Newton, Isaac

English physicist and mathematician who laid the foundations of physics as a modern discipline. During 1665–66, he discovered the binomial theorem, differential and integral calculus, and that white light is composed of many colours. He developed the three standard laws of motion (Newton's laws of motion) and the universal law of gravitation, set out in Philosophiae naturalis principia mathematica (1687), usually referred to as the Principia. He was knighted for his work in 1705.

Newton's greatest achievement was to demonstrate that scientific principles are of universal application. Using these principles, scientists could predict the results of their experiments when carried out in controlled conditions, enabling the more rapid development of new ideas. He clearly defined the nature of mass, weight, force, inertia, and acceleration.

In 1679 Newton calculated the Moon's motion on the basis of his theory of gravity and also found that his theory explained how the planets, including the Earth, orbited the Sun. The laws of planetary motion had been worked out by German astronomer Johannes Kepler on the basis of observations of the planets; Newton provided the scientific evidence to back up Kepler's theory.