How many hearts does an octopus have?
Three — two for the gills, one for the rest of the body.
General Knowledge
A little of everything — food and language, numbers and customs, the everyday facts worth the knowing.
376 questions · tap a question to reveal the answer
Which sense is most strongly tied to memory?
Smell — it wires almost directly into the memory centres.
What do we call molten rock once it reaches the surface?
Lava — underground the same stuff is magma.
Which vitamin does your skin make from sunlight?
Vitamin D — which is why northern winters are a problem.
What is a group of geese in flight called?
A skein — in the air, a gaggle on the ground.
Where do polar bears live in the wild?
The Arctic — only - penguins have the other end to themselves.
How many colours are traditionally counted in a rainbow?
Seven — a number Newton chose rather than measured.
Which shape has the most sides: a pentagon, a hexagon or an octagon?
The octagon — eight, against six and five.
What is the study of the weather called?
Meteorology — nothing to do with meteors, oddly.
How many strings does a standard violin have?
Four — a guitar has six.
How many players from one team are on a football pitch?
Eleven — including the goalkeeper.
What do you call frozen rain that falls as lumps of ice?
Hail — built up in layers inside a thundercloud.
How many minutes are in a full day?
1,440 — twenty-four lots of sixty.
Which material is glass mostly made from?
Sand — melted and cooled too fast to crystallise.
What do you call a baby kangaroo?
A joey — born the size of a jellybean.
Which sense do bats mostly use to hunt in the dark?
Hearing — they listen for the echo of their own calls.
What is the freezing and boiling range of water in Celsius?
0 to 100 — the Fahrenheit figures are 32 and 212.
How many degrees are there in a circle?
360 — a number we inherited from Babylon.
What do you call a word that reads the same backwards?
A palindrome — like 'level' or 'racecar'.
How many ribs does a typical human have?
24 — Twenty-four - twelve pairs, and men have no fewer than women.
What is the name for animals with backbones?
Vertebrates — and we are heavily outnumbered by the others.
What do you call the study of stars and planets?
Astronomy — astrology is the other thing.
What is the world's most widely spoken first language?
Mandarin Chinese — Mandarin - though English wins once you count second languages.
What do you call a triangle with three equal sides?
Equilateral — and all three angles are 60 degrees.
What do we call a young swan?
A cygnet — grey before it turns white.
What do pandas mostly eat?
Bamboo — up to 38 kilograms a day.
What do we call animals that only eat plants?
Herbivores
Which sport uses a bat and a ball and has home runs?
Baseball
Which famous ship hit an iceberg in 1912?
Titanic — on its maiden voyage.
How many strings does a standard guitar have?
Six
Which sport is played at Wimbledon?
Tennis — since 1877.
Which of these animals hibernates through winter?
Bear — sleeping through the cold months.
What do you call the white part of an egg?
Albumen — or egg white.
What do moth caterpillars spin around themselves?
A cocoon — a chrysalis is not spun, it is moulted.
Which layer of the Earth are we standing on?
The crust — proportionally thinner than the skin of an apple.
What causes the fainter second bow in a double rainbow?
Light reflecting twice inside a drop — A second internal reflection - and its colours run in reverse.
Why does ice float on water?
It expands as it freezes — Water expands about 9% on freezing - almost nothing else does.
What are clouds made of?
Water droplets — Tiny water droplets and ice crystals.
Where were the first written rules of football drawn up?
Cambridge — in 1848 - the rules that shaped the modern game.
Why does February gain a day every four years?
The year is not exactly 365 days — Earth takes about 365.24 days to go round the Sun.
Why is summer warm - is the Earth closer to the Sun?
No, the axis is tilted — Tilt, not distance - Earth is furthest from the Sun in July.
How much bamboo must a giant panda eat each day?
Up to 40 kg — it digests very little of it, so it eats constantly.
What are Saturn's rings actually made of?
Water ice — Almost pure water ice, from dust grains to house-sized boulders.
Why are honeycomb cells hexagonal?
Least wax for the most space — A hexagon tiles with no gaps and the shortest total walls.
How long ago were dogs domesticated from wolves?
At least 15,000 years — before farming, before anything else.
How long is a kangaroo pregnant for?
About a month — Roughly 33 days - the rest of it happens in the pouch.
What did the Aswan High Dam stop happening?
The annual Nile flood — The flood that laid down free silt every year for millennia.
What does the word million originally mean?
Big thousand — Italian milione - a big thousand.
Why can most adults in the world not digest milk?
Lactase switches off after infancy — Lactase normally stops being produced - keeping it is the mutation.
Why is pi the same number for every circle?
All circles are the same shape scaled — Every circle is a scaled copy of every other, so the ratio never changes.
Why do bats roost hanging upside down?
Their tendons lock shut — The grip locks with no muscular effort - hanging costs a bat nothing.
Which months were added to the Roman calendar last?
January and February — the old year began in March.
How much of the Earth's water is fresh and accessible?
Well under one per cent — Under one per cent - most fresh water is locked up in ice.
Which reaction browns both toast and steak?
The Maillard reaction — sugars meeting amino acids under heat.
Which of these is botanically a berry?
A banana — and the strawberry is not a berry at all.
What is Big Ben actually the name of?
The bell — the tower is the Elizabeth Tower.
What is unique about reindeer among deer?
Females grow antlers too — Both sexes grow antlers - the only deer where that is true.
Why do your fingers wrinkle in the bath?
Your nerves do it on purpose, for grip — It is an active nervous response - it improves grip on wet things.
Why can you see your breath on a cold day?
Water vapour in it condenses into droplets — The vapour cools and condenses - it is a tiny cloud.
Why does a mirror swap left and right but not up and down?
It swaps front and back, and you do the rest — It reverses front to back; you turn yourself around to compare.
Why do we have leap years?
A year is about a quarter of a day longer than 365 — Earth takes 365.2422 days, so the quarters are collected up.
Why do onions and apples taste alike if you hold your nose?
Most of taste is actually smell — Flavour is mostly smell; the tongue detects only a handful of tastes.
Why do we get an afternoon on Mars that is only slightly longer than ours?
A Martian day is about 24 hours 37 minutes — A sol is 24 hours 37 minutes - oddly close to Earth's day.
Why does cutting a worm in half not give you two worms?
