49 Fun Facts About Blaise Pascal

In which French city was Blaise Pascal born in 1623?

Clermont-Ferrand. His father, a local judge, later left the town for Paris so that he could educate his gifted children himself.

In 1970 Niklaus Wirth honoured Pascal by giving his name to a new what?

Programming language. Wirth built Pascal to teach students tidy, structured programming, and it became a staple of university computing courses.

By his sister's account, the 12-year-old Pascal secretly worked out geometry proofs matching those of which ancient text?

Euclid's Elements. His father had kept mathematics from him until his languages were mastered, but on catching the boy drawing proofs in charcoal on the floor tiles he relented and gave him the book.

What did the 16-year-old Pascal call the six-point figure at the heart of his Essay on Conics?

The Mystic Hexagram. Join any six points on a conic into a hexagon and its three pairs of opposite sides meet on one straight line, a result from which he said he drew some 400 corollaries.

Which philosopher shrugged off the teenage Pascal's conics essay, judging before reading half that its ideas were borrowed?

René Descartes. He wrote to Mersenne that the boy had plainly learned it from an older geometer, a cool response to an essay admirers were calling the strongest work since Archimedes.

Why did the young Pascal build his mechanical calculator in 1642?

To ease his father's tax calculations. French money was not decimal, so some of the machine's wheels had to count in twelves and twenties rather than tens.

When a digit on Pascal's calculator rolled past 9, what did the machine do unaided?

Carried one to the next wheel. Pascal used small falling weights he called sautoirs, so a whole row of nines could roll over in a ripple without extra effort from the user.

Why did the Pascaline fail commercially?

It was extraordinarily expensive and cumbersome. From 1649 Pascal held a royal monopoly on making calculating machines in France, yet few were ever sold.

Two decades before Pascal's calculator, Wilhelm Schickard sketched a 'calculating clock' in letters to which astronomer?

Johannes Kepler. One of his biographers, Franz Hammer, publicised the letters in 1957; until then Pascal had been celebrated for three centuries as the inventor of the mechanical calculator.

With which mathematician did Pascal correspond in 1654, founding probability theory?

Pierre de Fermat. Their letters worked out how two gamblers should split the stakes of an unfinished game, and the idea of expected value grew out of the answer.

Which gambling friend's puzzles set Pascal writing the 1654 letters that founded probability theory?

The Chevalier de Méré. Born Antoine Gombaud, the soldier, author and gamester wanted to know how two players who quit a game early should share the pot.

Who published the first book on probability after hearing in Paris of Pascal's 1654 letters on games of chance?

Christiaan Huygens. The young Dutchman visited Paris in 1655, learned of the problems, solved them his own way at home and printed a short treatise on games of chance two years later.

What did Pascal call the tabular arrangement of binomial coefficients that now bears his name?

The arithmetical triangle. He applied it to the question of how the stakes of an unfinished game should be divided, proving its rules with an early explicit use of mathematical induction.

In Iran, Pascal's triangle is named after which Persian mathematician, who described it centuries earlier?

Omar Khayyam. China calls the same array Yang Hui's triangle and Italy calls it Tartaglia's, because all three men set it out long before Pascal was born.

What ailment did Pascal take as a heavenly sign to proceed with his 1658 study of the cycloid?

A toothache that vanished. He had given up mathematics for religion four years earlier, yet eight days of work later he had solved the curve's problems and set Europe's mathematicians a prize challenge.

Which English architect sent Pascal a proof of the cycloid's exact length during his 1658 prize challenge?

Christopher Wren. Years before he rebuilt St Paul's he was a professor of astronomy in London, and his proof, the first to be published, gave the exact length of a cycloid's arch.

Whose barometer experiments, involving a tube of mercury inverted in a bowl, did Pascal build on in 1647?

Evangelista Torricelli. Galileo's former pupil was explaining a pump-makers' puzzle, why suction would not lift water much beyond ten metres, and he blamed the weight of the air.

What did Pascal's 1647 work argue filled the space above the mercury in a barometer tube?

A vacuum. A Jesuit critic, Père Noël, insisted the gap must hold some subtle matter, and Pascal answered that a single contrary observation is enough to sink a hypothesis.

Which mountain did Pascal's brother-in-law climb with a barometer in 1648 to test air pressure?

Puy de Dôme. Too ill to climb, Pascal had Florin Périer leave one mercury tube with a friar in the town below and carry another to the summit, where the column stood clearly lower.

Pascal's law says that pressure applied to a confined fluid is passed on in what way?

Equally in every direction. A rise in pressure at one point is matched undiminished at every other point of the fluid, the principle behind the brakes of cars and aircraft.

What allegedly happened when Pascal filled a thin tube attached to a water cask to a great height?

The barrel leaked. Other tellings have it burst outright; either way, a tall thin tube holding only a little water was enough to split a full cask.

Which two devices is Pascal credited with inventing through his work on fluids?

The hydraulic press and the syringe. The press multiplies force, turning a light push on a small piston into a heavy one on a large piston, the idea that carries his name in physics.

The pascal, the SI unit of pressure, is defined as what?

One newton per square metre. That is a very small pressure: ordinary air at sea level presses with about 101,000 pascals, so everyday readings come in multiples of a hundred or a thousand.

Weather forecasters adopted the hectopascal because it exactly equals which older pressure unit?

Millibar. When science moved to the pascal, meteorologists wanted to keep the numbers they were used to, so they simply attached the prefix hecto, meaning a hundred.

