The Case for God

by Karen Armstrong

Arguably the most brilliant of these pioneering scientists was the German astronomer Johannes Kepler (1571–1630),54 who had corresponded with Brahe, helped him in his work, and succeeded him in the post of imperial astrologer. Like Copernicus, Kepler was convinced that mathematics was the key to understanding the cosmos and that the scientist’s task was to test his mathematical theories against rigorous empirical observation. In 1609, he published Mysterium cosmographicum, the first public attempt to justify and refine Copernicus’s heliocentric theory, which had been unnecessarily complicated by Copernicus’s retention of the circular planetary orbits; there were also outstanding problems with his hypothesis. What kept terrestrial objects from flying off the earth as it traveled through space at such high speed? After struggling for ten years to find a way of confirming the idea that the planets moved in perfect circles, Kepler was finally persuaded by Brahe’s remarkably accurate observations to jettison it and, basing his calculations on Euclidean geometry, formulated the first “natural laws”—precise, verifiable statements about particular phenomena that were universally applicable.55