🎯 By the end of this lesson you will…
🦠 Fact 1 — You are more bacteria than human
Your body contains roughly 37 trillion human cells — but it also hosts approximately 38 trillion bacterial cells. You are, in the most literal sense, a walking ecosystem. The majority live in your gut and are essential for digestion, immunity and even mood regulation.
If you removed every bacterial cell from your body, you would lose about 200 grams — roughly the weight of a bar of chocolate. You are a habitat.
⚡ Fact 2 — Your brain generates electricity
Your brain produces about 20 watts of electrical power — enough to power a dim light bulb. This electricity is generated by neurons firing electrochemical signals. An EEG (electroencephalogram) machine detects this electrical activity and displays it as brain waves.
You have been glowing, very faintly, your entire life. The human body emits biophotons — actual light particles — at levels 1,000 times too dim for the naked eye to see. We literally glow in the dark.
😶 Fact 3 — Your brain cannot feel pain
The brain has no pain receptors (nociceptors) of its own. Brain surgery can be performed on a conscious patient without them feeling anything in their brain — surgeons sometimes do this deliberately to test responses. The headaches you feel are caused by pain receptors in the surrounding tissue, not the brain itself.
🦴 Fact 4 — You have fewer bones than a baby
Babies are born with approximately 270–300 bones. Adults have 206. As you grow, many bones fuse together — a process that isn't complete until your mid-20s. The kneecap (patella) doesn't fully harden from cartilage to bone until around age 3.
The hyoid bone in your throat is the only bone in the human body not connected to any other bone. It floats, anchored only by muscle and ligament.
👁️ Fact 5 — Your eyes are always the same size
Unlike your nose and ears, which grow throughout your life, your eyeballs do not grow from birth. The eyes you have now are almost exactly the same size as when you were born. This is why newborn babies look like they have disproportionately large eyes — they do, relative to the rest of their face.
🩸 Fact 6 — Your blood vessels could circle the Earth
If you laid all the blood vessels in a human body end to end — arteries, veins, and capillaries — they would stretch for approximately 100,000 kilometres. The Earth's circumference is about 40,000 km. Your blood vessels could wrap around the planet two and a half times.
🃏 True or Too Weird to be True?
Each statement below is either a genuine scientific fact or a clever fake. Can you tell which is which? Click your verdict — then read the explanation!
❓ Quick Knowledge Check
📋 Portfolio Task — Annotated Body Diagram
For each body part or system, write your own surprising annotation — in your own words, not copied! Aim for one sentence that would genuinely surprise someone who doesn't know this fact.
🃏 Portfolio: Your Lesson 1 Fact Card
Choose ONE fact from this lesson that surprised you most. Fill in your fact card below — this becomes page 1 of your Science Curiosity Portfolio.
Personal Glossary — Lesson 1
Define each term in your own words. Don't just copy — explain it as if to a friend.
Research Rabbit Hole — Pick ONE body fact to go deeper
Choose the fact from this lesson that surprised you most. Go online and find out more about the science behind it. Use at least two sources.
Lesson 1 Complete
You now know six astonishing facts about your own body — and you've started your portfolio. Save your work and move on to physics, where things get even stranger.
🎯 By the end of this lesson you will…
⏱️ Fact 1 — Time moves slower near heavy objects
Einstein's General Theory of Relativity predicts — and we have confirmed — that gravity slows time. The closer you are to a massive object, the slower time passes for you relative to someone further away. GPS satellites have to correct for this: clocks on satellites tick faster than clocks on Earth because they are further from Earth's gravity. Without this correction, GPS would be inaccurate by kilometres within hours.
Astronaut Scott Kelly spent 340 days on the International Space Station. When he returned, he was 0.01 seconds younger than his identical twin brother Mark — who had stayed on Earth. Time travel into the future is real. It just requires extreme patience.
🫸 Fact 2 — Nothing ever actually touches anything
When you pick up a pen, your fingers don't touch it. The electrons in your fingers and the electrons in the pen repel each other due to electromagnetic force. You are always separated from everything by a tiny but non-zero gap. What we call "touching" is actually the sensation of electromagnetic repulsion. You have never, in your entire life, physically touched anything.
🐱 Fact 3 — A particle can be in two places at once
Quantum superposition is the phenomenon where a quantum particle exists in multiple states simultaneously — until it is observed. The famous thought experiment "Schrödinger's Cat" illustrates this: a cat in a sealed box could be simultaneously alive and dead until you open the box and look. This isn't just a thought experiment — particles genuinely behave this way, confirmed in thousands of experiments.
Quantum computers use superposition to perform calculations using qubits that can be 0 and 1 simultaneously — making them potentially millions of times more powerful than classical computers for certain problems.