Only the head end can regrow, and not always — The head end may regrow a tail; the tail end has no brain and dies.
Why does bread go stale even in a sealed bag?
The starch recrystallises - it is not just drying — Starch retrogradation, which is why warming bread revives it briefly.
Why do cats always seem to land on their feet?
They twist without pushing against anything — A mid-air twist that appears to break the rules of spinning.
Why does a struck tuning fork get louder when you touch it to a table?
The table surface moves much more air — More air is moved, so it is louder and dies away faster.
Why do we not feel the Earth moving at 1,600 kilometres an hour?
Everything around us moves with it, at a steady speed — Only changes in motion are felt, and the spin is very steady.
Why does swallowed food still reach your stomach upside down?
Muscles squeeze it along in waves — Peristalsis - the same wave that moves food along a worm.
Why do old paintings crack in a fine net of lines?
Paint and canvas shrink at different rates — Craquelure - layers age and move by different amounts.
Why does a helium balloon rise and a lead ball sink in air?
Both are floating - the balloon is just lighter than air — Buoyancy in air; anything less dense than air floats up.
Why is there almost no wind at the eye of a hurricane?
Air is being flung outward, leaving a calm centre — Air spirals around the centre rather than through it.
Why does the same recipe fail at high altitude?
Water boils cooler, so food cooks slower — Lower pressure means a lower boiling point - about 88 C in La Paz.
Why does a struck bell keep ringing after you stop touching it?
The metal goes on vibrating — The bell itself is still moving, thousands of times a second.
Why do dogs pant instead of sweating?
They have almost no sweat glands in their skin — Evaporation from the tongue and airway does the cooling.
Why is the inside of a fig full of tiny flowers rather than seeds?
A fig is a flower turned outside in — A fig is an inverted cluster of flowers, pollinated by a tiny wasp.
Why does the second hand of a clock sometimes seem to pause when you look at it?
Your brain edits out the eye's movement — Chronostasis - the brain backfills the gap while the eye moves.
Why do we sleep on a roughly 24-hour cycle even in a dark cave?
The body keeps its own clock, close to but not exactly 24 hours — An internal clock, which daylight resets each morning.
Why do stars twinkle but planets usually do not?
A star is a point of light and a planet is a small disc — Air distorts a point sharply; a small disc averages it out.
Why does salt melt ice on a road?
It lowers the temperature water can freeze at — Salt water freezes below zero, so the ice cannot stay solid.
Why do we recognise a friend's face instantly but struggle to describe it?
The brain handles faces whole, not feature by feature — A dedicated face system, which is why upside-down faces are so hard.
Why can a small boat float when the steel it is made of sinks?
The hull shape displaces far more water than the steel — Shape, not material - it displaces its own weight in water.
How many bones does an adult human have, roughly?
206 — babies are born with about 300.
What are the northern lights called?
Aurora borealis — australis is the southern one.
How many teeth does an adult human usually have?
32 — including four wisdom teeth.
Why was Berlin divided by a wall?
To stop people leaving the east — To stop the exodus - 3.5 million had already gone west.
Which language is spoken in Brazil?
Portuguese — a colonial legacy.
How often does your skin replace itself?
About every month — Roughly monthly - much of household dust is the old version.
What is a group of lions called?
A pride
What are animals without backbones called?
Invertebrates — about 97 percent of animals.
What does a barometer measure?
Air pressure — useful for forecasting.
How many sides does a pentagon have?
Five
In which sport would you perform a slam dunk?
Basketball
Why was purple dye once worth more than gold?
It took thousands of sea snails — Tyrian purple came from murex snails - thousands per gram.
Which dinosaur had huge jaws and tiny arms?
Tyrannosaurus rex
Which New World food reached Italian cooking only after 1500?
The tomato — Italian food is unimaginable without it, and it is an import.
What does the Richter scale measure?
Earthquakes — their magnitude.
Which sense do dogs rely on most?
Smell — up to 100,000 times keener than ours.
Who was the first man to walk on the Moon?
Neil Armstrong — in July 1969.
What lies under most of modern Cairo's suburbs?
Ancient Memphis and its cemeteries — The necropolis of Memphis - Giza is the edge of it.
What do you call the study of plants?
Botany
What is the freezing point of water in Celsius?
0 degrees — Celsius.
What is the name for a shape with ten sides?
Decagon — A decagon.
Which vitamin do we get from sunlight?
Vitamin D — made in the skin.
Which body part keeps you balanced?
The inner ear
What was the name of the first artificial satellite in space?
Sputnik 1 — launched by the USSR in 1957.
Which food group do beans and lentils belong to?
Legumes — rich in protein.
Which of these languages uses characters instead of an alphabet?
Chinese — thousands of characters.
What did mapmakers actually write on unknown territory?
Almost never 'here be dragons' — The phrase appears on essentially one surviving globe.
Which famous physicist developed E = mc squared?
Albert Einstein — in 1905.
What is the national sport of Japan?
Sumo wrestling — centuries old.
Why are triangles used in bridges and roof trusses?
They cannot deform — A triangle cannot change shape without a side breaking.
What do you call molten rock while it is still underground?
Magma — it becomes lava at the surface.
Why do bats tolerate viruses that devastate other mammals?
Their immune system stays part-activated — A permanently primed defence - which is why they are studied so hard.
Which nut is used to make marzipan?
Almond
What destroyed Lisbon in 1755 and changed European thought?
An earthquake — A quake, fire and tsunami on All Saints' Day - it shook the Enlightenment.
How many chambers does the human heart have?
Four — two atria and two ventricles.
Why is a broken hip so dangerous in old age?
The blood supply can be cut off — The femur's head is fed through a narrow route the break can sever.
What was the Parthenon being used for when it exploded in 1687?
A gunpowder store — Ottoman munitions - a Venetian shell hit it and took out the middle.
In what year did the Titanic sink?
1912 — on its maiden voyage.
What is the main language of Mexico?
Spanish
In Greek myth, who flew too close to the sun?
Icarus — his wax wings melted.
How do sailfish hunt together?
They herd fish into a ball and take turns — They flash colour to signal whose turn it is, and avoid stabbing each other.
Which US state is famous for Hollywood?
California
Which chess piece can only move diagonally?
The bishop
Why can no weather forecast reach beyond about two weeks?
