Cobra Effect

All stories

306 short illustrated stories, read aloud. Each one has a test and the sources it rests on.

Ideas

Ideas worth knowing

Start here

The one idea the rest depend on.

• What you measure is what you get. Why the number you chase quietly replaces the thing you wanted.

Incentives and systems

Why people do what you pay them to do, and what that costs.

• The Cobra effect. Why paying for a result can breed more of the problem.
• Goodhart’s law. A measure turned into a target stops telling you the truth.
• Second order effects. Every fix has consequences, and those have consequences too.
• The tragedy of the commons. Why shared things get used up, and how communities stop it.
• Moral hazard. Shield people from a risk and they take more of it.
• The Jevons paradox. Why making something efficient can make us use more of it.
• Braess’s paradox. Why adding a road can make everyone’s journey slower.
• Path dependence. Why early choices stay locked in long after better ones appear.
• The Lindy effect. The longer an idea has lasted, the longer it is likely to last.
• Antifragility. Some things get stronger from knocks, and fail without them.
• The Streisand effect. Trying to hide something is often the best way to spread it.
• The principal-agent problem. When someone acts for you, their own interests quietly steer the work.
• Feedback loops. Why some systems spiral out of control and others settle down.
• The race to the bottom. When rivals keep undercutting each other, everybody loses.
• Network effects. Why the biggest network tends to swallow the rest.
• The winner’s curse. Win an auction for something uncertain and you probably overpaid.
• Externalities. Why things get overdone when someone else pays part of the cost.
• Schelling’s segregation model. Mild preferences can add up to a sharply divided world.
• The Red Queen effect. When everyone improves at once, running hard only keeps you in place.

Thinking and evidence

The ways a mind fools itself, and how to catch it.

• The razors. Simple rules for cutting away explanations you do not need.
• Survivorship bias. The failures you never see can reverse the lesson you draw.
• The Dunning Kruger effect. Why the least skilled are often the worst judges of their skill.
• Confirmation bias. We look for evidence that agrees, and rarely test what could say no.
• The planning fallacy. Why projects nearly always take longer than we plan.
• Base rate neglect. A good test for a rare thing still gives mostly false alarms.
• Anchoring. The first number you hear bends every estimate that follows.
• The availability heuristic. Vivid stories make rare dangers feel common.
• The narrative fallacy. We invent causes for events because stories feel like explanations.
• Hindsight bias. Once you know the ending, it always looks obvious.
• Outcome bias. Judge a decision by what was known, not by how the dice fell.
• The framing effect. The same facts, worded differently, lead to different choices.
• Loss aversion. Losing something hurts about twice as much as gaining it pleases.
• The curse of knowledge. Once you know something, you cannot see what a beginner is missing.
• Bayesian updating. Change your mind in proportion to the strength of the evidence.
• Overconfidence. Why we feel more certain than our knowledge allows.
• The halo effect. One good quality colours how we judge all the others.
• Motivated reasoning. We set a lower bar for evidence we want to believe.
• The Texas sharpshooter fallacy. Draw the target after the shots and any pattern looks meaningful.
• The Semmelweis reflex. Why experts reject evidence that says they have done harm.
• The illusion of explanatory depth. We think we know how things work until we try to explain them.
• Gell-Mann amnesia. We spot the errors in our own field, then trust everything else.
• The decoy effect. A worse option added to a menu can steer what you choose.
• The endowment effect. We value things more simply because they are ours.
• Inattentional blindness. Focus hard enough and you miss what is right in front of you.
• Post hoc ergo propter hoc. Coming first does not mean causing what came after.
• Correlation is not causation. Two things moving together may share a hidden cause.
• Steelmanning. Argue against the strongest version of a view, not the weakest.
• Choice overload. Too many options that are hard to compare can stop people choosing.

Statistics and probability

Numbers that lie, and the questions that make them stop.

