139 Fun Facts About Common Sense

Which Roman leader gave the calendar its leap day?

Julius Caesar's calendar, drawn up with the astronomer Sosigenes, added a day every fourth year; that overshoots the true year by about 11 minutes, so a later reform had to drop three leap days every 400 years.

What shape is a standard stop sign?

Octagon: US highway officials picked it in the 1920s so that drivers could recognise a stop sign by its outline alone, even in the dark when the lettering could not be read, and no other American road sign may use the shape.

Which kitchen measure equals three teaspoons?

A tablespoon is three teaspoons, about 15 ml, in most kitchens, but measures that share a name are not quite the same size in every country, so a recipe from abroad can come out slightly wrong.

Which mountain is the tallest in the world when measured from its base rather than from sea level?

Mauna Kea stands only 4,207 m above sea level, but the Hawaiian volcano starts on the sea floor about 6,000 m down, so base to peak it measures roughly 10,210 m, well over a kilometre more than Everest.

Which continent is the smallest by land area?

Australia is the smallest continent yet one of the largest countries on Earth; Greenland, less than a third of its size, marks the cut-off and is counted as the world's largest island instead.

Roughly what share of people worldwide are left-handed?

About 10% is the usual estimate, 10.6% in a large 2020 analysis, though the answer runs from roughly 9% to 18% depending on whether people who favour the left hand for only some tasks are counted.

How many bones does an adult human skeleton have?

206 is the adult count, but a baby is born with far more, roughly 270 to 300 by different counts; the number falls because many grow together and fuse as the child matures.

Which instrument's four strings are tuned G, D, A and E?

The violin's strings, tuned G, D, A, E, were traditionally made of 'catgut', which despite the name is sheep intestine and has nothing to do with cats; the viola and cello are both tuned up from a low C instead.

Which river is traditionally ranked as the world's longest, narrowly ahead of the Amazon?

The Nile has traditionally been ranked first, but the title is disputed: in 2007 Brazilian scientists claimed the Amazon was longer after tracing its headwaters to a snow-capped mountain in southern Peru.

Which is the largest country in the world by area?

Russia covers nearly twice the territory of Canada, the runner-up, and spans eleven time zones, so when clocks in Kaliningrad say 9 pm it is already 7 am the next day in Kamchatka.

Which is the largest and deepest of Earth's five oceans?

The Pacific covers about a third of the planet, more than all the land put together; Ferdinand Magellan gave it the name, meaning 'peaceful', in 1520 because the water was calm when his ships sailed into it.

Which fruit did the US Supreme Court rule to be a vegetable?

Tomato importers argued in 1893 that it was botanically a fruit and so free of the vegetable tariff, but the court went by everyday use, noting that tomatoes are served at dinner and not, like fruits, as dessert.

The peanut is not a true nut but which of these?

A legume, like peas and beans: the peanut's pods ripen underground, and bacteria in its roots feed nitrogen into the soil, which is why farmers value it as a crop to plant in rotation.

Which of these fruits is botanically a berry?

Banana: to a botanist a berry is a fleshy fruit formed from a single ovary, which fits bananas and grapes, while a strawberry's flesh grows from another part of the flower altogether.

Which structure is falsely said to be visible to the naked eye from space?

The Great Wall of China is long but narrow and close in colour to the land around it; China's first astronaut, Yang Liwei, came back in 2003 and admitted he had not been able to see it.

The Latin name of the Canary Islands means islands of which animal?

Dogs: the Latin name Canariae Insulae means 'islands of the dogs', though why the Romans called them that is uncertain, and the songbird was later named after the islands, not the reverse.

Which colour did Isaac Newton add to his rainbow to make seven?

Indigo was added because Newton wanted seven colours, to match the seven notes of a musical scale.

Which planet is closest to the Sun?

Mercury has almost no atmosphere to hold the heat it gets, so its surface swings from about 430 °C in daylight to around -180 °C at night.

Which food, properly stored, essentially never spoils?

