100 Fun Facts About Math and Science

Pi, about 3.14159, is the ratio of a circle's circumference to which of its measurements?

Its diameter: pi is the same for every circle, so any wheel rolls just over three times its own width in one full turn.

The sequence 0, 1, 1, 2, 3, 5, 8, 13 is named after which mathematician?

Fibonacci: he brought the sequence to European readers in his 1202 book Liber Abaci, through a puzzle about breeding rabbits.

The Pythagorean theorem says the square on which side equals the sum of the squares on the other two?

The hypotenuse: US President James Garfield published his own proof of the theorem in 1876, while he was still a congressman.

In flat geometry, the interior angles of a triangle add up to how many degrees?

180: on a curved surface such as a globe, a triangle's angles add up to more, as much as 540 degrees.

A googol is 10 raised to which power?

100: Edward Kasner's young nephew is said to have coined the name, and Google's founders named their company as a play on it.

A Möbius strip is a famous example of what kind of surface?

Non-orientable: give a paper strip a half twist before taping its ends, and the loop has only one side and one edge.

Which mathematician finally proved Fermat's Last Theorem in 1994, after centuries of failed attempts?

Andrew Wiles: his first proof, announced in 1993, had a flaw, and fixing it took another year and help from Richard Taylor.

Which theorem, proved in 1976, was the first major theorem proved by computer?

Four colour theorem: four colours can fill any map with no neighbours matching, but some mathematicians did not accept a proof no human could check by hand.

Which 17th-century English mathematician first used the sideways-eight infinity symbol?

John Wallis: during the English Civil War he was also Parliament's codebreaker, deciphering Royalist messages.

In Roman numerals, what number does the letter M represent?

1000: a Roman mile was mille passus, a thousand paces, which is where the English word mile comes from.

Which famous puzzle asks whether to switch doors?

Monty Hall problem: when Marilyn vos Savant wrote in Parade that switching wins two times in three, thousands of readers, PhDs among them, wrote in to insist she was wrong.

In computing, what is a single binary digit, a 0 or a 1, called?

Bit: computer pioneer John Tukey coined the word by squeezing 'binary digit' into three letters, probably because 'bit' already meant a small piece.

Ada Lovelace's notes, often called the first computer program, were written for which machine?

Analytical Engine: Charles Babbage never completed it, so the Bernoulli-number program in her notes had no machine to run on.

A topologist famously can't tell a coffee mug from which food?

A doughnut: a soft clay doughnut could be reshaped into a mug without tearing, its hole becoming the handle, so topology counts them as the same shape.

Euclid, the "father of geometry", is chiefly known for which treatise?

Elements: Euclid gathered earlier Greek results into one ordered chain of proofs, and it stayed at the centre of mathematics teaching for 2,000 years.

Which mathematician did his contemporaries dub the 'Prince of Mathematicians'?

Carl Friedrich Gauss: as a schoolboy he is said to have added up 1 to 100 in moments by pairing the numbers into 50 pairs of 101.

Hypatia, the celebrated ancient philosopher and mathematician, lived and taught in which city?

Alexandria: she advised the Roman prefect there in his bitter feud with the city's bishop, Cyril, and in 415 Christian zealots murdered her.

1729 is the smallest number expressible as the sum of two of what, in two different ways?

Cubes: when G. H. Hardy called his taxi's number, 1729, rather dull, Ramanujan replied that it was a very interesting number, for exactly this reason.

Katherine Johnson, whose calculations were critical to early US crewed spaceflights, worked for which organisation?

NASA: before his 1962 orbital flight, John Glenn asked engineers to 'get the girl' to check the computer's calculations by hand.

Which paper size's sides are in the ratio 1 to √2?

A4: with that ratio, cutting a sheet in half gives two sheets of the same shape, so a copier can shrink two A4 pages onto one.

Which ancient people counted in base 60, still used for measuring time?