• Regression to the mean. Extreme results drift back towards normal, whatever you do.
• The Monty Hall problem. Why switching doors wins twice as often as staying put.
• The birthday problem. Coincidences are far more likely than they feel.
• The gambler’s fallacy. Chance has no memory, so nothing is ever due.
• Berkson’s paradox. Filtering who you look at can create links that are not there.
• Simpson’s paradox. A trend in every group can reverse when the groups are combined.
• The law of small numbers. Small samples swing wildly, and the swings look like signals.
• The prosecutor’s fallacy. A rare match is not the same as a small chance of innocence.
• The St Petersburg paradox. A huge prize is worth less to you than its average suggests.
• Benford’s law. In real data, numbers starting with 1 far outnumber those starting with 9.
• The hot hand. Streaks are mostly chance, though not always entirely.
• The law of large numbers. Averages settle down over many tries, but a run never gets corrected.
• Mean and median. Why the average can describe nobody at all.
• The Literary Digest poll. A small sample chosen well beats a huge one of the wrong people.
• The garden of forking paths. Choosing the analysis after seeing the data makes flukes look real.

People and organisations

What happens when you put humans in a group and give them a goal.

• Parkinson’s law. Work expands to fill the time you give it.
• The Peter principle. Why people get promoted until they reach a job they cannot do.
• Brooks’s law. Adding people to a late project makes it later.
• Conway’s law. Systems end up shaped like the teams that build them.
• The Hawthorne effect. Being watched changes what people do, and muddies what you measure.
• Dunbar’s number. Why groups stop working the old way once they pass about 150.
• The bystander effect. The more people who see a problem, the less each one acts.
• The fundamental attribution error. We blame people’s character and overlook their situation.
• The Abilene paradox. How a group can agree to something that nobody wants.
• The Pygmalion effect. What we expect of people quietly shapes what they become.
• Groupthink. How close, loyal teams talk themselves into bad decisions.
• Asch’s conformity experiments. Why people go along with a group they can see is wrong.
• Psychological safety. Teams only learn from the mistakes they feel safe to admit.
• Little’s law. How long things wait depends on how many are already waiting.
• The Ringelmann effect. The bigger the group, the less effort each person puts in.
• Milgram’s obedience experiments. Ordinary people follow harmful orders when the setting pushes them.
• Pluralistic ignorance. Everyone can privately doubt a rule that nobody questions out loud.
• Gall’s law. Complex systems that work grow out of simple ones that worked.
• Cunningham’s law. The fastest way to get the right answer is to post a wrong one.
• Pournelle’s iron law of bureaucracy. In any organisation, those who serve the organisation end up in charge.
• The bus factor. How many people could leave before the work stops.
• The iron law of oligarchy. Even democratic groups end up run by a permanent few.
• The Shirky principle. Institutions tend to preserve the problem they exist to solve.
• Sayre’s law. The smaller the stakes, the fiercer the argument.
• Amara’s law. We overrate new technology in the short run and underrate it in the long.
• Tuckman’s stages. Why new teams have to fight before they can work well.
• The Robbers Cave experiment. Rival groups make peace when they need each other, not when they mix.
• The ninety-ninety rule. The last tenth of a project takes as long as the first nine.
• Span of control. Why a manager can only really lead a handful of people.
• Broken windows theory. Visible neglect invites more of it, though the crime claims are contested.

Decisions and strategy

Choosing well when the future is unknown and the past is expensive.

• Chesterton’s fence. Before removing a rule, find out why it was put there.
• The sunk cost fallacy. Money already spent is gone, so it should not steer the next choice.
• Inversion. To find the path to success, first ask what would guarantee failure.
• The broken window fallacy. Destruction makes visible work and hides the cost of what was lost.
• The map is not the territory. Every model leaves something out, and that is where it fails.
• The pre-mortem. Imagine the project has already failed, then ask why, before it starts.
• The prisoner’s dilemma. Why two sensible people can both choose the worst outcome.
• The Overton window. Ideas move from unthinkable to normal before politicians touch them.
• Satisficing. Good enough, chosen quickly, often beats the endless hunt for best.
• Schelling points. Without talking, people meet at whatever stands out.
• Two-way doors. Decide reversible things fast, and save care for what you cannot undo.
• The Pareto principle. A few causes usually produce most of the results.
• The Eisenhower matrix. Urgent things crowd out important ones unless you protect them.
• Hofstadter’s law. It always takes longer than you expect, even when you allow for that.
• Ulysses contracts. Bind your future self before the temptation arrives.
• Zero sum thinking. Most deals are not fixed pies, and treating them as one wastes value.
• Tit for tat. Cooperate first, answer a betrayal once, then forgive.
• BATNA. Your power in a negotiation is what you will do if you walk away.
• Explore and exploit. When to try something new, and when to stick with what works.
• First principles. Rebuild a problem from what must be true, not from what everyone does.
• Opportunity cost. The real price of anything is the best thing you gave up for it.

