57 Fun Facts About Isaac Newton

The Royal Society couldn't fund Newton's Principia after overspending on a lavish book about what?

Fish: the Society had emptied its coffers on a lavishly illustrated history of fish that sold poorly, so Newton's masterpiece had to be paid for by a friend.

Newton shares credit for inventing calculus with which German mathematician?

Gottfried Wilhelm Leibniz reached calculus independently and published first, in 1684, while Newton sat on his earlier method; their priority fight soured the last decades of Newton's life.

Newton was born at a manor house in which county?

Lincolnshire: his father, a well-off man who could not sign his own name, died shortly before the boy was born.

According to the Julian calendar then used in England, Newton was born on which holiday in 1642?

Christmas Day 1642 on England's old calendar was already 4 January 1643 on the modern Gregorian one, which is why his birth year appears both ways.

Newton was so small at birth that his mother said he could have fit inside what?

A quart mug, by his mother's account, would have held him; he was so frail that nobody expected him to last the day, yet he lived into his eighties.

Newton's twice-widowed mother pulled him out of school in his teens to train him for which occupation?

Farmer was her plan, since he was to manage the family estate, but he neglected the work for his books until his uncle and his headmaster persuaded her to send him back to school.

As a schoolboy, Newton built a working model windmill and made which animal turn it as his 'miller'?

A mouse ran the mill from inside, and the boy joked that his 'mouse miller' was a thief who ate all the corn put in to be ground.

Which Cambridge college admitted Newton in June 1661?

Trinity was his uncle's old college; he arrived older than most of his classmates because his schooling had been interrupted, and stayed for more than thirty years.

Newton entered Cambridge as a 'subsizar', which meant he paid his way by doing what?

Performing valet duties for others earned his keep even though his mother was well off; a scholarship in 1664 ended the chores.

Why did Cambridge University close in 1665, sending Newton home for his 'golden years' of discovery?

The Great Plague kept him at home for most of two years, where he laid the foundations of calculus, his theory of colours and his law of gravitation.

Which physicist held Newton's old Lucasian chair at Cambridge from 1979 to 2009?

Stephen Hawking held the chair for thirty years; Newton kept the title for years after he had left Cambridge to work at the Mint in London.

Whom did Newton succeed as Lucasian Professor in 1669?

Isaac Barrow gave up the chair to devote himself to divinity and recommended Newton in his place, having already sent the young man's work to London as that of a genius.

What did Newton do, his assistant recalled, when no students came to hear him speak?

Gave a shortened lecture to the walls: so few came, and fewer understood, that he often read to an empty room, left early and went back to his experiments.

Newton built the first working reflecting telescope to sidestep which flaw of lens telescopes?

Chromatic aberration, the coloured fringing a lens adds, seemed incurable to him, so he used a mirror instead; he was wrong, as John Dollond's colour-corrected lenses later proved.

Newton named seven colours in the rainbow; which one did he place between blue and violet?

Indigo made seven: Newton first listed fewer colours, then stretched the count to match the seven notes of the musical scale.

Newton reported that his new reflecting telescope showed him the crescent phase of which planet?

Venus appeared with a 'Moon-like phase', he wrote, and the little instrument that showed it won him election to the Royal Society in 1672.

Newton ground the mirrors for his telescopes from a custom composition of what?

Speculum metal, a hard, brittle alloy of copper and tin, was used because it takes a bright polish; silvered glass, which later replaced it, had not yet been invented.

What name did Newton give to the multicoloured band of light that emerges from a prism?

Spectrum is Latin for 'appearance'; Newton borrowed the word for the band and showed that a lens and a second prism could merge its colours back into white light.

Newton's Opticks of 1704 first appeared in which language?

English came first, a break from the scholarly Latin of his Principia; a Latin translation did not follow until 1706.

In Opticks, Newton argued that light is fundamentally composed of what?

