157 Fun Facts About High School

Whose theorem says the square of a right triangle's hypotenuse equals the sum of the squares of the other sides?

Babylonian clay tablets show the relationship was known a thousand years before Pythagoras was born; he just got the naming rights.

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

Its diameter fits around the circumference about 3.14 times; Archimedes trapped pi between 223/71 and 22/7 using 96-sided polygons drawn inside and outside a circle.

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

180 degrees holds only on a flat surface: on a globe, a triangle drawn from the North Pole down to the equator can have a right angle at every corner.

What is the only even prime number?

2 is the only even prime because every other even number can be divided by 2, which gives it a factor besides 1 and itself.

In the quadratic formula, the expression b² − 4ac is called what?

The discriminant b² − 4ac tells how many real roots a quadratic has: negative means none, zero means one repeated root, positive means two.

The imaginary unit i is defined by which equation?

i² = −1 is the whole definition of the imaginary unit; electrical engineers write it as j instead, because the letter i already stands for electric current.

What is the highest possible score on the SAT?

1600 is two sections of up to 800 points each; from 2005 to early 2016 a third section, writing, pushed the maximum to 2400.

Which organelle is nicknamed the 'powerhouse of the cell'?

The mitochondrion carries its own small loop of DNA, normally inherited only from the mother, a leftover from the free-living bacterium it descends from.

Adenine, cytosine and guanine are three of DNA's four bases; what is the fourth?

Thymine takes its name from the thymus: Albrecht Kossel and Albert Neumann first isolated it in 1893 from the thymus glands of calves.

What shape do the two strands of DNA form?

DNA's two strands twist into a double helix, the structure Watson and Crick published in 1953 using X-ray diffraction images from Rosalind Franklin's lab.

Gregor Mendel worked out the basic laws of heredity by breeding which plants?

Peas let Mendel follow traits such as seed shape through thousands of plants in his monastery garden from 1856; his findings were ignored until other botanists rediscovered them in 1900.

Which type of cell division produces sperm and egg cells?

Meiosis halves the chromosome number and swaps stretches of DNA between paired chromosomes as it goes, which is why brothers and sisters inherit different mixes of their parents' genes.

Which pigment do plants use to absorb light for photosynthesis?

Chlorophyll absorbs red and blue light to power photosynthesis and reflects green, which is why leaves look green.

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

O negative red cells carry no A, B or RhD antigens, so they can be given to patients of any blood type; AB positive is the universal recipient.

Which element has atomic number 1?

Hydrogen is the lightest element and makes up about 75 percent of the universe's normal matter by mass; stars such as the Sun shine by fusing it into helium.

On the pH scale, what value is neutral?

Below 7 is acidic and above 7 is basic; each step is a tenfold change, so pH 5 is a hundred times more acidic than pH 7.

Helium, neon, argon and krypton belong to which group of elements?

Helium, neon, argon and krypton are noble gases, group 18 of the periodic table; their full outer electron shells make them almost completely unreactive.

Who published the first widely accepted periodic table in 1869?

Dmitri Mendeleev's 1869 table left gaps for undiscovered elements and predicted their properties; gallium (1875) and germanium (1886) later filled two of them.

How many chemical elements are on the modern periodic table?

118 elements fill the modern table, and the heaviest two dozen were first made artificially rather than found in nature.

The constant 6.022 × 10^23, a fixture of chemistry class, is named after which Italian scientist?

Amedeo Avogadro never knew the number: he proposed in 1811 that equal volumes of gas hold equal numbers of molecules, and Jean Perrin named the constant for him in 1909.

A rocket moves forward by throwing exhaust backward, an example of which of Newton's laws?

Third law of motion: the exhaust pushes back on the rocket as hard as the rocket pushes it out, so a rocket needs no air to push against, as Robert Goddard showed in a vacuum chamber.

Roughly how fast does light travel in a vacuum?

Light travels about 300,000 km per second in a vacuum, exactly 299,792,458 metres per second; since 1983 that value has defined the metre.

