🇬🇧Isaac
Newton

Isaac Newton was born prematurely on January 4, 1643, in Woolsthorpe-by-Colsterworth in Lincolnshire, England — small enough, according to family legend, that he could have fit inside a quart pot. His father, a prosperous but illiterate farmer, had died three months before his birth. His mother remarried when Isaac was three, leaving him to be raised by his grandmother. The psychological mark of this abandonment was lifelong: Newton was a solitary, prickly, suspicious man who developed virtually no warm friendships and pursued scientific priority disputes with a ferocity that unnerved even his admirers. He channeled almost everything into thought. He was, by any measure, the most productive intellect in the history of science.

At school in Grantham, Newton showed more interest in building mechanical models — sundials, windmills, water clocks — than in his lessons, but his performance was sufficient to earn him a place at Trinity College, Cambridge, in 1661. He was eighteen. Cambridge was still formally committed to Aristotelian natural philosophy, but Newton taught himself, largely from books he purchased with his own money, the mathematics of Descartes, the physics of Galileo, and the astronomy of Kepler. He discovered that the work currently being done in mathematics and physics was riddled with gaps and unsolved problems. He began, methodically, to solve them.

In 1665, Cambridge closed due to plague. Newton retreated to Woolsthorpe, his family's farm, for approximately two years. During this forced isolation — he was twenty-two when it began and twenty-four when it ended — he invented the differential and integral calculus, formulated the law of universal gravitation, conducted the prism experiments that revealed white light is composed of all colors, and worked out the early foundations of what would become his theory of mechanics. He later described this period as his most creative. He published almost none of it at the time. He kept it largely to himself.

His calculus — which he called the "method of fluxions" — was a systematic way of calculating rates of change and accumulated totals, allowing for the first time a precise mathematical treatment of motion, curves, and physical processes that vary continuously. Gottfried Wilhelm Leibniz independently developed an equivalent method in the 1670s, and the resulting priority dispute — prosecuted with ferocious bitterness by Newton — poisoned European mathematics for a generation. Newton's version is, in retrospect, somewhat clumsier in notation than Leibniz's, but the underlying mathematics is the same calculus that engineers and physicists use today.

Newton returned to Cambridge and in 1669, at twenty-six, was appointed Lucasian Professor of Mathematics — the chair that Hawking would hold three centuries later. In 1687, after being prodded by the astronomer Edmond Halley, he published the Philosophiæ Naturalis Principia Mathematica — almost universally regarded as the greatest single scientific work ever published. In it, Newton stated the three laws of motion (every body remains in uniform motion unless acted upon by a force; force equals mass times acceleration; for every action there is an equal and opposite reaction), derived Kepler's laws of planetary motion from first principles, explained the tides as a consequence of gravitational attraction between the Earth, Moon, and Sun, and predicted the shape of the Earth as an oblate spheroid. He solved, in a single book, problems that the combined scientific output of Europe had been unable to touch for a century.

His optical work, summarized in "Opticks" (1704), demonstrated through careful prism experiments that white light is not pure but a mixture of all colors, and introduced the reflecting telescope, which he built himself, bypassing the chromatic aberration that afflicted all refracting telescopes of the era. In the 1690s, Newton largely abandoned active research. He moved to London, became Master of the Royal Mint, where he managed a major recoinage of England's debased silver currency with the same systematic rigor he had applied to the planets, and tracked down and prosecuted counterfeiters with personal relish. He was elected president of the Royal Society in 1703 and knighted by Queen Anne in 1705. He died on March 31, 1727, at eighty-four, having never married, maintained few close relationships, and spent his final decades writing more on biblical prophecy and alchemy than on physics. He was buried in Westminster Abbey. Voltaire attended his funeral and returned to France to write the essays on Newton's philosophy that sparked the French Enlightenment.