Newton's Principia Mathematica — Law of Universal Gravitation
Isaac Newton published Principia Mathematica in July 1687 at the urging (and expense) of Edmond Halley. In three books, Newton: stated his three laws of motion (inertia, F=ma, action-reaction); derived the law of universal gravitation (every mass attracts every other mass with a force proportional to the product of their masses and inversely proportional to the square of the distance); demonstrated mathematically that Kepler's three laws of planetary motion follow necessarily from universal gravitation; explained the tides, the precession of the equinoxes, and the trajectories of comets — all within a single unified framework. The Principia completed the Copernican Revolution: the heliocentric system was now not merely observed (Galileo) but explained by a single mathematical law. It also established the template for modern physics: phenomena are explained by mathematical laws derived from a small set of axioms and tested against observation. Voltaire brought Newton's ideas to France after 1726, and the Principia became the intellectual foundation of the Enlightenment's faith in reason and natural law.
- Year: 1687 CE
- Category: Scientific