Tiny errors grow exponentially — Chaos - Lorenz found it by rounding a number in 1961.
What is the largest land carnivore?
Polar bear
What was the name of Beethoven's famous piano piece for Elise?
Fur Elise
What holds a violin's soundpost in place?
Friction alone — Nothing but pressure - Italian makers call it the soul.
What are the Wright brothers famous for?
The first powered flight — in 1903.
What makes a ruby red and a sapphire blue?
Trace impurities in the same mineral — Both are corundum - chromium makes ruby, iron and titanium sapphire.
Why does an octopus prefer crawling to swimming?
Its main heart stops when it swims — The systemic heart stops beating when it jets - swimming exhausts it.
What does a seismologist study?
Earthquakes — and the Earth's tremors.
What is happening to Jupiter's Great Red Spot?
It is shrinking fast — It has halved since the 1800s and nobody knows if it is dying.
In which sport do you use a shuttlecock?
Badminton
Who composed The Four Seasons?
Vivaldi — Antonio Vivaldi, around 1720.
Why did the Great Wall fail in 1644?
A general opened the gates — The wall was intact - Wu Sangui let the Manchus through at Shanhai Pass.
Who leads a wild wolf pack?
The parents — It is a family - the breeding pair are simply mother and father.
What was New York called before 1664?
New Amsterdam — the English took it and renamed it.
Which is the world's highest waterfall?
Angel Falls — in Venezuela, 979 metres.
What is at Saturn's north pole?
A hexagonal storm — A six-sided cloud pattern 30,000 km across, and nobody is sure why.
Why did Roman numerals make arithmetic so hard?
There is no zero and no place value — No zero, no columns - you cannot do long multiplication in them.
Which sport awards a yellow jersey to its leader?
Cycling — the Tour de France.
Which fictional detective lives at 221B Baker Street?
Sherlock Holmes
Which language has the most native speakers?
Mandarin Chinese — around 900 million.
What actually lives inside a coral polyp?
Photosynthetic algae — Algae that hand over most of the sugar they make - and leave when it gets too warm.
In what year did the Berlin Wall fall?
1989 — on the night of November 9th.
Why is Norway so wealthy for its size?
North Sea oil, saved in a fund — A sovereign fund holding over a trillion dollars - roughly 1% of global equities.
What falls as rain on Titan?
Methane — at minus 180 degrees it does what water does here.
What is the largest artery in the human body?
The aorta — leaving the heart.
How did Brazil finally stop hyperinflation in 1994?
With an imaginary currency — A fake unit everyone priced in until expectations reset, then made real.
In which sport would you see a googly?
Cricket — a deceptive spin delivery.
What is the human body's largest joint?
The knee
Who was the first woman to win a Nobel Prize?
Marie Curie — in 1903.
What is the boiling point of water in Fahrenheit?
212 — degrees Fahrenheit.
Who is the Norse god of thunder?
Thor — with his hammer Mjolnir.
What was the Concorde?
A supersonic airliner — London to New York in 3.5 hours.
Who composed the Moonlight Sonata?
Beethoven — in 1801.
What did crows do to researchers who once trapped them?
Scolded them for years, and taught others — Birds never trapped themselves learned the face and passed it on.
Why can Mars build volcanoes so much bigger than Earth's?
Its crust does not move — No plate tectonics - eruptions pile onto one spot for 100 million years.
What is the deepest mine on Earth?
A South African gold mine — Mponeng, nearly 4 km down, where the rock face is over 60 degrees.
How was Neptune found?
By mathematics before anyone looked — Predicted from Uranus's wobble, then found the same night.
Who sculpted David?
Michelangelo — completed 1504.
Why does Finland have so many lakes?
Glaciers scraped the basins — 188,000 of them, gouged by ice - and the land is still rising.
What does the Japanese name for Japan actually mean?
Origin of the sun — Nihon - origin of the sun, a name written from China looking east.
What is the term for a camel with two humps?
Bactrian — camel.
What does an entomologist study?
Insects
What is the main ingredient of hummus?
Chickpeas — with tahini.
Who was the youngest person to win the Nobel Peace Prize?
Malala Yousafzai — at 17.
What is the traditional Japanese art of paper folding?
Origami
Which crop made Vietnam the world number two almost from nothing?
Coffee — from negligible in 1990 to second in the world.
Why has nobody ever farmed spiders for silk?
They eat each other — Spiders are territorial and cannibalistic - you cannot keep them together.
Which board game features the squares Boardwalk and Park Place?
Monopoly — in its US edition.
What is the medical name for the voice box?
The larynx
How many time zones does Russia span?
Eleven — from Kaliningrad to Kamchatka.
What is the longest nerve in the human body?
The sciatic nerve — hip to foot.
What did Siam give up to stay independent?
Its border provinces — Chunks of Laos, Cambodia and Malaya - the periphery, to keep the centre.
Who composed the Brandenburg Concertos?
Johann Sebastian Bach — J.S. Bach.
What is the study of fungi called?
Mycology
Where did the bones of the middle ear come from?
The reptilian jaw joint — Two jaw bones migrated into the ear - we hear with repurposed jaw.
What is the fear of spiders called?
Arachnophobia
Who developed the periodic table's ordering by atomic mass in 1869?
Dmitri Mendeleev — Mendeleev — he even predicted missing elements.
What is the Italian word for 'scratched drawing', a wall art form?
Graffiti — from graffiato.
Who was the Roman god of fire and the forge?
Vulcan — Hephaestus to the Greeks.
Which English county is Stonehenge in?
Wiltshire — on Salisbury Plain.
Which is the only US state name with one syllable?
Maine
What did the first crewed dive to Challenger Deep achieve?
Almost nothing - the silt blinded them — Piccard and Walsh stirred up so much silt they saw nearly nothing, in 1960.
What is the longest running West End musical?
Les Miserables — since 1985.
Why is Jupiter visibly squashed?
It spins very fast — A ten-hour day flattens it about 7% at the poles.
Who composed Rhapsody in Blue?
George Gershwin — Gershwin, in 1924.
What is the fear of confined spaces called?
Claustrophobia
What is the unit of electrical resistance?
Ohm
Usain Bolt's 100m world record is just under which time?
9.6 seconds — 9.58 seconds, set in Berlin in 2009.
