How to Make the Earth Orbit the Sun in 1614

Abstract

In 1614 the Jesuit astronomer Christoph Scheiner and his student, Johann Georg Locher, proposed a physical mechanism to explain how the Earth could orbit the sun. An orbit, they said, is a perpetual fall. They proposed this despite the fact that they rejected the Copernican system, citing problems with falling bodies and the sizes of stars under that system. In 1651 and again in 1680, Jesuit writers Giovanni Battista Riccioli and Athanasius Kircher, respectively, considered and rejected outright this idea of an orbit as a perpetual fall. Thus this important concept of an orbit was proposed, considered, and rejected well before Isaac Newton would use an entirely different physics to make the idea that an orbit is a perpetual fall the common way of envisioning and explaining orbits.