Honey holds too little water and too much sugar and acid for microbes to grow, and bees add an enzyme that makes hydrogen peroxide; left unsealed, though, it soaks up moisture from the air and can spoil.

Which sea animal has three hearts and blue blood?

The octopus has two hearts that pump blood through its gills and a third that sends it round the body, and the blood is blue because it carries oxygen with copper rather than iron.

Which is the largest living bird?

The ostrich cannot fly, so it runs instead, in bursts of up to about 70 km/h, the fastest of any animal on two legs, and when cornered its kick is powerful enough to kill a lion.

Which is the longest bone in the human body?

The femur, or thigh bone, is also among the body's strongest bones, so it takes great force to break one: a snapped femur usually means a serious accident such as a car crash.

Which continent is the driest and windiest on average?

Antarctica gets so little snow that most of it counts as a polar desert, and its fierce winds are katabatic: cold, heavy air sliding downhill off the ice cap under gravity.

A light-year is a unit of what?

Distance: a light-year is how far light travels in a year, about 9.46 trillion km, so the glow we see from the nearest star beyond the Sun set out more than four years ago.

Roughly how hot does the air around a lightning bolt get?

30,000 °C is about five times hotter than the surface of the Sun, and the air heats so fast that it expands explosively, sending out the shock wave we hear as thunder.

Roughly what fraction of an iceberg is above the water?

One-tenth is the usual figure, which is where the phrase 'tip of the iceberg' comes from; the hidden bulk below the waterline is why icebergs are treated as a serious hazard to shipping.

What is the fastest land animal?

The cheetah can go from a standstill to nearly 100 km/h in three seconds, but it can keep that pace for only a few hundred metres, so a hunt is won or lost in one short sprint.

Which are the only mammals capable of true, sustained flight?

Bats fly by flapping wings of skin stretched over long finger bones, much like a hugely stretched human hand, whereas flying squirrels and the other so-called fliers can only glide.

Wisdom teeth are the last of which kind of tooth to come through?

Molars: wisdom teeth are the third molars, named for arriving so late, usually in the late teens or twenties; many jaws have no room for them, so they get stuck and are often taken out.

What is the largest organ of the human body?

The skin covers up to two square metres on an adult and never stops rebuilding itself, shedding dead cells constantly so that its surface is renewed every few weeks.

Which of these differs even between identical twins?

Fingerprints are shaped partly by conditions in the womb as the ridges form between the third and sixth months of pregnancy, so identical twins end up with similar but not matching prints despite sharing their DNA.

What do the abbreviations a.m. and p.m. stand for?

Ante meridiem / post meridiem are Latin for 'before midday' and 'after midday', which leaves noon and midnight as neither, so style guides advise writing '12 noon' or '12 midnight' to avoid confusion.

About how long does sunlight take to reach Earth?

8 minutes, or a little more, is the journey time at the speed of light, so we always see the Sun as it was then: if it went dark this instant, we would not notice for another eight minutes.

The Moon always shows Earth the same face because of which effect?

Tidal locking: Earth's gravity tugged on a bulge it raised in the young Moon and slowed its spin until one turn took exactly as long as one orbit, so the far side never swings into view.

What do the interior angles of any triangle add up to?

180 degrees is the rule only on a flat surface: on a globe, a triangle running from the North Pole down two meridians a quarter-turn apart to the equator has three right angles, 270 degrees in all.

Which tradespeople give their name to a 'dozen' that actually numbers thirteen?

Bakers: a baker's dozen is thirteen, by one common account because medieval English bakers faced harsh penalties for selling short weight and added an extra loaf to be safe.

At what temperature does water freeze on the Fahrenheit scale?

32 °F it is, because by Fahrenheit's own account his scale put zero at the freezing point of a salty brine, colder than plain ice, which leaves pure water freezing at 32 and boiling at 212.

Which letter appears most often in ordinary English text?

E makes up roughly one letter in every eight in ordinary English, which is why Morse code gives it the shortest signal of all, a single dot.

Which instrument has 88 keys in its standard modern form?

