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Last Updated on May 7, 2015, by eNotes Editorial. Word Count: 1811

Isaac Newton was the most famous scientist of his generation. One of his major accomplishments was the application of the law of gravity to the motion of planets, the path of comets, and the influence of the moon on ocean tides. He also wrote a comprehensive book on optics which...

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Isaac Newton was the most famous scientist of his generation. One of his major accomplishments was the application of the law of gravity to the motion of planets, the path of comets, and the influence of the moon on ocean tides. He also wrote a comprehensive book on optics which corrected numerous earlier mistaken ideas about light. He developed the mathematics of differential and integral calculus. He carried out extensive chemical experiments and did biblical research on the concept of the Trinity but chose to keep these findings hidden from publication. After age fifty, he became politically active as a member of Parliament, was appointed by King James I to oversee the coinage of money, was knighted by Queen Anne in 1705, and became president of the Royal Society for some twenty years. At his death, he received a state funeral and was entombed at Westminster Abbey.

James Gleick quotes a memorable statement attributed to Newton after he had become famous: “I don’t know what I may seem to the world, but, as to myself, I seem to have been only like a boy playing on the sea-shore, 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.” Such an expression of modesty from a man of tremendous accomplishments and the recipient of the highest honors is remarkable. In this biography, however, Gleick gives a more human portrait of Newton, showing him sometimes involved in petty quarrels with fellow scientists, embellishing his own reputation, and reluctant to admit errors in his work.

Isaac Newton was born in 1642 at Woolsthorpe, a small village some hundred miles north of London. His father died shortly before he was born, and his mother remarried soon after, leaving the young child to be raised by his grandmother. During his youth, England was torn by a civil war, the so-called Great Rebellion, with roaming bands of mercenary troops plundering the countryside for supplies. The monarchy eventually was reestablished after the death of Oliver Cromwell in 1658. Newton learned to read and write at a country school. At home he built a sundial that was precise enough to tell the time of day to within fifteen minutes.

From ages ten to sixteen Newton attended school at Grantham, about eight miles from home, where he lived in the house of the local apothecary as a boarder. He is portrayed as a curious child, building a scale model of a water-powered mill that allowed him to study how gears, levers, and pulley wheels worked. A small notebook kept by Newton at this age has survived to modern times, showing his developing interests: geometrical figures, a water clock, kite flying, Latin phrases, and a word list of more than two thousand nouns. Gleick quotes numerous primary and secondary sources of biographical information about Newton in sixty pages of endnotes.

At age sixteen, Newton was called home by his mother to manage the land and tend to the farm animals. He was negligent in his duties, however, preferring to read books while fences went unrepaired and animals got out to a neighbor’s land. His Grantham schoolmaster intervened to get him admitted to Cambridge University in June of 1661. There he was introduced to Aristotle’s classical worldview but also heard about the theoretical possibility that the earth moves in an orbit around the Sun. Newton began keeping a notebook with questions about many topics: How can a cannonball continue to move in flight when nothing is pushing it; what causes the ocean tides; does matter fill all space or can there be a vacuum; what is light and how does it travel through space? He was not satisfied with traditional answers to such questions. Aristotle had justified disagreements with his teacher by saying, “Plato is my friend, but truth is my greater friend.” Newton wrote this same aphorism into his notebook but substituted Aristotle for Plato. In his third year at Cambridge, Newton came under the influence of Isaac Barrow, a newly appointed professor of mathematics. He attended Barrow’s lectures on Euclidian geometry and was introduced to algebraic equations. In his private notebook Newton set mathematical problems for himself such as finding the tangent to a curved line, a familiar type of problem assigned in a modern calculus course.

In 1665, when Newton was twenty-three and in his fourth year of study at Cambridge, an outbreak of plague started in London. It became an epidemic that eventually killed one-sixth of the population. Cambridge University had to shut down, and Newton returned to his home at Woolsthorpe. For the next twenty months he worked essentially by himself on the many unanswered questions that had intrigued him, recording his speculations and calculations in a series of handwritten notebooks. It was an incredibly creative period which has been called Newton’s annus mirabilis.

Gleick gives an overview of what the notebooks contain. For example, simple geometric formulas were well known to calculate the area of a rectangle or a circle, but Newton wanted to figure out how to find the area under a hyperbola or other curved line. He developed a method of summing up a large number of infinitesimally small pieces of the area, a procedure which is now called integral calculus. Newton drew diagrams of apparatuses to make quantitative measurements in mechanics, fluid dynamics, and optics. He designed and built a new type of telescope using a curved reflecting mirror. He speculated that the force of gravity that makes an apple fall to Earth might be what holds the moon in its orbit, but this force would have to diminish inversely with the square of the distance from Earth. He struggled with the whole concept of force, trying to define it so it could be measured quantitatively. In 1666 he performed a crucial experiment in optics, first using a prism to break up light from the sun into its colors (which was well known) but then using a second prism to recombine the colors back into white (which was his unique contribution). This experiment went against the then common (but incorrect) idea that a prism adds color to the white light. In all these investigations, Newton worked in isolation and kept the results to himself.