Babylonians: because 60 divides evenly by 2, 3, 4, 5 and 6, fractions such as a third, which never end in base 10, come out exact in base 60.

Goldbach's conjecture, unproven as of 2025, says every even number greater than 2 is the sum of two of what?

Prime numbers: in 2000 the publisher Faber and Faber offered a $1 million prize for a proof within two years, but no one claimed it.

Mathematician Charles Dodgson wrote as whom?

Lewis Carroll: he made up stories for the three young Liddell sisters, and in 1862 Alice asked him to write one down, which grew into Alice's Adventures in Wonderland.

Which mathematician first used the notation f(x) for the value of a function?

Leonhard Euler: going almost totally blind barely slowed him, and with scribes to take dictation, he kept turning out papers.

Which Newton book set out his three laws of motion?

Principia: the Royal Society was broke, so the astronomer who had urged Newton to write it paid for the printing out of his own pocket.

Albert Einstein won the 1921 Nobel Prize in Physics for which discovery?

The photoelectric effect: he explained why light below a certain frequency frees no electrons from a metal, however brightly it shines.

Who was the first person to win a Nobel Prize twice?

Marie Curie: when Pierre Curie died in 1906, she took over his professorship in Paris, the first woman ever to hold the post.

Which element did an alchemist first isolate by boiling down urine?

Phosphorus: the alchemist was seeking the philosopher's stone, and the substance he made glowed in the dark, so its name comes from the Greek for 'light-bearer'.

Which is the lightest and most abundant chemical element in the universe?

Hydrogen: stars like the Sun shine by fusing it into heavier atoms, and that fusion powers all of the Sun's heat and light.

Which element has the chemical symbol Au?

Gold: its symbol comes from the Latin aurum, and because gold doesn't corrode, it is used to coat the electrical connectors inside computers and other electronics.

The speed of light in a vacuum is roughly how many kilometres per second?

300,000: even at that speed, sunlight takes about eight minutes to reach Earth, so you always see the Sun as it was eight minutes earlier.

Watson and Crick's 1953 model showed that DNA has what shape?

A double helix: they beat Linus Pauling, whose rival model of DNA was a triple helix with several basic mistakes.

Absolute zero, −273.15 °C, is the zero point of which temperature scale?

Kelvin: the scale carries William Thomson's title, Lord Kelvin, because in 1848 he proposed an absolute scale built on Sadi Carnot's theory of heat.

Penicillin was discovered in 1928 by which scientist?

Alexander Fleming: mould had grown by accident on a dish of bacteria, and he noticed it had cleared the bacteria all around it.

Edward Jenner's pioneering 1796 vaccine protected against which disease?

Smallpox: he used material from cowpox sores, which is why 'vaccine' comes from vacca, the Latin word for cow.

Dry air is about 78% which gas?

Nitrogen: it is so unreactive that food makers fill packaging with it to keep food fresh, while oxygen makes up only about a fifth of the air.

Which comet's namesake predicted its return but died before it came back?

Halley's Comet: Edmond Halley linked sightings from 1531, 1607 and 1682 to one comet, and it duly reappeared in 1758, 16 years after he died.

Which Russian chemist formulated the periodic law and an early periodic table?

Dmitri Mendeleev: he left gaps for elements nobody had found yet and predicted their properties, and when gallium turned up, it filled one of his gaps.

Gregor Mendel, founder of modern genetics, worked out his laws of inheritance by breeding which crop?

Pea plants: he published his results in 1866, but botanists only rediscovered them in 1900, 16 years after his death.

In which 1859 book did Charles Darwin publish his theory of evolution?

On the Origin of Species: Darwin hurried out his theory after the naturalist Alfred Russel Wallace sent him a paper describing the same idea.

George Westinghouse licensed Nikola Tesla's motor patents for which kind of electrical system?

Alternating current: Westinghouse went on to win the contract for the Niagara Falls power plant, using generators based on Tesla's AC work.

