Mass, Speed, Direction: John Buridan's 14th-Century Concept of Momentum

“Modern science began in the Middle Ages,” a fact that has been forgotten thanks to the celebrated accomplishments of Copernicus and Galileo, who did not acknowledge their predecessors. So states James Hannam in a January 2010 article in History Today. Among the scientists of the Middle Ages that Hannam mentions is John Buridan, a French thinker who was the first to develop modern concepts of inertia and momentum.¹ Buridan's work has been known to historians of science for decades² and remains a topic of discussion among them today.³,⁴ However, it is not well-known in physics circles,⁵ although there was an American Journal of Physics discussion of Buridan 35 years ago as part of a history of inertia.⁶ Readers of The Physics Teacher may find Buridan of interest both as a matter of history and because Buridan presents important physics ideas in a different sort of way, which may be of value in the physics classroom.