Johannes Kepler changed forever our understanding of the universe. Through his efforts to chart the orbits of the planets—elliptical, not circular—Kepler became one of the most important astronomers of all time. His contributions continued as he laid the groundwork for the discovery of gravitation, setting physics on the course of revelation it follows to this day. Yet if it hadn't been for the now lesser known Tycho Brahe, the Royal Court Mathematician at Prague, the man for whom Kepler worked, Kepler would be a mere footnote in today's science books. Brahe was the foremost astronomer of his era and one...