Why can the liver lose most of its function before you notice?
It has no pain receptors — No pain nerves in the tissue - which is why cirrhosis is found late.
What is the term for animals active at dawn and dusk?
Crepuscular — like deer and rabbits.
Why does Cuba have such famously old American cars?
A 1962 embargo froze imports — Nothing American could be imported after 1962, so the 1950s fleet was kept running.
Which physicist formulated the uncertainty principle?
Werner Heisenberg — Heisenberg, in 1927.
Which is the world's largest bay by shoreline?
Hudson Bay — in Canada.
Why is wiring made of copper if silver conducts better?
Cost — Silver wins on conductivity and loses on price by a wide margin.
Which ship did Charles Darwin sail on to the Galapagos?
HMS Beagle — 1831-1836.
What is the traditional Japanese rice wine called?
Sake
Which Renaissance banking family ruled Florence?
The Medici — patrons of the Renaissance.
What is the medical term for the collarbone?
Clavicle
What was the code name for the D-Day landings?
Operation Overlord — Overlord, June 6th 1944.
Which mathematician proved Fermat's Last Theorem in 1994?
Andrew Wiles — Wiles, after seven secret years.
Which kingdom did the samurai serve?
Japan — retainers of the daimyo lords.
What is the longest human chromosome called?
Chromosome 1 — the largest by base pairs.
Who was the Greek goddess of wisdom?
Athena — born from Zeus's head.
What killed Mozart at 35?
Nobody knows — Rheumatic fever, kidney failure and strep are all candidates. Not Salieri.
What is the deepest cave system known in the world?
Veryovkina Cave — Veryovkina in Georgia — over 2.2 km deep.
What did J.J. Thomson and his son each win a Nobel for?
Proving the electron is a particle, then a wave — Father showed it was a particle, son that it was a wave. Both correct.
Which shogunate ruled Japan for over 250 years until 1868?
The Tokugawa — shogunate.
Why does Orwell's appendix on Newspeak matter?
It is written in the past tense — It describes the regime's language historically - implying it fell.
What is the SI unit of pressure?
Pascal
Which particle was confirmed at CERN in 2012?
The Higgs boson
Why can submarines pass Gibraltar with engines off?
Two currents run opposite ways — Atlantic water flows in on top, saltier Mediterranean water out beneath.
What is the half-life concept used to measure?
Radioactive decay — rates.
What does bile actually do to fat?
Breaks it into droplets — Emulsifies it, so enzymes have far more surface to work on.
Who choreographed and composed the ballet The Rite of Spring's score?
Igor Stravinsky — Stravinsky — it caused a riot in 1913.
What is the name of the supercontinent that existed 250 million years ago?
Pangaea — 'all Earth'.
Who developed the polio vaccine announced in 1955?
Jonas Salk — Salk — he refused to patent it.
Which musical note lasts half as long as a minim?
A crotchet — a quarter note.
What is the second brightest natural object in Earth's night sky?
Venus — after the Moon.
What is the name for a triangle's longest side, opposite the right angle?
The hypotenuse
What does the name Burkina Faso mean?
Land of upright people — Coined in 1984 from two local languages to replace Upper Volta.
What is the medical term for the kneecap?
Patella
Which strait separates Alaska from Russia?
The Bering Strait — 82 km across.
Who composed the Enigma Variations?
Edward Elgar — Elgar, in 1899.
How did the Library of Alexandria actually end?
Slow decline over centuries — Funding cuts, expelled scholars and neglect - not a single blaze.
What is the only letter that does not appear in any US state name?
Q — Arizona has a Z, Texas an X.
Why is Wellington so windy?
Wind funnels through a strait — The Roaring Forties squeeze through Cook Strait - gusts over 200 km/h.
Who formulated the laws of inheritance using pea plants?
Gregor Mendel — Mendel, an Austrian monk.
Who composed the Goldberg Variations?
J.S. Bach — Bach, published 1741.
Which enzyme begins starch digestion in the mouth?
Amylase — in saliva.
Which moon has a magnetic field of its own?
Ganymede — a magnetosphere inside Jupiter's, found nowhere else.
Who sculpted the Ecstasy of Saint Teresa?
Gian Lorenzo Bernini — Bernini, master of the Baroque.
Why is 'oldest university' such a contested title?
The definition keeps changing — Bologna, al-Qarawiyyin and Al-Azhar all win under different definitions.
Which layer of the atmosphere contains the ozone layer?
The stratosphere
What is the term for rock formed from cooled lava at the surface?
Extrusive igneous — rock, like basalt.
What made the Dutch Golden Age possible?
A new kind of company and stock market — The VOC, the first joint-stock company, and the first stock exchange.
What did two centuries of Mongol rule leave in Russia?
A census, a postal relay and taxes — Administrative machinery Moscow inherited and used to dominate its rivals.
Which gland is known as the master gland?
The pituitary — controlling other glands.
What blooms in the Atacama after a rare rain?
A desert of flowers — Seeds wait years in the soil and carpet the ground within weeks.
Which Greek mathematician calculated pi's bounds with polygons?
Archimedes — of Syracuse.
Which 1815 volcanic eruption caused the Year Without a Summer?
Mount Tambora — Tambora — 1816 crops failed worldwide.
How did Louis XIV keep the French nobility harmless?
He made them compete over court etiquette — Versailles replaced politics with ceremony - and bankrupted them attending.
What is the smallest prime number greater than 100?
101
Who popularized the term 'black hole' in 1967?
John Wheeler — John Archibald Wheeler.
Which novelist created the fictional county of Yoknapatawpha?
William Faulkner — Faulkner, for his Mississippi novels.
Which vitamin deficiency causes scurvy?
Vitamin C — the sailors' curse.
Which Icelandic sagas' word gave us 'saga'?
Old Norse tales — Old Norse — saga means 'what is told'.
Which French region gives its name to true sparkling champagne?
Champagne — everything else is just sparkling wine.
Which economic work did Adam Smith publish in 1776?
The Wealth of Nations
Which pope launched the First Crusade in 1095?
Urban II — at Clermont.
What is the unit of magnetic flux density?
Tesla
Which strait separates Sicily from mainland Italy?
The Strait of Messina — Messina — home of Scylla and Charybdis.
Which musical interval spans eight notes?
An octave — The octave.
