Topic
Your body
Bones, senses, and what is happening inside you — 79 tiny stories from every shelf.
Not what you think
Why Do Astronauts Float?
Astronauts float because they and their ship are falling around Earth together.
Let’s go →Working outside
What Is a Spacewalk Like?
A spacewalk means leaving the ship with your own tiny spaceship wrapped around you.
Let’s go →A hidden middle
What Keeps Things From Falling Over?
Things stay upright while their centre of gravity stays over their base.
Let’s go →Light, sorted
Where Do Colours Come From?
Colour is which parts of white light an object bounces back at your eyes.
Let’s go →It makes nothing — it slows
Does a Coat Make You Warm?
A coat does not warm you. It traps air and slows the escape of the heat your body already produces.
Let’s go →Newton's third law
Every Push Has a Push Back
Forces always come in pairs — push anything and it pushes you back.
Let’s go →Rubbed the wrong way
Why Do You Get Shocks?
Static shocks happen when rubbing moves electric charge, and it jumps back all at once.
Let’s go →Scrubbing, and rebuilding
What Is Toothpaste Actually Doing?
Toothpaste is a mild abrasive with detergent, flavour and fluoride — and the fluoride is the part that rebuilds enamel.
Let’s go →When sweat stops working
Why Do Some Hot Days Feel Worse Than Others?
Humid air is already full of water, so your sweat cannot evaporate and cool you.
Let’s go →Losing your warm coat of air
Why Does Wind Make You Colder?
Wind blows away the warm layer of air your skin has heated, so you lose heat much faster.
Let’s go →A defence aimed at nothing
Why Does Pollen Make Some People Sneeze?
An allergy is your immune system mounting a real defence against something harmless, and the symptoms are the defence, not the pollen.
Let’s go →A windscreen wiper you never think about
Why Do You Blink?
Blinking spreads a fresh layer of tears across your eye, and your brain edits out the moment of darkness.
Let’s go →Four things in a river
What Is Blood Made Of?
Blood is mostly water, carrying red cells, white cells and platelets around the body.
Let’s go →The one blush you cannot fake
Why Do You Go Red When You Are Embarrassed?
Blushing is blood vessels in your face opening on their own — a signal you cannot start, stop, or fake.
Let’s go →Stiff and springy together
What Are Bones Made Of?
Bone mixes hard mineral with flexible protein, giving strength without brittleness.
Let’s go →Predicting, not just reacting
What Does Your Brain Do?
The brain constantly predicts what is happening and corrects itself using the senses.
Let’s go →Fetching oxygen, dumping waste
Why Do We Breathe?
We breathe to collect oxygen for burning food and to get rid of carbon dioxide.
Let’s go →Watching blood being cleared up
Why Does a Bruise Change Colour?
A bruise changes colour because the spilled blood is dismantled in stages, and each stage is a different colour.
Let’s go →Air that took a wrong turn
Where Does a Burp Come From?
A burp is swallowed air coming back up — gas rises through liquid and the top of your stomach is the only way out.
Let’s go →A sudden gale, from inside
Why Do You Cough?
A cough seals your airway, builds pressure behind it, and releases it as a blast fast enough to sweep the tube clear.
Let’s go →Fluid that keeps going
Why Does Spinning Make You Dizzy?
Dizziness happens because the fluid in your ear keeps swirling after you stop, so your ears insist you are still turning.
Let’s go →A brain rehearsing offline
Why Do We Dream?
Dreams happen while a sleeping brain replays and sorts the day, with the body held still.
Let’s go →Demand outrunning supply
Why Does Exercise Make You Puff?
You puff during exercise because muscles need far more oxygen than at rest.
Let’s go →A backstop for your fingertip
What Are Fingernails For?
Fingernails are a hard backstop that lets your soft fingertip press against something, making fine touch and picking things up possible.
Let’s go →Living things too small to see
What Are Germs?
Germs are microscopic organisms that multiply in your body and cause illness.
Let’s go →Moving the focus point
How Do Glasses Help You See?
Glasses pre-bend light so the image lands exactly on the back of your eye.
Let’s go →A reflex for fur you lost
Why Do You Get Goosebumps?
Goosebumps are tiny muscles pulling your hairs upright, a leftover reflex from furry ancestors.