Particles, or 'corpuscles', were his answer, and that view reigned until the wave theory was revived in the nineteenth century.

The coloured pattern seen where a curved lens rests on flat glass is known as Newton's what?

Rings: studying them in Opticks, Newton found he could explain the pattern only by adding wave-like behaviour to his own theory of light.

Newton's first law of motion, that a body keeps its state unless something acts on it, is the law of what?

Inertia is the name; the idea that a moving body needs no push to keep going came from Galileo, and Newton made it the first law of his system.

Which astronomer encouraged and paid for the publication of the Principia?

Edmond Halley coaxed the book out of Newton and then paid for the printing himself, because the Royal Society's funds were exhausted.

Which term did Newton coin for the inward pull that keeps a planet in its orbit?

Centripetal force first appears in a nine-page tract of 1684, written to answer a visitor's question about orbits, that grew within three years into the Principia.

What is the literal meaning of 'gravitas', the Latin word Newton used for the effect we call gravity?

Weight, or heaviness, is the literal sense; by using one everyday word for falling stones and the orbiting Moon, Newton claimed that a single pull governs both.

Newton's 'hypotheses non fingo' answered critics who dismissed his gravity as what kind of quality?

Occult was the charge, because his gravity acted across empty space with no visible mechanism; Newton answered that he would describe it without guessing at its cause.

How long did Newton famously take to solve Johann Bernoulli's 1696 brachistochrone problem?

One night was enough: he came home tired from the Mint at four, solved it by four in the morning and sent it off unsigned, yet Bernoulli knew 'the lion by his claw'.

In 1693 the diarist Samuel Pepys asked Newton for advice on a probability problem involving what?

Throwing dice: Pepys asked which of three wagers was likeliest, and Newton showed that the simplest, at least one six from six dice, beat the bigger throws Pepys had favoured.

As a young man, Newton extended which theorem to fractional and negative powers?

Binomial expansions had been limited to whole-number powers; Newton's version turned roots and fractions into infinite series, which became a mainstay of his mathematics.

What name did Newton give to his own version of calculus?

The method of fluxions was finished in 1671, but Newton failed to get it printed and it reached the public only in 1736, nine years after his death.

Which king's attempt to Catholicise Cambridge University did Newton help to resist in 1687?

James II lost the fight and then his throne; in the aftermath the university chose Newton, a leader of its resistance, to sit in Parliament.

In a list of sins he wrote at nineteen, Newton confessed threatening to burn the house over his mother and whom?

His stepfather, the Reverend Barnabas Smith, had moved Newton's mother to another village on their marriage, leaving the small boy behind; the threat sits in a list of sins he wrote in shorthand.

In Newton's England, coining counterfeit money was classed as which crime?

High treason: forging the king's coin had counted as an attack on the Crown since the Middle Ages, so a convicted coiner faced execution rather than a fine.

Which serial counterfeiter did Newton successfully prosecute, sending him to the gallows?

William Chaloner, a rich and brazen forger, was hanged at Tyburn in March 1699 after Newton had spent months gathering witnesses against him.

How did Newton gather much of the evidence against London's counterfeiters himself?

A draft letter about the operation survives tucked into his own first-edition copy of the Principia.

Which planet was discovered in 1846 almost exactly where calculations using Newton's laws said it would be?

Neptune turned up within a degree of where Urbain Le Verrier, working from unexplained wobbles in the orbit of Uranus, had said to look; it was found on the first night of searching.

Newton's 1717 report on the value of the guinea effectively moved Britain onto what?

The gold standard followed: his rate overvalued gold, so silver coins left circulation, and historians still debate whether he meant it.

Newton showed that an inverse-square pull toward the Sun explains whose laws of planetary motion?

Johannes Kepler had drawn his three rules from observations of the planets; Newton showed that all of them follow from his laws of motion and a single law of gravitation.

Which monarch knighted Newton during a royal visit to Cambridge in 1705?

