Class of 1953
259 things have changed since you graduated
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What’s changed since 1953
Everything here shifted in 1953 or later, some of it too recently to be in any textbook you were handed. These are the corrections the next edition hasn’t printed yet.
Revision level: Fully revised. 100% of the archive changed after 1953. Most of the archive changed after you left. You were taught a different planet.
- 259things changed
- 125were actually wrong
- 134just got sharper
- 10subjects affected
- Language & CultureUpdated
'Ain't' isn't a word either
Changed in1961Taught'Ain't' ain't a word. It is not in the dictionary, it marks you as uneducated, and using it in writing is an error.
NowIt has been in dictionaries for centuries and is labelled nonstandard. Webster's Third New International Dictionary included it without condemnation in 1961 and caused a national scandal. It originated as a perfectly respectable contraction used by the English upper class.
- Earth ScienceReplaced
Continental drift is an interesting but unproven theory
Changed in1968TaughtAlfred Wegener noticed the continents fit together like a jigsaw, but he could not explain how they moved, so the idea remains speculative and most geologists reject it.
NowPlate tectonics is the unifying framework of the earth sciences, settled by 1968. GPS now measures plate motion directly, in real time, to millimeter precision. The Atlantic widens about 2.5 centimeters a year, roughly the rate your fingernails grow.
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- BiologyDisproved
Lemmings commit mass suicide by jumping off cliffs
Changed in1983TaughtWhen lemming populations get too large, the animals instinctively march to the sea and hurl themselves off cliffs to thin the herd.
NowLemmings do not commit suicide. The belief comes largely from Disney's 1958 documentary White Wilderness, in which the filmmakers threw the animals off a cliff themselves.
- Physics & ChemistryReplaced
The meter is defined by a metal bar in Paris
Changed in1983TaughtThe meter is defined by the International Prototype Metre, a platinum-iridium bar kept near Paris, or by a specific number of wavelengths of krypton-86 light.
NowSince 1983 the meter has been the distance light travels in a vacuum in 1/299,792,458 of a second. The definition is built from the speed of light, which is now fixed by definition rather than measured.
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- HistoryDisproved
The Titanic sank in one piece
Changed in1985TaughtThe Titanic slipped beneath the surface intact and settled on the seabed as a whole ship. The official British inquiry of 1912 concluded she went down in one piece.
NowShe broke in two at the surface. Robert Ballard's 1985 discovery of the wreck found the bow and stern lying roughly 600 meters apart, and survivor accounts that had described the ship breaking apart were vindicated after 73 years.
- BiologyReclassified
The giant panda is not really a bear
Changed in1986TaughtDespite the name, giant pandas are more closely related to raccoons than to bears. Their classification is a long-standing puzzle.
NowMolecular evidence settled it: the giant panda is a bear, in the family Ursidae. The red panda is the one that is not, and sits in its own family.
- Earth ScienceDisproved
Summer happens when Earth is closer to the Sun
Changed in1987TaughtEarth's orbit is an ellipse. When we swing closer to the Sun it is summer, and when we are farthest away it is winter.
NowSeasons come from the 23.4 degree axial tilt, which changes the angle of incoming sunlight and the length of the day. Earth is actually closest to the Sun in early January, during northern winter, and the orbit is nearly circular anyway.
- Physics & ChemistryDisproved
TaughtSuperconductivity requires cooling to near absolute zero with liquid helium, which makes it a laboratory curiosity with no practical use.
NowHigh-temperature superconductors discovered in 1986 and 1987 work above 77 K, the boiling point of liquid nitrogen, which is cheap and easy to handle. Current records exceed 130 K at ambient pressure.
- BiologyDisproved
Dogs see in black and white
Changed in1989TaughtDogs are completely colorblind. Their world is a grayscale film.
NowDogs have two types of cone cell and see blues and yellows. They cannot distinguish red from green, which is why a red ball vanishes into green grass for them.
- Astronomy & SpaceDisproved
Saturn is the only planet with rings
Changed in1989TaughtSaturn is unique in the solar system: it is the one planet with a ring system.
NowAll four giant planets have rings. Uranus's were found in 1977, Jupiter's by Voyager 1 in 1979, and Neptune's rings were confirmed by Voyager 2 in 1989.
- GeographyRenamed
The country is called Burma
Changed in1989TaughtBurma, capital Rangoon, in Southeast Asia.
NowThe ruling military junta renamed it Myanmar in 1989, with Rangoon becoming Yangon. The capital then moved again in 2005 to a purpose-built city called Naypyidaw.
- BiologyDisproved
Bats are blind
Changed in1990TaughtBats cannot see at all. They navigate purely by echolocation, which is why we say "blind as a bat."
NowNo bat species is blind. All have functional eyes, many see well in low light, some see ultraviolet, and the large fruit bats rely on vision rather than echolocation.
- BiologyDisproved
Camels store water in their humps
Changed in1990TaughtA camel's hump is a water tank. That is how it crosses the desert without drinking.
NowHumps store fat, not water. The fat is an energy reserve; the camel's desert endurance comes from a suite of other adaptations, including red blood cells that survive extreme dehydration.
- Health & NutritionDisproved
Carrots give you excellent night vision
Changed in1990TaughtEat your carrots and you will be able to see in the dark.
NowCarrots supply vitamin A, which is needed for normal vision, but if you are not deficient, extra carrots do nothing for your night vision. The exaggeration was seeded by British wartime propaganda.
- HistoryRefined
Gutenberg invented printing
Changed in1990TaughtJohannes Gutenberg invented the printing press and movable type around 1440, and books existed only after that.
NowMovable type was invented in China by Bi Sheng around 1040, and metal movable type was used in Korea well before Gutenberg. The oldest surviving book printed with metal movable type is the Korean Jikji of 1377, 78 years before the Gutenberg Bible.
- BiologyReplaced
Life is divided into five kingdoms
Changed in1990TaughtAll living things belong to one of five kingdoms: Animalia, Plantae, Fungi, Protista, and Monera.
NowCarl Woese's three-domain system, proposed in 1977 and formalized in 1990, puts Bacteria, Archaea, and Eukarya at the top level. Archaea turned out to be as different from bacteria as you are.
- Earth ScienceDisproved
Lightning never strikes the same place twice
Changed in1990TaughtLightning never strikes the same place twice, so a spot that has just been hit is the safest place to stand.
NowLightning strikes favored places repeatedly and by preference. The Empire State Building is hit roughly 20 to 25 times a year. A single flash often contains multiple strokes down the same channel within a fraction of a second, so lightning frequently strikes the same place twice within milliseconds.
- HistoryDisproved
Marie Antoinette said 'let them eat cake'
Changed in1990TaughtTold that the peasants had no bread, Queen Marie Antoinette replied "let them eat cake," a remark whose cruelty helped ignite the French Revolution.
NowThere is no evidence she ever said it. The line appears in Rousseau's Confessions, written around 1765, describing an unnamed "great princess," when Marie Antoinette was a nine-year-old child in Austria who had never set foot in France.
- BiologyDisproved
Ostriches bury their heads in the sand when frightened
Changed in1990TaughtA frightened ostrich sticks its head in the sand, believing that if it cannot see the predator, the predator cannot see it.
NowNo ostrich has ever done this. They would suffocate. The impression comes from ostriches lowering their heads to the ground, either to turn their eggs in a ground nest or to lie flat when hiding.
- HistoryDisproved
The pyramids were built by slaves
Changed in1990TaughtThe Great Pyramids were raised by vast gangs of slaves driven under the whip, an image usually paired with the Exodus story.
NowThe pyramid builders were paid Egyptian laborers, organized into rotating crews, fed beef and beer, given medical care, and buried in tombs of their own beside the pyramids they built.
- HistoryDisproved
The Salem witches were burned at the stake
Changed in1990TaughtIn 1692 the Puritans of Salem burned witches at the stake on Gallows Hill.
NowNobody was burned at Salem. Nineteen people were hanged, one man was pressed to death under stones, and at least five died in jail. Burning was never a penalty for witchcraft under English law, which treated it as a felony.
- GeographyReplaced
There are two Germanys
Changed in1990TaughtEast Germany and West Germany are separate countries, divided by the Iron Curtain, with Berlin split by a wall.
NowGermany reunified on 3 October 1990. There is one Germany, and its capital is Berlin. The wall came down in November 1989.
- Language & CultureDisproved
Vikings wore horned helmets
Changed in1990TaughtViking raiders wore helmets with horns curving from the sides, as seen in every illustration, cartoon, and sports mascot.
NowNo horned helmet has ever been found in a Viking burial or settlement. Exactly one reasonably complete Viking-age helmet exists, the Gjermundbu helmet from Norway, and it has no horns. The image was invented for a Wagner opera in 1876.
- HistoryDisproved
Columbus proved the Earth was round
Changed in1991TaughtEducated Europeans in 1492 believed the Earth was flat and feared sailing off the edge. Columbus defied the flat-earthers and proved them wrong.
NowEvery educated European in 1492 already knew the Earth was a sphere, and had known for roughly eighteen centuries. The argument against Columbus was that he had the planet's size badly wrong, and his critics were right.
- Language & CultureDisproved
Eskimos have a hundred words for snow
Changed in1991TaughtEskimos have dozens, or hundreds, of words for snow, proving that language shapes how you perceive the world.
NowThe claim collapsed under examination. Inuit and Yupik languages are polysynthetic, meaning they build long words from roots and suffixes, so counting "words" is meaningless: any language can do the same by that method. The root inventory for snow is comparable to English's.
- BiologyRefined
Nobody knows what killed the dinosaurs
Changed in1991TaughtScientists have many competing theories about the dinosaur extinction: climate change, disease, volcanoes, mammals eating the eggs, or possibly an asteroid.
NowAn asteroid roughly 10 km across struck what is now the Yucatán Peninsula about 66 million years ago. The Chicxulub crater was confirmed in 1991 and the impact is the accepted primary cause.
- GeographyReplaced
The Soviet Union is one country
Changed in1991TaughtThe USSR is the largest country on Earth, a single red mass covering a sixth of the land surface, stretching from Poland to the Pacific.
NowThe Soviet Union dissolved on 26 December 1991 into fifteen independent countries: Russia, Ukraine, Belarus, Kazakhstan, Uzbekistan, and ten others.
- Physics & ChemistryDisproved
Crystals cannot have five-fold symmetry
Changed in1992TaughtA crystal is a periodic repeating lattice. Five-fold rotational symmetry is geometrically impossible in a crystal: you cannot tile a plane with pentagons.
NowQuasicrystals have ordered but non-repeating structures with forbidden symmetries. Dan Shechtman observed one in 1982, was ridiculed for years, and won the 2011 Nobel Prize in Chemistry.
- MedicineReplaced
Put babies to sleep on their stomachs
Changed in1992TaughtLay an infant face-down to sleep. It is safer, because a baby on its back might choke on spit-up, and stomach sleeping is more settled.
NowBack sleeping is the safe position. The American Academy of Pediatrics reversed the advice in 1992 and launched Back to Sleep in 1994. SIDS rates in the US fell by more than half, and healthy infants do not choke on their backs.
- GeographyReplaced
Czechoslovakia is a country
Changed in1993TaughtCzechoslovakia sits in central Europe with its capital at Prague.
NowIt split peacefully into the Czech Republic and Slovakia on 1 January 1993, in what is called the Velvet Divorce. In 2016 the Czech Republic adopted Czechia as its official short name.
- BiologyDisproved
Different parts of your tongue taste different things
Changed in1993TaughtThe tongue map: sweet at the tip, salty and sour along the sides, bitter across the back.
NowAll taste regions of the tongue detect all basic tastes. The map came from a mistranslation of a 1901 German paper, and there was never good evidence for it.
- GeographyUpdated
Ethiopia has a coastline
Changed in1993TaughtEthiopia sits on the Red Sea, with ports at Massawa and Assab.
NowEritrea became independent on 24 May 1993, taking the entire coastline with it. Ethiopia is now landlocked, and with over 130 million people it is the most populous landlocked country in the world.
- MedicineDisproved
Ulcers are caused by stress and spicy food
Changed in1994TaughtStomach ulcers come from stress, worry, and a hard-driving personality, aggravated by spicy food. The treatment is antacids, a bland diet, and calming down. You will have them for life.
NowMost peptic ulcers are caused by Helicobacter pylori, a bacterium, and most of the rest by NSAIDs like aspirin and ibuprofen. A course of antibiotics cures them. Barry Marshall and Robin Warren won the 2005 Nobel Prize for it.
- BiologyDisproved
Bulls charge at the color red
Changed in1995TaughtRed enrages a bull. That is why matadors use a red cape.
NowCattle are dichromats and cannot distinguish red from green. Bulls charge the movement of the cape, not its color. The cape is red to hide blood.
- Earth ScienceDisproved
Diamonds are made from coal under pressure
Changed in1995TaughtSqueeze coal hard enough for long enough and you get a diamond. It is the standard classroom metaphor for pressure making something beautiful.
NowAlmost no natural diamond came from coal. Most formed 150 to 200 kilometers deep in the mantle from carbon that has been there since the planet formed, and most are older than the land plants that coal is made from.
- BiologyDisproved
Houseflies only live for 24 hours
Changed in1995TaughtA housefly lives for a single day. Try to feel sympathy for it.
NowHouseflies live around 15 to 30 days as adults. The one-day lifespan belongs to mayflies, and even they spend most of a year as aquatic nymphs first.