The piano grew as composers demanded more from it: the first ones spanned just four octaves, and makers kept adding keys until the range passed seven octaves.

How many squares are on a chessboard?

64 squares, eight by eight, come from India: chess grew out of chaturanga, a game well over a thousand years old played on a plain board called the ashtapada, and the light-and-dark chequering was added later.

Which suit's ace is traditionally the most ornate card in a standard deck?

Spades: from the 1700s England's tax on playing cards was marked on the ace of spades, first by stamp and then with an official printed design, which makers kept imitating once free to draw their own; forging one was a capital offence.

Which city's 1908 Olympic marathon ran 26.2 miles to reach the royal box?

London's organisers ran the 1908 race from Windsor Castle to the royal box in the Olympic stadium, and in 1921 that accidental length was made the official standard.

How many stripes are on the flag of the United States?

13 stripes stand for the original colonies; the flag went up to fifteen stripes when Vermont and Kentucky joined, but in 1818 Congress went back to 13 and let only the stars keep growing.

A snowflake's arms grow from an ice crystal of which shape?

Hexagon: the first crystal is a tiny six-sided plate, and as it falls more water vapour freezes onto each of its corners, building the six arms that every classic snowflake has.

Which of these animals has a stomach with four compartments?

The cow's four compartments let it swallow grass quickly, ferment it with microbes in the rumen, then bring it back up as cud to chew again, which can take up over a third of its day.

What is a baby kangaroo called?

A joey is born barely an inch long after about a month's pregnancy, then hauls itself unaided through its mother's fur into the pouch, where it stays for around nine months.

How many chambers does the human heart have?

Four chambers keep two circuits apart: one side sends used blood to the lungs for oxygen, and the other pumps the refreshed blood out to the rest of the body.

Which human lung is smaller?

The left lung is the smaller one because the heart bulges into its side of the chest, leaving it with a notch and only two lobes where the right lung has three.

For daylight saving time, which way do clocks move in spring?

Forward one hour, as in 'spring forward, fall back'; the idea goes back to New Zealand insect collector George Hudson, who in 1895 proposed a two-hour shift because he prized daylight after work for his hobby.

In Roman numerals, what does the letter M stand for?

1,000 is the largest of the seven standard symbols, so ordinary Roman numerals run out at MMMCMXCIX, or 3,999; to go higher, a bar drawn over a numeral multiplies it by a thousand.

Pi is the ratio of a circle's circumference to what?

Its diameter: Archimedes pinned pi down by drawing many-sided polygons inside and outside a circle, trapping it between 3 10/71 and 3 1/7.

How many feet are in a mile?

5,280 feet is an awkward total because in 1593 England fixed the mile at eight furlongs of 660 feet each, the farmers' measure, instead of keeping the Roman mile of 5,000 feet.

Which unit of length was fixed at exactly 0.9144 metres in 1959?

A yard is three feet; the English-speaking nations agreed the figure together, but US surveyors kept an older foot that differed by a hundredth of a foot per mile, giving America two feet for decades.

Why does ice float?

It is less dense than the liquid: water expands by about 9% as it freezes, so ice forms a floating lid on a pond instead of sinking, and fish and plants survive the winter in the water beneath.

Roughly how fast does sound travel in air at room temperature?

343 m/s means sound takes about three seconds to cover a kilometre, which is why counting the gap between a lightning flash and its thunder tells you how far away the strike was.

Which reflex is wrongly said to be impossible with your eyes open?

A sneeze shuts the eyes only because the eyelid muscles tighten involuntarily along with the rest, and that reflex can be suppressed, so the old claim is simply wrong.

In the Northern Hemisphere, on which date does the shortest day of the year usually fall?

21 December (occasionally the 22nd) is the winter solstice, yet the coldest weather usually comes weeks later, because land and sea go on losing stored heat after the days begin to lengthen.

What happened to Pluto's status in 2006?

It was reclassified as a dwarf planet when the International Astronomical Union agreed a three-part definition of 'planet': Pluto orbits the Sun and is round, but it has not cleared other objects from its orbit.

