Isaac Newton

Sir Isaac Newton (Woolsthorpe 1642 - London 1727) is one of the giants in the history of science. He laid the foundations of differential and integral calculus and classical mechanics—often referred to as "Newtonian mechanics". His name became a byword for genius and the use of mathematical models to explain the entire universe.

Life

Newton was born on Christmas day December 25, 1642--the year Galileo died--in Woolsthorpe, Lincolnshire; his father died before his birth. The Newtons were a well-to-do, upwardly mobile family, but never had a prominent member. When he was a little more than two years old, his mother Hannah (1610–1679), remarried, and his upbringing was taken over by his maternal grandmother. He began his schooling in neighboring villages, and, at ten, was sent to the grammar school at Grantham, the nearest town of any size. He boarded during terms at the house of an apothecary from whom he may have derived his lifelong interest in chemistry. The young Newton seems to have been a quiet, not particularly bookish, lad, but very ready with his hands; he made sun dials, model windmills, a water clock, a mechanical carriage, and flew kites with lanterns attached to their tails.

In 1656, Newton's mother, on the death of her second husband, returned to Woolsthorpe and took her son out of school with the idea of making him a farmer. He hated farming. His mother, after considerable persuasion by his teacher at Grantham, who had recognized his intellectual gifts, allowed him to prepare for entrance to Cambridge University. In June 1661, he was admitted to prestigious Trinity College as a lowly "sub-sizar" (a student required to do work-study). The main curriculum was the study of Aristotle, but early in 1664, as Newton's notebooks indicate, he began an intensive self-study of geometry, Copernican astronomy and optics. On his own he read Descartes, Pierre Gassendi, Galileo, Robert Boyle, Thomas Hobbes, Kenelm Digby, Joseph Glanville, and Henry More. He was a loner with only one friend, but he was stimulated by the distinguished mathematician and theologian Isaac Barrow, Lucasian Professor of Mathematics, who recognized Newton's genius and did all he could to foster it. Newton took his bachelor's degree in January 1665.

Later in life Newton became master of the Mint, and received in 1705 a knighthood because of his valuable work on the English money reform.

annus mirabilis

The year 1666 is known as Newton's annus mirabilis (miraculous year), about twenty-four years of age. He latter recalled, "At this time I was in the prime of my age for invention, and minded mathematics and philosophy more than at any time since." (By "philosophy" he meant physics.)

Optics

While waiting out the plague he began to investigate the nature of light. White light, according to the prevailing theories, was homogeneous. His first experiments with a prism provided the true explanation of color. Passing a beam of sunlight through a prism, he observed that the beam spread out into a colored band of light (spectrum). While others had undoubtedly performed similar experiments, it was Newton who showed that the differences in color were caused by differing degrees of refrangibility. A ray of violet light, for example, when passed through a refracting medium, was refracted through a greater angle than a ray of red light. His conclusions, checked by ingenious experiments, were that sunlight was a combination of all the colors and that the colors themselves were monochromatic (his term was "homogeneal"), and separated merely because they were of differing refrangibility.

Gravity

see gravitation

Newton had already made great progress in his devising "method of fluxions" (the infinitesimal calculus). An outbreak of plague at the time caused a general exodus from the university, and Newton fled to Woolsthorpe, where he remained for nearly two years. It was during this time that he recorded his first thoughts on gravitation, to which he is said to have been led by observing the fall of an apple in an orchard. According to a report of a conversation with Newton in his old age, he said he was trying at that time to determine what type of force could hold the moon in its path. The fall of the apple led him to think that it might be the same gravitational force, suitably diminished by distance, that had acted on the apple. Thereby he discovered the law of gravitation (attraction is proportional with inverse distance squared). He verified his conjecture approximately by a numerical calculation. He did not, at the time, pursue the matter, because the problem of calculating the combined attraction of the whole earth on a small body near its surface was obviously one of great difficulty. It seems that he associated the fall of the apple with the motion of the moon. The same year he discovered the rudiments of differential and integral calculus.