💡 Fact 4 — Light has no experience of time
From light's own "perspective" (if it had one), no time passes at all during its journey. A photon of light emitted by a star 10 billion light-years away travels for 10 billion years by our measurement — but experiences zero time. This is a direct consequence of Special Relativity: at the speed of light, time dilation becomes infinite. Light lives in an eternal present.
🌌 Fact 5 — Most of the universe is invisible
Everything we can see — every star, planet, galaxy, and atom of ordinary matter — makes up only 5% of the universe. The remaining 95% is split between dark matter (27%) and dark energy (68%), neither of which we can see, touch or directly detect. We know they exist only because of their gravitational effects. We have no idea what they actually are.
🃏 True or Too Weird to be True?
All of these sound impossible. Most are real. Can you tell which is the fake?
🏆 Rank the Physics Facts by Weirdness
Drag these physics facts from 1 = Slightly Weird to 5 = Brain Fully Broken in your own order. There's no right answer — just justify your ranking in the reflection box below.
Portfolio Task — Myth-Busting Explainer
Write this for a Year 7 student. No jargon. Use analogies. Make them say "wait, really?"
Personal Glossary — Lesson 2
Define in your own words.
🃏 Portfolio: Your Lesson 2 Fact Card
Fill in your second fact card — the one physics fact that most broke your brain.
Research Rabbit Hole — Go deeper into quantum physics
Search for the famous "double-slit experiment" — one of the most mind-bending experiments in all of physics. Watch a short video or read an article and summarise what happens.
Lesson 2 Complete
Your myth-busting explainer is a key portfolio piece. Next — the animal kingdom, where evolution has produced things stranger than any physicist.
🎯 By the end of this lesson you will…
🐻 Fact 1 — Tardigrades can survive in outer space
Tardigrades (also called water bears) are microscopic animals about 0.5mm long. They can survive: temperatures from −272°C to +150°C, pressures 6× deeper than the Marianas Trench, radiation 1,000× lethal to humans, and the vacuum of outer space. In 2007, European scientists exposed thousands of tardigrades to open space on a satellite — most survived. They do this by entering a state called cryptobiosis, where they essentially pause all biological processes.
Tardigrades have survived all five of Earth's mass extinction events. They will almost certainly outlive humans. They may be the last living things on Earth when the Sun eventually expands and swallows the planet.
🦐 Fact 2 — Mantis shrimp see 16 colour channels
Humans see colour using 3 types of photoreceptors (red, green, blue). Most birds have 4. The mantis shrimp has 16. They can see ultraviolet, infrared, and polarised light invisible to all other known animals. Their punch — used to break open crab shells — accelerates faster than a speeding bullet and hits with the force of a .22 calibre bullet. The shockwave alone can stun prey.
🐦 Fact 3 — Crows hold grudges and teach them to their children
Researchers at the University of Washington wore masks and captured crows on campus. The captured crows began dive-bombing those specific masked faces — and only those faces — for years. More remarkably, they taught their chicks to mob the same masks, even though the chicks had never encountered the original capturers. Crows have demonstrated memory, pattern recognition, tool use, and now inter-generational cultural transmission of grudges.
In Japan, crows have been observed dropping hard nuts onto zebra crossings, waiting for cars to crack them, then waiting for the green light before collecting the food. They are using traffic infrastructure as a tool.
🐙 Fact 4 — Octopuses have three hearts and blue blood
Octopuses have three hearts: two pump blood to their gills; one pumps it to the body. When an octopus swims, the main heart stops — which is why they prefer crawling. Their blood is blue because it uses haemocyanin (copper-based) instead of haemoglobin (iron-based) to carry oxygen. Haemocyanin is better at delivering oxygen in cold, low-oxygen environments. Two-thirds of an octopus's neurons are in its arms — each arm can act semi-independently.
🐝 Fact 5 — Bees can recognise human faces
Bees can be trained to recognise individual human faces and remember them for at least two days. This is remarkable because bees have a brain the size of a sesame seed with about one million neurons (humans have 86 billion). They use a technique called configural processing — the same technique humans use — assembling facial features into a whole pattern rather than processing each feature separately.
🃏 True or Too Weird to be True?
Research your chosen animal and fill in its stats. Higher = better/more extreme. Score out of 10.
Most astonishing fact
Sources used
Personal Glossary — Lesson 3
Research Rabbit Hole — Find the most extreme animal adaptation
Search for an animal adaptation that wasn't covered in this lesson — something that seems physically impossible. Research it and report back.
🃏 Portfolio: Your Lesson 3 Fact Card
Lesson 3 Complete
Your Top Trumps card is your most creative portfolio piece so far. Next — history, where real events are more bizarre than any fiction.