Which is the largest planet in the Solar System?

Jupiter holds more than twice the mass of all the other planets put together, and its gravity is strong enough to have torn comet Shoemaker-Levy 9 into fragments that crashed into it in 1994.

Which planet would float if you could find a bath of water big enough?

Saturn is made mostly of hydrogen and helium, the two lightest elements, so for all its bulk it is the one planet light enough for its size to float.

Which is the hottest planet in the Solar System?

Venus is wrapped in a thick atmosphere that traps the Sun's heat in a runaway greenhouse effect, holding its surface at about 465 °C, hot enough to melt lead.

Which of these mammals lays eggs?

The platypus is one of only five egg-laying mammals, alongside the four echidnas, and it has no teats: once the young hatch, they drink milk that seeps onto patches of fur on the mother's belly.

Spiders, scorpions and ticks belong to which group of animals?

Arachnids differ from insects in having eight legs instead of six, and spiders take only liquid food: the stomach works as a pump, sucking in prey that has been turned to a soup.

Which mosquitoes bite people?

Only the females bite, because they need a blood meal for their eggs to mature; for their own energy, males and females alike feed on plant nectar.

What are shark skeletons made of?

Cartilage is flexible and durable yet much lighter than bone, so a shark's skeleton weighs little and the fish saves energy as it swims.

Which animal's fur is clear and hollow?

The polar bear's hairs are clear, hollow tubes with no pigment at all; they scatter the light that falls on them, which is what makes the coat look white.

Where do wild penguins live?

Almost only south of the equator: the one exception is the Galápagos penguin, whose islands straddle the line, and it survives in the tropics thanks to the cool ocean currents that wash them.

The koala is not a bear but which kind of mammal?

A marsupial: a newborn koala, the size of a jelly bean, crawls into its mother's pouch for six to seven months, and adults sleep up to twenty hours a day while they digest their leafy diet.

What colour is a zebra's skin under the stripes?

Black: the stripes are only in the hair, and the skin underneath is dark all over, which is why some people argue a zebra is really a black animal with white stripes.

Experiments show a goldfish can remember things for at least how long?

3 months at least: goldfish can be trained to tell apart shapes, colours and sounds and still respond weeks or months afterwards, so the famous three-second memory is a myth.

Which of these reptiles cannot stick out its tongue?

The crocodile's tongue is not free: it is held fast to the floor of the mouth, so the animal cannot poke it out however wide it opens its jaws.

Starboard is a ship's right-hand side, so what is the opposite side called?

Port: early ships were steered with an oar on the right, the 'steer-board' side, so they tied up to the dock on the other side, which was first called larboard and later port.

Which sea animal has no brain, heart or blood and is almost entirely water?

A jellyfish is about 95% water, held in shape by the sea around it, with only a loose net of nerves; lifted out of the water it collapses into a shapeless blob.

Which colour did the orange carrot's ancestors most commonly come in?

Purple was the norm: about a thousand years ago cultivated carrots were purple, with yellow ones close behind, and the orange kind is thought to have been bred only centuries later, by Dutch growers.

Which of these foods is about 95% water?

Cucumber is about 95% water, so there is very little else in it: a 100-gram serving has only about 16 calories.

Botanically, a coconut is which of these?

A drupe, because like a peach it has three layers: a thin outer coat, a middle layer, which in the coconut is the dry fibrous husk, and a hard stone enclosing the seed.

A mushroom is the fruiting body of what kind of organism?

A fungus lives mostly out of sight as a web of threads in soil or wood, and the mushroom is only its spore-making fruit; one fungus in Oregon's Blue Mountains spreads over about nine square kilometres.

Which food is named after an 18th-century English earl?

The sandwich is named after John Montagu, 4th Earl of Sandwich, who is commonly said to have ordered beef between slices of bread so that he could go on playing cards without stopping for a meal.

The hamburger takes its name from a city in which country?