- Astronomy & SpaceDisproved
No planets have been found outside our solar system
Changed in1995TaughtOther stars may have planets, but we have never detected one, and we may never be able to.
NowThe first planet confirmed orbiting a Sun-like star, 51 Pegasi b, was announced in 1995. More than 6,000 exoplanets have been confirmed since.
- Health & NutritionDisproved
Sugar makes children hyperactive
Changed in1995TaughtSugar causes hyperactivity. Cut it out before a test, and blame the birthday cake for the chaos afterward.
NowA 1995 meta-analysis in JAMA covering 23 controlled studies found sugar does not affect children's behavior or cognition. The effect is in the parents' expectations, which has been demonstrated experimentally.
- HistoryRenamed
The Dark Ages
Changed in1995TaughtAfter Rome fell, Europe entered the Dark Ages: roughly a thousand years of ignorance, stagnation, and lost knowledge, until the Renaissance switched the lights back on.
NowHistorians retired the term. The period is called the Early Middle Ages, and it produced Carolingian scholarship, the university, mechanical clocks, water and wind power, Gothic engineering, and the preservation of the classical texts the Renaissance later celebrated.
- Physics & ChemistryUpdated
There are three states of matter
Changed in1995TaughtSolid, liquid, gas. Water is the example: ice, water, steam.
NowPlasma is the fourth and by far the most common state in the universe. Bose-Einstein condensate, predicted in 1924, was finally created in a laboratory in 1995, and other exotic states exist.
- MedicineDisproved
Your deoxygenated blood is blue
Changed in1995TaughtBlood carrying oxygen is red, and blood returning to the heart is blue. That's why your veins look blue, and why the diagram has red arteries and blue veins.
NowHuman blood is never blue. Deoxygenated blood is dark red, close to maroon. Veins look blue because of how skin scatters and absorbs light, not because of what is inside them.
- BiologyRefined
Dinosaurs went extinct 65 million years ago
Changed in1996TaughtDinosaurs ruled the Earth and then went completely extinct 65 million years ago. Birds may be distantly related to them.
NowBirds are dinosaurs, not relatives of dinosaurs. Non-avian dinosaurs died out about 66 million years ago, but the group survives: there are roughly 11,000 living dinosaur species.
- BiologyDisproved
Dinosaurs were scaly, sluggish reptiles
Changed in1996TaughtDinosaurs were cold-blooded, slow-moving, scaly reptiles: essentially oversized lizards.
NowMany dinosaurs had feathers, and the group was active and warm-blooded or something close to it. The first clearly feathered dinosaur, Sinosauropteryx, was described from China in 1996.
- Technology & ComputingDisproved
No computer will ever beat a chess grandmaster
Changed in1997TaughtChess requires intuition and creativity that machines fundamentally lack. Computers can calculate, but a world champion will always see what brute force cannot.
NowIBM's Deep Blue beat world champion Garry Kasparov in a match in May 1997. Today a free chess engine on a phone plays far above any human who has ever lived, and no top player would take the game.
- HistoryDisproved
TaughtThe Americas were empty until Clovis hunters walked across the Bering land bridge and through an ice-free corridor about 13,000 years ago. Their distinctive fluted spear points mark the first human presence in the hemisphere.
NowPeople were in the Americas thousands of years before Clovis. Monte Verde in Chile is securely dated to about 14,500 years ago, and footprints at White Sands push human presence back to roughly 23,000 years ago.
- GeographyRenamed
Zaire
Changed in1997TaughtZaire is the large country in central Africa, capital Kinshasa.
NowIt reverted to the Democratic Republic of the Congo in 1997 when Mobutu Sese Seko was overthrown. It is not the same country as the neighboring Republic of the Congo.
- MedicineDisproved
Get antibiotics for that cold
Changed in1998TaughtIf you have a bad cold, a sore throat, or an ear infection, the doctor prescribes antibiotics and you get better. Antibiotics are the answer to being sick.
NowColds are viral, and antibiotics do nothing to viruses. Roughly 28 percent of outpatient antibiotic prescriptions in the US are unnecessary, and antimicrobial resistance was associated with nearly 5 million deaths globally in 2019.
- Physics & ChemistryDisproved
Glass is a liquid that flows very slowly
Changed in1998TaughtGlass is a supercooled liquid. The proof is old cathedral windows, which are thicker at the bottom because the glass has flowed downward over centuries.
NowGlass is an amorphous solid. It does not flow at room temperature on any human or civilizational timescale. Medieval windows are uneven because of how they were made.
- HistoryDisproved
Napoleon was unusually short
Changed in1998TaughtNapoleon Bonaparte stood about five feet two, and his aggression compensated for his height, which is why we call it a Napoleon complex.
NowHe was about 5 feet 7 inches, average or slightly above for a Frenchman of his era. The confusion comes from French inches, which were longer than English ones, plus relentless British wartime caricature.
- Physics & ChemistryDisproved
Neutrinos have no mass
Changed in1998TaughtNeutrinos are massless particles that travel at the speed of light and pass through matter without interacting.
NowNeutrinos have mass. Super-Kamiokande showed in 1998 that they oscillate between types, which is only possible if they are massive. The Standard Model had to be amended.
- Language & CultureDisproved
Never end a sentence with a preposition
Changed in1998TaughtA preposition is not a word to end a sentence with. Rewrite it: "With whom are you going?", not "Who are you going with?"
NowThere is no such rule in English, and there never was. Merriam-Webster, Chicago, and the Oxford dictionaries all reject it. It was a personal preference expressed by the poet John Dryden in 1672, based on Latin, and it hardened into schoolroom law.
- Language & CultureDisproved
Never split an infinitive
Changed in1998TaughtNever put a word between 'to' and its verb. "To boldly go" is an error, and it should be "to go boldly." Red pen.
NowEvery major usage authority now accepts split infinitives. Fowler defended them, the Chicago Manual of Style and Merriam-Webster call the prohibition unfounded, and the 2016 AP Stylebook explicitly permitted them. The rule was invented by nineteenth-century writers imitating Latin.
- Earth ScienceDisproved
Open your windows when a tornado approaches
Changed in1998TaughtA tornado's low pressure will make your sealed house explode, so open the windows on the side away from the storm to equalize pressure before you take shelter.
NowDo not open windows. Houses are not airtight, pressure equalizes on its own, and the explosion theory is wrong. Opening windows wastes the seconds you need to get to shelter and lets wind and debris in. Go to the lowest interior room, away from windows.
- Technology & ComputingReplaced
Reference books are how you find things out
Changed in1998TaughtResearch means the library. Use the card catalogue, find the Dewey Decimal number, consult the Reader's Guide to Periodical Literature, and copy the quotation onto an index card.
NowSearch engines answered the retrieval problem. Google launched in 1998, and card catalogues were withdrawn through the 1990s and 2000s. The Library of Congress stopped printing catalogue cards in 1997 and OCLC ended its card service in 2015.
- Technology & ComputingDisproved
TaughtThe internet is a research network for universities and hobbyists. Nobody will put a credit card into a computer, and no serious commerce will happen online.
NowGlobal e-commerce runs in the trillions of dollars annually. More than five billion people use the internet, and the largest companies in the world by market capitalization are almost entirely internet businesses.
- Astronomy & SpaceDisproved
The universe's expansion is slowing down
Changed in1998TaughtThe universe has been expanding since the Big Bang, and gravity is gradually slowing that expansion. The open question is whether it slows enough to collapse again.
NowTwo teams studying distant supernovae found in 1998 that the expansion is accelerating. The cause, called dark energy, appears to make up roughly 68% of the universe.
- BiologyDisproved
You cannot grow new brain cells
Changed in1998TaughtYou are born with all the neurons you will ever have. Every one you lose is gone forever, so do not hit your head.
NowAdult neurogenesis occurs in the hippocampus, demonstrated in humans in 1998. The extent in adults remains genuinely contested, but the absolute claim is dead.
- GeographyUpdated
Hong Kong is a British colony
Changed in1999TaughtHong Kong is a British territory, and Macau is Portuguese.
NowBritain handed Hong Kong to China on 1 July 1997, and Portugal handed over Macau on 20 December 1999. Both are now Special Administrative Regions of China.
- BiologyRefined
Humans have five senses
Changed in2000TaughtSight, hearing, smell, taste, and touch. Five senses.
NowDepending on how you count, humans have somewhere between nine and thirty-something senses. The list Aristotle wrote down leaves out balance, body position, temperature, pain, and several internal senses.
- BiologyUpdated
There are four basic tastes
Changed in2000TaughtSweet, salty, sour, and bitter. Four tastes, no more.
NowUmami is the fifth, confirmed when its receptor was identified in 2000. Evidence for a distinct fat taste is now strong, and a sixth is plausible.
- MedicineDisproved
Tilt your head back for a nosebleed
Changed in2000TaughtNosebleed? Tip your head back and pinch the bridge of your nose until it stops.
NowLean forward and pinch the soft part of the nose, below the bony bridge, for 10 to 15 minutes without checking. Tilting back sends blood down your throat, where it can cause vomiting or, rarely, be aspirated.
- BiologyDisproved
You only use 10% of your brain
Changed in2000TaughtHumans use only about 10% of their brains. Imagine what we could do if we unlocked the rest.
NowBrain imaging shows virtually all of the brain is active over the course of a day, and there is no dormant 90%. Damage to almost any region causes deficits.
- GeographyRenamed
Bombay, Calcutta, and Madras
Changed in2001TaughtIndia's great cities are Bombay, Calcutta, Madras, and Bangalore.
NowBombay became Mumbai in 1995, Madras became Chennai in 1996, Calcutta became Kolkata in 2001, and Bangalore became Bengaluru in 2014.
- GeographyUpdated
East Timor is part of Indonesia
Changed in2002TaughtThe eastern half of the island of Timor is an Indonesian province.
NowTimor-Leste became fully independent on 20 May 2002, the first new sovereign state of the twenty-first century, after a UN-supervised transition.
- MedicineDisproved
Suck the venom out of a snakebite
Changed in2002TaughtSnakebite first aid: cut an X over the fang marks, suck out the venom, and apply a tourniquet above the bite to stop it spreading.
NowDo none of that. Cutting, sucking, extractor pumps, tourniquets, ice, and alcohol all cause harm and remove essentially no venom. Keep the person calm, immobilize the limb at heart level, remove rings, and get to a hospital for antivenom.
- Earth ScienceRefined
The Earth is a sphere
Changed in2002TaughtThe Earth is a sphere, like the globe on the teacher's desk.
NowIt is an oblate spheroid, bulging at the equator by about 21 kilometers, and lumpy on top of that. GRACE satellite gravity mapping from 2002 produced the true shape, the geoid, which is irregular enough that its exaggerated rendering is nicknamed the potato.
- Physics & ChemistryDisproved
You cannot fold a piece of paper more than seven times
Changed in2002TaughtIt is physically impossible to fold any piece of paper in half more than seven times, no matter how big or thin it is.
NowBritney Gallivan, a high school student, folded paper twelve times in 2002 after deriving the equation governing the loss. The limit is about paper dimensions, not a law of nature.
- Health & NutritionDisproved
You must drink eight glasses of water a day
Changed in2002TaughtDrink eight 8-ounce glasses of water daily, and coffee and tea do not count because caffeine dehydrates you.
NowThere is no scientific basis for the 8x8 rule. Heinz Valtin searched for the evidence in 2002 and found none. Food contributes substantial water, and caffeinated drinks are net hydrating.
- BiologyDisproved
Goldfish have a three-second memory
Changed in2003TaughtA goldfish forgets everything after about three seconds, which is why it can live happily in a small bowl.
NowGoldfish form memories lasting months. They can be trained to respond to signals, navigate mazes, tell colors apart, and learn to press a lever at feeding time.
- BiologyUpdated
Humans have around 100,000 genes
Changed in2003TaughtThe human genome contains roughly 100,000 genes: we are complicated animals, so we must need a lot of them.
NowAbout 19,000 to 20,000 protein-coding genes. The Human Genome Project's draft in 2001 and completion in 2003 cut the estimate by a factor of five.
- GeographyDisproved
The Great Wall of China is visible from space
Changed in2003TaughtThe Great Wall of China is the only human-made structure visible from space, or from the Moon.
NowIt is not visible from the Moon, and it is extremely difficult to see from low Earth orbit with the naked eye. China's first astronaut looked for it in 2003 and reported that he could not see it.
- Astronomy & SpaceRefined
The universe is 10 to 20 billion years old
Changed in2003TaughtThe universe is somewhere between 10 and 20 billion years old. Estimates vary widely and astronomers disagree.
Now13.8 billion years, known to better than 1%. WMAP delivered the first precise figure in 2003; Planck refined it in 2013.
- Astronomy & SpaceUpdated
The universe is made of the stuff on the periodic table
Changed in2003TaughtEverything in the universe is made of atoms: the elements in the periodic table, arranged into stars, planets, and people.
NowOrdinary atomic matter is about 5% of the universe's energy content. Roughly 27% is dark matter and 68% is dark energy, and we do not know what either is.
- BiologyReplaced
Human evolution was a straight march of progress
Changed in2004TaughtThe famous parade: an ape stands up, becomes Australopithecus, then Homo erectus, then Neanderthal, then us. One species at a time, each better than the last.
NowHuman evolution is a branching bush with many species coexisting. At times several kinds of human shared the planet, and the discovery of Homo floresiensis in 2004 made that impossible to ignore.
- Technology & ComputingReplaced
TaughtComputer class means BASIC or Pascal. The Advanced Placement Computer Science exam is taught in Pascal, so that is the language you learn to think in.