The Ring of Fire, home to about 90 percent of the world's earthquakes, surrounds which ocean?

The Ring of Fire is a horseshoe of deep trenches and volcanic arcs rimming the Pacific Ocean, where oceanic plates sink beneath their neighbours.

Which language has the most native speakers in the world?

Mandarin has roughly twice as many native speakers as Spanish, the runner-up; English, third on that list, comes out on top only when second-language speakers are counted.

Who accepted Robert E. Lee's surrender at Appomattox?

Ulysses S. Grant let Lee's soldiers keep their horses and mules for the spring planting and sent rations across the lines to the hungry Confederates.

Which amendment to the US Constitution abolished slavery?

The 13th Amendment took effect in December 1865 when Georgia ratified it; Mississippi held out until 1995 and did not file the paperwork until 2013.

How many amendments make up the Bill of Rights?

The Bill of Rights is the first 10 amendments, ratified in 1791. Twelve were sent to the states in 1789; the one on lawmakers' pay was finally ratified in 1992 as the 27th.

The United States bought the Louisiana Territory in 1803 from which country?

France sold the territory for about 15 million dollars, nearly doubling the United States, after a slave revolt in Haiti wrecked its plans for an American empire.

What does 'score' mean in Lincoln's 'four score and seven years ago'?

Twenty years make a score, so four score and seven is 87: speaking in 1863, Lincoln was counting back to 1776.

In which city did the Constitutional Convention meet in 1787?

Philadelphia's Pennsylvania State House, now Independence Hall, hosted the convention under a rule of secrecy: no reporters or visitors were admitted, so delegates could argue freely.

Which amendment recognized women's right to vote nationwide in 1920?

The 19th Amendment was ratified in August 1920 when Tennessee became the 36th state to approve it, after young legislator Harry Burn switched his vote on his mother's advice.

The Wright brothers' first powered flight in 1903 was near Kitty Hawk, in which state?

Kitty Hawk is on North Carolina's Outer Banks; the Wright brothers, from Dayton, Ohio, chose it for steady winds and soft sand, flying on December 17, 1903.

The Wall Street crash's panic selling on 29 October 1929 is remembered by what name?

Black Tuesday followed Black Monday: the Dow fell nearly 13 percent one day and nearly 12 percent the next, and the slide did not hit bottom until July 1932.

Which 1954 Supreme Court case ruled that racial segregation in public schools was unconstitutional?

Brown v. Board of Education (1954) unanimously held that segregated public schools are inherently unequal, overturning the 'separate but equal' doctrine of Plessy v. Ferguson (1896).

How many members does the US Senate have?

The Senate has 100 members, two per state, serving staggered six-year terms so roughly a third of the seats are contested every two years.

The US House's 435 seats are reshuffled among the states after each what?

Census counts, taken every ten years, decide how the seats are shared out; a 1929 law froze the total at 435, so one state's gain is another state's loss.

Who sets the number of US Supreme Court justices?

Congress sets the number by ordinary law, not the Constitution: the Court began with six justices in 1789, reached ten in 1863 and has had nine since 1869.

A presidential candidate needs 270 votes in which body?

The Electoral College has 538 electors, so 270 is the smallest possible majority; in 2000 and 2016 the winner reached it while losing the nationwide popular vote.

The assassination that triggered World War I killed the heir to which throne?

Austria-Hungary's Franz Ferdinand had already survived a bomb that morning in Sarajevo; then his driver took a wrong turn and stalled the car right beside Gavrilo Princip.

World War II in Europe began in September 1939 when Germany invaded which country?

Poland was soon caught between two invaders: the Soviet Union attacked from the east on 17 September, under a secret deal with Hitler to divide the country.

Bastille Day, the national holiday marking the 1789 storming of a Paris prison, falls on which date?

The Bastille fell on 14 July 1789; the crowd found only seven prisoners inside, and the date became a national holiday in 1880.

Which monarch sealed Magna Carta at Runnymede in 1215?