Using an improved telescope he built himself, Galileo discovered the largest moons of which planet?

Jupiter: moons circling another planet showed that not everything orbits Earth, and Galileo went on to champion Copernicus's Sun-centred system.

DNA pioneer Rosalind Franklin was an expert in which technique?

X-ray crystallography: her images of DNA helped reveal its structure, but she died in 1958, before Watson, Crick and Wilkins won the 1962 Nobel Prize.

Which sea animal has three hearts and blue blood?

Octopus: its blood is blue because haemocyanin, the protein that carries its oxygen, contains copper rather than the iron in our haemoglobin.

Pencil 'lead' is mostly which form of carbon?

Graphite: sticks of pure graphite used in England from the 1500s were called 'black lead', which is how pencil 'lead' got its name.

What is the longest bone in the human body?

Femur: breaking a healthy one takes so much force that it usually happens only in serious trauma, such as a car crash.

Frederick Banting and Charles Best isolated insulin in 1921 at a university in which Canadian city?

Toronto: in January 1922 their first extract failed to help a dying 13-year-old boy, but a refined one 12 days later rapidly improved his health.

Anders Celsius, who proposed his temperature scale in 1742, was from which country?

Sweden: his original scale ran the other way, with 0 for boiling and 100 for freezing, and it was turned around into today's form about the time he died.

Charles Richter's magnitude scale was first built to measure earthquakes in which US state?

California: its original formula only worked for California quakes recorded on one type of seismograph, so experts now use the moment magnitude scale.

Which massless particle can only ever move at the speed of light?

Photon: it has no mass but still carries momentum, which is why sunlight can push a solar sail, as Japan's IKAROS spacecraft showed from 2010.

The neutron was discovered in 1932 by which physicist?

James Chadwick: with no electric charge, the neutron isn't repelled by atomic nuclei, so it can slip inside and split even the heaviest atoms.

Scientists put the age of the universe at roughly how many years?

13.8 billion: the figure comes from the Planck satellite's map of the Big Bang's leftover glow, the cosmic microwave background.

Olympus Mons, the largest known volcano in the Solar System, is found on which planet?

Mars: with no plate tectonics, its crust sat still over one hot spot, so lava kept piling up until the volcano rose about 22 km high.

What is the point on the ground directly above where an earthquake begins called?

Epicenter: seismologists find it by comparing when a quake's waves reach several distant stations, then drawing circles on a map where they cross.

On the Mohs hardness scale, which mineral scores the maximum 10?

Diamond: Friedrich Mohs ranked minerals simply by which could scratch which, so the scale shows their order, not how much harder each step is.

Mole Day, from 6:02 am on 23 October, honours which constant?

Avogadro's number: the day was created to foster interest in chemistry, and many high schools celebrate it with mole-themed activities.

Which mathematician is widely considered the father of theoretical computer science?

Alan Turing: despite his war work, he was convicted in 1952 over a relationship with a man, and received a royal pardon only in 2013, decades after his death.

What shapes sat atop the tomb of Archimedes, as described by Cicero, marking his proudest result?

A sphere and a cylinder: he proved a sphere has two-thirds the volume of the cylinder around it, and Cicero found the overgrown tomb by spotting the carving.

Archimedes is said to have cried 'Eureka!' in his bath after solving a puzzle about a king's what?

Crown: displacing water let him measure its volume, to test whether a craftsman had swapped in cheaper silver, a story first told by Vitruvius two centuries later.

The SI unit of energy is named after which scientist?

James Joule: by showing how heat relates to mechanical work, he helped establish the law of conservation of energy.

Which type of human cell, once mature, contains no mitochondria?

Red blood cell: as it matures, it sheds its nucleus and most other organelles, leaving more room for the haemoglobin that carries oxygen.

Which test pilot was first confirmed to fly faster than sound in level flight, in 1947?