A popular but unproven story credits Pascal's hunt for perpetual motion with inventing which casino game?

Roulette. The game is first recorded in France decades after his death; the 'roulette' Pascal really did write about was his own name for the cycloid curve.

Which Catholic movement, named by its detractors, did Pascal and sister Jacqueline join in 1646?

Jansenism. Two bonesetter brothers spent three months with the family mending his father's fall on the ice, shared their strict faith, and Blaise was the first to be won over.

Which convent did Jacqueline Pascal enter as a postulant in 1652, over her brother's objections?

Port-Royal. Blaise pleaded with her not to go, yet three years later, after his own conversion, he was making retreats at the same convent.

After noting the date, Pascal's record of his religious experience of 23 November 1654 opens with which single word?

Fire. He sewed the note into the lining of his coat and moved it whenever he changed clothes; nobody knew of it until a servant came across it after his death.

What Jesuit-favoured ethical method did the Provincial Letters attack as reasoning that excused moral laxity?

Casuistry. Pascal made his case by quoting the Jesuits' own handbooks back at them, above all Antonio Escobar's, turning dry case-by-case rulings into comedy.

In what state did Pascal leave the Pensées when he died in 1662?

As bundles of unfinished notes. They were raw material for a book defending Christianity, and editors have disagreed ever since about the order in which the fragments should be read.

Pascal wrote that man is 'the weakest in nature', a mere reed, but a reed of what kind?

Thinking. A vapour or a drop of water is enough to kill him, Pascal goes on, yet man is nobler than whatever crushes him because he knows that he is dying and the universe knows nothing.

Pascal's wager says one should live as though God exists because the potential gain is what?

Infinite. Set an endless reward against a finite stake of earthly pleasures, Pascal argued, and even a slim chance that God exists makes belief the sensible bet.

In the Pensées, Pascal says the whole face of the world would have changed had whose nose been shorter?

Cleopatra. It is his example of how trifles steer history: a charm too small to name, he says, can set princes, armies and a whole country in motion.

What did Pascal launch in Paris in March 1662, five months before he died?

A public coach service. The coaches kept to fixed routes and left at set times even when empty, and Pascal meant his share of the takings to go to the poor.

Which Enlightenment writer answered Pascal's Pensées point by point, rejecting his gloomy view of humankind?

Voltaire. He tacked the essay onto his Letters on the English, quoting Pascal's thoughts one at a time and countering each with a more cheerful account of human life.

Pascal claimed that all human unhappiness comes from people being unable to do what?

Stay quietly in their own room. He thought people hunt, gamble and even go to war for 'diversion', anything to avoid being left alone with themselves.

In which Paris church, a few steps from the Panthéon, is Pascal buried?

Saint-Étienne-du-Mont. The remains of the playwright Racine were later moved into the same church, so two masters of French prose and verse lie under one roof.

Which company announced a 'Pascal' graphics microarchitecture named for him in 2014?

Nvidia. It names its chip designs after scientists, so Pascal followed Maxwell and gave way to Volta and Turing; the first Pascal graphics cards went on sale in 2016.

In Pascal's triangle, how is each number inside the triangle found?

By adding the two numbers above it. That one rule hides other famous patterns: add along the shallow diagonals and the Fibonacci numbers 1, 1, 2, 3, 5 appear.

What ended Pascal's family's comfortable Paris income in 1638?

Richelieu defaulted on government bonds. France needed the money for the Thirty Years' War, and when Étienne joined the protests he had to flee Paris to stay out of the Bastille.

How did the fugitive Étienne Pascal win his pardon in 1639?

His daughter charmed the cardinal. Jacqueline, already known as a child poet, acted in a play staged for him and afterwards asked him to forgive her father, who was soon given a senior post.

Which queen received one of Pascal's calculators as a gift?

Christina of Sweden. Pascal sent the machine in 1652 with a letter of dedication; the young queen was then famous for gathering Europe's scholars at her court.

In the Provincial Letters, Pascal apologised that one letter was long because he lacked what?

Time to make it shorter. He was writing anonymously and in haste, each letter rushed through underground presses while the authorities searched for its author.

Which mathematician's work on conic sections particularly inspired the teenage Pascal?

Girard Desargues. Pascal's essay said outright that he owed 'the little that I have found' to the geometer from Lyon and had tried to imitate his method.

Which pope marked the 400th anniversary of Pascal's birth with an apostolic letter in his honour?

Francis. There is a twist in the tribute: he was the first Jesuit pope, and Pascal's Provincial Letters are a celebrated satire on the Jesuits.

Rapunzel's silent sidekick in Disney's Tangled shares Pascal's name and is what kind of animal?

A chameleon. Pascal never speaks, and in the short sequel Tangled Ever After he and Maximus the horse lose the royal wedding rings and cause havoc chasing them.

Which Italian director made the television biopic Blaise Pascal in the early 1970s?

Roberto Rossellini. The neorealist pioneer, once married to Ingrid Bergman, had announced that he was leaving cinema for television, where he made history films on Socrates and Augustine too.

What are recorded as Pascal's last words, spoken in August 1662?

"May God never abandon me". His doctors, sure he was in no danger, had for days refused his pleas for the last sacraments; he said this as he finally received them.

Which poet's introduction to the Pensées called Pascal 'a man of the world among ascetics'?

T. S. Eliot. In the same essay he remarks that most people are too 'lazy-minded' and 'incurious' to be capable of either much doubt or much faith.