Learning and memory

How knowledge actually sticks, according to the people who measured it.

• The spacing effect. Spread your study out over time and it lasts far longer.
• The testing effect. Pulling an answer from memory teaches more than reading it again.
• Desirable difficulties. The practice that feels hardest is often the practice that sticks.
• Interleaving. Mixing problem types feels worse and teaches better.
• The Feynman technique. If you cannot explain it simply, you have found a gap.
• Chunking. Experts see patterns where beginners see pieces.
• Deliberate practice. Hours alone do not build skill. Focused work on weaknesses does.
• The method of loci. Pin what you need to remember to a place you already know.
• The Zeigarnik effect. Unfinished tasks stay on your mind until they are closed.
• Dual coding. Words and pictures together stick better than either alone.
• Cognitive load. The mind can juggle only a few new things at once.
• The illusion of competence. Feeling familiar with material is not the same as knowing it.
• The generation effect. Trying to produce an answer first makes it stick, even when you are wrong.
• The learning styles myth. Matching lessons to a preferred style does not improve learning.
• Sleep and consolidation. Sleep is when the day’s learning gets filed away.

Science and philosophy

The thought experiments and rules of evidence worth carrying around.

• Falsifiability. A claim that nothing could disprove tells you nothing.
• The problem of induction. A long run of past successes cannot prove the next one.
• The ship of Theseus. Replace every part, and ask whether it is still the same thing.
• The trolley problem. Why harm that follows from a plan feels different from harm that is the plan.
• The placebo effect. Much of what a dummy pill seems to do would have happened anyway.
• The replication crisis. Why many famous findings vanished when others tried them again.
• Cargo cult science. Science can copy every outward form and still miss the honesty.
• Fermi estimation. Break an impossible question into small guesses you can make.
• Absence of evidence. Finding nothing only counts if you would have found it.
• Clarke’s third law. Advanced technology can look like magic, and so can a good trick.
• Schrodinger’s cat. A thought experiment built to show where the quantum rules run out.
• The veil of ignorance. Write the rules as if you did not know which seat you would get.
• Pascal’s wager. When a small cost seems to buy protection from an endless loss.
• Kuhn’s paradigm shifts. How science changes, not step by step, but by revolution.
• Galileo’s ship. Why you cannot feel steady motion from the inside.
• Eratosthenes measures the Earth. How a shadow and some arithmetic measured the size of the Earth.
• The sorites paradox. Vague words have no edges, but rules force them to have one.
• Zeno’s paradoxes. Endless steps can still add up to a finish line.
• The experience machine. Would you trade real life for guaranteed happy feelings?
• The nirvana fallacy. Rejecting a good plan for not being perfect keeps a worse one.

Science

How the world works, one experiment at a time

Quantum mechanics

How the smallest things behave, one experiment at a time.

• Superposition and the double slit. One electron at a time, and still a pattern only waves should make.
• The photoelectric effect. The experiment that showed light arrives in packets, not only as waves.
• Atomic spectra and energy levels. Why each element glows in its own few colours, like a fingerprint.
• The uncertainty principle. Why pinning down where a particle is spreads out where it is going.
• Spin, and the magnet that split a beam. The magnet experiment that showed atoms answer in just two ways.
• Quantum tunnelling. How particles slip through walls they lack the energy to climb.
• The exclusion principle. Why no two electrons can share a place, and why that makes matter solid.
• Entanglement and Bell’s test. Why two distant particles share results no advance plan can explain.
• Decoherence. Why big things never show two states at once.
• A photon is a ripple in a field. What a photon actually is: the field itself, raised by one whole step.