Newton struggled with how to conceptualize gravity. He had early rejected Descartes's vortex account of the cause of the motion of the planets. Descartes had argued that forces were transmitted through contact and that this required that matter be continuous and that hence there could be no vacuums. As early as 1665 Newton attempted to find a physical explanation of the cause of gravity but never found a suitable answer. As Newton said later in his Principia, "I have not as yet been able to deduce from phenomena the reason for these properties of gravity, and I do not feign hypotheses. For whatever is not deduced from the phenomena must be called hypothesis; and hypotheses, whether metaphysical or physical, or based on occult qualities, or mechanical, have no place in experimental philosophy". Thus Newton offers no explanation of gravity but shows through his mathematics that it "acts" in accordance to the mathematical laws he offers us in the Principia. This was a difficult approach for his contemporaries to accept. Robert Hooke, in particular, saw experimentation as the heart of science and disapproved of Newton's focus on theory and mathematics.

Three laws

see Classical mechanics

Later in life, as a holder of the Cambridge Lucasian chair of mathematics, Newton worked out his initial ideas into a set of mechanical laws, with his second and most important law: Force is mass times acceleration ($\scriptstyle F=ma~$). Newton was the first to understand the concept of inertial forces, notably the centrifugal force, although Christian Huyghens was close to understanding this effect. In 1684 Newton proved that Kepler's laws follow from his own second law in conjunction with his gravitational law. This proof completed the astronomical revolution initiated by Copernicus.

Principia Mathematica

Newton avoided publishing his results, preferring to communicate them to close colleagues. It took Edmond Halley great efforts to convince Newton to write his opus magnum Philosophiae Naturalis Principia Mathematica (written in Latin, it was called the Principia) that appeared in 1687, a work on [Classical mechanics|mechanics]], not on calculus. Although Newton had communicated his discoveries in the calculus privately, he had not published anything formal about it, until finally in 1704 he published Opticks. In the meantime the German mathematician Gottfried Wilhelm Leibniz had developed his own very similar version of the calculus. Although he acknowledged that Newton was earlier, a nasty priority conflict broke out in the 1710s. Newton and his (mainly English) followers accused Leibniz of plagiarism. The modern view is that both mathematicians discovered the calculus independently.

Newtonianism

Feingold (2004) explains the rapid dissemination of Newton's science came first via the members of the Royal Society, both British and Continental. The scientists, mathematicians, and philosophers of Germany, Holland, France, and Italy read the editions of the Principia and the Opticks and taugfht the ideas to their students. Newton's work was widely accepted, except in Italy, where the Catholic Church, having silenced Galileo, tried as well to suppress Newton's ideas. Despite the importance of Descartes to the French, Newton carried the day in France. Voltaire in particular made Newton the great hero of the modern world of ideas. Voltaire's Elemens de la philosophie de Neuton, (1737), was a success that rendered Newton intelligible and his work accessible, to the nonspecialist and amateurs who flourished in the Enlightenment. In Germany Leibniz praised Newton's Principia, but was uncomfortable with Newton's position regarding gravity. It was philosophically untenable to merely dismiss the problem of its cause. Leibniz and Newton became enemies over the issue of the credit for inventing the calculus. French scientists, especially Laplace (1749-1827]] developed and systemized ideas into modern form in the late 18th century. Newton's science dominated science and educated though throughout the 18th century, being seen as the highest achievement of pure reason and classical culture. In the 19th century, however, Romantic scientists went in entirely new directions, exploring non-Newtonian topics in electricity and magnetism and thermodynamics.