Newton returned to Cambridge in 1667, when the university reopened. Two years later he was elected to the post of professor of mathematics, replacing his former teacher, who had resigned. Meanwhile in London, a group of learned men had formed the Royal Society, dedicated to discussions of philosophy and new scientific knowledge. In 1672 the secretary of the Royal Society invited Newton to become a member and to submit a description of his improved type of telescope. Newton complied with the request. When his letter was read at one of the weekly meetings, Robert Hooke, who was curator of experiments for the society, claimed that he himself had invented the reflector telescope before Newton thought of it. This was the start of a lengthy antagonism between the two men. Gleick quotes extensively from the unpleasant arguments that these two had on various scientific questions. To avoid controversy, Newton withdrew from the Royal Society in 1675 and did not rejoin until after Hooke’s death in 1703.

In the 1680’s Newton was encouraged by Edmond Halley, the English astronomer, to publish his ideas about gravity and the general laws of motion. This became the famous Principia, which was printed at Halley’s expense in 1687. Nicolaus Copernicus, a Polish astronomer, had speculated in 1543 that the earth might be in motion around the Sun, and Johannes Kepler in Germany later had shown that these planetary orbits were elliptical rather than circular. In 1609 the Italian scientist Galileo Galilei first observed the moons of Jupiter in his telescope, showing planetary motion around a planet. It remained for Newton to provide the mathematical framework to explain how gravitational attraction between two objects, acting through empty space, could cause the observed motions.

There are two topics which Newton worked on extensively but kept hidden in his private notebooks: alchemy and theology. Alchemists used secret chemical recipes to produce magic potions or to convert one element into another. Gleick points out that as astrology evolved into the science of astronomy, so alchemy eventually evolved into chemistry. The existence of Newton’s theological writings was generally unknown until the 1930’s, when John Maynard Keynes, the English economist, purchased some Newton documents from private collectors who had inherited them with their family estates. According to these documents, Newton rejected the idea of the Trinity of Father, Son, and Holy Ghost, based on his study of ancient Greek and Latin biblical texts. He believed in God but regarded Jesus to be descended from God, not coequal with him. It would have been dangerous to express this idea publicly because he would have lost his faculty position at Cambridge and probably would have been put on trial for heresy. Newton produced thousands of handwritten pages on theology but kept them to himself.

In the 1690’s England was approaching a crisis of confidence in its coinage. Many coins in circulation were counterfeit, while silver coins frequently had less than their full weight after illegal trimming. A completely new set of coins was proposed, and Newton was appointed to be in charge of the minting process. He left Cambridge in 1696 and moved to London to take up this responsibility. It may seem like an unlikely career change from professor of mathematics to warden of the mint, but Newton diligently fulfilled his new duties for more than twenty-five years. While living in London, he rejoined the Royal Society, presided at its meetings, suggested experimental demonstrations, and published his book on optics, based on work he had done at Woolsthorpe forty years earlier. He got into a dispute with the German mathematician Gottfried Leibniz, who claimed to have invented the mathematical technique of “fluxions” (as in calculus) prior to Newton. Gleick points out that Newton had the idea somewhat earlier but did not publish it, while Leibniz did.

Gleick is widely known from his other books for writing in a conversational style that appeals to a nonspecialist readership. This biography of Newton, less than two hundred pages in length, is an enjoyable popularization. It has sixty pages of end notes with numerous quotations, so it is also a scholarly, academic work. Gleick’s main thesis is to show that Newton influenced people to think scientifically, to realize that nature follows definite rules, and that this orderliness can be understood by experiments and mathematical calculations.

Review Sources

Booklist 99, no. 17 (May 1, 2003): 1561.

The Economist 368, no. 8338 (August 23, 2003): 68.

Kirkus Reviews 71, no. 7 (April 1, 2003): 520-521.

Library Journal 128, no. 15 (September 15, 2003): 107.

New Scientist 179, no. 2404 (July 19, 2003): 50.

The New York Times, July 14, 2003, p. E6.

The New York Times Book Review, June 15, 2003, p. 22.

Publishers Weekly 250, no. 13 (March 31, 2003): 53.

The Wall Street Journal, June 24, 2003, p. D8.

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