Germany: the word is short for 'Hamburg steak', a chopped-beef dish linked to Hamburg, though exactly how it reached America and landed in a bun is disputed, and no ham was ever involved.

Which fastener did Walter Hunt twist from wire in 1849, selling the patent for $400?

The safety pin was dreamed up to clear a $15 debt; whoever held the rights went on to make fortunes from it, while Hunt never earned another penny.

What is the 'lead' in a pencil actually made of?

Graphite and clay are baked together to make the core; it is called lead because when a pure graphite deposit was found at Borrowdale in northern England in the 1500s, people took it for a form of lead.

Which Hungarian newspaper editor invented the ballpoint pen after noticing how fast newspaper ink dried?

László Bíró fled wartime Europe for Argentina with his brother and launched the pen there, which is why Argentines still call a ballpoint a 'birome', a blend of Bíró and the name of his partner Meyne.

Which pope's 1582 calendar reform dropped ten days and still bears his name?

Gregory XIII ordered that Thursday 4 October 1582 be followed by Friday 15 October; Protestant Britain held out until 1752, by which time it had to skip eleven days to catch up.

The early Roman year began with which month?

March opened the early Roman year, which is why September, from the Latin for seven, was then the seventh month; the names stuck after January and February were added and the start of the year moved to January.

Which invention did Swiss engineer George de Mestral conceive in 1941 after picking burrs off his dog?

Velcro copies the burrs: under a microscope de Mestral saw hundreds of tiny hooks that caught on loops of fur and cloth, and he named his version from the French velours and crochet, 'velvet' and 'hook'.

A 3M scientist's failed attempt at a super-strong glue in 1968 led to which office product?

Post-it Notes use Spencer Silver's glue, which turned out tacky but weak; it sat unused for years until his colleague Art Fry coated paper with it to make a bookmark that stayed put in his hymn book.

Which country has the earliest recorded use of toilet paper, in the 6th century?

China already made paper, and in 589 the scholar Yan Zhitui wrote that he would not dare use sheets bearing the words of the sages for toilet purposes.

Which organism grows in the grooved fur of sloths, giving them a greenish tint?

Algae settle in grooves along each hair, and the green tint helps hide the slow-moving sloth among the leaves.

Which bird can hover in place and even fly backwards?

The hummingbird sweeps its wings in a figure of eight, dozens of times a second, which lets it fly like a tiny helicopter: up, down, sideways, backwards and even upside down.

Which month is the only one that can pass without a full moon, as it did in 2018?

February can miss a full moon because in common years its 28 days are shorter than the lunar cycle. It will next happen in 2037.

Which bright colour are aircraft flight recorders painted so searchers can spot them in wreckage?

Orange, heat-resistant paint makes the recorder stand out in debris. The unit usually sits in the aircraft's tail, the part most likely to survive a crash.

To which family of instruments does the saxophone, invented by Adolphe Sax in the 1840s, belong?

Woodwind is the family because a saxophone sounds through a single vibrating reed, even though its body is usually made of brass.

Which fruit is dried to make raisins, sultanas and the small 'currants' used in baking?

Grapes of different varieties give the whole trio. A sultana is a golden dried grape, and a baking currant is a tiny dried seedless Corinth grape.

Which plant, the main food of the giant panda, is a giant member of the grass family?

Bamboo includes some of the fastest-growing plants in the world. Certain species can shoot up about 91 centimetres within 24 hours.

Which living animal, weighing up to about 200 tonnes, is the largest known ever to have existed?

Blue whale hearts are the largest known in any animal, yet the giant feeds mostly on krill, small crustaceans it strains from the sea.

Which gas makes up about 78 percent of the air in Earth's atmosphere?

Nitrogen dominates every breath, while the oxygen that keeps people alive is only about 21 percent of the air.

Which bird of prey, clocked at over 300 km/h in its hunting dive, is the fastest animal known?

Peregrine falcon dives, called stoops, start from a great height and end by striking one wing of the prey so the hunter is not hurt on impact.

Which day of the week is named after the thunder god known to the Norse as Thor?