King John sealed Magna Carta on 15 June 1215 under pressure from rebel barons, then had Pope Innocent III annul it by late August, reigniting civil war.

Which US president urged Gorbachev to 'tear down this wall'?

Ronald Reagan kept the line in his 1987 speech although the State Department and National Security Council tried to cut it; the Wall opened 29 months later.

The Western Roman Empire's fall in 476 traditionally begins which period?

The Middle Ages are conventionally dated from 476, when the general Odoacer deposed the young emperor Romulus Augustulus and the imperial regalia were sent away to Constantinople.

Shakespeare's Romeo and Juliet is set in which Italian city?

Verona's famous 'Juliet's balcony' is a 20th-century addition, fitted to the old house centuries after Shakespeare wrote the play.

Shakespeare's Hamlet is a prince of which country?

Denmark's Kronborg Castle at Helsingør is the play's Elsinore; Hamlet was first staged there in 1816, with soldiers from the castle garrison as the cast.

Who wrote To Kill a Mockingbird?

Harper Lee published To Kill a Mockingbird in 1960 and won the 1961 Pulitzer Prize for Fiction; she did not publish another book until Go Set a Watchman in 2015.

Who wrote The Great Gatsby?

F. Scott Fitzgerald's novel sold poorly in 1925, and its fame came late: during World War II it was handed free to American soldiers as an Armed Services Edition.

In Orwell's Nineteen Eighty-Four, what is the Party's official language called?

Newspeak's vocabulary shrinks every year: the Party keeps cutting words so that, by 2050, a disloyal thought would have no words to be thought in.

In Orwell's Animal Farm, the pig Napoleon is an allegory for which leader?

Joseph Stalin was a wartime ally when Orwell finished the book in 1944, so several publishers turned it down, among them T. S. Eliot at Faber.

Who wrote Of Mice and Men?

John Steinbeck wrote Of Mice and Men in 1937 as a 'play-novelette' so it could go straight to the stage; it opened on Broadway that November.

In Lord of the Flies, what object do the boys use to call their meetings?

The conch shell, blown by Ralph to summon the boys, gives its holder the right to speak; its shattering when Piggy is killed marks the end of order.

In Homer's Odyssey, Odysseus is king of which island?

Odysseus rules Ithaca, an island in the Ionian Sea; he takes ten years to get home from Troy while Penelope holds off a houseful of suitors.

Who wrote Frankenstein?

Mary Shelley started it at 18 after Lord Byron challenged his guests to each write a ghost story.

Arthur Miller's play The Crucible dramatizes which historical event?

The Crucible dramatizes the Salem witch trials of 1692–93; Miller wrote it in 1953 as an allegory for McCarthyism and was called before HUAC himself in 1956.

Holden Caulfield narrates which 1951 novel?

The Catcher in the Rye made J. D. Salinger so famous that he withdrew to rural New Hampshire and published nothing after 1965.

The epic poem Beowulf was written in which language?

Beowulf is written in Old English (Anglo-Saxon); its 3,182 alliterative lines survive in a single manuscript scorched in the 1731 Cotton library fire.

What is the chemical symbol for gold?

Au comes from aurum, the Latin word for gold; gold is element 79 on the periodic table.

Which astronomer formulated the three laws of planetary motion?

Johannes Kepler inherited Tycho Brahe's observations and wrestled with the orbit of Mars for years before accepting that planets travel in ellipses, not circles.

What is the largest organ of the human body?

The skin outranks every other organ in size and even makes vitamin D when sunlight strikes it; the liver is the largest organ inside the body.

Who narrates The Great Gatsby?

Nick Carraway rents the cottage beside Gatsby's mansion and is Daisy's cousin, which is why Gatsby cultivates him: he wants Nick to bring the two of them back together.

In George Orwell's Nineteen Eighty-Four, what is Winston Smith's job at the Ministry of Truth?

Rewriting historical records is Winston's daily work: he alters back issues of The Times so the past always matches the Party's current line, then drops the originals into a 'memory hole' to be burned.