Chuck Yeager: he had broken ribs falling from a horse shortly before, so he sealed the plane's hatch using a sawed-off broom handle.

Sound travels fastest through which of these noble gases?

Helium: sound moves faster in light gases, so a lungful of helium raises the resonances of your throat and mouth, making your voice sound squeaky.

Which engineer introduced horsepower as a unit?

James Watt: he used it to compare steam engines with the draft horses they could replace, and the watt, the unit of power, was later named in his honour.

Which astronomer, now honoured by a famous space telescope, showed that the Milky Way is only one of many galaxies?

Edwin Hubble: he proved that fuzzy 'nebulae' many astronomers had placed inside our galaxy were really separate galaxies far beyond it.

The digits 0 to 9 are often called Arabic numerals, but mathematicians from which land invented them?

India: Arab mathematicians adopted the system and it reached Europe through their writings, which is why Europeans called the digits Arabic.

The Long Count calendar, with its shell glyph for zero, is most associated with which civilisation?

The Maya: a Long Count cycle ended on 21 December 2012, sparking doomsday rumours, but the calendar simply rolled on into a new cycle.

Which famous triangle is known in China as Yang Hui's triangle, after a 13th-century mathematician?

Pascal's triangle: Yang Hui said he learned it from Jia Xian's 11th-century treatise, so it was known in China centuries before Pascal.

Which artist drew the illustrations for Luca Pacioli's 1509 book on the golden ratio, Divina proportione?

Leonardo da Vinci: he and Pacioli met at the duke of Milan's court, and when French troops took the city in 1499, the two fled together.

The golden ratio is the ratio of a regular pentagon's diagonal to which other length?

Its side: that link is why Euclid could use the golden ratio to construct a regular pentagon, and from it the twelve-faced dodecahedron.

Which planet takes longer to spin once on its axis than it does to orbit the Sun?

Venus turns once every 243 Earth days but laps the Sun in about 225, and it spins backwards compared with most planets.

Honeybees build their wax comb cells in which shape, proved in 1999 to be the most efficient?

Hexagon grids split a flat surface into equal cells using the least total wall, a hunch a Roman scholar recorded and Thomas Hales finally proved in 1999.

Which metal, with the chemical symbol Hg, is the only one that is liquid at room temperature?

Mercury was long known as quicksilver; its nearest rivals caesium, gallium and rubidium are solid at room temperature but melt just above it.

Which primatologist saw wild chimpanzees fish for termites with grass stalks at Gombe in Tanzania?

Jane Goodall showed that chimpanzees make and use tools, overturning the long-held belief that toolmaking set humans apart from other animals.

Which Austrian physicist imagined a cat sealed in a box that is both alive and dead until observed?

Erwin Schrödinger devised the cat in 1935 not to celebrate quantum strangeness but to show what he thought was wrong with his rivals' view of it.

Isaac Newton and Gottfried Leibniz fought a long priority dispute over which branch of mathematics?

Calculus takes its name from the Latin for pebble, because the Romans did their reckoning with small stones on counting boards.

Which substance, about 96% mineral, is the hardest material in the human body?

Tooth enamel, unlike bone, has no way to regenerate, which is why a cavity never heals by itself.

Which green plant pigment, built around a magnesium atom, captures light for photosynthesis?

Chlorophyll absorbs red and blue light most strongly and is a poor absorber of green, which is why leaves look green to the eye.

Which English logician gave his name to the overlapping-circle diagrams he popularised in the 1880s?

John Venn also built a cricket bowling machine with his son, and in 1909 it bowled out one of the visiting Australian team's star batsmen.

Which volcanic rock is so full of gas bubbles that it floats on water and can form rafts at sea?

Pumice forms when gas bubbles freeze into frothy lava, leaving a rock so porous it can drift on the ocean for years before it sinks.

Which star, nicknamed the Dog Star, is the brightest one visible in Earth's night sky?

Sirius is almost twice as bright as Canopus, the runner-up, while Polaris, often assumed to be the brightest, does not even make the top 40.