🎯 By the end of this lesson you will…
🍯 Event 1 — The Great Molasses Flood (Boston, 1919)
On 15 January 1919, a 14.6-metre tall steel tank containing 8.7 million litres of molasses burst in Boston's North End. A wave of molasses up to 4.5 metres high travelled at 56 km/h through the streets. It killed 21 people, injured 150, and demolished buildings and an elevated railway structure. Rescue workers, horses and dogs were trapped in the viscous flood. The area reportedly smelled of molasses on hot summer days for decades.
Molasses at cold temperatures is very thick (high viscosity). As temperatures rose suddenly that day, it became thinner and flowed rapidly. The tank had been filling beyond its design capacity for years and had known structural weaknesses. Corporate negligence caused a disaster that shaped American industrial safety law.
💃 Event 2 — The Dancing Plague of 1518 (Strasbourg)
In July 1518, a woman named Frau Troffea began dancing in the streets of Strasbourg and couldn't stop. Within a week, 34 people had joined her. Within a month, there were approximately 400 involuntary dancers. Some danced until they collapsed from exhaustion, heart attacks or strokes. The authorities, baffled, hired musicians to encourage the dancing — thinking it would pass faster. Historians believe it was a case of mass psychogenic illness (mass hysteria), triggered by extreme stress and famine in the region.
💣 Event 3 — The USA accidentally dropped nuclear bombs on itself (multiple times)
Between 1950 and 1968, the United States accidentally dropped or nearly detonated nuclear weapons on American soil at least 32 times. The most famous: in 1961, a B-52 broke apart over Goldsboro, North Carolina, releasing two 3.8-megaton nuclear bombs (each 250× more powerful than Hiroshima). One of them went through five of its six safety mechanisms before being recovered. A single switch prevented detonation. A later report, declassified in 2013, confirmed the bomb "came close to detonating."
The concept of a nuclear accident is known as a "broken arrow" event in US military terminology. These incidents shaped the development of modern nuclear weapon safety systems, including the Permissive Action Link (PAL) — electronic locks preventing unauthorised or accidental detonation.
🐦 Event 4 — The Great Emu War (Australia, 1932)
In 1932, the Australian government deployed soldiers with two Lewis guns and 10,000 rounds of ammunition to cull approximately 20,000 emus that were destroying wheat crops in Western Australia. The campaign failed almost completely. Emus scattered into small groups that were hard to target, and the Lewis guns repeatedly jammed. The commanding officer, Major G.P.W. Meredith, eventually withdrew. He reportedly commented: "If we had a military division with the bullet-carrying capacity of these birds it would face any army in the world. They could face machine guns with the invulnerability of tanks." The emus won.
🃏 True or Too Weird to be True?
Portfolio Task — Newspaper Front Page
Choose ONE event from this lesson. Write a newspaper front page as if you are a journalist who was there.
Personal Glossary — Lesson 4
🃏 Portfolio: Your Lesson 4 Fact Card
Lesson 4 Complete
Your newspaper front page is the most creative portfolio piece yet. Next — mathematics, where the numbers themselves refuse to behave.
🎯 By the end of this lesson you will…
🎂 Fact 1 — The Birthday Problem
How many people do you need in a room before there's a 50% chance two of them share a birthday? Most people guess around 183 (half of 365). The real answer is just 23. With 70 people, the probability is 99.9%.
Why? Because we don't need a specific match — we need any match. With 23 people, there are 253 possible pairs of people. Each pair has a small chance of sharing a birthday. The cumulative probability of at least one match becomes surprisingly high, surprisingly quickly.
How many people are in your school year? Almost certainly enough for multiple shared birthdays. The intuition that this seems unlikely is exactly what makes it such a powerful example of how badly our brains handle probability.
∞ Fact 2 — Infinity comes in different sizes
There are infinitely many whole numbers: 1, 2, 3, 4… There are also infinitely many decimal numbers between just 0 and 1. But the German mathematician Georg Cantor proved in 1874 that these two infinities are different sizes. The infinity of decimals is provably, mathematically larger than the infinity of whole numbers. There is no way to match them one-for-one. Mathematicians call these different "sizes" of infinity cardinalities.
Imagine listing all decimal numbers. Cantor showed you can always construct a new decimal number that isn't on your list — no matter how long the list. This proves the decimals can never be fully listed. They are uncountably infinite, while the whole numbers are only countably infinite.
🏨 Fact 3 — Hilbert's Hotel: a hotel with infinite rooms that is always full
Imagine a hotel with infinitely many rooms, all occupied. A new guest arrives. Can the hotel accommodate them? Yes — move every guest from room n to room n+1. Room 1 is now free. What if a bus with infinitely many new guests arrives? Move every guest from room n to room 2n. All the odd-numbered rooms are now free — infinitely many empty rooms. Infinity + 1 = Infinity. Infinity × 2 = Infinity. This isn't a paradox — it's how infinity actually works.