Relativity

What happens to time, space and light when you move fast or fall.

• The constant speed of light. Why light is measured at the same speed by everyone, however they move.
• Moving clocks run slow. Why moving clocks run slow, and how muons and airliners proved it.
• Mass and energy are the same thing. Why mass and energy are the same thing, and why a gram holds so much.
• Falling feels like floating. Why falling feels like floating, and how that led Einstein to gravity.
• Gravity bends light. Why starlight bends around the Sun, and how a 1919 eclipse proved it.
• Gravity slows time. Why clocks run slower in stronger gravity, and why GPS has to allow for it.
• Space itself can ripple. Why colliding black holes shake space, and how LIGO finally felt it.
• Where not even light escapes. Why some stars collapse into places light cannot leave, and how we found them.

Heat and energy

What temperature really is, where energy goes, and why heat only flows one way.

• Heat is things jiggling. Why heat is really motion, and how jiggling pollen proved molecules are real.
• Energy never disappears. Why energy only ever changes form, and how a brewer’s paddle wheel proved it.
• Heat only flows one way. Why heat only flows from hot to cold, and what entropy is really counting.
• Maxwell’s demon. Why a sorting demon cannot beat the second law, and what forgetting costs.
• No engine can be perfect. Why no engine can turn all its heat into work, and what sets the ceiling.
• Moving heat is cheaper than making it. Why a heat pump delivers more heat than the electricity it uses.

Light and electricity

What light is made of, how electricity and magnetism turned out to be one thing, and how that gave us radio.

• White light is every colour at once. How a second prism showed the colours were in sunlight all along.
• There is light on both sides of the rainbow. How thermometers, silver salts and a glowing screen found light we cannot see.
• Light takes time to arrive. How a moon of Jupiter and a spinning wheel showed that light takes time to arrive.
• Lightning is a giant spark. How a thread, a jar and an iron rod showed that lightning is electricity.
• A frog’s twitch led to the first battery. How an argument over twitching frogs’ legs gave the world its first battery.
• A moving magnet makes electricity. How a swinging compass needle led, in eleven years, to the first generator.
• Light is a wave of electricity and magnetism. How equations predicted invisible waves, and sparks across a room proved them real.
• Why the sky is blue. How a hazy glass tube and a calculation explained the colour of the sky.

Evolution

How living things change over generations, and how we have caught it happening.

• Nature does the selecting. How mockingbirds, finches and a letter from Wallace led to the theory of evolution.
• Evolution you can watch. How two biologists measured every finch on one island and watched evolution happen.
• The moth that turned black. How soot turned Britain’s peppered moths black, and clean air turned them pale again.
• A fish with a neck and wrists. How a team predicted where to dig, and found a fish with a neck and wrists.
• Evolution in a flask. How twelve flasks and a giant dish let scientists watch bacteria evolve.
• The foxes that became friendly. How breeding the calmest foxes for a few decades changed their behaviour and their looks.

Genetics

How features are passed on, what genes are made of, and how we learned to read them.

• Peas that counted. How a friar counted thousands of peas and found the rules of inheritance.
• The fly with white eyes. How one white-eyed fly showed that genes sit on chromosomes.
• Genes are made of DNA. How dead bacteria, a purified extract and a kitchen blender showed genes are made of DNA.
• The shape that explained heredity. How an X-ray photograph and a chemical rule revealed the double helix of DNA.
• Reading the whole book of a human. How reading all three billion letters of human DNA changed what we know about ourselves.
• Scissors that find their own place. How a bacterial defence against viruses became a tool for editing genes.
• The pattern only you carry. How patterns of DNA bands reunited a family and solved a murder.

Body and medicine

How the body works, what makes us ill, and the discoveries that changed medicine.