What is the name for a young eel?
An elver
Who composed the Messiah oratorio, with its Hallelujah chorus?
George Frideric Handel — Handel — written in just 24 days in 1741.
What happens to helium below about two kelvin?
It flows up walls — It becomes a superfluid with no viscosity and climbs out of its container.
What is the name of the hypothetical particle that mediates gravity?
The graviton — still undetected.
Who composed the 48 preludes and fugues of The Well-Tempered Clavier?
J.S. Bach — Bach — two books of 24.
What are Titan's dunes made of?
Solid hydrocarbons — Organic grains from the atmosphere, piled into dunes hundreds of km long.
What is the term for the evolutionary resemblance of unrelated species?
Convergent evolution — dolphins and sharks.
Which mathematician's incompleteness theorems shook logic in 1931?
Kurt Godel — Godel — some truths cannot be proved.
Which philosopher's 'categorical imperative' anchors his ethics?
Immanuel Kant — Kant, in 1785.
Who first observed the moons of Jupiter in 1610?
Galileo Galilei — Galileo — the four Galilean moons.
What is the coldest naturally occurring place in the universe known?
The Boomerang Nebula — colder than deep space.
Which Ottoman sultan conquered Constantinople in 1453?
Mehmed II — Mehmed the Conqueror, aged 21.
How do migrating birds appear to sense magnetic fields?
A light-sensitive protein in the eye — Cryptochrome - they may literally see the field as a visual pattern.
Who developed calculus independently of Newton?
Gottfried Leibniz — Leibniz — his notation survived.
What is the heaviest known living organism?
A stand of aspen — Pando - 47,000 stems, one root system, about six million kilograms.
What is the name of the deepest layer of Earth's mantle boundary with the core?
The D'' layer — The D-double-prime layer.
Which is the only venomous primate?
The slow loris
Which family holds the most Nobel Prizes?
The Curies — Five between them - and Irene won one of her own.
Which Carthaginian general was Hannibal's father?
Hamilcar Barca
What is the study of the pituitary's hormone system and glands generally called?
Endocrinology
Which Polish astronomer's De Revolutionibus moved the Sun to the center?
Copernicus — published as he died in 1543.
Which particle accelerator first exceeded a teraelectronvolt?
The Tevatron — Fermilab's Tevatron, in 1983.
Which Roman festival in December inspired later gift-giving seasons?
Saturnalia — role reversals and presents.
Which mathematician founded graph theory with the Konigsberg bridges?
Leonhard Euler — Euler, in 1736.
Which Indian mathematician's notebooks stunned Cambridge in 1913?
Srinivasa Ramanujan — Ramanujan, self-taught genius.
What is the term for a species found nowhere else on Earth?
Endemic — like the kakapo to New Zealand.
How did Casals find the Bach Cello Suites?
In a second-hand shop at 13 — He practised them daily for twelve years before performing one in public.
Which pirate republic thrived at Nassau around 1715?
The Bahamas — Nassau in the Bahamas — Blackbeard's haunt.
Which African site preserves 3.2-million-year-old 'Lucy'?
Ethiopia's Afar region — Hadar in Ethiopia's Afar Triangle.
Which Venetian traveled the Silk Road to Kublai Khan's court?
Marco Polo — from 1271.
How was the Antikythera mechanism finally read?
X-ray CT through the corrosion — Imaging in 2005-6 recovered 2,000 characters of instructions inside it.
Which Mexican painter's Blue House is now her museum?
Frida Kahlo — in Coyoacan.
Which biogeographic line separates Asian wildlife from Australian wildlife?
The Wallace Line — through the Indonesian islands.
What did Lorenz actually change to discover chaos?
He rounded a number — Restarted a run from 0.506 instead of 0.506127, and got a different world.
Which Egyptian script bridged hieroglyphs and the Rosetta Stone's Greek?
Demotic — the stone's middle script.
What did Athens nearly do with the silver that built its navy?
Share it out among citizens — The assembly was about to distribute it. Themistocles argued for ships.
The first statin drug was isolated from which kind of organism?
A mold — A Penicillium mold — mevastatin, found in 1976.
The 'Harvard Computers' who cataloged the stars worked at which institution?
Harvard Observatory — Harvard — women like Annie Jump Cannon classified 350,000 stars.
Which Scottish engineer's improvements made the steam engine practical?
James Watt — Watt, with the separate condenser.
Which language isolate is spoken in the western Pyrenees?
Basque — no relative has ever been demonstrated.
Basque is a language spoken by Basques and other residents of the Basque Country, a region that straddles the westernmost Pyrenees in adjacent parts of southwestern France and northern Spain. Basque is the only known language isolate in all of Europe. The Basques are indigenous to and primarily inhabit the Basque Country. Basque has…
Wikipedia · Basque languageWhat is the term for being unable to recall a word that is on the tip of your tongue?
Lethologica — the word you cannot fetch.
Tip of the tongue is the phenomenon of failing to retrieve a word or term from memory, combined with partial recall and the feeling that retrieval is imminent. The phenomenon's name comes from the saying, "It's on the tip of my tongue." The tip of the tongue phenomenon reveals that lexical access occurs in stages.
Wikipedia · Tip of the tongueWhich Central Asian conqueror built a pyramid of skulls at Isfahan?
Timur — (Tamerlane), in 1387.
Timur, also known as Tamerlane, was a Turco-Mongol conqueror, first ruler of the Timurid dynasty, and the founder of the Timurid Empire, which ruled over modern-day Afghanistan, Iran, and Central Asia. He was undefeated in battle and is widely regarded as one of the greatest military leaders and tacticians in history, as well as one of…
Wikipedia · TimurWhich mathematician solved the Poincare conjecture and refused the Fields Medal?
Grigori Perelman — Perelman, in 2003.
Grigori Yakovlevich Perelman is a Russian mathematician and geometer who is known for his contributions to the fields of geometric analysis, Riemannian geometry, and geometric topology. In 2005, Perelman resigned from his research post in Steklov Institute of Mathematics and in 2006 stated that he had quit professional mathematics, owing…
Wikipedia · Grigori PerelmanWhich particle physics symmetry violation earned Cronin and Fitch the Nobel?
CP violation — found in kaons in 1964.
James Watson Cronin was an American particle physicist.