In Nineteen Eighty-Four, what is the name of the Party's dictatorial leader whose face is everywhere?

Big Brother stares from every poster, yet the novel never settles whether he is a real person; O'Brien tells Winston only that Big Brother will never die.

Who was the principal author of the US Declaration of Independence?

Thomas Jefferson drafted it for the Committee of Five, and the delegates then cut roughly a quarter of his text, including a passage condemning the slave trade.

How long was Abraham Lincoln's Gettysburg Address, delivered in November 1863?

The Gettysburg Address ran about 270 words and under two minutes; the main speaker, Edward Everett, had talked for two hours before Lincoln rose.

Mount Everest sits on the border between Nepal and which other country?

China and Nepal long differed over Everest's height, because China measured to the rock and Nepal to the snow on top; in 2020 they jointly announced 8,848.86 metres.

What is the largest hot desert in the world?

The Sahara covers about 9.2 million square kilometres of North Africa, yet it is only the third-largest desert: Antarctica and the Arctic count too, because deserts are defined by dryness, not heat.

In which English town was William Shakespeare born in 1564?

Stratford-upon-Avon recorded only his baptism, on 26 April 1564; the birthday kept on 23 April is a tradition, appealing because he died on that date in 1616.

The Mona Lisa, painted by Leonardo da Vinci, hangs in which museum?

The Louvre, Paris, lost it in 1911 to Vincenzo Peruggia, a workman who had helped fit its protective glass; he hid it for two years and was arrested in Florence trying to sell it.

Which Beethoven symphony ends with a choral setting of Schiller's 'Ode to Joy'?

The Ninth premiered in Vienna in 1824; Beethoven, by then deaf, kept beating time until a soloist turned him round to see the applause he could not hear.

About how many bones does an adult human skeleton have?

206 is the adult count; babies are born with around 270, but many fuse together as they grow.

How many bits make up one byte?

8 bits became the standard byte only with IBM's System/360 in the 1960s; before that, computers commonly used bytes of six or nine bits.

The Nile flows north and empties into which sea?

The Mediterranean receives the Nile through a delta north of Cairo; the river's yearly flood renewed Egypt's fields with silt until the Aswan High Dam ended it in 1970.

Water boils at about 70 °C atop Mount Everest because what is lower there?

Air pressure on Everest's summit is about a third of that at sea level, so water boils near 70 °C instead of 100 °C, too cool to cook food properly without a pressure cooker.

Which Apollo 11 astronaut stayed in lunar orbit while Armstrong and Aldrin walked on the Moon?

Michael Collins orbited alone in Columbia for more than 21 hours, losing all radio contact for 48 minutes of every lap as he passed behind the Moon.

In To Kill a Mockingbird, Atticus Finch is appointed to defend which character?

Tom Robinson is convicted even though Atticus shows that his crippled left arm could hardly have caused Mayella Ewell's injuries; he is later shot dead trying to escape from prison.

Newton's first law of motion is also known as the law of what?

Inertia is a body's resistance to any change in its motion; Galileo argued it before Newton, against Aristotle's view that motion needs a constant push.

The Challenger Deep, the lowest known point in the world's oceans, lies in which trench?

The Mariana Trench's Challenger Deep is about 10,900 metres down, deep enough to swallow Everest with 2 km to spare; it is named for HMS Challenger, whose 1870s expedition first sounded it.

In which Greek city is Shakespeare's 'A Midsummer Night's Dream' set?

Athens is ruled in the play by Duke Theseus, whose wedding frames the plot; in the woods outside the city, the sprite Puck gives the weaver Bottom a donkey's head.

The title of 'A Raisin in the Sun' comes from a poem by which writer?

Langston Hughes's poem 'Harlem' asks what happens to a dream deferred; the play echoes Hansberry's own family, who fought a whites-only housing covenant up to the Supreme Court in 1940.

Which river is the largest in the world by discharge volume?

The Amazon carries about a fifth of all river water reaching the oceans; in 1500 the Spanish explorer Vicente Pinzón met so much fresh water at its mouth that he named it the 'Sweet Sea'.