Let’s go →Cartilage turning into bone
How Do You Grow Taller?
You grow taller at soft zones near the ends of your bones, mostly during sleep.
Let’s go →A name that is probably wrong
Do Growing Pains Really Come From Growing?
Growing pains are real aches with a misleading name — bones grow far too slowly and too painlessly to be the cause.
Let’s go →Dead rope, pushed out of a living hole
Why Does Cutting Hair Not Hurt?
Cutting hair does not hurt because the living part is buried in your skin and the visible strand is dead protein.
Let’s go →Vibration turned into signals
How Do You Hear?
Hearing converts air vibrations into nerve signals through the eardrum and hair cells.
Let’s go →A pump squeezing
What Is a Heartbeat?
A heartbeat is a muscle squeezing blood around your body's loop.
Let’s go →An empty tube, squeezing anyway
Why Does Your Stomach Rumble?
A rumble is your empty stomach and gut sweeping themselves clean, and hunger is a hormone clock, not an empty feeling.
Let’s go →Guess everything, keep what works
How Does Your Body Fight a New Germ?
Your immune system makes millions of random shapes in advance, then mass-produces whichever one happens to fit the invader.
Let’s go →A recipe, copied twice
Why Do You Look Like Your Parents?
You inherit half your instructions from each parent, shuffled into a brand new combination.
Let’s go →Seven metres of grabbing
Why Are Your Intestines So Long?
Your intestines are long because food is only absorbed at the wall, and length, folds and fuzz all buy more wall.
Let’s go →Drowning out one signal with another
Why Does Scratching Feel So Good?
Itch travels on its own slow nerves, and scratching drowns it out with pain signals your spinal cord prioritises.
Let’s go →Throw it all out, take back what you need
What Do Kidneys Actually Do?
Kidneys clean blood by throwing nearly everything out and carefully taking back the water and salt you need.
Let’s go →The chemistry room
What Is a Liver For?
The liver is where everything you absorb goes first — to be stored, rebuilt into something useful, or made safe.
Let’s go →Half a tennis court, folded up
Why Are Lungs Spongy Instead of Hollow?
Lungs are spongy because oxygen can only cross where air touches blood, and folding gives an enormous amount of touching.
Let’s go →Only ever pulling
How Do Muscles Move You?
Muscles move you by pulling, which is why they come in opposing pairs.
Let’s go →An alarm, not a measurement
Why Does It Hurt?
Pain is an alarm your brain chooses to sound — which is why the same injury can hurt very differently.
Let’s go →A net, cast in seconds
How Does a Cut Stop Bleeding?
A cut stops bleeding when platelets plug the hole and a protein mesh forms across it, trapping blood cells into a scab.
Let’s go →Muscles working for the heat, not the movement
Why Do You Shiver When You Are Cold?
Shivering makes your muscles do pointless work on purpose, because most of what a muscle produces is heat.
Let’s go →Light in, picture built
How Do Your Eyes See?
Eyes convert light into nerve signals, and the brain builds the image.
Let’s go →More than a wrapper
What Does Your Skin Do?
Skin keeps things out, controls temperature, senses the world and repairs itself.
Let’s go →Maintenance time
Why Do We Sleep?
Sleep is when your body repairs and your brain sorts and stores the day.
Let’s go →Catching actual molecules
How Does Smelling Work?
You smell things because their molecules float into your nose and lock onto receptors.
Let’s go →Blasting the nose clear
Why Do We Sneeze?
A sneeze is an automatic blast of air that clears irritants from your nose.
Let’s go →Taken apart, then absorbed
What Happens to Food You Eat?
Digestion breaks food into molecules small enough to enter your bloodstream.
Let’s go →Cooling by evaporation
Why Do We Sweat?
Sweating cools you because evaporating water takes heat from your skin.
Let’s go →Five basics, plus your nose
How Does Taste Work?
The tongue detects five basic tastes; the rest of flavour is smell.
Let’s go →Three kinds of tear
Why Do We Cry?
There are three kinds of tears: constant maintenance, emergency rinsing, and emotional ones.
Let’s go →A toolkit in your mouth
Why Do Teeth Have Different Shapes?
Teeth have different shapes because cutting, tearing and grinding need different tools.
