 Isaac Newton was born in Lincolnshire, England on Christmas Day, 1642. Newton came from a family of farmers, but never knew his father, who died before he was born. His mother remarried and left him in the care of his grandmother. He attended grammar school in Grantham, where he had not shown much promise in academic work; his school reports described him as 'idle' and 'inattentive'. An uncle decided that he should be prepared for university, and he entered Trinity College at Cambridge in 1661. Newton's goal was a law degree, but in his third year he studied the philosophy of Rene Descartes and others. The new algebra and analytical geometry of Vičte, Descartes, and Wallis, and the mechanics of the Copernican astronomy of Galileo, attracted him. His scientific genius emerged suddenly when the plague closed the University in the summer of 1665, and he had to return to Lincolnshire. There, in a period of less than two years, while still under 25 years old, he began revolutionary advances in mathematics, optics, physics, and astronomy. While Newton remained at home, he laid the foundation for differential and integral calculus, several years before its independent discovery by Leibniz. He had the insight that the integration of a function is merely the inverse procedure to differentiating it. Taking differentiation as the basic operation, Newton produced simple analytical methods that unified many separate techniques previously developed, to solve apparently unrelated problems such as finding areas, tangents, the lengths of curves and the maxima and minima of functions. (Alberta students first learn about these methods in Mathematics 31, at the grade 12 level) 
Newton returned to Cambridge, where he became Lucasian Professor of Physics. His first work was on optics. He had decided that white light is not uniform in composition. Every scientist since Aristotle had believed that white light was a basic single entity, but the chromatic aberration in a telescope lens convinced Newton otherwise. When he passed a beam of sunlight through a glass prism, Newton noted the spectrum of colours that formed.
Newton argued that white light is really a mixture of many different types of rays, which are refracted at slightly different angles, and that each different type of ray produces a different colour. But fellow scientists Hooke and Huygens objected to Newton's attempt to prove, by experiment alone, that light consists of the motion of small particles rather than waves. However, Newton's particle theory became accepted as true ... until the wave theory was revived in the 19th century, and when soon after, Albert Einstein explained that light was both a particle and a wave. Newton's greatest achievement was his work in physics and celestial mechanics, which led him to the theory of universal gravitation. By 1666, Newton had early versions of his three laws of motion. Newton's idea was to imagine that the Earth's gravity influenced the Moon; from his law of centrifugal force and Kepler's third law of planetary motion, he deduced the inverse- square law. In 1687 Newton published the 'Philosophiae Naturalis Principia Mathematica', or 'Principia', as it is better known. The Principia is recognized as the greatest scientific book ever written. Newton analysed the motion of bodies in frictional and non-frictional media under the action of centripetal forces. The results were applied to orbiting bodies, projectiles, (cannonballs, not bullets), pendulums, and free-fall near the Earth. He further demonstrated that the planets were attracted toward the Sun by a force varying as the inverse square of the distance, and generalized that all heavenly bodies mutually attract one another. Newton explained a wide range of previously unrelated phenomena:- the eccentric orbits of comets; the tides and their variations; the precession of the Earth's axis; and the motion of the Moon as it is perturbed by the gravity of the Sun. Never in history has one person shown such an amazing output of new and revolutionary ideas, especially in such a short time! After suffering a nervous breakdown in 1693, Newton retired from research to take up a government position in London, becoming Warden of the Royal Mint (1696) and Master(1699). In 1703 he was elected president of the Royal Society and was re-elected each year until his death. He was knighted in 1708 by Queen Anne, the first scientist to be so honoured. Visit our second page where we explain Newton's Law of Universal Gravitation, or our third page where we illustrate his Three Laws of Motion. |