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Everyday wonders

Everyday wonders

Kitchen, bubbles, echoes, and odd little magic

Fruit rusting

Why Does a Cut Apple Turn Brown?

A cut apple browns because a released enzyme reacts with oxygen to build brown pigment.

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A gas being made

Why Does Baking Soda Fizz?

Baking soda fizzes because it reacts with acid to make carbon dioxide gas.

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Air pushing back

Why Does a Balloon Stay Blown Up?

A balloon stays inflated because air molecules inside push outward against the stretched rubber.

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Water turning to gas inside itself

What Are the Bubbles When Water Boils?

Boiling bubbles are water vapour forming inside the liquid, not trapped air.

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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.

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A fungus breathing out

Why Does Bread Rise?

Bread rises because living yeast produces gas bubbles trapped inside the dough.

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The laziest possible shape

Why Are Bubbles Always Round?

Bubbles are round because a sphere uses the least surface to hold the air inside.

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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.

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A magnet inside a bigger magnet

How Does a Compass Work?

A compass needle is a magnet that lines up with Earth's magnetic field.

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A grain that drinks

Why Does Rice Need Exactly the Right Water?

Rice grains swell by absorbing a set amount of water, so the measure matters more than the time.

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Atoms joining a queue

How Do Crystals Grow?

Crystals grow as atoms leave a solution and lock into a repeating pattern.

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Broken up, not vanished

Where Does Sugar Go in Water?

Dissolving breaks a solid into single molecules spread evenly through the liquid.

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A skin that shoves the air

How Does a Drum Make a Sound?

A drum's stretched skin is hit, shudders, and shoves the air — with the shell shaping how long and low it rings.

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Sound coming back

What Is an Echo?

An echo is sound reflecting off a surface and returning to you delayed.

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Far, hard and facing you

Why Do Canyons Echo So Well?

Canyons echo because their walls are far away, hard and steeply angled back at you.

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Nothing left to absorb sound

Why Are Empty Rooms So Echoey?

Empty rooms echo because there is nothing soft left to absorb the reflected sound.

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Ridges that grip and feel

Why Do We Have Fingerprints?

Fingerprint ridges improve grip on wet surfaces and sharpen your sense of touch.

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A squashed cable

Why Does Your Foot Go to Sleep?

A squashed nerve stops sending signals, and pins and needles are those signals restarting.

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Ice leaving without melting

What Is Freezer Burn?

Freezer burn is ice escaping food as vapour without ever melting, leaving it dry.

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Locking into a pattern

What Happens When Water Freezes?

Freezing locks water molecules into an open pattern that takes up more space.

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Smell molecules escaping

Why Does a Fridge Smell of Everything at Once?

Foods release smell molecules that build up in a sealed fridge and settle on everything.

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Thickness, tightness, length

Why Do Guitar Strings Sound Different?

A string's note depends on how thick, how tight and how long it is — and a guitar lets you change all three.

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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.

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A muscle misfiring

What Causes Hiccups?

A hiccup is the diaphragm spasming while the vocal cords snap shut.

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Heat always moving in

Why Does Ice Cream Melt?

Ice cream melts because heat always flows from the warmer room into it.

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Lowering the freezing point

Why Does Salt Melt Ice?

Salt lowers water's freezing point, so ice melts at temperatures below zero.

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Iron, made temporarily magnetic

Why Do Magnets Stick to the Fridge?

Magnets stick to fridges because the door's steel becomes temporarily magnetic itself.

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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.

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Waves that overlap themselves

Why Does a Microwave Heat Unevenly?

Microwaves bounce off the metal walls and overlap, creating fixed hot and cold spots.

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Every mix absorbs more

Why Does Mixing Paint Make Brown?

Mixed paints absorb more and more light, so the result heads towards brown.

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A fungus, eating your lunch

What Is the Fluff on Old Bread?

Mould is a fungus digesting the bread and raising stalks that release spores into the air.

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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.