Which document served as the first constitution of the United States?

The Articles of Confederation left the central government unable to tax or to regulate trade, and its treasury ran dry; that weakness is why the Constitution replaced them in 1789.

Chemical elements are distinguished from each other by the number of which particle?

Protons define the element: every atom with six is carbon, whatever its neutrons or electrons, so no chemical reaction can turn one element into another; only a nuclear one can.

Which bacterium caused the Black Death?

Yersinia pestis was confirmed as the cause only in 2010–11, when its DNA was recovered from the skeletons of Black Death victims in mass graves, settling a long dispute.

Some of the colonists who dumped tea at the 1773 Boston Tea Party wore which disguise?

Native Americans were the disguise some of the Sons of Liberty chose before dumping about 340 chests of tea; Parliament answered by closing Boston's port until the tea was paid for.

Who wrote the 1932 dystopian novel 'Brave New World'?

Aldous Huxley once taught French at Eton to Eric Blair, the future George Orwell, and years later wrote to tell him he doubted that a 'boot-on-the-face' tyranny could last.

The Byzantine Empire ended with the fall of Constantinople to which power in 1453?

The Ottomans under Mehmed II took Constantinople on 29 May 1453; the empire's people had always called themselves Romans, and the name 'Byzantine' was applied only after it fell.

Which molecule stores the energy released by cellular respiration?

ATP is the cell's energy currency, spent and rebuilt so quickly that an adult's body recycles tens of kilograms of it every day.

With whom did Charles Darwin jointly present the theory of natural selection?

Alfred Russel Wallace's 1858 letter from the Malay Archipelago prompted the joint reading of his and Darwin's papers at the Linnean Society on 1 July 1858.

What is the value of 5 factorial, written 5!?

5! = 5 × 4 × 3 × 2 × 1 = 120, which is why five people can line up in 120 different orders; add a sixth person and the count jumps to 720.

Which type of chemical bond involves sharing electron pairs between atoms?

Covalent bonds share electron pairs between atoms; a rigid lattice of them is what makes diamond, which is pure carbon, the hardest natural material.

Which Soviet leader agreed to pull his missiles out of Cuba, ending the 1962 crisis?

Nikita Khrushchev announced the withdrawal on October 28, 1962, after 13 days; in a secret side deal, the US agreed to remove its own Jupiter missiles from Turkey.

Who is the protagonist of Arthur Miller's 'Death of a Salesman'?

Willy Loman, a worn-out Brooklyn salesman, ends the play by crashing his car on purpose so that his son Biff can collect the life insurance.

The change in pitch of a passing siren is named after which physicist, who proposed it in 1842?

Christian Doppler proposed the effect in an 1842 paper on binary-star light; Buys Ballot confirmed it for sound in 1845 using trumpeters on a moving train.

Which band of the electromagnetic spectrum has the highest frequency?

Gamma rays have the highest frequency of all light; Earth's atmosphere absorbs them, so astronomers had to send detectors up on balloons and satellites to see the gamma-ray sky.

An electron is roughly how many times lighter than a proton or neutron?

2,000 is the round figure: a proton weighs about 1,836 electrons, so almost all of an atom's mass sits in its tiny nucleus.

Lincoln's 1863 Emancipation Proclamation declared enslaved people free in which part of the country?

Confederate-held territory was all it covered: Lincoln issued it as a war measure against the rebellion, so slavery stayed legal in the slave states that had remained loyal to the Union.

What are the molecules that enzymes act upon called?

Substrates fit an enzyme's active site like a key in a lock, an image Emil Fischer proposed in 1894, which is why most enzymes act on only one or a few molecules.

Roughly how far is it around the Earth at the equator?

40,000 km is no accident (it is 40,075 km exactly): the metre was first defined in the 1790s as one ten-millionth of the distance from the North Pole to the equator.

What is the name of the fireman protagonist of 'Fahrenheit 451'?

