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Every explanation we've ever written. Search, filter, explore.
What happened at Hiroshima?
On August 6, 1945, the world changed forever when the first atomic bomb was dropped on a Japanese city, ending World War II in the most devastating way imaginable.
What was the Holocaust?
The Holocaust was the systematic murder of six million Jewish people and millions of others by Nazi Germany during World War II.
What happens when two black holes collide?
When two black holes crash into each other, they create ripples in space itself that we can detect billions of years later.
What is gravitational lensing?
Massive objects in space bend light like a cosmic magnifying glass, letting us see galaxies that would otherwise be invisible.
How does autocorrect work?
Your phone's autocorrect isn't actually reading your mind — it's using clever probability tricks to guess what word you meant to type.
What is the dark web?
The dark web is like a hidden neighbourhood on the internet where you need special tools to visit — and it's not all as scary as it sounds.
How does voice recognition work?
Your phone can recognise your voice better than some humans can — here's the clever tech that makes it happen.
What is a blockchain?
Imagine a record book that's impossible to fake, copies itself everywhere, and no single person controls it — that's basically what a blockchain is.
How does a VPN work?
A VPN creates a secret tunnel through the internet that hides your online activity from prying eyes — like having a private conversation in a crowded room.
How does a microchip work?
Every microchip is like a tiny city where billions of invisible switches flip on and off millions of times per second to power your digital world.
What is globalisation?
The story of how your trainers, phone, and breakfast probably travelled thousands of miles before reaching you this morning.
What is a bond?
A bond is basically an IOU that governments and companies sell to borrow money — and you can buy one to become a lender who gets paid back with interest.
How does bankruptcy work?
Bankruptcy is like hitting a financial reset button when you can't pay your debts — but it comes with some serious consequences.
What is a startup?
A startup is like a business experiment where people try to solve problems in brand new ways, hoping their idea will grow huge.
What is universal basic income?
What if everyone received free money from the government every month, no questions asked — would that fix poverty or create chaos?
How does nuclear fission work?
Nuclear fission is like cracking open the world's tiniest nuts to release enormous amounts of energy — enough to power entire cities.
What causes cancer?
Cancer happens when your body's cells start breaking the rules and growing out of control — but understanding why can help us fight back.
How does anaesthesia work?
Anaesthesia turns off your brain's pain signals like flipping a switch, but the science behind this medical magic is surprisingly mysterious.
What was Chernobyl?
In 1986, a nuclear power station in Ukraine exploded — the worst nuclear accident in history, and a disaster that helped bring down a superpower.
What was apartheid?
For nearly 50 years, South Africa's government enforced a system of racial separation that denied basic rights to the majority of its own people.
What is open source software?
Open source software shares its recipe with the world — anyone can read it, improve it, or use it for free.
How do companies go bust?
Even big famous companies can run out of money — here's how businesses collapse and what happens when they do.
What is austerity?
When governments cut spending to reduce debt, it's called austerity — but economists argue fiercely about whether it actually works.
What is a trade union?
Trade unions give workers a collective voice — so that individuals aren't negotiating alone against large, powerful employers.
What is a monopoly?
When one company controls an entire market, it can charge whatever it likes — and that's bad news for everyone else.
What was the Cuban Missile Crisis?
For 13 days in October 1962, the world came closer to nuclear war than at any other moment in history. Two superpowers faced each other down — and somehow both chose to step back.
How does a self-driving car work?
A self-driving car has no idea what a road "is" — it just processes enormous amounts of sensor data every second and makes decisions. Here's what's actually going on behind the windscreen.
What is a neural network?
The AI systems behind face recognition, voice assistants, and ChatGPT are all built on neural networks — computer systems loosely inspired by the way brains work. Here's the idea.
What is biometric data?
Your fingerprint, face, voice, and even the way you walk are all unique to you. When technology collects and uses that information, it's called biometric data — and it's become central to both security and surveillance.
What are microplastics?
Plastic doesn't disappear when you throw it away — it just breaks into smaller and smaller pieces. Those tiny fragments are now in our oceans, our food, our air, and our blood.
What is coral bleaching?
Coral reefs are some of the most biodiverse places on Earth — and they're dying. When seawater gets too warm, corals expel the algae that give them colour and food, turning ghostly white. Here's what's happening.
What was the transatlantic slave trade?
For over 300 years, millions of African people were captured, shipped across the Atlantic, and forced to work without freedom or pay. It is one of the greatest crimes in human history — and its effects are still felt today.
What was the Great Depression?
In the 1930s, the global economy collapsed. Banks failed, millions lost their jobs, and people queued for bread. The Great Depression was the worst economic catastrophe of the 20th century — and it changed how governments think about money forever.
What is the placebo effect?
Sometimes a sugar pill that does nothing can make people genuinely feel better. That's not self-delusion — it's one of the most powerful and least understood phenomena in medicine.
What is DeepSeek?
In January 2025, a Chinese AI lab released a model that matched the best American AIs at a fraction of the cost. Stock markets shook. Here's what DeepSeek actually is and why it mattered.
How does a large language model work?
