Kepler's Move from Orbs to Orbits: Documenting a Revolutionary Scientific Concept

Commentary 01 on Goldstein 1980

“…He replaced the old concept of orbs (i.e. spherical shells), to which the planets were attached, with the revolutionary concept of orbit, that is, the path of the planet in space governed by physical laws (Goldstein and Hon, 2005). These laws, however, are not what were later called Kepler’s three laws of planetary motion.…”

The Object Bias and the Study of Scientific Revolutions: Lessons from Developmental Psychology

“…Many historians have recently pointed out that the real revolutionary figure in this revolutionary change was Kepler, and the key achievement of the so-called Copernican revolution consists in transforming theoretical astronomy from one that was understood in terms of ORB to one that was understood in terms of ORBIT (Barker, 1990;Barker & Goldstein, 1998;Goldstein & Hon, 2005). From antiquity to the 16th century, astronomy was built on a specific ontology that attached planets to spherical shells called orbs.…”