Kepler's law
photo by wikipedia
The Austrian astronomer Johannes Kepler was deeply convinced that the revolution of the planets around the Sun is subject to certain and precise laws. He dreamed of revealing these laws and expounding them in a large astronomical work conceived by him under the title "Harmony of the World". Kepler persistently searched for this harmony in the planetary system. He devoted several years to calculations, wishing to reveal the relationship between the times of revolution of the planets around the Sun and their average distances from the Sun.
Kepler multiplied these quantities, raised them to a power, extracted square and cube roots... He worked tirelessly. He was not too lazy to repeat each of his calculations several times in order to avoid mistakes. The perseverance with which Kepler strove for the intended goal, his incredible diligence and perseverance amazed astronomers who got acquainted with his manuscripts.