🃏 Fact 4 — The Monty Hall Problem
You are on a game show. Behind one of three doors is a car; behind the others, goats. You pick door 1. The host (who knows what's behind each door) opens door 3 to reveal a goat. He offers you the chance to switch to door 2. Should you switch? Most people say it doesn't matter — 50/50. They are wrong. Switching gives you a 2/3 chance of winning. Sticking gives you 1/3. This was published in a newspaper in 1990 and caused enormous controversy — even professional mathematicians wrote in to say it was wrong. It isn't.
When you first chose, you had a 1/3 chance of being right. That means there was a 2/3 chance the car was behind one of the other two doors. The host's action doesn't change your original odds — it concentrates the 2/3 probability onto the single remaining unchosen door. Switching harvests that 2/3 probability.
🃏 True or Too Weird to be True?
📋 Portfolio Task — The "Convince Me" Paragraph
Your friend says: "That birthday thing can't be right — 23 people is nowhere near enough." Write a paragraph that convinces them. You must include a worked example with real numbers. No jargon. Plain English only.
💬 Now convince a sceptic about the Monty Hall Problem
Personal Glossary — Lesson 5
🃏 Portfolio: Your Lesson 5 Fact Card
Lesson 5 Complete
Your "Convince Me" paragraphs are the most intellectually demanding pieces in your portfolio. One lesson left — and the universe has saved its best for last.
🎯 By the end of this lesson you will…
💎 Fact 1 — There is a planet made mostly of diamond
55 Cancri e is an exoplanet approximately twice the size of Earth, orbiting a star 40 light-years away. It is so rich in carbon, at such extreme pressures and temperatures, that scientists believe its interior may be largely composed of diamond. The surface temperature is approximately 2,400°C. The "diamond" layer may be around 8,000 km deep. The planet's entire mass of diamond would be worth approximately $26.9 nonillion — far more than the entire global economy.
🌅 Fact 2 — A day on Venus is longer than its year
Venus rotates so slowly on its axis that it takes 243 Earth days to complete one rotation (one Venusian day). But it only takes 225 Earth days to orbit the Sun (one Venusian year). Venus also rotates backwards compared to most planets — on Venus, the Sun rises in the west and sets in the east. Its surface temperature is 465°C — hotter than Mercury, which is twice as close to the Sun — because its thick CO₂ atmosphere traps heat in a runaway greenhouse effect.
⭐ Fact 3 — You are made of dead stars
Every atom of carbon in your body, every atom of oxygen in the water you drink, every atom of iron in your blood — was forged inside a dying star. The Big Bang only produced hydrogen and helium. Heavier elements were created inside stellar cores over billions of years through nuclear fusion. When those stars exploded in supernovae, they scattered those elements across the universe. Eventually they formed new stars, planets, and — on at least one of them — you.
"The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of starstuff."
🔇 Fact 4 — The universe is mostly silence and void
If you removed all the empty space from every atom in every human being on Earth, all 8 billion of us would fit in a sugar cube. Atoms are almost entirely empty space. The nearest star to our Sun (Proxima Centauri) is 4.2 light-years away — approximately 40 trillion kilometres. If the Sun were the size of an orange on a table in London, Proxima Centauri would be another orange in Berlin. Between them: nothing.
🕳️ Fact 5 — Black holes can sing
In 2003, NASA's Chandra X-ray Observatory detected pressure waves emanating from a supermassive black hole at the centre of the Perseus galaxy cluster, 250 million light-years away. These pressure waves are sound — but at a frequency 57 octaves below middle C. That is a million billion times lower than the lowest note audible to human hearing. The universe's deepest note has been playing for over a billion years.
🌍 Fact 6 — We have already sent a message to alien civilisations
The Voyager 1 spacecraft, launched in 1977, is now over 23 billion kilometres from Earth — the furthest any human-made object has ever travelled. It carries a Golden Record containing sounds and images of Earth, greetings in 55 languages, and 90 minutes of music. It is currently travelling at 61,000 km/h. It will reach the nearest star system in approximately 70,000 years. It is, technically, our first diplomatic mission to the universe.
🃏 True or Too Weird to be True?
Portfolio Task — Planetary Mission Briefing
Choose a real planet or moon. Research it and fill in your mission brief. This is the final and most substantial portfolio piece.
Personal Glossary — Lesson 6
📋 Portfolio Final Reflection
You have completed all 6 lessons and built a Science Curiosity Portfolio. Answer these final questions.
Unit Complete — You Are Made of Starstuff
Six lessons. Six portfolio pieces. Hundreds of facts that sound impossible but are completely true. Keep asking questions. Keep following the rabbit holes. The universe is stranger than anyone has yet imagined.