Wikipedia · James CroninWhich pre-Roman Italian civilization taught Rome the arch?
The Etruscans
The Etruscans created a civilization in Etruria in ancient Italy, with a common language and culture, and formed a federation of city-states. After adjacent lands had been conquered, its territory covered, at its greatest extent, roughly what is now Tuscany, western Umbria and northern Lazio, as well as what are now the Po Valley,…
Wikipedia · Etruscan civilizationWhat is the name of the paradox where a heap loses grains yet stays a heap?
The sorites paradox — from the Greek for heap.
The sorites paradox, sometimes known as the paradox of the heap, is a paradox that results from vague predicates. A typical formulation involves a heap of sand, from which grains are removed individually. With the assumption that removing a single grain does not cause a heap not to be considered a heap anymore, the paradox is to consider…
Wikipedia · Sorites paradoxWhich trench-dwelling amphipod was named for the plastic found inside it?
Eurythenes plasticus — a PET fragment was in the type specimen.
Eurythenes plasticus is a species of amphipod of the genus Eurythenes, first described in 2020. It was named in reference to the PET plastic found in its stomach, after researchers wanted to highlight the impact of plastic pollution.
Wikipedia · Eurythenes plasticusWhich mathematical constant is the limit of (1 + 1/n)^n?
e — Euler's number e, about 2.718.
The number e is a mathematical constant, approximately equal to 2.71828, that is the base of the natural logarithm and exponential function. It is sometimes called Euler's number, after the Swiss mathematician Leonhard Euler, though this can invite confusion with Euler numbers, or with Euler's constant, a different constant typically…
Wikipedia · E (mathematical constant)Which shipwreck yielded the oldest known analog 'computer' alongside bronzes?
Antikythera — wreck, found 1900.
The Antikythera mechanism is an ancient Greek hand-powered orrery built in the 2nd century BC and discovered in 1901. It is the oldest known example of an analogue computer. It could be used to predict astronomical positions and eclipses decades in advance. It could also be used to track the four-year cycle of athletic games similar to…
Wikipedia · Antikythera mechanismWhich people's quipu knots recorded numbers without writing?
The Inca — cords as accounting.
The Inca Empire, officially known as the Realm of the Four Parts, was the largest empire in pre-Columbian America. The administrative, political, and military center of the empire was in the city of Cusco. The Inca civilisation rose from the Peruvian highlands sometime in the early 13th century. The Portuguese explorer Aleixo Garcia was…
Wikipedia · Inca EmpireWho deciphered Babylonian cuneiform using the Behistun inscription?
Henry Rawlinson — Rawlinson, copying the cliff carvings at great risk.
General Henry Seymour Rawlinson, 1st Baron Rawlinson,, known as Sir Henry Rawlinson, 2nd Baronet between 1895 and 1919, was a senior British Army officer in the First World War who commanded the Fourth Army of the British Expeditionary Force at the battles of the Somme (1916) and Amiens (1918) as well as the breaking of the Hindenburg…
Wikipedia · Henry Rawlinson, 1st Baron RawlinsonWhich SI prefix denotes 10 to the power of minus 15?
Femto
A metric prefix is a unit prefix that precedes a basic unit of measure to indicate a multiple or submultiple of the unit. All metric prefixes used today are decimal. Each prefix has a unique symbol that is prepended to any unit symbol. The prefix kilo, for example, may be added to gram to indicate multiplication by one thousand: one…
Wikipedia · Metric prefixWhich philosopher's 'ship' paradox questions identity over replacement?
Theseus — The Ship of Theseus.
Theseus was a divine hero in Greek mythology, famous for slaying the Minotaur. The myths surrounding Theseus, his journeys, exploits, and friends, have provided material for storytelling throughout the ages.
Wikipedia · TheseusWhich moth's larvae produce wild 'tussah' silk?
The Antheraea moths — Antheraea — wild silk moths.
Silk is a natural protein fiber, some forms of which can be woven or knitted into textiles. The protein fiber of silk is composed mainly of fibroin (75-80%) and a smaller coating of sericin (20-25%). It is most commonly produced from the cocoons of certain insect larvae. The best-known silk is obtained from the cocoons of the larvae of…
Wikipedia · SilkWhich satellite first detected ripples in the cosmic microwave background?
COBE — in 1992 — a Nobel-winning map.
The cosmic microwave background, or relic radiation, is microwave radiation that fills all space in the observable universe. With a standard optical telescope, the background space between stars and galaxies is almost completely dark. However, a sufficiently sensitive radio telescope detects a faint background glow that is almost uniform…
Wikipedia · Cosmic microwave backgroundWhich Welsh mathematician introduced the equals sign?
Robert Recorde — Recorde, in 1557 — 'no two things can be more equal'.
Robert Recorde was a Welsh physician and mathematician. He invented the equals sign (=) and also introduced the pre-existing plus (+) and minus (−) signs to English speakers in 1557.
Wikipedia · Robert RecordeWhich khan's fleet was wrecked twice by 'kamikaze' typhoons?
Kublai Khan — Kublai — Japan's divine winds, 1274 and 1281.
Kublai Khan, also known by his temple name as the Emperor Shizu of Yuan and his regnal name Setsen Khan, was the founder and first emperor of the Mongol-led Yuan dynasty of China. He proclaimed the dynastic name "Great Yuan" in 1271, and ruled Yuan China until his death in 1294.
Wikipedia · Kublai KhanWhich receptor, also triggered by physical heat, does capsaicin activate?
TRPV1 — the burn is a genuine heat signal.
Capsaicin (8-methyl-N-vanillyl-6-nonenamide) is a toxin that is the main active component of chili peppers and gives them their distinct pungent, "spicy" or "hot" taste. It is a potent irritant for mammals for which it produces a sensation of burning in any tissue with which it comes into contact. Capsaicin and several related amides…
Wikipedia · CapsaicinRoughly how many stars are expected to collide when Andromeda meets the Milky Way?
Essentially none — galaxies are overwhelmingly empty space.
The Andromeda Galaxy is a barred spiral galaxy and is the nearest major galaxy to the Milky Way. It was originally named the Andromeda Nebula and is cataloged as Messier 31, M31, and NGC 224. Andromeda has a D25 isophotal diameter of about 46.56 kiloparsecs (152,000 light-years) and is approximately 765 kpc (2.5 million light-years) from…
Wikipedia · Andromeda GalaxyWhich orbital point lets telescopes like JWST hover with Earth?