• The blood goes round. How a simple sum showed that the same blood goes round and round the body.
• From a milkmaid’s hand to the end of smallpox. How a country saying about milkmaids led to the first vaccine and the end of smallpox.
• Penicillin needed more than luck. How a mouldy dish became a medicine only after a team made it work.
• The doctor who drank the germ. How a doctor drank a germ to prove that bacteria, not stress, cause most ulcers.
• The extract that saved a boy. How a quarrelling team in Toronto turned a deadly disease into one people could live with.
• Germs do not come from nowhere. How a swan-neck flask and a country doctor proved that germs cause disease.
• The pump that spread cholera. How a map of deaths around one pump showed that cholera spreads through water.

Chemistry

What things are made of, how substances change, and the patterns hidden in the elements.

• Weighing everything changed chemistry. How weighing everything before and after overturned an old idea about burning.
• The table that predicted missing elements. How a table of the elements left gaps, and the gaps were filled as predicted.
• The ore that gave off too many rays. How rays that were too strong to explain led to two new elements.
• The bounce that revealed the nucleus. How a few particles bouncing back off gold foil revealed the nucleus.
• Fertiliser made from thin air. How chemists learned to pull fertiliser out of the air, and what else it made.
• The ozone hole and the treaty that worked. How a warning about spray-can chemicals led to a treaty every country signed.

Earth

How the ground beneath us formed, how it moves, and the records of the past it keeps.

• The rocks that revealed deep time. How rocks on a Scottish shore showed that the Earth is immensely old.
• The continents that drift. How matching coasts, fossils and rocks suggested that continents move.
• The magnetic stripes on the sea floor. How stripes of magnetism in the sea floor showed that the oceans are spreading.
• Dating the Earth, and finding lead everywhere. How measuring the age of the Earth uncovered lead pollution everywhere.
• The clay layer that pointed to an asteroid. How a thin layer of clay led to an asteroid, and a crater in Mexico.
• The curve that tracks carbon dioxide. How patient measurements on a Hawaiian volcano revealed carbon dioxide rising.
• Ancient air trapped in ice. How bubbles and layers in polar ice record hundreds of thousands of years of climate.

Space

Planets, stars and galaxies, and how we learned how big and how old the universe is.

• The moons that circled Jupiter. How a few moving dots beside Jupiter challenged the old picture of the heavens.
• The planet found with pen and paper. How a planet straying off course led mathematicians to an unseen world.
• The stars that measure the universe. How a pattern in pulsing stars gave astronomers a way to measure the universe.
• The universe that is growing. How shifts in galaxies' light and their distances revealed that the universe is expanding.
• The hiss left over from the Big Bang. How a hiss in a radio antenna turned out to be the afterglow of the Big Bang.
• The galaxies that spin too fast. How galaxies spinning too fast revealed matter that no one can see.
• The first planet around a Sun-like star. How a star's tiny wobble revealed a giant planet where none was expected.

Evidence in medicine

How doctors learned to tell a cure from a hope, through fair trials, hard lessons and the rules that followed.

• Twelve sailors and a fair test. How a fair test at sea pointed to a remedy for scurvy, decades before the Navy acted.
• The doctors who tracked smoking. How two doctors showed smoking causes lung cancer without a single experiment.
• The reviewer who asked for more. How one reviewer's demand for better evidence kept thalidomide off American shelves.
• Nearly two million children and a fair test. How a vast, blinded trial showed the polio vaccine worked, and why checking went on.
• The first public operation under ether. How a public test in Boston made painless surgery believable.
• The cells that would not stop growing. How one woman's cells changed medicine, and the question of consent they raised.

Particles

The electron, cosmic rays, antimatter, the neutron, the neutrino and the Higgs, and how each was found.

• The particle smaller than an atom. How a bent beam in a glass tube revealed the first particle smaller than an atom.
• The radiation that came from the sky. How balloon flights showed that radiation pours in from space.
• The mirror image of the electron. How an equation predicted antimatter, and a cloud chamber photograph found it.
• The particle with no charge. How recoiling atoms revealed a particle that leaves no track.
• The ghost particle that took decades to catch. How a desperate guess about missing energy led to catching a ghostly particle.
• The particle that revealed a hidden field. How a 1964 prediction about mass was confirmed at CERN in 2012.

