Isaac Newton

By Lin Yue

He was born on Christmas Day 1642 — 1643 by the modern calendar — premature, tiny, in a Lincolnshire farmhouse, three months after his father's death; his mother would later say he could have fit into a quart mug. From that unpromising beginning came the single most powerful intellect in the history of science. Isaac Newton entered Cambridge in 1661, and when the plague closed the university in 1665 he retreated to Woolsthorpe for the annus mirabilis — the miraculous year — in which, by his own account, he laid the foundations of the calculus, discovered the composition of white light, and began thinking about gravity. He told no one for decades.

The calculus came first in private: the method of fluxions, worked out in the 1660s, kept in manuscript while he perfected it — the delay that would ignite the most poisonous priority dispute in scientific history with Leibniz. The optics came next in public: with a prism in a darkened room he showed white light is a mixture of colors, each refracted differently — the experimentum crucis — and built the first reflecting telescope. Elected to the Royal Society at twenty-nine, he published little and feuded much, withdrawing the Opticks for thirty years after Hooke's criticisms.

Then, in 1684, Edmond Halley asked him what orbit a planet would follow under an inverse-square attraction, and Newton answered instantly: an ellipse. Halley gasped — and badgered, funded, and cajoled the reluctant genius into writing the Philosophiae Naturalis Principia Mathematica, published in 1687: three books deriving Kepler's laws, the tides, the comets, and the fall of an apple from a single universal gravitation. It is the greatest book in the history of science — the moment physics became the science of everything.

The later Newton was Warden and then Master of the Mint — he prosecuted counterfeiters with zeal and recoinaged England's currency — president of the Royal Society, a secret heretic who denied the Trinity, and an obsessive alchemist who wrote more about theology and transmutation than about physics. He died in 1727, a national monument, buried in Westminster Abbey. He had, as he put it, stood on the shoulders of giants — and then become the shoulders everyone else stood on.

Impact on civilization

Newton's Principia created modern physics: universal gravitation united the fall of an apple with the orbit of the moon, proving heaven and earth obey the same laws — the most profound unification in scientific history. The calculus (with Leibniz) gave science its mathematical language; his optics founded the science of light and spectroscopy. His laws of motion governed engineering, astronomy, and spaceflight for three centuries until Einstein, and remain the working physics of the everyday world. More than any individual, Newton established the ideal of science itself: precise mathematics, tested against nature, describing everything.