Thursday began as the day of Thunor, the Anglo-Saxon name for the same thunder god. Danish, Norwegian and Swedish still call it Torsdag.

Which language, spoken from birth by nearly a billion people, has the most native speakers?

Mandarin leads on native speakers, but English is the most spoken language overall because more people learn it as a second language than grow up with it.

Which animal is the tallest living on land and also the largest of the cud-chewing ruminants?

Giraffe necks owe their length to stretched neck bones, not extra ones: the vertebrae lengthened instead of multiplying.

Which currency, whose name comes from a word meaning 'round', is the official money of Japan?

Yen shares its origin with the yuan and the won, names that all go back to a word for round silver coins.

Which city, selected by Queen Victoria, is the capital of Canada?

Ottawa took its name in 1855 from the river it stands on, a word that comes from the Algonquin for 'to trade'.

Which country, covering just 44 hectares, is the smallest in the world by both area and population?

Vatican City is an enclave within Rome, ruled by the pope, and serves as the administrative centre of the Catholic Church.

Which US state, with a longer coastline than all the others combined, is the largest by area?

Alaska covers more area than Texas, California and Montana combined, yet it is the most sparsely populated state in the country.

Which desert, third largest overall behind the two polar ones, is the world's largest hot desert?

Sahara sands and rock cover about 9.2 million square kilometres, yet the frozen deserts at the top and bottom of the globe are bigger still.

Which mountain, first climbed by Tenzing Norgay and Edmund Hillary, rises highest above sea level?

Mount Everest is known in Nepali as Sagarmatha, and its first documented ascent in 1953 followed the Southeast Ridge.

Which 'sea' bordering Iran and Kazakhstan is often listed as the largest lake in the world?

Caspian Sea water is brackish, about a third as salty as the ocean, and the basin holds over 40 percent of all the lake water in the world.

Which country staged the ancient Olympic Games at Olympia and the first modern Games in 1896?

Greece held the ancient contests in honour of Zeus from the 8th century BC to the 4th century AD, and Athens hosted the 1896 revival.

Which continent is the largest in the world by both land area and population?

Asia is home to roughly 4.7 billion people, which is well over half of everyone alive.

Which gemstone ranks at the very top of the Mohs scale of mineral hardness?

Diamond packs more atoms into a given volume than any other known substance, which is why it is both the hardest and the least compressible.

On which temperature scale, named after a Swedish astronomer, does water boil at 100 degrees?

Celsius first proposed the scale upside down in 1742, with water boiling at 0 degrees and freezing at 100. The values were later reversed.

Which chemical compound, written NaCl, is the main ingredient of ordinary table salt?

Sodium chloride was once valuable enough to leave its mark on language: the word 'salary' comes from the Latin word for salt.

Which element makes up about 75 percent of all normal matter in the universe?

Hydrogen is the lightest element as well as the commonest, and stars including the Sun consist mainly of it.

Rust is the flaky reddish-brown coating formed when which metal reacts with oxygen and moisture?

Iron gets no protection from its rust, which is flaky and crumbles away, unlike aluminium and tin, which form stable oxide layers.

Which chemical symbol, taken from a Latin name, stands for gold, the element with atomic number 79?

Au is short for aurum, the Latin name for gold, just as silver's symbol Ag comes from argentum.

Which force, described by Einstein as curved spacetime, gives physical objects their weight?

Gravity is still handled for most purposes with Newton's older law, in which the pull between two bodies depends on the product of their masses.

Which galaxy, a barred spiral of 100 to 400 billion stars, contains the Solar System?

Milky Way describes how the galaxy looks from Earth: a hazy band of light made by stars too far away to pick out with the naked eye.

Which unit of power, equal to one joule per second, is named after a Scottish steam-engine pioneer?

Watt, who improved the Newcomen steam engine in 1776, also adopted the term 'horsepower' to compare his engines with draft horses.

Which raw material, melted with soda and lime, is the main ingredient of ordinary window glass?