NowAP Computer Science moved to C++ in 1999, then to Java in 2004. Python overtook everything as the introductory language, and by 2024 was the most popular language on GitHub. Pascal and BASIC have effectively vanished from schools.
- Physics & ChemistryDisproved
Two-dimensional materials cannot exist
Changed in2004TaughtA one-atom-thick sheet is thermodynamically unstable and would crumple or roll up. Strictly two-dimensional crystals cannot exist at finite temperature.
NowAndre Geim and Konstantin Novoselov isolated graphene in 2004 using adhesive tape and a block of graphite. They won the 2010 Nobel Prize.
- Technology & ComputingUpdated
Never trust Wikipedia, use the encyclopedia
Changed in2005TaughtWikipedia is written by anonymous strangers and is unreliable by design. Use Encyclopaedia Britannica in the library, which is written by experts and fact-checked.
NowA 2005 Nature study found Wikipedia's science articles had roughly comparable error rates to Britannica. Britannica ended its print edition in 2012 after 244 years. Wikipedia is now standard reference infrastructure, though it remains a tertiary source you cite through, not from.
- Earth ScienceReplaced
Stand in a doorway during an earthquake
Changed in2005TaughtWhen the shaking starts, get into a doorway. The frame is the strongest part of the house and it will hold when the rest comes down.
NowDrop, cover, and hold on. Get under a sturdy table, or against an interior wall covering your head and neck. Doorways in modern buildings are no stronger than any other part of the structure, and standing in one leaves you exposed to falling objects and a swinging door.
- HistoryDisproved
Tutankhamun was murdered by a blow to the head
Changed in2005TaughtX-rays of the boy king's mummy revealed a bone fragment inside the skull, proving he was assassinated, most likely struck from behind by a rival for the throne.
NowCT scanning in 2005 found no skull fracture and no sign of a blow. The loose bone fragments were caused after death, by Howard Carter's team removing the mummy from its coffin. He most likely died of complications from a broken leg, compounded by malaria and congenital frailty.
- Health & NutritionDisproved
Wait 30 minutes after eating before you swim
Changed in2005TaughtSwimming on a full stomach causes cramps that will make you drown. Wait at least half an hour. Preferably an hour.
NowThere is no evidence for it. Digestion diverts some blood to the gut, but nowhere near enough to cause dangerous cramping, and drowning statistics show no association with eating.
- Astronomy & SpaceReclassified
Ceres is the largest asteroid
Changed in2006TaughtBetween Mars and Jupiter lies the asteroid belt, and the biggest rock in it is Ceres.
NowThe same 2006 IAU resolution that demoted Pluto promoted Ceres. It is round under its own gravity, so it is a dwarf planet.
- Language & CultureUpdated
New words don't just get invented
Changed in2006TaughtThe dictionary is a fixed authority. Words are either in it or they are not, and made-up words are not real English.
NowDictionaries add hundreds of words a year based on documented usage. 'Google' became a verb in Merriam-Webster and the OED in 2006. Selfie, podcast, unfriend, ghost, doomscroll, and rizz all entered major dictionaries, most of them after 2010.
- Astronomy & SpaceReclassified
Pluto is the ninth planet
Changed in2006TaughtThe solar system has nine planets, and the ninth and smallest is Pluto.
NowIn 2006 the International Astronomical Union defined the word "planet" for the first time, and Pluto did not meet the third criterion. It is now a dwarf planet. The solar system has eight planets.
- Technology & ComputingUpdated
A powerful computer fills a room
Changed in2007TaughtSerious computing power means a mainframe: a machine the size of a room, run by specialists, that you submit jobs to. Personal computers are for word processing and games.
NowThe phone in your pocket is a supercomputer by the standards of most of the twentieth century. A modern smartphone outperforms the Cray-2, the fastest machine on Earth in 1985, by orders of magnitude, and the iPhone's 2007 launch made that the default condition of ordinary life.
- Health & NutritionReplaced
Always stretch before exercise to prevent injury
Changed in2007TaughtLine up and do static stretches before you run. Hold each one for 30 seconds. It prevents injury and improves performance.
NowStatic stretching before activity does not meaningfully prevent injury and temporarily reduces muscle power and strength. The current recommendation is a dynamic warm-up first, and static stretching afterward if at all.
- MedicineDisproved
Grief has five stages
Changed in2007TaughtGrief proceeds through five stages in order: denial, anger, bargaining, depression, acceptance. If you are stuck in a stage, or skipping one, something is wrong with your grieving.
NowThe stage model has never been supported by good evidence. Grief is highly variable, and the most common trajectory is resilience: most bereaved people do not pass through fixed stages at all. Elisabeth Kübler-Ross's 1969 model described dying patients, not the bereaved, and she said so.
- MedicineDisproved
The appendix is a useless leftover
Changed in2007TaughtThe appendix is a vestigial organ, a shrivelled remnant of a plant-eating ancestor's gut, with no function at all. Its only role in your life is to occasionally become infected and try to kill you.
NowThe appendix appears to be a reservoir of beneficial gut bacteria, a safe house that helps repopulate the intestine after illness flushes it out. It also carries substantial lymphoid tissue and plays a role in immune function.
- BiologyDisproved
Chameleons change color to match their background
Changed in2008TaughtA chameleon changes color to blend in with whatever it is sitting on.
NowColor change is mostly communication and temperature regulation, signaling mood, dominance, and readiness to mate. Camouflage is a secondary use at best.
- Astronomy & SpaceDisproved
Mars is a dry, dead world with no water
Changed in2008TaughtMars might have had water long ago, but today it is a dry desert. Any water is speculation.
NowMars Odyssey detected vast subsurface hydrogen in 2002, and NASA's Phoenix lander physically touched and identified water ice in the Martian soil in 2008. There is enough ice at the poles to cover the planet in a global ocean meters deep.
- Astronomy & SpaceUpdated
The Milky Way has four spiral arms
Changed in2008TaughtOur galaxy is a four-armed spiral, and there is a diagram in the back of the book showing exactly where we sit in one of them.
NowData from NASA's Spitzer Space Telescope showed the Milky Way has two dominant spiral arms of stars, Scutum-Centaurus and Perseus, plus minor arms and spurs. It is also a barred spiral.
- GeographyReplaced
Yugoslavia is a country
Changed in2008TaughtYugoslavia is a single federal country on the Balkan peninsula, capital Belgrade.
NowIt broke apart across two decades of conflict into seven states: Slovenia, Croatia, Bosnia and Herzegovina, Serbia, Montenegro, North Macedonia, and Kosovo, the last of which declared independence in 2008 and is not universally recognized.
- Language & CultureDisproved
I before E except after C
Changed in2009TaughtI before E, except after C. The reliable spelling rhyme, drilled from primary school.
NowThe UK government's National Strategies advice in 2009 told teachers to stop teaching it, on the grounds that there are so many exceptions it is not worth the confusion. Analyses of large word lists find the rule fails more often than it holds.
- Astronomy & SpaceDisproved
The Moon is completely dry
Changed in2009TaughtApollo samples showed the Moon is bone dry. There is no water there in any form.
NowThere is water ice in permanently shadowed polar craters, confirmed when NASA's LCROSS mission deliberately crashed into Cabeus crater in 2009, and water molecules exist even on the sunlit surface.
- BiologyDisproved
You have a learning style, and teaching to it helps
Changed in2009TaughtEveryone is a visual, auditory, or kinesthetic learner. Find yours and you will learn better when material is presented that way.
NowA 2008 review commissioned by Psychological Science in the Public Interest found essentially no credible evidence for the core prediction. Matching teaching to a supposed style does not improve learning.
- BiologyDisproved
Humans and Neanderthals never interbred
Changed in2010TaughtNeanderthals were a separate species that modern humans replaced. They died out and left no descendants.
NowThe draft Neanderthal genome, published in 2010, showed that people with ancestry outside Africa carry roughly 1 to 2% Neanderthal DNA. They are in your family tree.
- Language & CultureDisproved
Playing Mozart to babies makes them smarter
Changed in2010TaughtClassical music raises IQ. Play Mozart to infants and they develop better spatial reasoning. Georgia handed out a free classical CD to every newborn.
NowA 2010 meta-analysis of 39 studies covering over 3,000 subjects found no reliable cognitive benefit. The original 1993 study involved 36 college students, tested one narrow spatial task, and the effect lasted about ten to fifteen minutes.
- Health & NutritionDisproved
TaughtSpinach has enormous amounts of iron, which is why Popeye eats it. Or, if you had a clever teacher: the iron claim came from a scientist misplacing a decimal point in 1870.
NowBoth versions are wrong. Spinach has a moderate amount of iron, poorly absorbed because of its oxalates. And the famous decimal point story is itself a myth, traced and debunked by Mike Sutton in 2010.
- MedicineDisproved
The MMR vaccine might cause autism
Changed in2010TaughtA 1998 Lancet paper raised a possible link between the MMR vaccine and autism. The question was presented as open and legitimately debated, and worth being cautious about.
NowThe paper was retracted in full by The Lancet in February 2010, and Andrew Wakefield was struck off the UK medical register in May 2010 for dishonesty and unethical conduct. Studies covering millions of children have found no link. The research was fraudulent, not merely mistaken.
- Technology & ComputingReplaced
TaughtCursive handwriting is a core skill. You will need it for every letter, exam, form, and signature for the rest of your life, and sloppy penmanship will cost you.
NowThe 2010 Common Core standards in the United States dropped cursive as a requirement, replacing it with keyboarding. Most adult writing is now typed. A partial reversal is underway, with more than 20 states legislating cursive back in, and California mandating it again from 2024.
- Health & NutritionDisproved
Cracking your knuckles causes arthritis
Changed in2011TaughtStop cracking your knuckles or you will get arthritis when you are older.
NowNo association has been found. A doctor cracked the knuckles on one hand only for over 60 years as a personal experiment and found no difference; a 2011 study of 215 people found no link either.
- HistoryReplaced
Farming came first, then villages, then temples
Changed in2011TaughtThe Neolithic sequence is fixed: agriculture produces food surplus, surplus produces settled villages, villages produce specialists, and only then can a society afford monumental religion.
NowGöbekli Tepe in southeastern Turkey is a complex of massive carved stone enclosures built around 9500 BCE by people with no pottery, no metal, no writing, and no domesticated crops. Monumental building came before farming, and may have helped drive it.
- Technology & ComputingReplaced
Save your work to a floppy disk
Changed in2011TaughtBring a floppy disk to computer class. A 3.5-inch disk holds 1.44 MB, enough for your essay, and you should always keep a backup copy on a second disk.
NowSony, the last major manufacturer, stopped making floppy disks in March 2011. The format survives only as the save icon, a picture of an object most students have never touched.
- GeographyUpdated
Sudan is Africa's largest country
Changed in2011TaughtSudan is the largest country in Africa by land area.
NowSouth Sudan became independent on 9 July 2011, taking about a quarter of Sudan's territory. Algeria is now Africa's largest country, and South Sudan is the world's newest widely recognized state.
- Health & NutritionReplaced
The Food Pyramid is how you should eat
Changed in2011TaughtEat 6 to 11 servings of bread, cereal, rice, and pasta a day. That is the base of the pyramid. Fats and oils go at the tiny tip: use sparingly.
NowThe USDA retired the pyramid in 2011 and replaced it with MyPlate, a divided dinner plate with half of it fruit and vegetables. The bread-heavy base and the blanket anti-fat message are gone.
- BiologyDisproved
Tongue rolling is a simple dominant trait
Changed in2011TaughtRolling your tongue is controlled by a single gene. Take a class survey, fill in the Punnett square, find out who is dominant.
NowIt is not a single-gene trait. Identical twins frequently differ, and people can learn to do it. The geneticist who proposed it publicly retracted the claim in 1975.
- MedicineReplaced
Tonsils should come out if they give you trouble
Changed in2011TaughtRecurrent sore throats mean the tonsils come out. It is a rite of passage, you get ice cream, and the tonsils are not good for anything anyway.
NowTonsillectomy rates fell dramatically as evidence showed limited benefit for most children with recurrent throat infection. The 2011 and 2019 clinical practice guidelines set specific thresholds, seven episodes in a year, five a year for two years, or three a year for three years, and recommend watchful waiting otherwise.
- BiologyRefined
98% of your DNA is useless junk
Changed in2012TaughtOnly about 2% of the genome codes for proteins. The rest is evolutionary debris: junk DNA with no function.
NowMuch of the noncoding genome regulates when and where genes switch on. The ENCODE project reported in 2012 that most of the genome is biochemically active, though how much is genuinely functional is still fiercely argued.
- Physics & ChemistryRefined
The Higgs boson is hypothetical and may not exist
Changed in2012TaughtThe Standard Model predicts a particle that gives other particles mass, but it has never been found and might not be there.
NowCERN announced the discovery of the Higgs boson on 4 July 2012. Peter Higgs and François Englert shared the Nobel Prize the following year.
- Technology & ComputingDisproved
You won't always have a calculator in your pocket
Changed in2012TaughtMemorize your times tables and learn long division by hand, because you will not always be carrying a calculator around with you.
NowRoughly 70 percent of humanity carries a smartphone. It contains a calculator, a graphing tool, a computer algebra system, and a camera that will solve a written equation by looking at it.
- Language & CultureUpdated
'Literally' can never mean 'figuratively'
Changed in2013Taught'Literally' means actually, in fact, without exaggeration. Saying "I literally died" is a mistake, because you did not.
