ABSTRACT
It is no coincidence that astronomers were extending our understanding of the heavens at exactly the same time as the great seafaring explorers were extending our knowledge of the Earth. Navigators need reliable star charts, and by the 1600s Kepler’s new way of calculating planetary orbits made the drawing up of these charts easier and more accurate. But the next question was: why do the planets move in these orbits? I do not believe that any scientist with normal curiosity could ignore that question, any more than Columbus could have stopped himself wondering what was on the other side of the New World.