Let’s go →A saltiness detector
How Does Your Body Know You Need a Drink?
Thirst comes from a patch of brain measuring how salty your blood is, not from a dry mouth.
Let’s go →Several senses at once
How Does Touch Work?
Touch is several different senses working together in your skin.
Let’s go →A rehearsal
How Do Vaccines Work?
Vaccines train your immune system on a harmless preview of a germ.
Let’s go →Two flaps, flapping very fast
How Do You Make Your Voice?
Air from your lungs makes two flaps in your throat vibrate, and your mouth shapes that buzz into speech.
Let’s go →A bag that reports on itself
Why Can't You Just Hold It Forever?
Your bladder measures stretch, not volume — which is why the urge comes in waves and why cold makes it worse.
Let’s go →Shouting at the world and listening back
How Does a Bat See in the Dark?
A bat finds its way by shouting and timing the echoes — and it is the only mammal that truly flies.
Let’s go →Seven bones, same as yours
Why Is a Giraffe's Neck So Long?
A giraffe reaches leaves nothing else can, and needs an extraordinary heart and valves to pump blood that high.
Let’s go →Sticky feet and a very fast eye
How Does a Fly Walk on the Ceiling?
A fly sticks to ceilings with clawed, glue-footed pads, sees the world far faster than you do, and tastes with its feet.
Let’s go →No brain, no heart, no bones
How Does a Jellyfish Live With No Brain?
A jellyfish has no brain, heart, bones or blood — a ring of nerves and a bag of water do the whole job.
Let’s go →It is not the bite, it is you
Why Does a Mosquito Bite Itch?
A mosquito's spit stops your blood clotting so it can drink — and your reaction to that spit is the itch.
Let’s go →Senses you do not have
How Does a Shark Find Its Food?
Sharks hunt with a stack of senses — smell, ripples, and electricity — that reach far past what eyes can do.
Let’s go →A whole body doing the work of feet
How Does a Snake Move With No Legs?
A snake moves by pressing its body against the ground and pushing sideways, with ribs and scales doing the work of legs.
Let’s go →One part, a dozen jobs
What Is a Tail For?
Tails do whatever an animal most needs — steering, balancing, gripping, signalling or keeping warm.
Let’s go →It depends on who does the delivering
Is Venom the Same as Poison?
Venom is injected by the animal, poison is only dangerous if you eat or touch the animal — and both are made of the same kinds of chemicals.
Let’s go →A wire crossed
Why Does Ice Cream Give You a Headache?
Brain freeze is a cold reflex in the roof of your mouth that your brain reports as head pain.
Let’s go →Kind to the blade, unkind to germs
Why Are Chopping Boards Made of Wood?
Wood is soft enough to protect a knife edge and dries out in a way that kills bacteria.
Let’s go →Ridges that grip and feel
Why Do We Have Fingerprints?
Fingerprint ridges improve grip on wet surfaces and sharpen your sense of touch.
Let’s go →A squashed cable
Why Does Your Foot Go to Sleep?
A squashed nerve stops sending signals, and pins and needles are those signals restarting.
Let’s go →Faster sound, same vibration
Why Does Helium Make Your Voice Squeaky?
Helium makes sound travel faster, shifting your throat's resonances up into a squeak.
Let’s go →A muscle misfiring
What Causes Hiccups?
A hiccup is the diaphragm spasming while the vocal cords snap shut.
Let’s go →It steals heat faster
Why Does Metal Feel Colder Than Wood?
Metal feels colder because it conducts heat away from your hand much faster than wood.
Let’s go →A chemical booby trap
Why Does Chopping Onions Make You Cry?
Cutting an onion mixes two chemicals into a stinging gas, and your eyes flood to rinse it away.
Let’s go →Your brain saw it coming
Why Can't You Tickle Yourself?
You cannot tickle yourself because your brain predicts your own touch and cancels the surprise.
Let’s go →Cooling and catching
Why Do We Yawn?
Yawning appears to cool the brain, and it spreads contagiously between people.
Let’s go →It notices charge, not pressure
How Does Glass Feel Your Finger?
A touchscreen does not feel pressure; it notices your body stealing a little charge from a grid of invisible wires.
Let’s go →