NowMerriam-Webster added the intensifier sense in 2013, and the OED has recorded it since 2011, noting use since 1769. Dictionaries describe how words are used rather than legislating how they should be, and this use is 250 years old.
- Astronomy & SpaceUpdated
No human object has left the solar system
Changed in2013TaughtVoyager 1 is heading out of the solar system and will eventually cross into interstellar space, sometime in the distant future.
NowVoyager 1 crossed the heliopause in August 2012, confirmed by NASA in September 2013. Voyager 2 followed in 2018. Both are now in interstellar space.
- HistoryDisproved
Richard III's grave was lost forever
Changed in2013TaughtAfter Bosworth Field in 1485, Richard III was buried at Greyfriars in Leicester, but the friary was destroyed at the Dissolution and his bones were thrown into the River Soar. The grave was gone for good.
NowHe was under a council car park. Excavation in 2012 found a skeleton in the choir of Greyfriars, and in February 2013 the University of Leicester confirmed it as Richard III through radiocarbon dating, battle wounds, scoliosis, and mitochondrial DNA matched to living descendants.
- MedicineReplaced
Shake off a head knock and get back in the game
Changed in2013TaughtYou got your bell rung. If you did not lose consciousness, it is not a real concussion. Count fingers, walk it off, and get back out there. Being tough about it is part of the sport.
NowLoss of consciousness happens in a minority of concussions and is not required for diagnosis. Any suspected concussion means immediate removal from play with no same-day return, and all 50 US states passed youth concussion laws between 2009 and 2014.
- BiologyDisproved
You are left-brained or right-brained
Changed in2013TaughtLogical, analytical people are left-brained. Creative, artistic people are right-brained. It is a personality type rooted in your brain.
NowA 2013 study analyzing over 1,000 brains found no evidence that people have a stronger left or right network overall. Some functions are lateralized; personalities are not.
- Health & NutritionRefined
Breakfast is the most important meal of the day
Changed in2014TaughtNever skip breakfast. It kick-starts your metabolism and skipping it makes you gain weight.
NowThe evidence is much weaker than the slogan. Randomized trials, including a 2014 study in the American Journal of Clinical Nutrition, found no significant weight effect from eating or skipping breakfast, and much of the supporting research was observational or industry-funded.
- GeographyUpdated
The Aral Sea is the fourth largest lake in the world
Changed in2014TaughtThe Aral Sea in Central Asia is the world's fourth largest lake.
NowIt has lost about 90% of its volume. The eastern basin dried up completely for the first time in modern history in 2014. Ships sit on sand dozens of kilometers from any water.
- BiologyRenamed
Brontosaurus never existed
Changed in2015TaughtBrontosaurus was a mistake. The name was withdrawn in 1903 and the animal is really an Apatosaurus. Stop saying Brontosaurus.
NowA 2015 study using a large statistical analysis of diplodocid anatomy concluded that Brontosaurus is distinct enough from Apatosaurus to be its own genus. The name is back, though not every paleontologist agrees.
- Health & NutritionUpdated
Eating cholesterol raises your blood cholesterol
Changed in2015TaughtLimit dietary cholesterol to 300 mg a day. Watch the eggs: no more than a few a week, and shrimp and liver are dangerous.
NowThe 2015 Dietary Guidelines Advisory Committee concluded that cholesterol is not a nutrient of concern for overconsumption, and the 300 mg cap was dropped. For most people, dietary cholesterol has a modest effect on blood cholesterol.
- Health & NutritionReplaced
TaughtDo not give peanuts to children under three, especially if allergies run in the family. Avoidance prevents allergy.
NowThe opposite. The LEAP trial in 2015 found that early, regular peanut introduction in high-risk infants reduced peanut allergy by about 80%. Guidelines now recommend introducing peanut protein at around 4 to 6 months.
- Health & NutritionDisproved
Margarine is the heart-healthy choice
Changed in2015TaughtButter is saturated animal fat and bad for your heart. Switch to margarine, which is made from vegetable oil.
NowThe hydrogenation that made margarine solid produced artificial trans fats, which are worse for cardiovascular health than the saturated fat they replaced. The FDA removed partially hydrogenated oils from the safe list in 2015 and the WHO has called for global elimination.
- Astronomy & SpaceUpdated
Pluto is a blurry smudge and always will be
Changed in2015TaughtPluto is too small and too far for us to see any detail. The best image is a handful of fuzzy pixels from Hubble.
NowNASA's New Horizons flew past Pluto in July 2015 and returned sharp images of nitrogen glaciers, water-ice mountains, and a haze-layered atmosphere.
- MedicineReplaced
TaughtRolled your ankle? RICE. Rest it completely, ice it, compress it, elevate it. Inflammation is the enemy and ice is how you fight it.
NowGabe Mirkin, the doctor who coined RICE in 1978, publicly retracted the rest and ice components in 2015. Current guidance favors early controlled movement and loading, and inflammation is now understood as part of healing rather than something to suppress.
- MedicineUpdated
TaughtYou are only 10 percent human. Microbial cells outnumber your own cells by ten to one, a striking statistic repeated in every biology and health class.
NowThe ratio is closer to 1.3 to 1, and it fluctuates around 1 to 1 depending on when you last used the bathroom. A single bowel movement can shift it. You are roughly half human by cell count, which is still remarkable but not the same claim.
- Technology & ComputingRefined
TaughtMoore's Law: processor speed doubles roughly every two years, without end. Just wait and your computer will be twice as fast.
NowTransistor counts still rise, but clock speeds stalled around 2005 and Dennard scaling ended. In 2016 the industry's own roadmap, the ITRS, published its final edition and stopped organizing around Moore's Law. Gains now come from more cores, specialized chips, and packaging.
- Technology & ComputingDisproved
Go is too complex for computers to master
Changed in2016TaughtChess fell to brute force, but Go has more legal positions than atoms in the observable universe, and it depends on intuition and shape judgement no algorithm can capture. Experts estimated a machine was decades away.
NowDeepMind's AlphaGo beat Lee Sedol 4 to 1 in March 2016. A year later AlphaGo Zero learned the game entirely from self-play, with no human games at all, and surpassed every previous version in days.
- Astronomy & SpaceRefined
Gravitational waves are predicted but undetectable
Changed in2016TaughtEinstein predicted ripples in spacetime, but they are so faint that detecting one is probably beyond any instrument we could build.
NowLIGO detected gravitational waves from two merging black holes on 14 September 2015, announced in February 2016. Detections are now routine, with hundreds recorded.
- BiologyRefined
Sunflowers always turn to follow the sun
Changed in2016TaughtSunflowers track the sun across the sky all day, every day, throughout their lives.
NowOnly young sunflowers track the sun. Once mature, the flower stops moving and faces permanently east. The tracking is driven by a circadian rhythm, shown in a 2016 study in Science.
- Physics & ChemistryUpdated
The periodic table ends around element 109
Changed in2016TaughtThe periodic table trails off in the hundreds with a few unnamed, provisional elements at the end.
NowThe seventh row was completed in 2016 when nihonium, moscovium, tennessine, and oganesson were named. The table now has 118 elements and no gaps.
- Language & CultureDisproved
'They' is plural, never use it for one person
Changed in2017Taught"Each student should bring their book" is an error. Use 'he' as the generic singular, or rewrite as 'he or she'. Singular 'they' is sloppy and modern.
NowSingular 'they' is accepted by every major authority. The AP Stylebook admitted it in 2017, Chicago's 17th edition in 2017, and Merriam-Webster named it Word of the Year in 2019 and added the nonbinary sense. It has been in continuous use since the 1300s.
- HistoryUpdated
TaughtHomo sapiens emerged roughly 200,000 years ago, in a single cradle in East Africa, and spread outward from there.
NowFossils from Jebel Irhoud in Morocco push the origin of our species back to about 300,000 years ago, and the emergence looks pan-African rather than confined to one cradle.
- Earth ScienceDisproved
Recycling solves the plastic problem
Changed in2017TaughtSort your plastics by the number in the triangle, put them in the right bin, and they become new products. Recycling is the answer to plastic waste.
NowAbout 9 percent of all plastic ever produced has been recycled. Roughly 12 percent has been incinerated and the rest is in landfills or the environment. Most plastics are not economically recyclable, and the industry knew this while promoting the bins.
- GeographyRefined
There are seven continents
Changed in2017TaughtSeven continents: Africa, Antarctica, Asia, Australia, Europe, North America, South America.
NowA 2017 paper argued that Zealandia, a 4.9-million-square-kilometer landmass 94% submerged around New Zealand, meets every geological test for a continent. It has since been fully mapped, though it is not in most school curricula.
- Earth ScienceUpdated
There are ten types of cloud
Changed in2017TaughtClouds come in ten genera: cirrus, cumulus, stratus, and the rest. Learn the chart on the classroom wall, because it is fixed.
NowThe World Meteorological Organization's International Cloud Atlas added twelve new classifications in March 2017, including asperitas, the first new formation added in over half a century, and volutus, cavum, and the human-made flammagenitus and homogenitus.
- HistoryDisproved
TaughtNeanderthals were shambling, grunting cave-dwellers, incapable of art, symbolism, or real language, and they were simply outcompeted by cleverer modern humans.
NowNeanderthals made cave art, used pigment and shell ornaments, buried their dead, made tar-based adhesive, and interbred with us. Their disappearance was absorption and attrition, not a contest of intelligence.
- GeographyRenamed
Swaziland
Changed in2018TaughtSwaziland is a small landlocked kingdom in southern Africa.
NowKing Mswati III renamed it the Kingdom of Eswatini in April 2018, on the fiftieth anniversary of independence from Britain.
- Earth ScienceUpdated
The ozone hole is growing and there's nothing to be done
Changed in2018TaughtA hole in the ozone layer is opening over Antarctica and expanding. It is one of the defining environmental catastrophes of your lifetime and it is getting worse every year.
NowIt is healing. The 2018 WMO/UNEP Scientific Assessment confirmed ozone recovering at roughly 1 to 3 percent per decade, and projections have the Antarctic hole closing around 2066. The Montreal Protocol worked.
- Physics & ChemistryReplaced
A kilogram is defined by a metal cylinder in Paris
Changed in2019TaughtThe kilogram is defined by the International Prototype Kilogram, a platinum-iridium cylinder kept in a vault outside Paris. It is the kilogram by definition.
NowOn 20 May 2019 the kilogram was redefined in terms of the Planck constant. The cylinder is now just an object. No SI base unit depends on a physical artifact any more.
- Astronomy & SpaceRefined
TaughtBlack holes are predicted by general relativity and the indirect evidence is suggestive, but by definition light cannot escape one, so we will never actually image one.
NowThe Event Horizon Telescope released the first image of a black hole's shadow, in galaxy M87, in April 2019, and one of Sagittarius A* at our own galaxy's center in 2022.
- GeographyRenamed
Macedonia
Changed in2019TaughtMacedonia, a small country north of Greece, formerly part of Yugoslavia.
NowIt became the Republic of North Macedonia in February 2019 under the Prespa Agreement with Greece, ending a naming dispute that had run for 27 years.
- Earth ScienceDisproved
The Amazon produces 20 percent of the world's oxygen
Changed in2019TaughtThe Amazon is the lungs of the planet, producing about a fifth of the oxygen we breathe. Cut it down and we suffocate.
NowThe Amazon's net oxygen contribution is close to zero. It consumes nearly all the oxygen it produces through respiration and decomposition. Most atmospheric oxygen came from marine phytoplankton over billions of years, and the atmospheric reservoir is so vast it would not budge in any case.
- Language & CultureUpdated
'Irregardless' is not a word
Changed in2020Taught'Irregardless' is not a word. It is a double negative and an illiterate mangling of 'regardless'. Never use it.
NowMerriam-Webster confirmed in 2020 that it has been in the dictionary since 1934 and in recorded use since 1795. It is a word, and it is labelled nonstandard, which means it exists and you should still avoid it in formal writing.
- Technology & ComputingDisproved
TaughtComputers manipulate symbols; they don't understand language. A machine might autocomplete a word or churn out stilted, robotic sentences, but it could never write an essay, an article, or a story fluent enough to pass as the work of a person.
NowIn June 2020 OpenAI released GPT-3, a 175-billion-parameter language model that produced paragraphs of coherent, on-topic prose from a short prompt. In OpenAI's own tests, human readers could barely tell its short news articles from ones written by people, doing little better than a coin flip.
- Health & NutritionUpdated
A little added sugar in a baby's food is harmless
Changed in2020TaughtThere was no official national advice for feeding children under two, so the working assumption was that a little sweetness (a spoon of sweetened yogurt, a flavored puree, a sip of juice) was fine for babies and toddlers.
NowThe 2020–2025 Dietary Guidelines for Americans, released in December 2020, were the first edition ever to cover children from birth to 24 months, and they set a firm line: no added sugars at all for children under age 2.
- Astronomy & SpaceDisproved
Betelgeuse's sudden dimming means it is about to explode
Changed in2020TaughtWhen Betelgeuse, the red shoulder of Orion, lost two-thirds of its brightness over the winter of 2019–2020, the natural reading was that the old supergiant was finally about to die, that we were watching the prelude to a supernova bright enough to cast shadows on Earth.
NowIn August 2020, Hubble observations showed the Great Dimming was a dust cloud, not a death rattle. The star had belched a huge bubble of hot plasma from its surface; as it drifted outward it cooled into dust that briefly veiled part of the star. By April 2020 Betelgeuse had already brightened back to normal.
