Isaac Newton formulated the three laws of motion published in his 1687 work Philosophiæ Naturalis Principia Mathematica.
Newton’s laws describe how forces affect motion. The first law states that an object remains at rest or moves uniformly unless acted on by a net external force. The second relates force, mass, and acceleration, commonly expressed as F = ma. The third states that forces occur in equal and opposite pairs.
The Principia also presented Newton’s law of universal gravitation, connecting falling objects on Earth with the motion of celestial bodies. Newton built on earlier work by Galileo Galilei and Johannes Kepler rather than working in isolation. His mechanics remained foundational for centuries, although Einstein’s theories showed that Newtonian descriptions need refinement at very high speeds, strong gravitational fields, and extremely precise scales.