Bibliography

• Bardi, Jason Socrates. The Calculus Wars: Newton, Leibniz, and the Greatest Mathematical Clash of All Time. (2006). 277 pp. excerpt and text search
• Bechler, Zev. Newton's Physics and the Conceptual Structure of the Scientific Revolution. (1991). 588 pp.
• Berlinski, David. Newton's Gift: How Sir Isaac Newton Unlocked the System of the World. (2000). 256 pp. excerpt and text search
• Buchwald, Jed Z. and Cohen, I. Bernard, eds. Isaac Newton's Natural Philosophy. MIT Press, 2001. 354 pp. excerpt and text search
• Christianson, Gale E. Isaac Newton and the Scientific Revolution. Oxford U. Press, 1996. 160 pp. excerpt and text search
• Christianson, Gale E. In the Presence of the Creator: Isaac Newton and His Times. (1984). 608 pp.
• Cohen, I. Bernard and Smith, George E., ed. The Cambridge Companion to Newton. (2002). 500 pp. focuses on philosophical issues only; excerpt and text search; complete edition online
• Cohen, I. Bernard. The Newtonian Revolution with Illustrations of the Transformation of Scientific Ideas. Cambridge U. Press, 1981. 404 pp. excerpt and text search
• DeGandt, François. Force and Geometry in Newton's Principia. Princeton U. Press, 1995. 296 pp.
• Dobbs, Betty Jo Teeter. The Janus Faces of Genius: The Role of Alchemy in Newton's Thought. Cambridge U. Press, 1991. 359 pp.
• Fara, Patricia. Newton: The Making of a Genius. Columbia U. Press, 2003. 347 pp excerpt and text search
• Fauvel, John et al., ed. Let Newton Be! Oxford U. Press, (1989). 272 pp.
• Feingold, Mordechai. The Newtonian Moment: Isaac Newton and the Making of Modern Culture. (2004) 218 pp. catalog of exhibit at New York Public Library, 2004-5
• Force, James E. and Hutton, Sarah, ed. Newton and Newtonianism: New Studies. (2004). 246 pp. excerpt and text search
• Gjertsen, Derek. The Newton Handbook. (1987). 665 pp.
• Gleick, James. Isaac Newton.(2003). 272 pp.
• Hall, A. Rupert. All Was Light: An Introduction to Newton's Opticks. Oxford U. Press, 1993. 252 pp.
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• Hofmann, Joseph Ehrenfried. Classical Mathematics: A Concise History of the Classical Era in Mathematics. (1959) online edition
• Hoskin, Michael. "Newton and Newtonianism" pp 130-67 in Hoskin, ed. The Cambridge Concise History of Astronomy (1999) excerpt and text search
• Kline, Morris. Mathematical Thought from Ancient to Modern Times. Volume: 1. (1972).
• Mandelbrote, Scott. Footprints of the Lion: Isaac Newton at Work. Cambridge U. Press, (2001). 142 pp
• Olby, R.c. et al. Companion to the History of Modern Science. (1990) online edition, on the history of Newtonianism
• Park, Katharine, and Lorraine Daston, eds. The Cambridge History of Science, Volume 3: Early Modern Science (2006) excerpt and text search
• Rankin, William. Introducing Newton (3rd ed. 2007) excerpt and text search
• Sepper, Dennis L. Newton's Optical Writings: A Guided Study. Rutgers U. Press, 1994. 224 pp. excerpt and text search
• Shapiro, Alan E. Fits, Passions, and Paroxysms: Physics, Method, and Chemistry and Newton's Theories of Colored Bodies and Fits of Easy Reflection. Cambridge U. Press, (1993). 400 pp.
• Thrower, Norman J. W., ed. Standing on the Shoulders of Giants: A Longer View of Newton and Halley: Essays Commemorating the Tercentenary of Newton's Principia and the 1985-1986 Return of Comet Halley. U. of California Press, 1990. 429 pp.
• Westfall, Richard S. Never at Rest: A Biography of Isaac Newton. 2 vol. Cambridge U. Press, 1981. 895 pp. the major scholarly biography excerpt and text search
  • Westfall, Richard S. The Life of Isaac Newton. Cambridge U. Press, (1993). 328 pp., short version excerpt and text search
• Westfall, Richard S. "Newton, Sir Isaac (1642–1727)", Oxford Dictionary of National Biography (2004); online edition
• White, Michael. Isaac Newton: The Last Socerer. (1998). 416 pp. Newton as alchemist online edition

Primary sources

• Newton, Isaac. The Principia: Mathematical Principles of Natural Philosophy. U. of California Press, (1999). 974 pp.
• Newton, Isaac. The Optical Papers of Isaac Newton. Vol. 1: The Optical Lectures, 1670-1672. Cambridge U. Press, 1984. 627 pp.
• Newton, Isaac. The Mathematical Papers of Isaac Newton, 8 vols. (Cambridge University Press, 1967–81).
• Newton, Isaac. The correspondence of Isaac Newton, ed. H. W. Turnbull and others, 7 vols. (1959–77) ·

• Brackenridge, J. Bruce. The Key to Newton's Dynamics: The Kepler Problem and the Principia: Containing an English Translation of Sections 1, 2, and 3 of Book One from the First (1687) Edition of Newton's Mathematical Principles of Natural Philosophy. U. of California Press, 1996. 299 pp.
• Newton's Philosophy of Nature: Selections from His Writings edited by H. S. Thayer, (1953), online edition