- Technology & ComputingDisproved
TaughtBatteries are too heavy, too slow to charge, and too weak. Electric cars are glorified golf carts with 60 miles of range, and the internal combustion engine is not going anywhere.
NowLithium-ion pack prices fell roughly 90 percent between 2010 and 2023. Electric vehicles passed 18 percent of new car sales globally in 2023, and several major markets have legislated end dates for new combustion-engine sales.
- Earth ScienceUpdated
Magnetic north sits in the Canadian Arctic
Changed in2020TaughtYour compass points to the magnetic north pole, which sits in the Canadian Arctic. It wanders a little, but it's essentially parked up there near Canada's northern islands.
NowThe magnetic north pole has bolted. It left Canada, crossed the international date line, and is heading toward Siberia so fast that the World Magnetic Model, which guides every phone map and ship's compass, had to be updated ahead of schedule in 2020, and again for 2025.
- GeographyUpdated
Mount Everest is 29,028 feet high
Changed in2020TaughtEverest is 29,028 feet, or 8,848 meters. Memorize the number.
NowChina and Nepal jointly announced a new official height of 8,848.86 m, about 29,031.7 feet, in December 2020, after separate surveys and years of disagreement.
- MedicineDisproved
TaughtAntibiotics do nothing against viruses, and for most viral infections there is no cure at all; you treat the symptoms and wait. Coronaviruses in particular have never had a single approved drug to fight them.
NowOn 22 October 2020 the FDA fully approved Veklury (remdesivir) for treating COVID-19, the first drug ever approved to treat any coronavirus infection. It is an antiviral that jams the machinery the virus uses to copy its own genome.
- BiologyUpdated
No dinosaur was built for swimming
Changed in2020TaughtDinosaurs were land animals. Some may have waded at the water's edge, but none was a true swimmer; nothing in the fossil record showed a non-bird dinosaur adapted to move and hunt underwater the way a fish or a crocodile does.
NowIn April 2020, a nearly complete Spinosaurus tail from Morocco, described in Nature, changed that. The tail was a tall, flexible fin shaped for propulsion, not balance. Robotic models of it produced real thrust in water, making Spinosaurus the first non-bird dinosaur known to have been adapted for active swimming.
- MedicineDisproved
No vaccine has ever been made from messenger RNA
Changed in2020TaughtEvery vaccine works by showing your immune system a weakened, killed, or fragmented version of a germ, grown in eggs or cell cultures over many months. Messenger RNA is far too fragile to use as a medicine, and no vaccine built from genetic instructions alone has ever been approved for anyone.
NowOn 11 December 2020 the FDA authorized the Pfizer-BioNTech COVID-19 vaccine: the first mRNA vaccine ever cleared for use in people, with Moderna's following a week later. It carries a strand of messenger RNA that instructs your own cells to make one harmless viral protein, training immunity without any piece of the virus itself.
- Astronomy & SpaceUpdated
Nobody knows what causes fast radio bursts
Changed in2020TaughtFast radio bursts, millisecond flashes of radio energy that release more power than the Sun does in days, were one of astronomy's great open mysteries. Every one had come from a distant galaxy, too far to trace to any particular object, and their source was genuinely unknown.
NowOn 28 April 2020, telescopes caught a fast radio burst coming from inside our own galaxy, from SGR 1935+2154, a magnetar about 30,000 light-years away. It was the first FRB ever tied to a known object, showing that at least some of these bursts are flares from the crushingly strong magnetic fields of dead stars.
- HistoryUpdated
Nobody knows where Stonehenge's giant stones came from
Changed in2020TaughtThe source of Stonehenge's huge upright sarsen stones is a mystery. We know the smaller bluestones came from Wales, but where the builders quarried the big ones has been debated for four centuries.
NowIn July 2020 a geochemical study matched 50 of the 52 sarsens to West Woods, a spot about 15 miles (25 km) north of the monument on the Marlborough Downs. A core drilled from Stone 58 in the 1950s, returned to England in 2018, gave researchers the chemical fingerprint to make the match.
- Language & CultureReplaced
Put two spaces after a period
Changed in2020TaughtTyping class: two spaces after every full stop. One space is a sign of carelessness.
NowMicrosoft Word began flagging two spaces as an error in 2020. Every major style guide, Chicago, AP, MLA, and APA, specifies one. The convention was a workaround for monospaced typewriters, and typewriters are gone.
- Technology & ComputingDisproved
Renewable energy will always be too expensive to compete
Changed in2020TaughtSolar and wind are noble ideas but hopelessly costly. They only exist because of subsidies, and fossil fuels will remain the cheap option indefinitely.
NowThe International Energy Agency stated in 2020 that solar is now the cheapest source of electricity in history. Photovoltaic module costs fell by roughly 99.9 percent from the late 1970s, and in most of the world new solar and wind undercut new coal and gas.
- GeographyRenamed
The country is called Holland
Changed in2020TaughtHolland and the Netherlands are two names for the same country, used interchangeably. The tulips, the windmills, the football team in orange, all of it is Holland.
NowFrom January 2020 the Dutch government officially dropped 'Holland' as a promotional name for the country and uses only 'the Netherlands'. Holland is really just two of the country's twelve provinces, North and South Holland, and the government retired the nickname to represent the whole nation.
- MedicineDisproved
There is no cure or approved treatment for Ebola
Changed in2020TaughtEbola is a near-certain death sentence. Doctors can only offer supportive care (fluids, oxygen, treating whatever else goes wrong) and hope. No drug has ever been approved to treat the virus itself.
NowOn 14 October 2020 the FDA approved Inmazeb, a cocktail of three monoclonal antibodies from Regeneron, the first approved treatment for Zaire ebolavirus. A second drug, Ebanga, was approved that December. In the trial that tested them, they roughly halved deaths, and cut them far more when given early.
- Physics & ChemistryDisproved
TaughtMatter comes in a fixed handful of phases, and nothing can keep cycling through a repeating motion forever without an energy source, that would be a perpetual-motion machine, which the laws of thermodynamics forbid.
NowIn 2021 physicists built a genuine time crystal, a new phase of matter, on Google's Sycamore quantum processor. Its qubits flip through a pattern that repeats in time indefinitely without absorbing any net energy, and it does so without violating the second law, because its entropy never falls.
- BiologyUpdated
TaughtDNA begins breaking apart the moment an organism dies. Even in the best-preserved permafrost fossils it degrades into unreadable fragments within a few hundred thousand years, so anything a million years old is far beyond reach; forget sequencing a creature that ancient.
NowIn February 2021, researchers reported in Nature that they had sequenced DNA from mammoth teeth frozen in Siberian permafrost for more than a million years, including one specimen around 1.6 million years old, shattering the previous record held by a roughly 700,000-year-old horse.
- MedicineDisproved
TaughtCRISPR gene editing works in the lab: you take cells out of a patient, edit them in a dish, and return them. You cannot inject the editing machinery into a living person and have it find and fix the right gene inside the body; that is far too imprecise and dangerous.
NowIn June 2021, Intellia and Regeneron reported in the New England Journal of Medicine the first successful in-vivo CRISPR editing in humans: a single intravenous infusion of NTLA-2001 switched off a disease gene in the livers of patients with transthyretin amyloidosis, cutting the harmful protein by up to 96%.
- Astronomy & SpaceDisproved
Only professionally trained astronauts can go to orbit
Changed in2021TaughtReaching Earth orbit takes years of professional astronaut training and the backing of a national space agency. The handful of 'space tourists' who went before all flew to a space station alongside career cosmonauts; a crew of ordinary civilians orbiting on their own is not something that happens.
NowFrom 15–18 September 2021, SpaceX's Inspiration4 mission put four private citizens, none of them professional astronauts, into orbit for three days aboard a Crew Dragon, with no career astronaut on board. It was the first all-civilian orbital spaceflight.
- Astronomy & SpaceUpdated
Only the United States has ever operated a rover on Mars
Changed in2021TaughtLanding and driving a rover on Mars is so hard that only NASA has ever done it. The Soviet Union and later Russia lost lander after lander; Mars's surface was, in practice, an American-only club.
NowOn 22 May 2021, China's Zhurong rover rolled onto the surface of Utopia Planitia, making China the second nation ever to operate a rover on Mars, and the first to orbit, land, and deploy a rover all on its first attempt.
- Astronomy & SpaceDisproved
Powered flight is impossible in Mars's thin atmosphere
Changed in2021TaughtMars's atmosphere is only about 1% as dense as Earth's, far too thin for wings or rotors to get a grip. A helicopter or airplane could never generate enough lift to fly there. Mars is explored by rovers on the ground, and always will be.
NowOn 19 April 2021, NASA's Ingenuity helicopter lifted off, hovered, and landed on Mars: the first powered, controlled flight by an aircraft on another world. It went on to fly 72 times over nearly three years, far outlasting its planned five flights.
- BiologyDisproved
TaughtA protein is a chain of amino acids that folds into a specific three-dimensional shape, and that shape determines what it does. Predicting the shape from the sequence alone is one of biology's hardest unsolved problems, and may remain so for decades.
NowIn 2020 DeepMind's AlphaFold solved structure prediction to near-experimental accuracy, and by 2021 its public database held predicted structures for nearly every protein known to science, over 200 million. Demis Hassabis and John Jumper shared the 2024 Nobel Prize in Chemistry for it.
- Earth ScienceDisproved
TaughtGlobal warming is a theory. Some scientists think humans are causing it, others think it is a natural cycle, and the debate is ongoing.
NowThe IPCC's Sixth Assessment Report in 2021 states that it is unequivocal that human influence has warmed the atmosphere, ocean, and land. "Unequivocal" is the strongest word the IPCC has ever used on attribution, and it has no qualifier.
- GeographyUpdated
The Earth has four oceans
Changed in2021TaughtPacific, Atlantic, Indian, and Arctic. Four oceans.
NowFive. The Southern Ocean around Antarctica was proposed by the International Hydrographic Organization in 2000 and formally recognized by National Geographic on World Oceans Day in 2021.
- HistoryUpdated
TaughtThe first humans crossed the Bering land bridge and reached the Americas around 13,000 years ago, at the end of the last Ice Age. These Clovis people, named for their distinctive spear points, were the continent's first inhabitants.
NowFossil human footprints at White Sands, New Mexico, dated to 21,000 to 23,000 years ago, place people in North America at the height of the last Ice Age, roughly 10,000 years earlier than the Clovis-first model allowed. First reported in 2021, the dates were independently confirmed in 2023.
- Health & NutritionDisproved
TaughtWeight is a matter of diet and willpower. The few prescription diet drugs that exist are marginally effective and often dangerous; the history of obesity medicine is a graveyard of withdrawn pills. Nothing on prescription reliably produces large, sustained weight loss.
NowOn 4 June 2021, the FDA approved Wegovy (semaglutide 2.4 mg), a once-weekly injection that produced an average weight loss of roughly 15–17% over 68 weeks in trials: results previously seen only with bariatric surgery, and far beyond any earlier weight-loss drug.
- MedicineDisproved
There is no vaccine for malaria
Changed in2021TaughtMalaria kills hundreds of thousands of people a year, most of them young children, and there is no vaccine against it. The parasite is too complex and shape-shifting a target; a century of attempts had produced nothing usable.
NowIn October 2021, the World Health Organization recommended the first malaria vaccine, RTS,S (Mosquirix), for widespread use in children across sub-Saharan Africa, the first vaccine ever recommended against a human parasitic disease.
- Technology & ComputingDisproved
There is no way to make breathable oxygen on Mars
Changed in2021TaughtMars's atmosphere is 95% carbon dioxide and almost unbreathable. Any human mission would have to carry every molecule of oxygen, for breathing and for rocket fuel, all the way from Earth, because there is no way to produce it there.
NowOn 20 April 2021, a toaster-sized instrument called MOXIE, riding on NASA's Perseverance rover, pulled oxygen out of the Martian air, splitting carbon dioxide to produce about 5 grams of breathable oxygen. It was the first time a natural resource had ever been harvested on another planet.
- HistoryRefined
Vikings reached America 'around the year 1000, maybe'
Changed in2021TaughtNorse sailors may have reached North America roughly a thousand years ago, according to the sagas, though the evidence was vague and the date uncertain.
NowNorse people were cutting timber at L'Anse aux Meadows in Newfoundland in exactly 1021 CE. The date comes from tree rings marked by a known solar storm, and it is the earliest precisely dated evidence of humans crossing the Atlantic.
- Earth ScienceUpdated
We can only guess at the minerals deep in the mantle
Changed in2021TaughtThe lower mantle is 660 to 2,900 km down and unreachable. We know its minerals only from laboratory experiments that squeeze samples to those pressures; we have never had an actual piece of one.
NowIn 2021, scientists confirmed a real sample of a lower-mantle mineral for the first time, calcium silicate perovskite, now named davemaoite, found trapped as a flaw inside a diamond from Botswana. It had been predicted for decades but never seen in nature until it hitched a ride to the surface.
- Technology & ComputingDisproved
TaughtSoftware can edit, filter, and rearrange existing pictures, but it cannot invent a new image from scratch. Describe 'an astronaut riding a horse in the style of a Renaissance painting' and no program could produce it; visual creativity is human.
NowIn 2022, text-to-image models made this routine. OpenAI released DALL·E 2 in April, and Stable Diffusion was released openly in August: systems that generate novel, coherent, high-resolution images from a plain-English prompt in seconds.
