Table of Contents

# Isaac Newton

- Born:
- January 4, 1643 England

- Died:
- March 31, 1727 (aged 84) London England

- Notable Works:
- “Opticks” “The Mathematical Principles of Natural Philosophy” “The Method of Fluxions and Infinite Series”

- Subjects Of Study:
- Newtonian reflector Newton’s rings inverse-square law reflection white light

- Role In:
- Scientific Revolution

**Isaac Newton**, in full **Sir Isaac Newton**, (born December 25, 1642 , Woolsthorpe, Lincolnshire, England—died March 20 , 1727, London), English physicist and mathematician, who was the culminating figure of the Scientific Revolution of the 17th century In optics, his discovery of the composition of white light integrated the phenomena of colours into the science of light and laid the foundation for modern physical optics In mechanics, his three laws of motion, the basic principles of modern physics, resulted in the formulation of the law of universal gravitation In mathematics, he was the original discoverer of the infinitesimal calculus Newton’s (, 1687) was one of the most important single works in the history of modern science

## Formative influences

Born in the hamlet of Woolsthorpe, Newton was the only son of a local yeoman, also Isaac Newton, who had died three months before, and of Hannah Ayscough That same year, at Arcetri near Florence, Galileo Galilei had died; Newton would eventually pick up his idea of a mathematical science of motion and bring his work to full fruition A tiny and weak baby, Newton was not expected to survive his first day of life, much less 84 years Deprived of a father before birth, he soon lost his mother as well, for within two years she married a second time; her husband, the well-to-do minister Barnabas Smith, left young Isaac with his grandmother and moved to a neighbouring village to raise a son and two daughters For nine years, until the death of Barnabas Smith in 1653, Isaac was effectively separated from his mother, and his pronounced psychotic tendencies have been ascribed to this traumatic event That he hated his stepfather we may be sure When he examined the state of his soul in 1662 and compiled a catalog of sins in shorthand, he remembered “Threatning my father and mother Smith to burne them and the house over them” The acute sense of insecurity that rendered him obsessively anxious when his work was published and irrationally violent when he defended it accompanied Newton throughout his life and can plausibly be traced to his early years

After his mother was widowed a second time, she determined that her first-born son should manage her now considerable property It quickly became apparent, however, that this would be a disaster, both for the estate and for Newton He could not bring himself to concentrate on rural affairs—set to watch the cattle, he would curl up under a tree with a book Fortunately, the mistake was recognized, and Newton was sent back to the grammar school in Grantham, where he had already studied, to prepare for the university As with many of the leading scientists of the age, he left behind in Grantham anecdotes about his mechanical ability and his skill in building models of machines, such as clocks and windmills At the school he apparently gained a firm command of Latin but probably received no more than a smattering of arithmetic By June 1661 he was ready to matriculate at Trinity College, Cambridge, somewhat older than the other undergraduates because of his interrupted education

## Influence of the Scientific Revolution

When Newton arrived in Cambridge in 1661, the movement now known as the Scientific Revolution was well advanced, and many of the works basic to modern science had appeared Astronomers from Nicolaus Copernicus to Johannes Kepler had elaborated the heliocentric system of the universe Galileo had proposed the foundations of a new mechanics built on the principle of inertia Led by René Descartes, philosophers had begun to formulate a new conception of nature as an intricate, impersonal, and inert machine Yet as far as the universities of Europe, including Cambridge, were concerned, all this might well have never happened They continued to be the strongholds of outmoded Aristotelianism, which rested on a geocentric view of the universe and dealt with nature in qualitative rather than quantitative terms

Like thousands of other undergraduates, Newton began his higher education by immersing himself in Aristotle’s work Even though the new philosophy was not in the curriculum, it was in the air Some time during his undergraduate career, Newton discovered the works of the French natural philosopher Descartes and the other mechanical philosophers, who, in contrast to Aristotle, viewed physical reality as composed entirely of particles of matter in motion and who held that all the phenomena of nature result from their mechanical interaction A new set of notes, which he entitled “” (“Certain Philosophical Questions”), begun sometime in 1664, usurped the unused pages of a notebook intended for traditional scholastic exercises; under the title he entered the slogan “Amicus Plato amicus Aristoteles magis amica veritas” (“Plato is my friend, Aristotle is my friend, but my best friend is truth”) Newton’s scientific career had begun

The “Quaestiones” reveal that Newton had discovered the new conception of nature that provided the framework of the Scientific Revolution He had thoroughly mastered the works of Descartes and had also discovered that the French philosopher Pierre Gassendi had revived atomism, an alternative mechanical system to explain nature The “Quaestiones” also reveal that Newton already was inclined to find the latter a more attractive philosophy than Cartesian natural philosophy, which rejected the existence of ultimate indivisible particles The works of the 17th-century chemist Robert Boyle provided the foundation for Newton’s considerable work in chemistry Significantly, he had read Henry More, the Cambridge Platonist, and was thereby introduced to another intellectual world, the magical Hermetic tradition, which sought to explain natural phenomena in terms of alchemical and magical concepts The two traditions of natural philosophy, the mechanical and the Hermetic, antithetical though they appear, continued to influence his thought and in their tension supplied the fundamental theme of his scientific career

Although he did not record it in the “Quaestiones,” Newton had also begun his mathematical studies He again started with Descartes, from whose he branched out into the other literature of modern analysis with its application of algebraic techniques to problems of geometry He then reached back for the support of classical geometry Within little more than a year, he had mastered the literature; and, pursuing his own line of analysis, he began to move into new territory He discovered the binomial theorem, and he developed the calculus, a more powerful form of analysis that employs infinitesimal considerations in finding the slopes of curves and areas under curves

By 1669 Newton was ready to write a tract summarizing his progress, (“On Analysis by Infinite Series”), which circulated in manuscript through a limited circle and made his name known During the next two years he revised it as (“On the Methods of Series and Fluxions”) The word , Newton’s private rubric, indicates that the calculus had been born Despite the fact that only a handful of savants were even aware of Newton’s existence, he had arrived at the point where he had become the leading mathematician in Europe

## Work during the plague years

When Newton received the bachelor’s degree in April 1665, the most remarkable undergraduate career in the history of university education had passed unrecognized On his own, without formal guidance, he had sought out the new philosophy and the new mathematics and made them his own, but he had confined the progress of his studies to his notebooks Then, in 1665, the plague closed the university, and for most of the following two years he was forced to stay at his home, contemplating at leisure what he had learned During the plague years Newton laid the foundations of the calculus and extended an earlier insight into an essay, “Of Colours,” which contains most of the ideas elaborated in his It was during this time that he examined the elements of circular motion and, applying his analysis to the Moon and the planets, derived the inverse square relation that the radially directed force acting on a planet decreases with the square of its distance from the Sun—which was later crucial to the law of universal gravitation The world heard nothing of these discoveries