Lagrange point L2 — L2, 1.5 million km out.
In celestial mechanics, the Lagrange points, also called the Lagrangian points or libration points, are points of equilibrium for small-mass objects under the gravitational influence of two massive orbiting bodies. Mathematically, this involves the solution of the restricted three-body problem.
Wikipedia · Lagrange pointWhich Baroque woman painter's Judith Slaying Holofernes stunned Florence?
Artemisia Gentileschi
Artemisia Lomi Gentileschi was an Italian Baroque painter. Gentileschi is considered among the most accomplished 17th-century artists, initially working in the style of Caravaggio. She was producing professional work by the age of 15. In an era when women had few opportunities to pursue artistic training or work as professional artists,…
Wikipedia · Artemisia GentileschiWhich physicist gave entropy its statistical definition, carved on his gravestone?
Boltzmann — S = k log W, in Vienna.
Entropy is a thermodynamic state variable that quantifies the probabilistic distribution of accessible microstates in a system. The term and the concept are used in diverse fields, from classical thermodynamics, to the microscopic description of nature in statistical physics, and the principles of information theory. It has found…
Wikipedia · EntropyPersisting lactase into adulthood is the unusual state — roughly what share of adults do?
About a third — tolerance is the mutation, not the norm.
Lactase (EC 3.2.1.108) is an enzyme produced by many organisms and is essential to the complete digestion of whole milk. It breaks down the sugar lactose into its component parts, galactose and glucose, simple sugars that can be absorbed into the bloodstream through an animal's intestines. A lactase is a type of β-galactosidase because…
Wikipedia · LactaseWhich kingdom built the temple complex of Angkor Wat?
The Khmer Empire — The Khmer, under Suryavarman II.
The Khmer Empire was an empire in mainland Southeast Asia, centred on hydraulic cities in what is now northern Cambodia. Known as Kambuja by its inhabitants, it grew out of the former civilisation of Chenla and lasted from 802 to 1431 AD. Historians call this period of Cambodian history the Angkor period, after the empire's most…
Wikipedia · Khmer EmpireWhich Georgian script's oldest form is Asomtavruli?
Georgian — three scripts, one language.
The Georgian scripts are the three writing systems used to write the Georgian language: Asomtavruli, Nuskhuri and Mkhedruli. Although the systems differ in appearance, their letters share the same names and alphabetical order and are written horizontally from left to right. Of the three scripts, Mkhedruli, once the official script of the…
Wikipedia · Georgian scriptsSailing 'westabout' around which cape is considered the hardest passage?
Cape Horn — beating into the westerlies.
Cape Horn is the southernmost headland of the Tierra del Fuego archipelago of southern Chile, and is located on the small Hornos Island. Although not the most southerly point of South America, Cape Horn marks both the northern boundary of the Drake Passage and where the Atlantic and Pacific Oceans meet.
Wikipedia · Cape HornWhich moon of Mars will crash or shred into a ring within 50 million years?
Phobos — spiraling inward each year.
Phobos is the innermost and larger of the two natural satellites of Mars, the other being Deimos. The two moons were discovered in 1877 by American astronomer Asaph Hall. Phobos is named after the Greek god of fear and panic, who is the twin brother of Deimos and son of Ares (Mars).
Wikipedia · Phobos (moon)Which cipher machine's naval version had four rotors?
Enigma — The Kriegsmarine Enigma M4.
The Enigma machine is a cipher device developed and used in the early- to mid-20th century to protect commercial, diplomatic, and military communication. It was employed extensively by Nazi Germany during World War II, in all branches of the German military. The Enigma machine was considered so secure that it was used to encipher the…
Wikipedia · Enigma machineWhich mathematician-astronomer of the House of Wisdom gave us the word algebra?
Al-Khwarizmi — from al-jabr, 'restoration'.
Muhammad ibn Musa al-Khwarizmi, or simply al-Khwarizmi was a mathematician active during the Islamic Golden Age, who produced Arabic-language works in mathematics, astronomy, and geography. Around 820, he worked at the House of Wisdom in Baghdad, the contemporary capital city of the Abbasid Caliphate. One of the most prominent scholars…
Wikipedia · Al-KhwarizmiWhich pigment's synthetic form freed painters from lapis lazuli's price?
French ultramarine — Synthetic ultramarine, from 1828.
A pigment is a chemical compound that gives a substance or organism color, or is used by humans to add or alter color or change visual appearance. Pigments are nearly or completely insoluble and chemically unreactive in water or another medium; in contrast, dyes are colored substances which are soluble or go into solution at some stage…
Wikipedia · PigmentWhich 1973 tomb find gave the oldest known Tao Te Ching, with its two halves reversed?
Mawangdui — the De section came first.
The Tao Te Ching or Dào Dé Jīng, or Laozi in Chinese and scholarship, is an ancient Chinese classic text and the foundational work of Taoism. Central to both philosophical and religious Taoism, it has been highly influential on Chinese philosophy and religious practice.
Wikipedia · Tao Te ChingWhich crystal structure do diamonds and silicon share?
The diamond cubic lattice
Monocrystalline silicon, often referred to as single-crystal silicon or simply mono-Si, is a critical material widely used in modern electronics and photovoltaics. As the foundation for silicon-based discrete components and integrated circuits, it plays a vital role in virtually all modern electronic equipment, from computers to…
Wikipedia · Monocrystalline siliconWhose paradoxes include Achilles never catching the tortoise?
Zeno of Elea — Zeno — motion itself put on trial.
Zeno of Elea was a pre-Socratic Greek philosopher from Elea, in Southern Italy. He was a student of Parmenides and one of the Eleatics. Zeno defended his instructor's belief in monism, the idea that only one single entity exists that makes up all of reality. He rejected the existence of space, time, and motion. To disprove these…
Wikipedia · Zeno of EleaWhat is the SI base unit of luminous intensity?
Candela — lumen and lux are derived from it.
Candela is the SI unit of luminous intensity. It measures the luminous power per unit solid angle emitted in a particular direction. A common wax candle has a luminous intensity of roughly 1 cd.
Wikipedia · CandelaWhich African kingdom was famed for its bronze plaques, later looted by British forces in 1897?