- Physics & ChemistryDisproved
TaughtFusion is the power source of the future and always will be. Every experiment consumes far more energy than the reaction gives back, and breakeven, getting out as much as you put in, has never been reached.
NowOn 5 December 2022 the National Ignition Facility reached ignition: 2.05 megajoules of laser energy delivered to the target produced 3.15 megajoules of fusion energy. It was the first time a controlled fusion reaction returned more energy than was delivered to it.
- Physics & ChemistryRefined
A proton is made of exactly three quarks
Changed in2022TaughtA proton is three quarks, two up and one down, bound by the strong force. That triplet is what a proton is, full stop.
NowIn 2022 the NNPDF collaboration reported the first strong evidence that the proton also carries an 'intrinsic' charm quark component built into its very structure, remarkable because a charm quark is heavier than the whole proton that contains it.
- BiologyDisproved
All bacteria are microscopic, invisible to the naked eye
Changed in2022TaughtBacteria are single cells so small you need a microscope to see them: a few micrometres across, thousands of times below the threshold of human vision. That tininess is practically part of the definition of a bacterium.
NowIn 2022, scientists described Thiomargarita magnifica in Science: a bacterium whose single cells grow to a centimetre or more, the length of an eyelash, visible to the naked eye and pickable up with tweezers, some 5,000 times larger than a typical microbe.
- Technology & ComputingDisproved
Computers can't understand ordinary language
Changed in2022TaughtMachines need exact commands. They cannot handle ambiguity, metaphor, or context, so you have to speak to them in code or in rigid menu choices. Natural conversation with a computer is science fiction.
NowLarge language models write, translate, summarize, explain, and code from plain conversational instructions. ChatGPT's launch in November 2022 reached an estimated 100 million users within two months, the fastest adoption of any consumer application to that point.
- Earth ScienceUpdated
TaughtThe Moon's tidal drag steadily brakes Earth's spin, so every century the day grows a couple of milliseconds longer. That is why we occasionally add a 'leap second'; the planet is always, gradually, slowing down.
NowOn 29 June 2022, Earth completed a rotation 1.59 milliseconds short of 24 hours: the shortest day since atomic clocks began measuring, part of a run of record-fast days since 2020. The planet has recently been speeding up, not slowing.
- Astronomy & SpaceDisproved
TaughtThe dinosaurs had no defense against the asteroid that killed them, and neither would we. If a large one were found on a collision course, our only real options would be to evacuate and hope. Actually deflecting one is science fiction.
NowOn 26 September 2022 NASA's DART spacecraft deliberately crashed into the asteroid moonlet Dimorphos and measurably changed its orbit, shortening it by about 32 minutes. It was the first time humanity has altered the motion of a celestial body on purpose.
- MedicineReplaced
TaughtOnce you reach middle age, a baby aspirin daily is basic preventive care. It thins the blood and protects against heart attack and stroke, with essentially no downside.
NowThe US Preventive Services Task Force reversed the recommendation in 2022. For adults 60 and over with no cardiovascular disease, do not start daily aspirin: the bleeding risk outweighs the benefit. For ages 40 to 59 it is now an individual decision with a doctor, not a default.
- Health & NutritionDisproved
TaughtVitamin D builds strong bones, so a daily supplement is a sensible way for adults to keep their bones dense and guard against fractures as they age.
NowThe large VITAL trial, reported in the New England Journal of Medicine in July 2022, found that vitamin D3 supplements did not lower the risk of fractures in generally healthy adults who were not deficient: no reduction in total, non-vertebral, or hip fractures.
- GeographyRenamed
The country is spelled Turkey
Changed in2022TaughtTurkey, capital Ankara, straddling Europe and Asia.
NowIn June 2022 the UN accepted the government's request to register the country's name in all languages as Türkiye, the Turkish spelling.
- Astronomy & SpaceUpdated
TaughtOur deepest look into the cosmos is the Hubble Space Telescope's Deep Field: a tiny patch of sky stared at for days, revealing thousands of distant galaxies. It is the benchmark image of how far back we can see.
NowOn 11 July 2022, NASA released Webb's First Deep Field of the cluster SMACS 0723: the deepest and sharpest infrared image of the universe ever taken, reaching fainter and earlier galaxies than Hubble's deepest fields, in about 12.5 hours rather than weeks.
- BiologyRefined
The human genome was fully sequenced in 2003
Changed in2022TaughtThe Human Genome Project finished in 2003, reading all three billion letters of human DNA from end to end. The book of life was complete.
NowThe 2003 sequence was about 92% complete. The hardest 8%, dense repetitive regions, resisted sequencing until 2022, when the Telomere-to-Telomere consortium published the first truly gapless human genome.
- HistoryRenamed
The Inca city is named Machu Picchu
Changed in2022TaughtThe famous Inca citadel in the Andes is called Machu Picchu, the name it has carried since Hiram Bingham brought it to the world's attention in 1911.
NowA 2022 study of Bingham's own field notes, early maps, and Spanish colonial land documents concluded the Incas called the site Huayna Picchu, or simply Picchu. 'Machu Picchu' is the name of the taller neighboring peak, and it got attached to the ruins essentially by a mapping accident in 1911.
- GeographyUpdated
There are five billion people on Earth
Changed in2022TaughtThe world population is about 5 billion and growing at a frightening exponential rate.
NowThe UN marked the 8 billionth person on 15 November 2022. Growth is also no longer exponential: the global fertility rate has roughly halved since 1970 and the population is projected to peak around 10.3 billion in the 2080s.
- Astronomy & SpaceDisproved
TaughtA supermassive black hole, Sagittarius A*, sits at the center of the Milky Way; we know it from the orbits of stars whipping around something invisible. But it is 27,000 light-years away and, by definition, emits no light, so an actual image of it is impossible.
NowOn 12 May 2022, the Event Horizon Telescope collaboration released the first image of Sagittarius A*: a glowing ring of superheated gas encircling the dark shadow of the black hole itself, direct visual confirmation of the object at our galaxy's heart.
- MedicineUpdated
TaughtTransplants come from human donors. The human immune system destroys animal organs within minutes to hours, 'hyperacute rejection', so putting a pig's heart into a living person is a fantasy that has never been, and may never be, achieved.
NowOn 7 January 2022, surgeons at the University of Maryland transplanted a genetically modified pig heart into David Bennett, a living man with end-stage heart failure. The organ was not rejected on the table; it beat and sustained him for two months.
- Health & NutritionDisproved
A daily glass of red wine is good for your heart
Changed in2023TaughtModerate drinking is healthier than not drinking at all. A glass of red wine a day protects your heart: the famous J-shaped curve, backed by the 'French paradox.'
NowIn January 2023 the WHO stated plainly that no level of alcohol consumption is safe for health, and better-controlled studies have shown the apparent benefit of moderate drinking largely dissolves once confounding is removed. Alcohol is a Group 1 carcinogen.
- Physics & ChemistryDisproved
TaughtThere is a fundamental physics limit (the Shockley-Queisser limit, about 33.7%) on how much sunlight a single-junction solar cell can turn into electricity. Real silicon panels top out around 27%, and the theoretical ceiling of roughly one-third is a wall you cannot climb over.
NowIn November 2023, LONGi's crystalline-silicon/perovskite tandem cell was certified at 33.9% efficiency by the U.S. National Renewable Energy Laboratory, the first time a solar cell exceeded the 33.7% single-junction Shockley-Queisser limit.
- Health & NutritionRefined
BMI tells you whether you are healthy
Changed in2023TaughtCalculate your Body Mass Index, look it up on the chart, and find out if you are underweight, normal, overweight, or obese.
NowIn 2023 the American Medical Association adopted policy stating that BMI is an imperfect measure that should not be used alone, because it ignores body composition and differs in meaning across ethnic groups and sexes.
- Earth ScienceUpdated
Earth's spin axis only wobbles from natural forces
Changed in2023TaughtEarth's rotational axis wanders slightly over time, a natural wobble driven by things like the melting of ancient ice sheets and shifts deep in the planet. It's a geological process, far beyond human influence.
NowA 2023 study found that humans pumping groundwater have measurably shifted Earth's spin axis. Extracting about 2,150 gigatonnes of groundwater between 1993 and 2010, and moving that water to the oceans, tilted the rotational pole roughly 80 cm eastward, about 4.3 cm per year.
- GeographyUpdated
Every continent has been fully mapped
Changed in2023TaughtThe age of exploration is over. Every continent has been surveyed, charted, and mapped; there are no blank spaces left on the map of Earth's landmasses.
NowIn 2023, Zealandia became the first continent in the world to have its full geology mapped, and it only counts as a continent at all because of work completed after 2017. Almost 95 percent of its five million square kilometres sits underwater, which is exactly why it took until 2023 to chart.
- MedicineUpdated
Gene editing is experimental, with no approved therapy
Changed in2023TaughtCRISPR is a remarkable laboratory tool for editing DNA, but using it to treat patients is years away and purely experimental. No gene-editing therapy has been approved for use in people.
NowOn 8 December 2023 the US FDA approved Casgevy, a CRISPR-based therapy for sickle cell disease, the first approved medicine that edits a patient's DNA. The UK had authorized it weeks earlier.
- Language & CultureDisproved
Good readers guess words from context
Changed in2023TaughtStuck on a word? Look at the picture. Think about what would make sense in the sentence. Check the first letter and take a guess. Sounding it out letter by letter is a last resort.
NowIn the 2023 legislative session alone, eight US states banned this method, called three-cueing, from K-3 classrooms: Florida, Indiana, North Carolina, Ohio, South Carolina, Texas, West Virginia, and Wisconsin. Decades of cognitive science show skilled readers decode words letter by letter; guessing from context is what struggling readers do.
- Technology & ComputingDisproved
TaughtDiscovering a new stable material, the kind that could make a better battery or a superconductor, is slow, hard lab work. Across all of history, chemists had characterized only a few tens of thousands of stable inorganic crystals, each the product of careful synthesis and testing.
NowIn November 2023, Google DeepMind reported in Nature that its GNoME AI had predicted 2.2 million new crystal structures, about 380,000 of them stable: roughly a tenfold jump over all the stable inorganic crystals humanity had catalogued before, generated in a matter of weeks.
- Technology & ComputingDisproved
TaughtA gruelling professional licensing exam (the bar for lawyers, the medical boards for doctors) tests years of specialized human judgement. A computer might answer trivia, but it could not pass the kind of exam that certifies a person to practice a profession.
NowIn March 2023, OpenAI reported that GPT-4 scored high enough on the Uniform Bar Exam to pass in most US jurisdictions, around 75%, and it cleared other professional and graduate exams too. A machine passing the bar went from thought experiment to done.
- Astronomy & SpaceDisproved
No spacecraft has ever landed near the Moon's south pole
Changed in2023TaughtEvery Moon landing (Apollo, the Soviet and Chinese landers) touched down in the relatively flat, easy terrain near the equator. The south polar region, with its rugged shadows and craters that may hold water ice, was a place probes flew over or crashed into, never a place anyone had softly landed.
NowOn 23 August 2023, India's Chandrayaan-3 lander touched down at about 69° south: the first soft landing anywhere near the lunar south pole, and the fourth country ever to land on the Moon.
- MedicineDisproved
Nothing can slow Alzheimer's, only ease the symptoms
Changed in2023TaughtThere is no way to slow or stop Alzheimer's disease. The available drugs treat symptoms like memory loss and agitation for a while, but the underlying decline is unstoppable.
NowIn 2023 the FDA fully approved lecanemab (Leqembi), an antibody that clears amyloid from the brain and modestly slows cognitive decline, the first treatment shown to change the course of the disease rather than only its symptoms.
- Earth ScienceRefined
The Earth has a crust, a mantle, and a core
Changed in2023TaughtCut the Earth in half and you get neat concentric shells: crust, mantle, liquid outer core, solid inner core. Four layers, colored on the diagram.
NowThere is evidence of a distinct innermost inner core, roughly 650 kilometers across, with a different crystal alignment from the rest of the inner core. Published in Nature Communications in February 2023, it makes a fifth layer.
- Astronomy & SpaceDisproved
TaughtLIGO can catch the sharp chirp of two black holes merging nearby, but the deep background hum (the overlapping ripples of countless supermassive black holes across all of cosmic history, stretching spacetime over years and decades) is far too slow and too faint for any instrument to pick out.
NowIn June 2023, the NANOGrav collaboration and three other pulsar-timing arrays announced compelling evidence for exactly that background: a sea of nanohertz gravitational waves, most likely from supermassive black-hole binaries, detected by watching pulsars scattered across the galaxy tick out of sync.
- MedicineUpdated
TaughtNaloxone (Narcan) can reverse an opioid overdose in minutes, but it is a medication; you get it through a pharmacist, a prescription, or a special standing order. It is not something you buy off a shelf like aspirin.
NowOn 29 March 2023 the FDA approved Narcan nasal spray for over-the-counter sale, the first naloxone product cleared for use without any prescription, clearing the way for it to be stocked in supermarkets, convenience stores, vending machines, and online.
- HistoryUpdated
The world is in a COVID-19 public health emergency
Changed in2023TaughtCOVID-19 is a Public Health Emergency of International Concern: the World Health Organization's highest level of global alarm, declared on 30 January 2020. The world is in an active, emergency phase of the pandemic.
NowOn 5 May 2023, the WHO declared that COVID-19 is no longer a public health emergency of international concern, ending the emergency phase after more than three years as immunity rose and deaths and hospitalizations fell.