Guy Montag is the fireman who starts stealing the books he is paid to burn; Ray Bradbury published the novel in 1953.

Alexander Hamilton and John Jay wrote the Federalist Papers with which future president?

James Madison wrote 29 of the 85 essays; the three rushed them into New York newspapers under one shared pen name, 'Publius', to win the state's vote to ratify the Constitution.

In the Fibonacci sequence, how is each element after the first two produced?

Sum of the two before it gives 1, 1, 2, 3, 5, 8, 13; Fibonacci introduced it to Europe in 1202 with a puzzle about how fast a pair of rabbits would multiply.

The French Revolution is conventionally said to end with a 1799 coup led by whom?

Napoleon Bonaparte's Coup of 18 Brumaire, on 9 November 1799, overthrew the Directory and made him First Consul; five years later he crowned himself emperor.

What is the name of the orphan whose education 'Great Expectations' depicts?

Pip nearly lost Estella for good: Dickens's first ending kept them apart, and he rewrote it before publication after novelist Edward Bulwer-Lytton called it too sad.

What term describes the time for a radioactive quantity to drop to 50% of its starting value?

Half-life is the time for half of a radioactive sample to decay; carbon-14's, about 5,700 years, lets archaeologists date once-living material back to roughly 50,000 years.

Which gas law says that halving a gas's volume doubles its pressure, at constant temperature?

Boyle's law, published by Robert Boyle in 1662, is why scuba divers must breathe out as they rise: the air in their lungs expands as the pressure around them falls.

In which country did the Industrial Revolution begin around 1760?

Great Britain tried to keep its lead by forbidding textile workers to emigrate, but Samuel Slater memorised the mill machinery and slipped away to America in 1789.

Under what pen name did Charlotte Brontë first publish 'Jane Eyre' in 1847?

Currer Bell hid Charlotte Brontë: she and her sisters kept their own initials but chose ambiguous names, suspecting that women authors were judged with prejudice.

Which two senators lead the conspiracy in Shakespeare's play about Caesar?

Cassius and Brutus lead the plot: Cassius wins his friend over by having forged letters, seemingly from worried citizens, thrown in at his window.

What is the formula for the kinetic energy of a non-rotating object?

Kinetic energy is ½mv², the work needed to accelerate a mass m from rest to speed v; doubling the speed quadruples the energy.

By what other name is the citric acid pathway of respiration known?

Krebs cycle honours Hans Krebs, whose 1937 paper describing it was turned down by the journal Nature; a small Dutch journal printed it, and it won him a share of the 1953 Nobel Prize.

What is the logarithm of 1000 to base 10?

log base 10 of 1000 is 3, because 10 × 10 × 10 = 1000; earthquake magnitudes work the same way, so each whole step up means ten times the measured shaking.

Which Shakespeare tragedy, first performed around 1606, is his shortest?

Macbeth is little more than half the length of Hamlet; theatre superstition holds that saying its name backstage brings bad luck, so actors call it 'the Scottish Play'.

Which Babylonian king had his laws, including 'an eye for an eye', carved on a tall stone pillar?

Hammurabi's pillar, taller than a person, was carried off as loot centuries later to Susa, in today's Iran, where French archaeologists dug it up in 1901.

Which 19th-century belief held that the United States was meant to expand across North America?

Manifest destiny first appeared in an 1845 essay urging the United States to annex Texas; the phrase is usually credited to magazine editor John O'Sullivan.

Which 1803 Supreme Court case established judicial review?

Marbury v. Madison was a loss for William Marbury: the Court said the law that let it order his commission delivered was unconstitutional, so it could not help him.

The Marshall Plan sent billions in American aid to rebuild which region after World War II?

Western Europe took the aid; it was offered to the Soviet Union and its allies too, but Moscow refused and made the Eastern Bloc states turn it down.

During which phase of the cell cycle does a cell copy its DNA?

S phase, short for synthesis, is when every chromosome is copied into two identical sister chromatids, which is what lets mitosis hand each daughter cell a full set.

Which SI base unit measures amount of substance?