Queen Anne knighted him on a visit to the Cambridge college he had entered 44 years earlier at the very bottom of its social ladder.

Newton's second law of motion says the force on a body equals its mass multiplied by what?

Acceleration completes the formula F = ma, though Newton himself put the law in words: a change of motion is proportional to the force impressed.

As an MP for Cambridge University, what were reportedly Newton's only recorded comments in Parliament?

He sat in 1689 and again in 1701 and complained of a cold draught in the chamber; that, by some accounts, was the sum of his contribution.

Newton lost heavily when which company's stock bubble burst in 1720?

South Sea shares cost him dearly; asked earlier how far the stock would rise, he reportedly said he could not calculate the madness of people.

Where was Newton buried in 1727 after his body had lain in state?

Westminster Abbey: the Lord Chancellor, two dukes and three earls carried his pall, and most of the Royal Society's fellows followed the coffin to its grave.

A rocket rises because it hurls exhaust the opposite way, a textbook case of which of Newton's laws?

Third law of motion: the engine pushes gas down and the gas pushes the rocket up just as hard, the same effect that shoves a boat backwards when you step off it.

Of the 1,752 identifiable books in Newton's library, the largest single subject was what?

It accounted for 477 volumes, while books on his famous scientific work made up less than 12 per cent of the shelves.

Newton's law of gravitation says the pull between two bodies weakens with the square of what?

Their distance apart is squared, so doubling the gap makes the pull four times weaker; Newton reached the rule in his twenties by wondering whether Earth's gravity stretched as far as the Moon.

Which economist bought a large share of Newton's papers when they were auctioned at Sotheby's in 1936?

John Maynard Keynes gradually reassembled about half of the scattered papers, and what he read there led him to call Newton 'the last of the magicians'.

Most scholars think Newton privately sided with which churchman, whose anti-Trinitarian teaching lost to Athanasius at Nicaea?

Arius's teaching was the heresy Newton is thought to have held in secret: he pulled an essay back from publication for fear that it would expose him.

Who passed the falling-apple story to Voltaire, from whom it spread to the world?

His niece Catherine Barton, a celebrated wit who kept house for him in London, passed it on; Newton had told the tale himself, late in life, over tea under some apple trees.

The apple tree at Newton's Woolsthorpe home is believed to be of which variety?

Flower of Kent is a rare old variety; the tree blew down in a storm in the early 1800s, re-rooted itself and went on growing.

Newton appeared on which Bank of England banknote from 1978 to 1988?

£1 notes carrying Newton's portrait were the last the Bank of England ever issued; the pound coin replaced them and the note ceased to be legal tender in 1988.

The SI unit named after Newton measures which quantity?

Force carries his name because his second law of motion was the first to give the idea an exact, measurable meaning.

Which poet wrote the epitaph for Newton that begins 'Nature, and Nature's laws lay hid in night'?

Alexander Pope's couplet ends 'God said, Let Newton be! and all was light', but it was not allowed on Newton's monument, which carries a Latin inscription instead.

Newton wrote 'standing on the shoulders of giants' in a 1675 letter to whom?

Robert Hooke had accused Newton of stealing his optical ideas, and the letter was part of a polite truce; it did not last, and Newton published Opticks only after his rival died.

Newton described what is now called the Magnus effect after watching the ball curve in which sport?

Tennis gave him the clue: in 1672 he wrote that he had often seen a ball struck with an oblique racket curve in flight, and reasoned that its spin made the air press harder on one side.

Which Astronomer Royal did Newton antagonise by prematurely publishing his star catalogue?

John Flamsteed won in the end: he got most of the unauthorised copies back and burned them, and his own catalogue appeared after his death.

Which Swiss-born mathematician was Newton's closest friend until their sudden break in 1693?

Nicolas Fatio de Duillier's letters stopped without explanation in 1693, and four months later Newton suffered a breakdown, firing off wild accusations at his friends.