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A liquid that panics

Why Can You Run on Cornflour and Water?

Cornflour mixed with water jams solid when hit and flows when pressed slowly.

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Trading height for distance

Why Does a Paper Plane Glide?

A paper plane glides by falling forward slowly while air pushes up on its wings.

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Cloudy water is useful water

Why Do Cooks Save the Pasta Water?

Pasta water carries starch, which thickens a sauce and helps it stick to the pasta.

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Eighty-eight little catapults

What Happens Inside a Piano?

A piano key throws a felt hammer at a string and releases it in mid-air, so the note can ring freely.

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Steam bursting out

Why Does Popcorn Pop?

Popcorn pops when trapped water turns to steam and bursts the hard shell.

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Stopping the heat walking out

Why Does a Lid Make Water Boil Faster?

A lid stops steam carrying heat away, so the pan reaches boiling much faster.

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Making water boil hotter

How Does a Pressure Cooker Cook Faster?

A sealed pot raises the pressure inside, so water boils hotter and food cooks faster.

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Colours bending differently

What Does a Prism Do?

A prism splits white light into colours because each colour bends differently.

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Air losing its grip on water

Why Do Windows Fog Up?

Windows fog when warm moist air touches cold glass and its water condenses.

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Tangled chains straightening out

Why Do Rubber Bands Snap Back?

Rubber snaps back because stretching straightens its tangled molecule chains.

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Iron combining with oxygen

Why Does Metal Go Rusty?

Rust forms when iron reacts with oxygen and water to make a flaky new substance.

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Blocking light, close and far

How Do Shadow Puppets Work?

Shadow puppets work because blocked light spreads out, so nearer objects cast bigger shadows.

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All the force in one line

Why Is a Sharp Knife Safer Than a Blunt One?

A sharp knife needs less force because all the push lands on a very thin edge.

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Notes that share their wobbles

Why Does Singing Together Sound Good?

Notes sound good together when their vibrations fit in simple whole-number ratios, so the waves line up rather than clash.

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A molecule with two ends

How Does Soap Clean?

Soap works because each molecule grips grease at one end and water at the other.

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Light bouncing off two surfaces

Why Are Soap Bubbles Colourful?

Bubble colours come from light reflecting off both surfaces of the film and interfering.

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Gas hiding in plain sight

Where Do the Bubbles in Fizzy Drinks Come From?

Fizzy drinks hold dissolved gas under pressure, and opening the bottle lets it bubble out.

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How tightly the molecules hold

Why Are Some Things Solid and Others Runny?

Solids, liquids and gases differ in how tightly their molecules hold together.

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Metal and protein shaking hands

Why Does Food Stick to the Pan?

Proteins bond to hot metal and release only once a crust has formed underneath.

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Air pressure pushing from outside

How Does a Straw Work?

A straw works because removing air lets outside air pressure push the drink up.

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A shadow swinging with the sky

How Does a Sundial Tell Time?

A sundial works because Earth's rotation swings the Sun's shadow steadily around.

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Pushing in time

How Do You Make a Swing Go Higher?

Pumping works because small pushes timed to a swing's natural rhythm build up over many arcs.

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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.

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Sugars and proteins reacting

Why Does Toast Go Brown?

Toast browns because heat makes sugars and proteins react into new flavour compounds.

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Thousands of tiny hooks

How Does Velcro Stick?

Velcro works because thousands of stiff hooks catch in thousands of soft loops.

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Proteins forced to unfold

How Does Egg White Turn Into Foam?

Whisking unfolds egg white proteins so they wrap around air bubbles and hold them.

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The same note, a different mix

Why Does a Piano Not Sound Like a Violin?

Instruments differ because each adds a different mix of quieter extra notes on top of the one being played.

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Angled blades catching moving air

How Does a Windmill Turn?

Windmills turn because angled blades deflect moving air and the air pushes back.

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Cooling and catching

Why Do We Yawn?

Yawning appears to cool the brain, and it spreads contagiously between people.

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