Sir Isaac Newton biography

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Isaac Newton Biography

NEWTON, Sir Isaac (1642–1727). A famous English mathematician and natural philosopher, born at Woolsthorpe in Lincolnshire, Dec. 25, 1642 (O. S.). Newton received his early education at the grammar school of Grantham, in the neighborhood of his home, at Woolsthorpe. On June 5, 1661, he left home for Cambridge, where he was admitted as subsizar at Trinity College. On July 8 following he matriculated as sizar of the same college. He immediately applied himself to mathematical studies and within a very few years not only made himself master of most of the works of value then existing, but had also begun to make some progress in original methods for extending the science. In the years 1665 and 1666 he made many important mathematical inventions and discoveries, including that of the binomial theorem, the method of tangents, the direct method of fluxions (integral calculus), and the action of gravity on the moon. According to a legend, which, however, is seriously considered by certain authorities, in the year 1665 the fall of an apple, as Newton sat in his garden at Woolsthorpe, suggested the most magnificent of his subsequent discoveries—the law of universal gravitation (q.v.). On his first attempt, however, to apply the law, to explain the lunar and planetary motions, he employed an estimate then in use of the radius of the earth which, based on the value of a degree of latitude then prevalent, was so erroneous as to produce a discrepancy between the value of the real force of gravity and that required by theory to explain the motions and indicated only an approximate verification of his theory. Further, he was unable at this time to show mathematically that a homogeneous attracting sphere behaved as if all the matter were concentrated at its centre. He accordingly abandoned for a number of years the hypothesis for other studies, which consisted chiefly of investigations of the nature of light and the construction of telescopes (q.v.). In 1666 he had acquired a prism and in 1668 completed his first reflecting telescope, with which he observed Jupiter's satellites. In a variety of ingenious and interesting experiments where a spectrum was produced by sunlight refracted through a prism in a darkened room, he was led to the conclusion that rays of light which differ in color differ also in refrangibility. This discovery enabled him to explain an imperfection of the telescope, which had not till then been accounted for. The indistinctness of the image formed by the object glass was not necessarily due to any imperfection of its form, but to the fact of the different colored rays of light being brought to a focus at different distances. He concluded rightly that it was impossible for an object glass consisting of a single lens to produce a distinct image. He went further, and too hastily concluding, from a single experiment, that the dispersive power of different substances was proportional to their refractive power, he pronounced it impossible to produce a perfect image by a combination of lenses. This conclusion—since proved erroneous by the invention of the achromatic telescope by Chester More Hall about 1729 and afterward, independently, by Dollond (q.v.) in 1758—turned Newton's attention to the construction of reflecting telescopes, and the form devised by him is the one which, at later periods, has proved so useful in astronomical researches.

It was on Jan. 11, 1672, that Newton was elected a member of the Royal Society, having become known to that body from his reflecting telescopes, and a month later his famous paper on a "New Theory about Light and Color" was read before that body, in which he states that "Light consists of rays differently refrangible" and that "Colors are not qualifications of light derived from refractions or natural bodies, as is generally believed, but original and connate properties which in divers rays are divers." He also said that "White light is ever compounded and to its composition are requisite all the aforesaid primary colors mixed in proper proportion." In 1675 Newton communicated to the Royal Society a paper on light and color, which contained an explanation of the production of colors by thin plates or films and in which were given the results of the first measurements of the colored rings now known as Newton's rings (q.v.). Newton formulated the emission theory of light from hypotheses previously advanced by Descartes, and a complete exposition of that theory was the result. All of Newton's investigations in light and color were collected into a work with the title of Opticks, published in 1704. The development of the theory was accomplished by rigid dynamical reasoning, and the explanations of reflection, refraction, diffraction, and the colors of thin plates were made on the basis that light was due to corpuscles sent out from the light-giving body. This theory, while it did not survive the work of Young and Fresnel, nevertheless had more points in common with the undulatory theory than is generally supposed (Opticks, book ii, part iii, prop. XII). At what period Newton resumed his calculations about gravitation does not clearly appear, but it was in the year 1684 that it became known to Halley that he was in possession of the whole theory and its demonstration. It was on the urgent solicitation of Halley that he was induced to commit to a systematic treatise these principles and their demonstrations, Halley undertaking to print it at his own expense. The principal results of his discoveries were set down in a treatise called De Motu Corporum and were afterward more completely unfolded in the great work entitled Philosophiœ Naturalis Principia Mathematica, which was finally published about midsummer 1687. In the Principia Newton formally introduced the ideas of mass and force and established the science of theoretical mechanics, as it exists today. In the entire history of science no single contribution of any man has been as important as this.

Shortly before the Principia was given to the public Newton, who since 1669 had occupied the Lucasian chair at Cambridge, was called to take an active part in defending the rights of the university against the illegal encroachments of James II. The conspicuous part which he had taken on that occasion procured him a seat in the Convention Parliament, in which he sat from January, 1689, to its dissolution in 1690. In 1696 he was appointed Warden of the Mint and in 1699 was promoted to the office of Master of the Mint, an office which he held till the end of his life. He again took seat in Parliament in the year 1701 as the representative of his university. In the interval of public duty, however, Newton showed that he still retained the scientific power by which his great discoveries had been made. He was president of the Royal Society from 1703 till his death, a period of 24 years, being each year reëlected. In this position and enjoying the confidence of Prince George of Denmark, he did much towards the advancement of science, and one of his most important works during this time was the superintendence of the publication of Flamsteed's Greenwich Observations. The controversy between Newton and Leibnitz as to priority of discovery of the differential calculus, or the method of fluxions, was raised rather through the partisanship of jealous friends than through the anxiety of the philosophers themselves, who were, however, induced to enter into and carry on the dispute with some degree of bitterness and mutual recrimination. Newton died on March 20, 1727 (O. S.), and his remains were interred in Westminster Abbey, where a monument was erected to his memory in 1731. A magnificent full-length statue of the philosopher, executed by Roubilliac, was erected in 1755 in the antechapel of Trinity College, Cambridge. This work was assisted by a cast of the face taken after death, which is preserved in the University Library at Cambridge. In 1699 Newton was elected a foreign associate of the Academy of Sciences, and in 1705 he received the honor of knighthood from Queen Anne. Among the best editions of Newton's principal works are the quarto edition of the Opticks (London, 1704) and the quarto edition of the Principia, published at Cambridge, England, in 1713.

The New International Encyclopaedia, Vol. XVII (New York: Dodd, Mead & Co., 1920) 64-65.