Newton's Principia
Three laws and universal gravitation explain both the falling apple and the orbiting Moon.
- When
- Known to
- ± 1 year
- Era
- Early Modern, Holocene
Published in 1687 after Halley pressed and paid for it, the Principia sets out laws of motion and a law of gravitation that applies everywhere, deriving Kepler's laws from first principles and unifying terrestrial and celestial mechanics — which had been separate domains since Aristotle. Newton also develops calculus, disputes its priority bitterly with Leibniz, and spends more of his life on alchemy and biblical chronology than on physics.