s meticulous astronomical notes.

Johannes Kepler would struggle for eight more years to produce a satisfactory conclusion.  He believed, as Copernicus before him, that the planets orbited in perfect circles.  The answer came one day when he “awoke from sleep and saw a new light break.”  In a brilliant stroke of understanding, he realized that the planets did not rotate in perfect circles.  Instead, they orbited around an ellipse; that is, a flattened circle with two centres very close together.  The proof was acquired through a straightforward mathematical explanation.

The work of Ptolemy and Copernicus had been vindicated once and for all.  But that was not the end. Johannes Kepler’s findings would act as the stimulus for questions that would lead to Isaac Newton’s theory of gravity.  The journey would continue.

“Truth is the daughter of time, and I feel no shame in being her midwife.”

Johannes Kepler