Who was Isaac Newton? What did Isaac Newton do?


Who was Isaac Newton? What did Isaac Newton do? Information on Isaac Newton life story, biography, works and contrubitions to science.

Isaac Newton; English mathematician : b. Woolsthorpe near Grantham, Lincolnshire, England, Dec. 25, 1642; d. Kensington, March 20, 1727. His father, Isaac, was a farmer who died a few months before he was born, and his mother, Hannah Ayscough Newton, remarried when he was three years old and left him in the care of his grandmother. He attended two village schools and in 1654 was sent to the grammar school at Grantham where after an indifferent start he distinguished himself as a leader.


At the age of 14 years he was removed from school to work on his mother’s farm, but he proved ill fitted for farming and, upon the advice of his old master, was sent back to school in 1660 in preparation for college, and was enrolled at Trinity College, Cambridge University, in 1661. His tutor was the celebrated Dr. Isaac Barrow who became Lucasian professor of mathematics at Cambridge in 1663. Newton, the shy but actively minded lad with a talent for mechanical invention, found an able teacher and fast friend in Barrow, and within two years showed his genius for mathematics.

Who Is Isaac Newton? What did Isaac Newton do?

Before graduating in 1665 and while at home in 1666 from college on account of the plague, he made two fundamental discoveries which have transformed mathematical science: (1) that of the differential calculus which he shared with Barrow; and (2) that of expansions into infinite series. Newton called (1) “the direct and inverse method of fluxions”; under (2) are comprised the binomial theorem, interpolation, and the calculus of finite differences. All were founded on the homeliest arithmetical devices; he took the common things and made them universal.

The fall of an apple, so goes the story related by Voltaire, led Newton to ponder on the nature of gravity and to reflect that what affected the apple might also affect the moon.

If the moon were held to an orbit round the earth by the pull of gravity, then, he surmised, the same would be true of the planets in their orbits round the sun. By enlisting Kepler’s periodic laws of planetary motion, he explained the pull of the sun upon the planet, supposing the force to vary inversely as the square of the distance.

This he checked for the case of the earth and the moon, a calculation that required as part of the data the exact distance from the surface to the center of the earth. As Newton was at the time absent from books, he took a current estimate of 60 miles to one degree of latitude, which was in error and brought out a resulting force greater by one sixth than was allowed by the observed facts. He concluded with characteristic caution that some other cause, perhaps the Cartesian vortices, might be latent, and put the matter aside until about 1685.

In 1667 he returned to Cambridge as a fellow of Trinity College. In 1668 Nicolaus Mercator published his Logarithmotechnia in which he obtained an infinite series as a formula for the area of a hyperbola by an algebraic generalization of arithmetic, which was one of the main secrets of Newton’s method. Barrow showed the work to Newton, who immediately gave him his own manuscript including this result and much else, the De analysi per aequationes numero terminorum infinitas, but did not publish it entire until 1711. In 1669 Newton succeeded Barrow in the Lucasian chair and began to lecture upon optics. These lectures were eventually published in 1728.

He had already discovered and named the spectrum, demonstrating that white light is composed of colored lights, each different color having its own index of refrangibility in a transparent medium. This fundamental discovery made with the aid of glass prisms intercepting a sunbeam in a darkened room directly affects the most recent physical investigations.

Within a year it also led Newton to perfecting the telescope.

Thinking erroneously that his discovery implied that chromatic aberration was irremovable from the finest lens, he invented in 1668 a reflecting telescope only six inches long and of surprising power, which he said was “an epitome of what may be done according to this way” (the 200-inch reflector at the Mount Palomar Observatory in California is its direct descendant). In 1672,Newton was elected a fellow of the Royal Society whither he had sent a replica of the telescope, having lost his original model.

This replica with its accompanying description and an account of the spectrum brought the genius of Newton to the notice of such eminent men as Sir Christopher Wren, Robert Hooke, Christian Huygens, and James Gregory. It led to a friendly rivalry between Newton and Gregory, the Scot, who had already in 1663 invented but failed to get made a reflecting telescope and who also discovered the calculus, prompted by Barrow (1670), and the binomial theorem.


