Isaac Newton

born: Dec 25, 1642 Woolsthorpe, England
died: March 20, 1727

I do not know what I may appear to the world; but to myself I seem to have been only like a boy playing on the seashore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.
(Isaac Newton)

Co-inventor of calculus. Discovered the law of Universal Gravitation. Newton’s three laws of motion. Corpuscular theory of light. Law of cooling. Professor, Theologian, Alchemist, Warden of the Mint.

Newton was a premature child and was very small at birth. His father had died before Newton’s birth, and, when he was three years old, his mother remarried and left him in the care of his grandmother. He was somewhat sickly as a child, and since he could not join the other children in games he kept himself amused by building mechanical toys such as wooden clocks and sundials and a mouse-powered flour mill. He read a great deal and kept a journal of observations.

Newton began his schooling in the village schools and later was sent to Grantham Grammar School where he became the top boy in the school. At Grantham he lodged with the local apothecary and eventually became engaged to the apothecary’s stepdaughter, Miss Storey, before he went off to Cambridge University at the age of 19. But Newton became engrossed in his studies, the romance cooled and Miss Storey married someone else. It is said he kept a warm memory of this love, but Newton had no other recorded ‘sweethearts’ and never married.

In 1661, Newton entered Trinity College, Cambridge as a student who earned his expenses by doing menial work. Not much is known of his college days, but his account book seems normal enough — it mentions several tavern bills and two losses at cards. He received his B.A. degree in 1664, the year that the bubonic plague was sweeping Europe. The colleges closed for what turned out to be two years, so Newton returned to Woolsthorpe to think.

Up until then Newton had been somewhat precocious and had been a successful student, but he had done nothing really outstanding. Now things started to happen. His two years at Woolsthorpe represent the greatest recorded achievement of a human intellect in a short period. In these two years, this ‘kid’ extended the binomial theorem, invented calculus, discovered the law of universal gravitation and had enough time left over to experimentally prove that white light is composed of all colors. Then he had his 25th birthday. If Newton had communicated these results and then died, his reputation would be almost a great as it is today. He lived for another 60 years and made a few additional contributions to the pool of knowledge, but, at most, these later results would have earned him a footnote in history. In two years he invented calculus, which would quickly grow into the largest and most important field in mathematics and which would first have a tremendous impact on physics and astronomy and more recently on fields of biology, economics, business and even political science. At the same time he discovered the law of universal gravitation which explains, on a large scale, how the universe operates.

When the plague subsided and the schools reopened in 1667, Newton returned to Trinity College as a Fellow (professor), and two years later Dr. Isaac Barrow, Newton’s teacher, resigned so Newton could become Lucasian Professor of Mathematics. He was now 26, and from here on it was mostly downhill, at least intellectually. Newton lectured on optics and calculus and physics; he built telescopes and observed Jupiter’s moons, and calculated orbits. But these areas became secondary interests. His heart was really in alchemy (“lead into gold,” the forerunner of chemistry) and theology and the spiritual universe. He attempted to reconcile the dates of the Old Testament with historical dates, became very involved with astrology and attempted to contact departed “souls.” In hindsight, it is easy to dismiss all of this as nonsense, but these were serious attempts of a serious man to understand the entire universe. It is unfortunate, however, that Newton devoted so little of the rest of his life to mathematics and physics. The few times he did return to these areas, he proved that he had not lost his genius.

Newton’s great discoveries in physics were finally published in 1687 as Philosophiae Naturalis Principia Mathematica (usually just called the Principia). By the late 1690s, the followers of Newton and Leibniz were involved in very heated nationalistic arguments over priority in the invention of calculus, and these arguments raged for over a century. Mostly, Newton and Leibniz remained above the squabbling, and the consensus is that each made the discoveries independently. Newton was the first to make the discoveries but he waited 20 years to publish them. Leibniz did not delay as long and published his results first. As a result of this squabble, British mathematicians ignored the fruitful developments in mathematics on the continent and stagnated for almost a century.

In developing the calculus, Newton used the method of “fluxions” (from the Latin “flow”): functions flowed and he considered their “rate of flow.” He routinely dealt with “infinitesimal” (infinitely small quantities) and used dots above the variable functions to denote derivatives. The notations we use in calculus are primarily due to the other inventor of calculus, Leibniz. Newton and Leibniz both used an intuitive idea of “limit,” but neither seemed to have a precise definition of it.

Newton served in Parliament twice. He was elected President of the Royal Society and held that position for 24 years. In 1696 he was appointed Warden of the Mint and put in charge of the system of coinage in the British Empire. In 1705 he was knighted by Queen Anne. Except for a few periods of severe insomnia and a persecution mania (perhaps due to overwork or mercury poisoning from his work at the Mint), Newton’s health was excellent until the last 3 years of his life. He died in his sleep at the age of 85, and was buried with full national honors in Westminster Abbey.

Condensed from Men of Mathematics by E.T. Bell (1937, Simon and Schuster) and An Introduction to the History of Mathematics by H. Eves (1976).

Last Updated September 22, 2022