- MedicineDisproved
There is no pill for postpartum depression
Changed in2023TaughtPostpartum depression is treated with the same general antidepressants used for everything else, which take weeks to work. There is no medication designed specifically for it, and the one dedicated drug that existed required a 60-hour IV infusion in a hospital.
NowOn 4 August 2023 the FDA approved Zurzuvae (zuranolone), the first oral medication developed specifically for postpartum depression, a once-daily pill taken for 14 days that can improve symptoms within days rather than weeks.
- MedicineDisproved
There is no vaccine for RSV
Changed in2023TaughtRespiratory syncytial virus (RSV) sends tens of thousands of older adults and infants to the hospital every year, and there is nothing to prevent it. Sixty years of vaccine attempts had failed (one 1960s trial made the disease worse) so RSV was the textbook example of a virus we could not vaccinate against.
NowIn May 2023 the FDA approved Arexvy, the world's first RSV vaccine, for adults 60 and older, followed within weeks by a second. In trials a single dose cut the risk of symptomatic RSV illness by about 83% and severe illness by roughly 94%.
- BiologyDisproved
Tyrannosaurus rex bared its huge teeth like a crocodile
Changed in2023TaughtPicture T. rex and you picture the teeth: rows of banana-sized daggers jutting out even when the mouth is shut, exposed to the air like a crocodile's. Every model, museum mount, and movie monster agreed.
NowA March 2023 study in Science concluded that T. rex and other big theropods had scaly, lizard-like lips that fully covered their teeth when the mouth was closed. The crocodile-style permanent snarl appears to be wrong.
- BiologyUpdated
We will never know what killed Beethoven
Changed in2023TaughtBeethoven died in 1827 after years of illness, deafness, and abdominal suffering, and the cause was lost to history. Without a body to examine, the best anyone could offer was speculation: lead poisoning, syphilis, a dozen guesses.
NowIn March 2023, researchers sequenced Beethoven's genome from authenticated locks of his hair and reported, in Current Biology, that he carried strong genetic risk factors for liver disease and had been infected with hepatitis B, a combination that, with his drinking, points to liver failure as the likely cause of death.
- Health & NutritionDisproved
TaughtA daily multivitamin is basic health insurance; it fills the gaps in an imperfect diet and, over a lifetime, helps you stay healthy and live longer.
NowA June 2024 analysis in JAMA Network Open, pooling nearly 400,000 healthy US adults followed for more than 20 years, found that daily multivitamin use was not associated with any lower risk of death.
- Physics & ChemistryDisproved
TaughtTwo-dimensional materials are a carbon curiosity. Graphene works because graphite is already made of weakly bound sheets you can peel apart; a true metal like gold is a three-dimensional lattice and would simply clump up long before you reached a single free-standing atomic layer.
NowIn 2024 researchers at Linköping University made 'goldene': a free-standing sheet of gold exactly one atom thick, the first two-dimensional metal. Cornered into two dimensions, gold even stops behaving like a normal metal and takes on semiconductor-like properties.
- Technology & ComputingDisproved
TaughtReusable rockets land the way SpaceX's Falcon 9 does, deploying legs and setting down on a pad or a drone ship. The idea of a skyscraper-sized booster steering itself back and being plucked out of mid-air by the launch tower is a rendering, not something anyone has done.
NowOn 13 October 2024, on the fifth Starship test flight, SpaceX's Super Heavy booster flew itself back to the launch tower and was caught in mid-descent by two giant mechanical arms, the 'chopsticks', on the first attempt. No booster had ever been recovered that way before.
- Technology & ComputingDisproved
TaughtQubits are so fragile that the more of them you string together, the more errors pile up. Error correction was a beautiful theory, but in practice every extra qubit added more noise than it removed, so a useful, scaled quantum computer stayed permanently over the horizon.
NowIn December 2024 Google reported in Nature that its Willow chip crossed the error-correction threshold: as it went from a 3×3 to a 5×5 to a 7×7 grid of physical qubits, the logical error rate was cut roughly in half at each step. For the first time, adding qubits made the encoded information more reliable, not less.
- Language & CultureUpdated
Cursive is obsolete, you'll never need it
Changed in2024TaughtWe don't do cursive anymore. It was dropped from the standards because you'll type everything that matters. Print your name, learn to keyboard, move on.
NowCursive is being legislated back into classrooms. California's AB 446, passed unanimously and in effect since January 2024, requires cursive instruction in grades one through six, joining a growing list of states that have re-mandated it after Common Core dropped it in 2010.
- BiologyUpdated
TaughtBeyond ABO and Rh, blood typing is a mostly closed book. The International Society of Blood Transfusion recognises a fixed roster of blood group systems, 44 of them, and the mysteries were solved long ago.
NowIn 2024, researchers at NHS Blood and Transplant and the University of Bristol described the MAL blood group system, the 47th recognised system, finally explaining the AnWj antigen, whose genetic basis had been a mystery since 1972.
- GeographyUpdated
Mount Everest's height is fixed
Changed in2024TaughtMount Everest is a certain fixed height. It rose when India collided with Asia millions of years ago, and now it just stands there as the world's tallest mountain.
NowA 2024 study found Everest is actively growing, rising up to about 2 millimetres a year, and is 15 to 50 metres taller than it 'should' be because a river gorge 75 km away is eroding away rock and letting the crust below rebound upward. The mountain is being pushed up by the loss of land nearby.
- Astronomy & SpaceUpdated
Nothing humanmade can survive flying close to the Sun
Changed in2024TaughtThe Sun's surface is thousands of degrees, and its corona is hotter still. Any spacecraft that ventured near it would be destroyed, so our star can only ever be studied from a safe distance.
NowOn 24 December 2024, NASA's Parker Solar Probe passed just 3.8 million miles from the Sun's surface (flying through the corona at about 430,000 mph, the closest and fastest any human-made object has ever come to a star) and radioed home days later, intact.
- BiologyDisproved
TaughtThe only complete wiring diagram of a brain (a 'connectome') belongs to the roundworm C. elegans, with its 302 neurons. Mapping every neuron and every connection in anything more complex is far beyond what anyone can do.
NowOn 2 October 2024, the FlyWire consortium published in Nature the complete connectome of an adult fruit fly brain: all 139,255 neurons and more than 50 million synapses, mapped and annotated. It is the most complex brain ever fully wired up.
- Astronomy & SpaceDisproved
TaughtSoft-landing on the Moon is so hard that only three superpowers (the United States, the Soviet Union, and China) have ever managed it. A soft landing is a feat of national space programs, not something a private company can do.
NowOn 22 February 2024, Intuitive Machines' Odysseus lander touched down near the Moon's south pole: the first soft landing on the Moon by a privately built spacecraft, and the first American landing of any kind since Apollo 17 in 1972.
- MedicineUpdated
TaughtThe U.S. Preventive Services Task Force recommended that routine screening mammograms begin at age 50. For women in their 40s, whether to screen was an individual decision to weigh with a doctor, not a blanket recommendation.
NowOn 30 April 2024, the USPSTF issued a final recommendation that all women at average risk begin screening mammography at age 40, every other year, through age 74, moving the universal starting age down a full decade.
- HistoryUpdated
Stonehenge's Altar Stone came from Wales
Changed in2024TaughtStonehenge's bluestones, including the large recumbent Altar Stone at the center, were brought from the Preseli Hills in west Wales, roughly 150 miles away.
NowA 2024 Nature study showed the six-tonne Altar Stone does not match Welsh rock at all. Its mineral ages and chemistry match the Orcadian Basin of northeast Scotland, more than 460 miles (750 km) away, the longest-distance megalith transport known from Neolithic Europe.
- Earth ScienceUpdated
The Dragon Hole is the deepest blue hole on Earth
Changed in2024TaughtThe deepest known underwater sinkhole (a 'blue hole') is the Dragon Hole in the South China Sea, plunging about 300 metres. That is the record you would have found in any recent reference.
NowIn 2024, researchers reported that Taam Ja' Blue Hole in Mexico's Chetumal Bay reaches at least 420 metres deep, more than 100 metres deeper than the Dragon Hole, and that the instrument never touched the bottom, so the true depth is greater still.
- HistoryDisproved
TaughtThe earliest figurative cave paintings are the European ones, Chauvet and Lascaux in France, Altamira in Spain, and Europe is where prehistoric art and visual storytelling began, around 30,000 to 40,000 years ago.
NowIn July 2024, a scene on the Indonesian island of Sulawesi was dated to at least 51,200 years ago, making it the oldest known figurative art anywhere. It shows three human-like figures around a wild pig, which also makes it the oldest known example of narrative storytelling in art.
- Earth ScienceUpdated
The world has never crossed the 1.5°C warming line
Changed in2024TaughtThe Paris Agreement's 1.5°C limit is a distant guardrail. Global temperatures are rising, but no calendar year has ever averaged more than 1.5°C above pre-industrial levels; that threshold is something to prevent in the decades ahead.
Now2024 was the first calendar year to average more than 1.5°C above the 1850–1900 baseline: about 1.55°C by the WMO's consolidated analysis of six datasets, and the warmest year on record. The line that anchored a generation of climate targets was crossed for a full year for the first time.
- MedicineDisproved
TaughtNon-alcoholic steatohepatitis (NASH), the serious, scarring form of fatty liver disease, has no medication. Despite affecting millions, the only treatment is losing weight through diet and exercise; every drug candidate had failed in trials.
NowOn 14 March 2024, the FDA approved resmetirom (Rezdiffra) for NASH, now called MASH, with moderate-to-advanced liver fibrosis. It is the first drug ever approved for the disease, after decades in which every candidate fell short.
- Earth ScienceUpdated
We have left the Holocene and entered the Anthropocene
Changed in2024TaughtHuman activity has pushed Earth out of the Holocene and into a new geological epoch, the Anthropocene, defined by our impact on the planet. It is the epoch we now live in.
NowIn March 2024 the scientific bodies that name geological time formally rejected the proposal to add the Anthropocene as an epoch. Officially, we are still in the Holocene. "Anthropocene" survives as a useful informal term, not a unit on the geological timescale.
- MedicineUpdated
You cannot transplant an animal's organ into a human
Changed in2024TaughtTransplants have to come from human donors. An organ from another species would be rejected by the immune system within minutes, so cross-species transplants are impossible.
NowOn 16 March 2024, surgeons at Massachusetts General Hospital transplanted a gene-edited pig kidney into a living patient, the first time an animal organ was placed in a living human. Earlier gene-edited pig hearts and kidneys had been tried in brain-dead recipients and, in 2022, in one living heart patient.
- Language & CultureReplaced
You'll take the SAT with a No. 2 pencil
Changed in2024TaughtBring two sharpened No. 2 pencils. Fill the bubble completely. Erase cleanly. Three hours, a paper booklet, and a proctor telling you when to put your pencil down.
NowThe paper SAT no longer exists. As of March 9, 2024, the test is digital-only, taken on a laptop or tablet through an app called Bluebook. It is also a different test: about two hours instead of three, adaptive, with shorter reading passages and a calculator allowed on all of the math.
A day on Uranus is 17 hours and 14 minutes long
Changed in2025TaughtUranus rotates once every 17 hours and 14 minutes. Voyager 2 measured it during its 1986 flyby by timing the planet's radio emissions and magnetic field, and that has been the figure ever since.
NowIn April 2025, using a decade of Hubble observations of Uranus's auroras, astronomers pinned the rotation period at 17 hours, 14 minutes and 52 seconds: about 28 seconds longer than Voyager's value, and a thousand times more precise.
A gene therapy has to be developed for a whole patient population, never for one child
Changed in2025TaughtDeveloping a gene-editing therapy takes many years and enormous cost, so it only makes sense for diseases shared by thousands of patients. A treatment designed and manufactured for a single individual's exact mutation is science fiction.
NowIn May 2025 a team at Children's Hospital of Philadelphia treated an infant known as KJ Muldoon, who had a severe CPS1 urea-cycle disorder, with a CRISPR base-editing therapy custom-built for his specific mutation, from diagnosis to dosing in about six months. It was the first personalized in-vivo gene-editing medicine made for one person.
Computers can't do original mathematical reasoning; no machine could win a math olympiad
Changed in2025TaughtComputers are fast calculators, but genuine mathematical creativity (reading a hard, unseen olympiad problem and inventing a multi-step proof) is a distinctly human act. A machine can crunch numbers; it cannot reason its way to a novel proof under exam conditions.
NowIn July 2025, AI systems from Google DeepMind and OpenAI both scored 35 out of 42 on the International Mathematical Olympiad, gold-medal level, solving five of six problems as free-form written proofs, under the same rules and time limits as human contestants.
Earth's inner core is a solid, rigid ball of iron
Changed in2025TaughtAt the centre of the Earth is the inner core, a solid ball of iron and nickel, frozen rigid by immense pressure despite being as hot as the Sun's surface. It's the one solid, unchanging part of the deep Earth.
NowA 2025 study found the inner core's surface is deforming and changing shape over time, its boundary flexing like something viscous, not standing rigid. Turbulence in the liquid outer core appears to be reshaping the inner core's near-surface at a surprisingly fast rate.
Internet slang isn't real English
Changed in2025TaughtSlang from the internet is not proper English. It's a fad, it won't last, and it certainly doesn't belong anywhere near a dictionary.
NowIn August 2025 the Cambridge Dictionary added 'skibidi', 'delulu', and 'tradwife' among 6,212 new words, phrases, and senses in a single year. The editors' stated bar was staying power: these words were tracked in real usage and stuck around long enough to earn entries.