The mole counts particles the way a dozen counts eggs; since 2019 it has been fixed by an exact number instead of by the atoms in 12 grams of carbon-12.

Which US foreign policy opposes foreign interference in the Western Hemisphere?

The Monroe Doctrine drew little notice from Europe's great powers when it was announced in 1823; it grew into a cornerstone of US foreign policy only decades later.

What are the electric signals fired by neurons called?

Action potentials are all-or-nothing electrical spikes; how they work was unravelled using the giant nerve fibre of a squid, thick enough to slip an electrode inside.

James Chadwick won the 1935 Nobel Prize in Physics for discovering which particle?

The neutron, which Chadwick found in 1932, has no electric charge; its discovery led within six years to nuclear fission and, by 1942, to the first nuclear reactor.

Which president introduced the phrase 'New Deal' when accepting his party's 1932 nomination?

Franklin D. Roosevelt broke with custom by flying to Chicago to accept the nomination in person, and there pledged 'a new deal for the American people'.

Ohm's law states current is directly proportional to what?

Ohm's law says current is proportional to voltage: I = V/R, so doubling the voltage across a fixed resistance doubles the current.

In osmosis, solvent moves through a membrane toward which region?

Higher solute concentration draws the water, which is why salt preserves meat: it pulls water out of bacteria until they can no longer grow.

Which anti-war Picasso painting depicts a 1937 bombing during the Spanish Civil War?

Guernica shows the bombing of a Basque town by German and Italian aircraft; Picasso would not let it go to Spain under Franco, so it arrived there only in 1981.

On a chemist's table of the elements, what are the horizontal rows called?

Periods are the rows, and each new one starts when atoms begin filling another electron shell; the columns are called groups.

The oxygen that plants release during photosynthesis comes from splitting which molecule?

Water gives up the oxygen, not the carbon dioxide plants take in: in 1941 Samuel Ruben and Martin Kamen used isotope tracers to show where it came from.

Which earlier idea does the theory of plate tectonics build on?

Plate tectonics builds on Alfred Wegener's 1912 theory of continental drift, which gained acceptance after seafloor spreading was confirmed in the 1960s.

Who is the protagonist of Jane Austen's 1813 novel Pride and Prejudice?

Elizabeth Bennet first appeared in a draft called 'First Impressions', which a London publisher declined by return of post in 1797 without reading it.

A natural number greater than 1 that is not prime is called what?

Composite numbers each break into primes in exactly one way, as 12 = 2 × 2 × 3; keeping that true is the main reason 1 is not counted as a prime.

What is the SI unit of electric charge?

The coulomb honours Charles-Augustin de Coulomb, who in 1785 used a torsion balance to show that the force between two charges weakens with the square of their distance.

Who devised the square diagram, around 1905, that predicts the genotypes of a genetic cross?

Reginald Punnett later put his genetics to work on poultry, breeding the Cambar, the first chicken whose chicks can be sexed at hatching by the colour of their down.

The quadratic formula comes from applying which method to a general quadratic equation?

Completing the square is literal: the 9th-century mathematician al-Khwarizmi justified it with geometry, adding a small square to a figure to fill out a larger one.

The 14th and 15th Amendments were both ratified during which era of US history?

Reconstruction's three amendments ended slavery and promised equal citizenship and voting rights, but Southern states later evaded them with poll taxes and literacy tests.

Which movement took Greek and Roman antiquity as its model in art and learning?

The Renaissance began in Florence in part because banking families such as the Medici had the money to pay artists, architects and scholars to revive the ancient world.

Which tsar was forced to abdicate by Russia's February Revolution of 1917?

Nicholas II gave up the throne in March 1917, ending three centuries of Romanov rule; the Bolsheviks who seized power that autumn had him and his family shot in July 1918.

Which empire's conquests in the 1200s put most of the Silk Road under a single ruler?

The Mongol Empire made the routes safe enough for merchants like Marco Polo to cross Asia; the name 'Silk Road' came much later, popularised by a German geographer in 1877.

