Isaac Newton

EARLY LIFE AND EDUCATION Isaac Newton was born at Woolsthorpe, Lincolnshire, England, on January 4, 1643, in the Gregorian calendar. In the Julian calendar then used in England, his birthday was December 25, 1642. This calendar difference explains why historical sources give different birth years. Newton entered Trinity College, Cambridge, in 1661. During the university’s disruption by plague in 1665–1666, he returned to Woolsthorpe and pursued investigations in mathematics, light and motion. He became a fellow of Trinity in 1667 and Lucasian Professor of Mathematics in 1669. MATHEMATICS AND CALCULUS Newton developed mathematical methods for studying changing quantities, curves and motion. These investigations formed a version of calculus, which he called the method of fluxions. Gottfried Wilhelm Leibniz developed calculus independently, and their supporters later became involved in a bitter dispute over priority. The importance of this mathematics extended far beyond the dispute. Calculus provided powerful ways to describe continuous change and became central to physics and engineering. THE PRINCIPIA AND UNIVERSAL GRAVITATION In 1687, Newton published Philosophiae Naturalis Principia Mathematica, commonly called the Principia. Edmond Halley played an important role in encouraging its development and bringing it to publication. The book presented Newton’s laws of motion and his account of universal gravitation. It showed how a common mathematical framework could describe both motion on Earth and the paths of celestial bodies. Rather than treating the heavens and everyday motion as entirely separate realms, Newton brought them into a unified physical theory. LIGHT, COLOUR AND TELESCOPES Newton’s experiments with prisms investigated the composition of white light. He argued that the colours separated by a prism were components of the incoming light, rather than colours created by the glass. He also built a successful reflecting telescope, using a mirror in its optical system. His Opticks, first published in 1704, brought together major investigations of light and colour. Together with the Principia, it became one of his most influential scientific works. PUBLIC SERVICE AND LATER LIFE Newton became Warden of the Royal Mint in 1696 and Master in 1699. He participated in the recoinage of English silver money, investigated counterfeiting and took an active interest in the accuracy of coin production. He was elected President of the Royal Society in 1703 and was knighted in 1705. His intellectual interests also included theology, biblical chronology and alchemy, subjects documented in his surviving manuscripts. DEATH AND LEGACY Newton died in Kensington on March 31, 1727, in the Gregorian calendar, corresponding to March 20 in the contemporary Julian calendar. He was buried in Westminster Abbey. His work transformed mathematics and natural philosophy. The laws of motion, universal gravitation and his research on light helped establish an enduring framework for investigating nature through mathematical reasoning, observation and experiment.