ChatGPT and tools like it can write essays, answer questions, and hold conversations. But there's no mind inside — just an extraordinarily clever pattern-matching machine trained on almost everything humans have ever written.
How does nuclear fusion work?
It's the same process that powers the Sun — smashing atoms together to release enormous energy. Scientists have been trying to do it on Earth for 70 years, and they're finally getting close.
What is CRISPR?
Scientists can now edit the genetic code inside living cells like editing a document — cutting out errors and replacing them with working instructions. CRISPR is the tool that made it possible.
How do GLP-1 drugs (like Ozempic) work?
Ozempic and drugs like it have changed how millions of people think about weight. But how does a weekly injection tell your brain you're not hungry?
What is quantitative easing?
When the economy is struggling, central banks can create new money out of nowhere and use it to buy things. It sounds like cheating — here's why they do it and what the catch is.
What is a hedge fund?
Hedge funds are exclusive investment pools for the very wealthy that use clever — and sometimes extremely risky — strategies to make money whether markets go up or down.
What is venture capital?
Some investors don't want safe bets — they want to find the next big thing before anyone else and put millions behind it. That's venture capital, and it funds the companies that reshape the world.
How does the housing market work?
Why do houses cost so much? Why do prices go up in some places and crash in others? The housing market has its own strange rules — and they affect almost everyone.
What is a trade war?
When two countries start hitting each other's goods with tariffs, prices rise, businesses suffer, and everyone loses a little. That's a trade war — and they're messier than they sound.
What is quantum computing?
Regular computers have been getting faster for 60 years. Quantum computers work on completely different principles — and for certain problems, they'd make today's fastest computers look like a pocket calculator.
What is a credit card?
A credit card lets you spend money you don't currently have. Used well, it's a useful tool. Used carelessly, it's an extremely expensive trap.
How does the NHS work?
The NHS is the world's largest publicly funded health service, treating over a million patients every 36 hours. Here's how it's organised — and how it's paid for.
How does social media work?
Billions of people use it every day. But what's the actual business model, and why are the apps designed the way they are?
How does facial recognition work?
Your phone unlocks by looking at your face. Police use it to identify suspects in crowds. Here's the technology behind it — and why it's so controversial.
What was the transatlantic slave trade?
Between the 16th and 19th centuries, over 12 million people were forcibly transported from Africa to the Americas and enslaved. Here's what happened and why it matters today.
Why did the First World War start?
A single assassination in Sarajevo triggered a war that killed 20 million people. But the assassination was just the spark — the gunpowder had been accumulating for decades.
What was the French Revolution?
In 1789, the French people overthrew their king, tore apart their society, and launched a decade of chaos that changed the world forever.
What causes climate change?
The planet has warmed by about 1.2°C since the Industrial Revolution. Here's what's causing it and why even small temperature changes matter enormously.
What is dark matter?
About 27% of the universe is made of something that doesn't emit light, doesn't absorb light, and can't be directly detected. We know it's there — but not what it is.
Could humans live on Mars?
Mars is the most Earth-like planet in the Solar System. But "most Earth-like" still means freezing, airless, and bombarded with radiation. Could we live there anyway?
What is virtual reality?
Strap on a headset and step into a different world entirely. Here's how VR tricks your brain into believing it's somewhere it isn't.
How does encryption work?
Every time you buy something online, your card details travel across the internet scrambled in a code so complex that no computer on Earth could crack it. Here's how.
What is a budget?
A budget isn't just a spreadsheet for boring adults. It's one of the most powerful tools for actually getting what you want in life — at any age.
What is the national debt?
The UK owes over £2.5 trillion. Who does it owe it to, does it ever get paid back, and should you be worried?
What is supply and demand?
It's the most fundamental idea in all of economics. Two forces — how much is available and how much people want it — determine the price of almost everything.
Why do exchange rates change?
One day your holiday money goes further; the next, it doesn't. Here's why the price of one currency against another is constantly shifting.
What is cryptocurrency?
Bitcoin, Ethereum, and thousands of others. Cryptocurrency promises to reinvent money — but what is it actually, and how does it work?
What is a recession?
The economy shrinks, jobs disappear, and everyone feels worse off. Here's what a recession actually is and why they happen.
What is a credit score?
A three-digit number decides whether you can get a mortgage, a phone contract, or a credit card — and most people have no idea how it's calculated.
What is a pension?
A pension is money you save during your working life so you can afford to stop working later. The sooner you start, the better — and here's the maths that explains why.
What is insurance?
Insurance is a way of sharing risk with a large group of people so that when something goes wrong, it doesn't completely ruin you financially.
Why do we age?
Ageing isn't just wear and tear — it's written into your biology at a cellular level. Scientists now understand quite a lot about why it happens.
Why did the Roman Empire fall?
For 500 years, Rome was the most powerful force in the Western world. Then, slowly and then all at once, it fell apart. Here's why.
What is the stock market?
Every day, billions of pounds of company ownership changes hands through the stock market. Here's how it actually works.
What is a computer virus?
Computer viruses are named after biological ones for a very good reason. Here's how malicious software works and why it spreads.
What is a mortgage?
Houses cost hundreds of thousands of pounds. Almost nobody has that in the bank. A mortgage is how most people buy one anyway.