Sand rich in quartz supplies the silica for soda-lime glass, the most prevalent type, used for windowpanes, bottles and jars.

Which organ, able to regenerate after damage, is the heaviest internal organ in the human body?

Liver tissue also forms the largest gland in the body, and the organ has a large reserve capacity that keeps it working when part is damaged.

Which bean-shaped organs behind the abdomen filter the blood in the human body to produce urine?

Kidneys filter about a fifth of the blood that flows into them, sending the waste down tubes called ureters to the bladder.

Which nutrient can the human body make for itself when sunlight's ultraviolet B rays reach it?

Vitamin D boosts the gut's absorption of calcium, and for most people the body's own production outweighs what they get from food.

Donors with which blood type are often called universal donors for red blood cell transfusions?

O negative red cells are in such demand that guidelines reserve them for matching patients, women who might be pregnant, and emergencies with no time to test.

Which substance, about 96 percent mineral, is the hardest found anywhere in the human body?

Enamel is mostly hydroxyapatite, a crystalline calcium phosphate, yet acids from food and drink can still wear it away.

In which part of the body is the stapes, the smallest and lightest bone in the human skeleton?

The ear holds the stapes, named from the Latin for the stirrup it resembles, which passes sound vibrations on to the inner ear.

The Komodo dragon of Indonesia is the largest living species of which kind of reptile?

Lizard is the right label for a hunter whose males can reach 3 metres in length and whose slashing bite is thought to deliver venom.

Spiders and scorpions are not insects, so to which class of animals do they belong?

Arachnids also include ticks, mites, harvestmen and the oddly named camel spiders and vinegaroons.

Cashmere, the soft fibre named after the Kashmir region, comes from the coat of which animal?

Goat breeds such as the cashmere and pashmina supply the fibre, and the Kashmir shawl made it a symbol of luxury in Europe.

Tofu is made by curdling and pressing the milk of which crop into solid blocks?

Soybeans give tofu its other name, bean curd, and the blocks are sold in grades of softness from silken to extra firm.

Which month did the Romans rename in 44 BC in honour of the general Julius Caesar?

July was chosen because it was the month of Caesar's birth; until then Romans had called it Quintilis.

Which scale, named after an American pharmacist, measures the pungent heat of chilli peppers?

Scoville scale ratings began in 1912 as a taste test: pepper extract was diluted in sugar water until a panel of trained tasters could no longer feel the heat.

In which sport do the points in a game run love, 15, 30 and then 40?

Tennis probably took 'love' from the phrase 'playing for love', meaning for nothing, though a rival theory points to l'œuf, 'the egg', for the shape of a zero.

Which chess piece moves only along diagonals and so stays on one square colour all game?

Bishop pairs matter because each one is stuck on a single colour: a king and two bishops on opposite-coloured squares can force checkmate.

Which Italian artist painted the Mona Lisa, the portrait stolen from the Louvre in 1911?

Leonardo da Vinci's portrait owes part of its fame to the thief, Vincenzo Peruggia, who believed it belonged in Italy; the painting returned to the Louvre in 1914.

Which Apollo 11 commander became the first person to walk on the Moon in 1969?

Neil Armstrong photographed crewmate Buzz Aldrin on the surface and can be seen in that picture only as a reflection in Aldrin's visor.

Which country, counting its overseas territories, uses more time zones than any other in the world?

France spans the clock because its overseas territories are scattered around the globe, and every one keeps a different time from the mainland.

Which country, home of the ancient Kushite kingdoms, has more pyramids than Egypt?

Sudan has more than 200 pyramids, smaller and steeper-sided than the Egyptian ones, built by the rulers of Nubia.

Which South American country is the true home of the straw hat misleadingly called the Panama hat?

Ecuador shipped its woven hats through the Isthmus of Panama, so buyers named them after the place of sale instead of the place of origin.

Which ingredient joins basil, garlic, Parmesan and olive oil in a traditional pesto genovese?

Pine nuts go into the paste that originated in the Ligurian city of Genoa, where it is used to dress pasta.