In mathematics, slope is the ratio of rise to what?

Run is the horizontal change; why slope is written m is a mystery: it is in print by 1844, and the idea that it stands for French 'monter', to climb, has no evidence behind it.

Sound travels fastest through which of these?

Iron carries sound at about 5,100 metres per second, roughly 15 times faster than air, because a stiff solid passes vibrations along quickly; sound cannot cross a vacuum at all.

Which museum acquired Van Gogh's 'The Starry Night' in 1941?

Museum of Modern Art, New York, has owned it since 1941; Van Gogh painted the view from his asylum window but added a village that was never there.

Huckleberry Finn's story is the direct sequel to which Mark Twain novel?

Tom Sawyer introduced Huck in 1876; the sequel, told in Huck's own dialect, was banned by the public library of Concord, Massachusetts, weeks after its 1885 US release, which only helped sales.

Pilgrims in 'The Canterbury Tales' travel to the shrine of which saint?

Thomas Becket was murdered in Canterbury Cathedral in 1170 by knights of Henry II; his shrine drew pilgrims until Henry VIII had it destroyed in 1538.

Which family is at the center of the 1939 novel 'The Grapes of Wrath'?

The Joads flee Dust Bowl Oklahoma for California, where the novel caused such anger that Kern County banned it from its schools and libraries within months.

Homer's Iliad tells of the rage of which Greek warrior?

Achilles quits the fighting when Agamemnon takes his captive Briseis, and returns only to avenge his friend Patroclus by killing Hector.

What is the name of the aging fisherman in 'The Old Man and the Sea'?

Santiago hooks a giant marlin after 84 days without a catch and fights it for days, only for sharks to strip it to the bone before he gets home.

Who wears the scarlet letter 'A' in Nathaniel Hawthorne's novel?

Hester Prynne is made to wear the 'A' for adultery, but she does so much good in the town that many people come to say the letter stands for 'Able'.

Which federal law set the Trail of Tears in motion?

The Indian Removal Act, signed by Andrew Jackson in May 1830, let the president trade land west of the Mississippi for tribal homelands in the East; tens of thousands of people were forced out, thousands dying en route.

The 1919 Treaty of Versailles was signed in which room of the palace?

The Hall of Mirrors was a pointed choice: the German Empire had been proclaimed in that very room in 1871, after the French defeat in the Franco-Prussian War.

Trigonometry takes its name from Greek words meaning what?

Triangle measure is the meaning, but the word is not ancient: the mathematician Bartholomaeus Pitiscus coined it from Greek roots in 1595 as the title of a treatise.

On which day is the Sun directly overhead at the Tropic of Cancer?

June solstice, around June 21; the tropic was named when the Sun then stood in the constellation Cancer, but Earth's slow wobble has since moved that spot into Taurus.

The painter Vincent van Gogh was born in which country?

The Netherlands-born painter worked for only about a decade; his fame came after his death in 1890, largely because his sister-in-law Johanna exhibited his work and published his letters.

In which city was Mozart born?

Salzburg did not keep him: Mozart quarrelled with his employer, the city's prince-archbishop, and was dismissed in 1781 with a literal kick from the archbishop's steward.

In which German city was Ludwig van Beethoven born?

Bonn baptised Beethoven on 17 December 1770; at 21 he moved to Vienna for good, and he made his whole career there.

Louis Pasteur's swan-neck flask experiments helped disprove which long-held idea?

Spontaneous generation held that life could arise from lifeless matter; Pasteur's boiled broth stayed clear in flasks whose curved necks let in air but trapped the dust.

Which 16th-century movement marked the beginning of Protestantism?

The Reformation began when Martin Luther published his Ninety-five Theses in Wittenberg in 1517, splitting Western Christianity and giving rise to Protestantism.

What did the initials of the ACT college admissions test originally stand for?

American College Testing began in Iowa in 1959, when professor E. F. Lindquist launched the exam as a rival to the SAT; the organisation shortened its name to plain ACT in 1996.