The Kingdom of Benin — in present-day Nigeria.
The Kingdom of Benin or Empire of Benin, also known as Great Benin, is a traditional kingdom in southern Nigeria. It has no historical relation to the modern republic of Benin, which was known as Dahomey from the 17th century until 1975. The Kingdom of Benin's capital was Edo, now known as Benin City in Edo State, Nigeria. The Benin…
Wikipedia · Kingdom of BeninWhat is the name for the boundary where two tectonic plates slide past each other horizontally?
A transform boundary — like California's San Andreas Fault.
Plate tectonics is the scientific theory that Earth's lithosphere comprises a number of large tectonic plates, which have been slowly moving since 3–4 billion years ago. The model builds on the concept of continental drift, an idea developed during the first decades of the 20th century. Plate tectonics came to be accepted by…
Wikipedia · Plate tectonicsWhat is the name of the current geological epoch, generally dated from about 11,700 years ago?
The Holocene — following the last glacial period.
The Holocene is the current geological epoch, beginning approximately 11,700 years ago. It follows the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene together form the Quaternary period. The Holocene is an interglacial period within the ongoing glacial cycles of the…
Wikipedia · HoloceneWhich Japanese art repairs broken pottery with gold, making the damage the feature?
Kintsugi — the seam is the point, not a concealment.
Whose 1854 map of a Soho water pump founded epidemiology?
John Snow — cholera plotted street by street.
Which Roman office was designed to be held for six months and never renewed?
Dictator — an emergency post, until it was not.
Which mathematical object has a boundary of infinite length enclosing a finite area?
The Koch snowflake — a fractal curve.
Which 1600 Dutch invention was refused a patent because too many people claimed it?
The telescope — three spectacle-makers claimed it at once.
Which people navigated the Pacific using stick charts of swell patterns?
The Marshallese — the chart maps water, not islands.
Which layer of the atmosphere gets warmer with altitude, trapping the one below it?
The stratosphere — which is why it does not churn.
Which physical constant did Cavendish effectively measure by weighing the Earth in a shed?
The gravitational constant — a torsion balance, 1798.
Which cave art site was closed to visitors because human breath grew mould on the paintings?
Lascaux — a replica takes the tourists now.
Which economic idea says a resource everyone may use and nobody owns will be exhausted?
The tragedy of the commons — and Ostrom showed it is escapable.
Which Mesoamerican civilization's writing was largely destroyed by one bishop in one night?
The Maya — Diego de Landa burned the codices at Mani.
Which unit of information did Shannon's 1948 theory of communication establish?
The bit — information measured as resolved uncertainty.
Which structure in the brain, removed from patient H.M., ended his ability to form new memories?
The hippocampus — taken from both sides, in 1953.
Which strait's closure has been the standing threat to a fifth of the world's oil?
Hormuz — 33 kilometres wide at the narrowest.
Which Renaissance anatomist corrected Galen by dissecting humans rather than animals?
Vesalius — De humani corporis fabrica, 1543.
Which effect makes a spinning ball curve sideways through the air?
The Magnus effect — pressure differs across the spin.
Which mathematician's marginal note went unproven for 358 years?
Fermat — proved by Andrew Wiles in 1994.
Which physical principle explains why you cannot unscramble an egg?
The second law of thermodynamics — The second law — the arrow of time is statistical.
Which Central American canal route was abandoned by France after 22,000 deaths?
Panama — mostly malaria and yellow fever.
Which language, revived from liturgical use, is the only one to have become a national tongue again?
Hebrew — spoken daily again within two generations.
Which optical illusion of the Moon has no agreed explanation after two millennia?
The Moon illusion — it looks larger near the horizon.
Which islands' finches were less important to Darwin at the time than their mockingbirds?
The Galapagos — the mockingbirds were labelled properly.
Which Ottoman institution took Christian boys as a levy and made them the elite corps?
The devshirme — the Janissaries came from it.
Which two metals will cold-weld together in vacuum simply by touching?
Any two clean identical metals — with no oxide layer between them.
Which mathematical result shows some infinities are strictly larger than others?
Cantor's diagonal argument — the reals outnumber the integers.
Which spice was worth more than gold and grew on one small group of islands?
Nutmeg — the Banda Islands, and the Dutch took them by massacre.
Which weather pattern's name means 'the boy child' because it arrives near Christmas?
El Nino — named by Peruvian fishermen.
Which African American mathematician's orbital calculations John Glenn insisted on rechecking by hand?
Katherine Johnson — he would not fly until she confirmed the machine.
Which classical structure did the Romans discover would self-heal when cracked by water?
Concrete — unmixed lime clasts reseal the crack.
Which social science finding says small groups of committed people shift a majority at about 25 per cent?
The tipping point in social convention — tested experimentally in 2018.
Which crop failure in a genetically uniform monoculture killed a million people in the 1840s?
The Irish potato — one clone, one blight.
Which computing concept did Ada Lovelace describe that Babbage's own notes did not?
A general-purpose algorithm — and machines beyond numbers.
Which sculpture technique lets a hollow bronze be cast from a model that is destroyed in the process?
Lost-wax casting — the model is melted out and lost.
Which document's decipherment depended on a Coptic liturgy still sung in churches?
Egyptian hieroglyphs — Coptic kept the language audible.
Which bacterium's discovery cost two researchers years of ridicule until one drank a culture?
Helicobacter pylori — Marshall gave himself the ulcer to prove it.
Which 1943 famine in British India killed some three million during a food-exporting year?
The Bengal famine — and the causes are still argued over.
Which mathematical constant relates a circle's circumference to its diameter in any curved space?
It does not — pi is flat-space only — It does not — on a sphere the ratio is less than pi.
Which Venetian institution ran a state-owned shipyard producing a galley a day?
The Arsenal — an assembly line four centuries early.
Which effect causes a moving source's pitch to drop as it passes you?
The Doppler effect — and it measures the universe's expansion too.
Which asteroid impact site was identified from oil-company gravity surveys decades after the fact?
Chicxulub — buried under Yucatan limestone.
Which philosopher argued that a private language is impossible?
Wittgenstein — meaning needs a public check.
Which cipher, unbroken for centuries, is theoretically unbreakable if the key is never reused?
The one-time pad — proven secure, and impractical.