Which astronomer's 1543 book placed the Sun, rather than Earth, at the centre of the universe?

Copernicus saw his book published only just before his death in 1543, and it set off the revolution in astronomy that bears his name.

Which word, from the Latin for blunted, describes an angle between a right angle and a straight line?

Obtuse literally means blunted, and by about 1500 the word was already being used for a slow-witted person, decades before geometry adopted it.

Which average, favoured for reporting household incomes, is the middle value of a sorted list?

Median income does not move when the largest incomes rise, whereas the mean is dragged upwards, so it gives a truer picture of a typical household.

Since 1808, an exclamation mark written after a number has signalled which mathematical operation?

Factorial means multiplying a number by every positive whole number below it, so it grows explosively: 5 factorial is 120, but 10 factorial is 3,628,800.

Which subatomic particle did J. J. Thomson identify in 1897 while experimenting with cathode rays?

An electron has only about 1/1836 the mass of a proton, so almost all of an atom's weight sits in its tiny nucleus.

Which supercontinent, its name Greek for 'all Earth', later broke apart into today's continents?

Pangaea is the single landmass that Alfred Wegener proposed in 1912, when he argued that the continents had once been joined and then drifted apart.

Tyrannosaurus rex lived during which geological period, the third and last of the Mesozoic Era?

Cretaceous T. rex died out about 66 million years ago, so it lived nearer in time to us than to the Jurassic Stegosaurus.

Which French mathematician gave his name to the x-and-y coordinate system he set out in 1637?

René Descartes set it out in La Géométrie, one of three essays attached to his Discourse on the Method, so that curves could be written as equations.

Which metal, used for the filaments of old light bulbs, has the symbol W from its German name?

Tungsten has the highest melting point of any metal, 3,422 °C, so a filament of it could glow white-hot without melting; the W stands for Wolfram.

Which Greek letter, eighteenth in its alphabet, is the mathematical symbol for summing a series?

Sigma has a second job in its lower-case form: statisticians write it for the standard deviation, the measure of how spread out a set of data is.

Which line, named from the Latin for 'touching', meets a circle at exactly one point?

A tangent to a circle is always perpendicular to the radius drawn to the point where it touches.

Which element accounts for almost half of Earth's crust, locked inside rocks such as silicates?

Oxygen is better known as a gas, but most of the planet's supply is bound into solid minerals, making it the commonest ingredient of the ground itself.

The word 'algorithm' comes from the Latinised name of which scholar at Baghdad's House of Wisdom?

Al-Khwarizmi also gave English the word algebra, taken from al-jabr in the short title of his treatise on solving equations.

Which Platonic solid is the shape of the twenty-faced die used in tabletop role-playing games?

Icosahedron shells turn up in nature too: many viruses, the adenovirus among them, pack their protein coats into this twenty-faced form.

Six and 28 each equal the sum of their proper divisors, earning which label in number theory?

Perfect numbers are so rare that early Greek mathematicians knew only four of them: 6, 28, 496 and 8,128.

The pH scale of acidity was devised in 1909 by a chemist at which brewery's research laboratory?

Carlsberg Laboratory chemist Søren Sørensen never explained what the letter p stands for, and its exact meaning has been disputed ever since.

Which chemist, who confirmed that mass is conserved in reactions, was guillotined in the French Revolution?

Antoine Lavoisier had bought into a royal tax-collecting company, and during the Terror he was executed despite appeals to spare him for his science.

An 18th-century puzzle asked if a walk could cross each of seven bridges exactly once in which city?

Königsberg, since renamed Kaliningrad, had no such route: the proof that the walk was impossible laid the foundations of graph theory.

Which mathematician, a pioneer of set theory, proved that some infinities are larger than others?

Georg Cantor showed that the real numbers outnumber the counting numbers, a result one rival attacked so fiercely that he called him a corrupter of youth.