But with Hooke and Huygens it led to controversy. Hooke, a great experimenter, on being invited to report on Newton’s work, claimed prior invention in 1664 of a “pocket tube” one inch long, and instead of discussing the facts of the spectrum as presented by the experiments of Newton, he examined them merely in relation to his own wave theory of light.

Newton sought to remove the misapprehension, but when lesser men inimical to Hooke magnified it, he shrank from publicity and withheld all the work which was virtually complete by 1675 until his Optiks appeared in 1704, one year after Hooke’s death. Newton’s theory has many likenesses to present-day theory—the coexisting waves and particles of light, the super-velocity of the phase wave, the phenomena of interference ; and he even measured the quantity that is now called a wave-length. But to call his theory corpuscular in contrast to Huygens’ undulatory theory is to oversimplify; Newton supplied all the elements of a wave theory but just failed to weld them together.

In 1679 his mother died, and for several months he was occupied with family affairs.

During the following winter he discovered a mathematical proof that according to his law of the inverse square a planet describes an ellipse about the sun as focus.

Meantime Hooke had independently become convinced of the same law of the inverse square but could not prove it. It was the astronomer Edmund Halley who consulted Newton in 1684 and, finding that Newton had a proof, persuaded him to publish it. This led to his grandest work, the Philosophiae naturalis principia mathematica. It is founded upon his three laws of motion: (1) every body continues in its state of rest or of uniform motion in a straight line, unless it is compelled to change that state by forces impressed on it; (2) change of motion is proportional to, and in the direction of the straight line of, the motive force impressed; (3) to every action there is always opposed an equal reaction.

On postulating further, universal gravitation by an inverse square law of force acting mutually between each particle of mass he accounted for the planetary motions. Upon hearing that Hooke claimed partial credit for the gravitational law, Newton nearly suppressed the third book of the Principia which is the crown of the work and contains the celestial mechanics; but Halley, who even undertook to see the whole printed at his own charge, persuaded Newton not to mutilate the work. It appeared in 1687: a composition that has changed the face of science. Newton’s teachings were introduced by David Gregory, his first disciple, at Edinburgh about 1690; within 15 years they superseded the Cartesian theory at Cambridge and Oxford, but were not accepted by French scientists for half a century.

From 1687 on, Newton took a more active part in public affairs. In that year he was one of the delegates sent by the University of Cambridge to maintain its rights before the High Commission Court when they were attacked by James II. Newton declared, “An honest courage in these matters will secure all, having law on our sides,” but the delegates were dismissed without attaining their objectives.

An outgrowth of his participation in the case was his election as a member of Parliament for the university in 1689.

In 1693 he suffered a long nervous illness and recovered. The following year he corresponded with the astronomer John Flamsteed about the moon’s motion. In 1696 he changed his whole mode of life by accepting a position as warden of the mint, from which office he advanced to the chief post of master in 1699 and rendered essential service at an epoch when a general recoinage was undertaken.

Although elected again to Parliament in 1701, he never played a prominent part in politics. In 1703 he was elected president of the Royal Society, and was annually re-elected for 25 years. He was knighted by Queen Anne in 1705. His latter years were embittered by two great scientific controversies : from 1705 to 1712 he was involved in an astronomical controversy with John Flamsteed, and from 1705 to 1724 with Leibniz over priority in the discovery of the calculus.

For long periods he was indifferent to science, but he never lost his powers. Problems set by Johann Bernoulli in 1696 and by Leibniz in 1716 to challenge “the acutest mathematicians in the world” were solved by Newton in a few hours. The genius of Newton has received tribute from all his great successors, from Joseph Lagrange to Albert Einstein. The integrity of his search for truth remains an inspiring legacy. He was buried in Westminster Abbey and his statue, by the French sculptor Louis François Roubillac, stands in the chapel of Trinity College. Among his later mathematical works were his Arithmetica universalis (1707) and the Enumeratio linearum tertii ordinis et methodus differentialis (1711) ; his theological works include Chronology of Ancient Kingdoms Amended (1728) and Observations upon the Prophecies of Daniel, and the Apocalypse of St. John (1733). He left quantities of unpublished work on mathematics, alchemy, chemistry, and theology.


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