الأصول الرياضية للفلسفة الطبيعية
Newton's cannonball was a thought experiment Isaac Newton used to hypothesize that the force of gravity was universal, and it was the key force for planetary motion. It appeared in his 1687 work "Philosophiæ Naturalis Principia Mathematica" (later editions printed in English as "A Treatise of the System of the World").