The brain

How we learned what nerve cells are, which parts of the brain do what, and how the brain changes with use.

• Is the brain one net or many cells?. How a black stain and a famous feud revealed that the brain is made of separate cells.
• The patient who could only say tan. How one patient's lost speech pointed to a part of the brain with a special job.
• The man who could not make new memories. How one man's lost memory showed that remembering and learning skills are separate.
• The patients with a divided brain. What patients with a divided brain revealed, and the myth it was stretched into.
• The cells that see edges. How an accident with a glass slide revealed brain cells that detect edges.
• The taxi drivers whose brains changed. How London's taxi drivers showed that intense learning can reshape the adult brain.

Microbes and the machinery of life

The tiny living things all around us, and how cells, genes and even proteins turned out to have surprising histories.

• The little animals in a drop of water. How a Dutch cloth merchant with homemade lenses discovered a hidden world of life.
• The flasks with necks like swans. How a bent glass neck showed that microbes come from other microbes.
• Lightning in a flask. How sparks in a glass loop made some of the building blocks of life.
• The cells that took in bacteria. How a rejected idea showed that parts of our cells were once free living bacteria.
• The third branch of life. How comparing one molecule revealed a whole domain of life hiding in plain sight.
• The infection with no genes. How a brain disease in sheep led to infectious proteins with no genes at all.

Human origins

Fossils, footprints and ancient DNA, and what they reveal about where we came from.

• Lucy, the ancestor who walked upright. How a skeleton from Ethiopia showed that walking upright came before big brains.
• Footprints in volcanic ash. How footprints in ancient ash captured upright walkers, and what they cannot tell us.
• The fossil that fooled experts for forty years. How a forged skull fooled many experts, and how it was finally exposed.
• The mother of all our mothers. What the woman nicknamed Mitochondrial Eve really was, and what the name got wrong.
• The Neanderthal inside us. How ancient DNA revealed that many living people carry a little Neanderthal in them.
• The ancient people known from a finger bone. How a tiny finger bone revealed a whole branch of the human family.
• The small humans of Flores. How a tiny skeleton on an Indonesian island turned out to be a distinct human species.

Computing and information

How machines came to follow instructions, how information was measured, and the codes that protect and break messages.

• The notes that imagined a computer. How Ada Lovelace's notes on an unbuilt machine imagined what computers could do.
• The question no machine can answer. How Alan Turing imagined the computer, and proved some questions have no answer.
• The man who measured information. How Claude Shannon turned information into something that could be measured in bits.
• The codebreakers who read Enigma. How Polish mathematicians and Bletchley Park broke Germany's Enigma machine.
• The codes that fix their own mistakes. How a frustrated mathematician invented codes that find and fix their own errors.
• The tiny switch that replaced the valve. How a slab of germanium at Bell Labs gave rise to every modern chip.

Maths and proof

How mathematicians showed things that can never be checked one case at a time, from endless primes to the limits of proof.

• The primes never run out. How a proof over two thousand years old shows the primes never run out.
• The long journey of zero. How zero grew from a gap in a number into a number in its own right.
• Seven bridges and a walk that could not be done. How Euler proved a walk impossible without trying a single route.
• Some infinities are bigger than others. How Georg Cantor showed that some infinities are larger than others.
• The limits of proof. How Kurt Godel found limits that no system of proof can escape.
• The margin that was too small. How Andrew Wiles proved Fermat's three hundred year old claim.

Weather and climate

How we learned what warms the planet, why weather is so hard to forecast, and how the oceans steer the skies.

• The gases that trap heat. How two experiments showed that a few invisible gases keep the Earth warm.
• A year of sums about carbon dioxide. How a chemist with a pencil made the first estimate of global warming.
• The first public weather forecasts. How a storm, a telegraph and a sea captain gave us the weather forecast.
• The rounded number that changed the forecast. How a rounded number revealed why the weather can't be forecast far ahead.
• The warm water that shifts the world’s weather. How warm water off Peru turned out to steer rain and drought around the world.
• The climate model that passed the test of time. How a simple computer model predicted climate change decades before it arrived.

