Spin off: The Surprising History of the Coriolis Effect and the Jesuits Who Investigated It

Abstract

This paper discusses six astronomers of the Society of Jesus who investigated the Coriolis Effect: the deflection of objects moving at Earth's surface that is caused by Earth's rotation. The paper includes introductory material on what the Coriolis Effect is and how it works, especially as regards the atmosphere of Earth and other planets. Four of the six Jesuits—Christoph Scheiner, Giovanni Battista Riccioli, Francesco Maria Grimaldi, and Claude François Milliet Dechales—worked in the seventeenth century. They envisioned the effect occurring if Earth rotated; they believed that no such effect actually occurred; and thus they investigated the effect as an argument against Earth's motion. The fifth, Angelo Secchi, experimented with the Foucault pendulum, the first clear demonstration of this effect. The sixth, Johann Georg Hagen, the first Jesuit Director of the Vatican Observatory, worked in the early twentieth century. He developed experimental tests for the effect. This paper provides a synopsis of information that recently has been published in books and journals related to physics and the history of astronomy regarding Jesuits and the Coriolis Effect.