Nothing you can be given lowers your risk of dementia
Changed in2025TaughtDementia is a matter of genes and age. There is no vaccine and no ordinary medication that measurably lowers a person's chance of developing it; prevention is limited to vague lifestyle advice.
NowIn April 2025 a study in Nature exploited a vaccine-eligibility cutoff in Wales as a natural experiment and found that people who received the shingles vaccine were about 20% less likely to be diagnosed with dementia over the following seven years, the strongest causal-leaning evidence yet that a widely used vaccine is associated with lower dementia risk.
TaughtObesity is one thing: a BMI of 30 or above. You either cross that line or you don't, and crossing it means you have the disease of obesity.
NowIn January 2025 a Lancet Diabetes & Endocrinology Commission of 58 experts split the concept in two ('clinical obesity,' an actual disease with organ dysfunction caused by excess body fat, and 'preclinical obesity,' excess fat with raised future risk but no current illness) and moved diagnosis beyond BMI alone.
TaughtInterstellar visitors are vanishingly rare. We have seen exactly two objects confirmed to come from beyond our solar system: 'Oumuamua in 2017 and comet Borisov in 2019. Catching a third is a someday hope.
NowOn 1 July 2025 the NASA-funded ATLAS survey spotted 3I/ATLAS, the third confirmed interstellar object, a comet on a wildly hyperbolic orbit that could only have come from another star system.
Pompeii was buried and abandoned in 79 CE
Changed in2025TaughtMount Vesuvius buried Pompeii in 79 CE, killing its inhabitants and sealing the city under ash. It lay empty and forgotten until its rediscovery and excavation in the eighteenth century.
NowExcavations reported in 2025 show people moved back into the ruins after the eruption and lived there for centuries. Survivors and newcomers built dwellings among the buried upper storeys, with coins, ceramics, ovens, and oil lamps documenting occupation from the late first century into the fifth.
TaughtFD&C Red No. 3 (erythrosine) is a federally approved color additive, used for decades in candy, drinks, and medicines. It is on the shelf, so it must be considered safe to eat.
NowOn 15 January 2025 the FDA revoked the authorization for Red No. 3 in food and ingested drugs, ordering it removed from the food supply. The dye had already been banned from cosmetics in 1990; the food ban closes a 35-year gap.
Saturn has 82 moons
Changed in2025TaughtSaturn is the moon champion of the solar system with 82 moons, having narrowly overtaken Jupiter. That is the tidy, memorizable number for the ringed planet's family.
NowIn March 2025 the International Astronomical Union recognized 128 newly confirmed moons of Saturn in one stroke, bringing its total to 274, more than every other planet in the solar system combined.
TaughtThe brain is the body's most protected organ, sealed off by the blood-brain barrier, a tight lining that evolution spent half a billion years perfecting to keep foreign material out. Environmental particles like microplastics circulate in the body but do not reach the brain.
NowA February 2025 study in Nature Medicine found that human brains contain roughly a plastic spoon's worth of micro- and nanoplastics, far more than the liver or kidneys, and that the amount rose about 50% between 2016 and 2024. The barrier is not the seal it was assumed to be.
The body of water south of the US is the Gulf of Mexico
Changed in2025TaughtThe large body of water bordered by the United States, Mexico, and Cuba is the Gulf of Mexico, a name it has held on maps for over four centuries.
NowIn 2025, a US executive order renamed it the 'Gulf of America' for federal use, and the US Geographic Names Information System updated the name on 10 February 2025. The change is binding only inside the US government, Mexico and most of the world still call it the Gulf of Mexico, and there is no international authority that can settle it.
TaughtOur galaxy and the Andromeda galaxy are falling toward each other and will smash together in roughly 4.5 billion years, merging into a single giant elliptical galaxy sometimes nicknamed 'Milkomeda.' It is a certainty, just a distant one.
NowA June 2025 study in Nature Astronomy ran 100,000 simulations with the latest Gaia and Hubble data and found only about a 50-50 chance the two galaxies collide within the next 10 billion years. The head-on merger is no longer a sure thing.
The tokamak is the only serious path to fusion; the stellarator is a scientific curiosity
Changed in2025TaughtMagnetic-confinement fusion means the tokamak, the doughnut design that holds every record. The stellarator, with its baroque twisted magnets, is an elegant idea that never kept up. It is a research sideline, not a contender.
NowOn 22 May 2025 the Wendelstein 7-X stellarator held the fusion 'triple product' (the combination of density, temperature and confinement time that gauges how close you are to a power plant) at a record level for 43 seconds, outperforming what any tokamak had sustained for that long.
TaughtThere is no HIV vaccine and no long-lasting way to prevent infection. Prevention comes down to condoms or, more recently, a pill taken every single day without fail.
NowIn June 2025 the FDA approved lenacapavir (Yeztugo), an injection given just twice a year that prevented HIV in essentially everyone who received it in trials, close to 100% effective.
We have no idea what a Denisovan looked like
Changed in2025TaughtDenisovans are an extinct human cousin known almost entirely from a finger bone, a few teeth, and the DNA inside them. There is no skull, and no real idea what their faces looked like.
NowIn June 2025, molecular analysis identified the near-complete "Dragon Man" skull from Harbin, China as Denisovan, the first Denisovan skull ever recognized and the first genuine look at their face.
We have no idea what a Denisovan looked like
Changed in2025TaughtDenisovans are an extinct human relative known only from a few teeth and a finger bone from a Siberian cave. We have their DNA but no skull, so we don't know what they looked like.
NowIn 2025, molecular analysis identified the near-complete 'Dragon Man' skull from Harbin, China, as Denisovan, giving the group its first face. Ancient proteins and DNA from the skull's tooth plaque tied the massive, heavy-browed cranium, at least 146,000 years old, to the Denisovan lineage.
TaughtMedicines work by binding a target protein and blocking it, like a key jammed in a lock. The drug has to stay bound to keep working, and proteins the body considers 'undruggable', with no good pocket to grab, are simply out of reach.
NowOn 1 May 2026 the FDA approved vepdegestrant (Veppanu), the first PROTAC ever authorized anywhere. Instead of blocking its target, it tags the protein for the cell's own disposal machinery, so the protein is destroyed rather than merely occupied.
TaughtThe CRISPR therapy Casgevy that can functionally cure sickle cell disease was approved for people twelve and older. Young children, who suffer the most damage from the disease early on, were left waiting on the sidelines.
NowOn 1 July 2026 the FDA expanded Casgevy (exagamglogene autotemcel) to children as young as two with severe sickle cell disease or transfusion-dependent beta thalassemia: the first one-time genetic therapy approved for that age group, adding roughly 5,500 eligible children in the US.
Cerebral folate deficiency has no treatment
Changed in2026TaughtWhen a genetic fault blocks folate from reaching the brain, children develop seizures, movement disorders, and severe developmental delay. It is a devastating, untreatable condition; you manage the symptoms and little else.
NowOn 10 March 2026 the FDA approved Wellcovorin (leucovorin calcium) as the first treatment for cerebral folate transport deficiency caused by variants in the FOLR1 gene. Leucovorin is a form of folate that can slip into the brain by a different route, bypassing the broken transporter.
TaughtWhen a child is born deaf because of a genetic defect, the ear is broken at the source. A cochlear implant can route sound around the damage, but there is no way to fix the underlying biology and give the ear its own hearing back.
NowOn 23 April 2026 the FDA approved Otarmeni (lunsotogene parvec), a one-time gene therapy for deafness caused by variants in the OTOF gene. It delivers a working copy of the gene to the inner ear, and most treated patients gained usable hearing, some reaching normal levels, including whispers.
TaughtArginase 1 deficiency lets the amino acid arginine build to toxic levels, causing stiffness, seizures, and developmental regression. There is no drug for it. Management means a severely protein-restricted diet, for life, and it is rarely enough.
NowOn 23 February 2026 the FDA granted accelerated approval to Loargys (pegzilarginase), an engineered enzyme injected to break down the excess arginine the body cannot clear on its own, the first therapy that directly targets the disease.
For early bladder cancer, BCG is the only option, and nothing has improved on it in decades
Changed in2026TaughtHigh-risk bladder cancer that hasn't invaded the muscle is treated by putting BCG, a tuberculosis vaccine, into the bladder. It has been the standard since the 1970s, and despite the cancer often coming back, nothing has been added to it in a generation.
NowOn 28 May 2026 the FDA approved durvalumab (Imfinzi) in combination with BCG for high-risk, non-muscle-invasive bladder cancer: the first immunotherapy combination for the disease, and the first genuinely new approach layered onto BCG in decades.
TaughtThree hundred million years ago, dragonfly-like insects grew to the size of hawks. The standard explanation: atmospheric oxygen was around 45% higher than today, and because insects breathe through passive tubes rather than lungs, only that oxygen-rich air could supply a body that large. When oxygen fell, giant insects became impossible.
NowA 2026 study in Nature found that the insect breathing system is nowhere near its oxygen-delivery limit, so oxygen alone cannot explain the giants. The prevailing high-oxygen theory of insect gigantism doesn't hold up.
TaughtFinding a new asteroid, or catching a supernova as it flares, is painstaking work: an astronomer comparing images, spotting a moving dot or a new point of light, confirming it night by night. Discoveries come in ones and tens, and the vast majority of the sky's changes pass unseen.
NowOn 30 June 2026, the NSF–DOE Vera C. Rubin Observatory began its 10-year Legacy Survey of Space and Time, imaging the entire southern sky every few nights. In just six weeks of early optimization runs it had already found over 11,000 new asteroids, and in full operation it issues up to about 7 million alerts of changes in the sky every single night.
No human has traveled beyond Earth orbit since 1972, and none will for the foreseeable future
Changed in2026TaughtThe last people to leave low-Earth orbit were the Apollo 17 astronauts in December 1972. Ever since, human spaceflight has been stuck circling a few hundred kilometres up (the Space Shuttle, the ISS) and returning to deep space felt perpetually a decade away.
NowOn 1 April 2026, NASA's Artemis II launched four astronauts on a flight around the Moon, the first crewed mission beyond low-Earth orbit since Apollo 17. They looped around the far side and splashed down safely on 10 April, traveling farther from Earth than any humans in history.
Nothing can reach the brain damage of Hunter syndrome
Changed in2026TaughtIn Hunter syndrome, a missing enzyme lets sugary molecules pile up in cells throughout the body and the brain. Enzyme replacement can help the body, but the replacement enzyme cannot cross the blood-brain barrier, so the cognitive decline is untouchable.
NowOn 25 March 2026 the FDA approved Avlayah (tividenofusp alfa), an enzyme replacement engineered to cross the blood-brain barrier: the first treatment for Hunter syndrome aimed at its neurological damage, and the first FDA approval for the disease in nearly twenty years.
The charred Herculaneum scrolls can never be read
Changed in2026TaughtThe library of carbonized papyrus scrolls from Herculaneum, charred solid by the same eruption that buried Pompeii, is unreadable. Unrolling them destroys them, so their contents are lost forever, a whole ancient library we can see but never open.
NowThey can be read without being opened. Using high-resolution CT scans and machine learning, the Vesuvius Challenge recovered the first words in 2023 and full passages in 2024, and in 2026 an entire scroll, PHerc. 1667, was virtually unwrapped and read end to end for the first time.
TaughtThe blockbuster weight-loss and diabetes drugs (semaglutide, tirzepatide) are peptides, fragile protein-like chains your stomach digests. That is why they come as weekly injections. You cannot simply put them in a swallowable, mass-produced tablet.
NowOn 1 April 2026 the FDA approved Foundayo (orforglipron), the first small-molecule GLP-1 receptor agonist: a once-daily pill you can take any time of day, with no food or water restrictions, and that can be manufactured at pharmaceutical scale like an ordinary tablet.
TaughtThe biologics that clear moderate-to-severe psoriasis are large antibody proteins. Swallow one and your gut digests it like food, so they only work as injections. A pill that targets the same pathway is not chemically possible.
NowOn 18 March 2026 the FDA approved Icotyde (icotrokinra), the first oral IL-23 pathway drug for plaque psoriasis. It is a small engineered peptide designed to survive the gut and block the same target the injected biologics hit.
TaughtHigh blood pressure is treated with the same handful of drug families your parents took: diuretics, ACE inhibitors, ARBs, calcium-channel blockers, beta-blockers. Nothing mechanistically new has arrived in decades, and for resistant patients the cupboard is bare.
NowOn 18 May 2026 the FDA approved baxdrostat (Baxfendy), an aldosterone synthase inhibitor, the first mechanistically new class of blood-pressure drug in decades. It blocks the enzyme that makes aldosterone, a hormone that drives hard-to-treat hypertension.
TaughtFocal segmental glomerulosclerosis scars the kidney's filters and marches toward dialysis or a transplant. There is no drug approved specifically for it; doctors borrow steroids and blood-pressure medicines off-label and hope.
NowOn 13 April 2026 the FDA gave full approval to sparsentan (Filspari) as the first medicine ever approved specifically to treat FSGS, based on the phase 3 DUPLEX trial showing it reduced the protein leakage that drives the disease.
TaughtTriple-negative breast cancer lacks the three receptors that targeted drugs aim at, which is what 'triple-negative' means. With no target to hit, treatment falls back on general chemotherapy, and outcomes are poor.
NowOn 22 May 2026 the FDA approved Datroway (datopotamab deruxtecan), the first targeted therapy to beat chemotherapy on survival in first-line metastatic triple-negative breast cancer. It homes in on a protein called TROP2 and delivers a chemotherapy payload directly to the tumor cells.
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