Engineering failures

What breaking aircraft, bridges and ships taught engineers about testing the things they build.

• The cracks nobody could see. How investigators found the hidden cracks that brought down the first jet airliner.
• The bridge that twisted itself apart. How a steady wind twisted a brand new bridge until it fell.
• The ships that cracked in the cold. How welded wartime ships cracked in the cold, and the scientist who worked out why.
• Two rods instead of one. How a small change to a design doubled the load on a hotel walkway.
• The rubber that could not spring back. How engineers warned that cold would stop Challenger's seals working, and were overruled.
• Cheap steel and a costly mistake. How cheap steel failed for everyone except its inventor, and why.

Measurement

How people pinned down length, time and mass, and what happened when the standards themselves proved uncertain.

• The metre and the lumpy Earth. How two astronomers measured the metre, and why it came out slightly short.
• The watch that found longitude. How a clockmaker solved longitude with a watch, and fought for years to be paid.
• The kilogram that drifted. How the kilogram stopped being a lump of metal, and became a constant of nature.
• Weighing the Earth in a shed. How Henry Cavendish measured the density of the whole Earth from inside a shed.
• A metre made of light. How the metre went from a metal bar to the speed of light.

How it works

The ideas inside everyday machines, and the people who found them

Everyday machines

How the machines around you actually work, and the long road to making them work.

• How GPS finds you by timing light. How GPS works out where you are by timing light, and allowing for relativity.
• Why a bright blue light took thirty years. How two teams made the bright blue LED that white LED lighting depends on.
• How a fridge moves heat out of a box. How a fridge carries heat out of a box, using a liquid that boils and condenses.
• How messages cross the internet in pieces. How messages cross networks as small pieces that each find their own way.
• How the barcode got from the beach to the checkout. How a pattern drawn in beach sand became the code on almost everything you buy.
• How a battery learned to carry lithium safely. How three scientists made a rechargeable battery that carries lithium safely.
• How a jet engine pushes a plane forward. How a jet engine drives a plane forward by throwing gas backward.
• How a touchscreen knows where you touched. How touchscreens sense your finger, and the decades of work behind them.
• The microwave oven and the melted snack bar. What the records show about how the microwave oven was invented, and how it heats.

Myths

Things everyone knows that are not so, and where they came from

Famous myths

Things everyone seems to know that are not so, where they came from, and what the evidence says.

• Do we only use ten percent of our brains?. How a vague remark and a book foreword became the ten percent brain myth.
• The tongue map that was never true. How a misread graph put a map of taste zones into school textbooks.
• Does old window glass flow downhill?. Why old window panes are uneven, and why it is not because glass flows.
• Did Vikings wear horned helmets?. How horned Viking helmets came from an opera costume designer, not from history.
• Did Einstein fail maths?. How a real exam failure turned into the myth that Einstein failed maths.
• Was Napoleon really short?. How enemy cartoons and French inches made an average man famously short.
• Do goldfish really forget in three seconds?. What experiments show about goldfish memory, and the joke that got it wrong.
• Did tulip mania ruin the Dutch?. What the Dutch archives show about tulip mania, and how the story grew.

Open questions

What science has not worked out yet, and how it is trying

Big open questions

What science knows, the leading ideas, and what would settle the questions it has not yet answered.

• Why do we sleep?. Why every animal seems to need sleep, and the rival ideas about what it is for.
• How did life begin?. What is known about how life began, and which parts are still guesses.
• What is dark matter?. What the evidence says about dark matter, and why nobody knows what it is.
• What is speeding up the universe?. Why the universe's expansion is speeding up, and the rival ideas about why.
• Why is there more matter than antimatter?. Why the universe is made of matter, when the Big Bang should have made equal antimatter.
• Why do we have experiences at all?. Why brain science can track experience, but not yet explain why it exists.
• Are we alone in the universe?. Why no sign of life beyond Earth has been confirmed, despite planets everywhere.