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Weather

Clouds, storms, and what tomorrow will do — 60 tiny stories across 5 shelves.

Earth & sky

Weather, light, and the air around us — 52 stories.

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It thins rather than ends

Where Does the Air Stop?

Half of all the air sits below five and a half kilometres, lower than several mountain ranges, and the space station still feels a whisper of it.

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A weak layer buried inside

Why Does a Snowy Slope Suddenly Let Go?

An avalanche happens when a buried weak layer collapses under a rigid slab of snow, so the whole sheet lets go at once instead of sliding.

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Weighing the sky

How Does a Barometer Work?

A barometer weighs the column of air above it, and that weight drops before a storm and rises before fine weather — hours ahead of the sky.

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Ice you cannot see

Why Is Black Ice So Dangerous?

Black ice is transparent and bubble-free, so it looks exactly like wet road while removing very nearly all of your grip. You see it once you are on it.

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One day, or thirty years

What's the Difference Between Weather and Climate?

Weather is what happened today; climate is what usually happens over decades — which is why one cold week proves nothing either way.

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Reading the sky

Why Do Clouds Have Different Shapes?

A cloud's shape is a picture of the air beneath it: rising bubbles pile into heaps, gentle slabs spread into sheets, and height decides water or ice.

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Droplets too small to fall

How Does Something That Heavy Float?

A cloud weighs tonnes, but its water is split into droplets so tiny that air resistance almost cancels their fall and updraughts do the rest.

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Where the rain never arrives

Why Are Deserts Dry?

A desert is dry for one of three reasons: air that sinks instead of rising, a mountain range wringing the rain out first, or sheer distance from any sea.

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The temperature where air gives up

What Is the Dew Point?

The dew point is the temperature at which air is completely full of water. Chill anything below it and the invisible vapour has to become visible drops.

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How hard the air pushed

Why Is Some Rain Gentle and Some Rain Heavy?

Drizzle falls from a shallow cloud with no lift in it. A downpour falls from a tall one whose updraughts held the drops up until they had grown huge.

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Rain going missing

What Is a Drought?

A drought is not simply no rain. It is a long shortfall against what a place is built around — and dry ground bakes hard, which makes the shortfall worse.

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When the ground stops drinking

Why Do Rivers Flood?

A flood is not extra rain — it is rain the ground could not swallow fast enough, running straight off into a channel that is already full.

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A cloud on the ground

What Is Fog?

Fog is a cloud that formed at your height instead of a kilometre up, when air cooled past the point where it could still hold its water.

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Air letting go of water

Why Is the Grass Wet in the Morning?

Grass cools overnight until the air touching it can no longer hold its water, which is left behind as dew, or as frost if it is cold enough.

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A blanket that lets light in

How Does the Air Keep Earth Warm?

The light coming in and the heat going back out are different waves — some gases ignore sunlight and absorb infrared, worth 33 degrees.

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Ice going round again

How Does Hail Form?

A hailstone gains one layer per trip through a storm's updraught, thrown up and falling back until it is finally too heavy to be lifted again.

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Air that will not leave

What Makes a Heatwave?

A heatwave is not stronger sunshine. It is a dome of sinking air blocking cloud and wind, so the same heat accumulates day after day instead of leaving.

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Old shapes and young ones

Why Are Hills Round and Mountains Pointed?

A rounded hill is usually a very old mountain. Peaks stay sharp only while they are still rising; weather rounds off everything that stops.

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Boulders in the wrong place

How We Found Out There Were Ice Ages

Boulders the size of houses sat on ground no river could have brought them to — that, and scratches only ice makes, gave the ice ages away.

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When sweat stops working

Why Do Some Hot Days Feel Worse Than Others?

You cool down by evaporating sweat, and humid air is already close to its water limit. It will not take any more, so your main cooling system simply stops.

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A heat engine over warm water

How Do Hurricanes Form?

A hurricane is a self-feeding heat engine. Warm sea evaporates, the water condensing high up releases its heat, and the storm spins itself stronger on it.

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Most of it would change nothing

What If All the Ice Melted?

Melting sea ice raises the sea by nothing at all. Everything depends on the ice sitting on land — and almost all of that is in one place.

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A fast band steering the weather

What Is the River of Wind Up High?

A band only a few hundred kilometres wide, carrying winds past two hundred kilometres an hour, thrown into a west-to-east track by the planet's spin.

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A giant spark

What Is Lightning?

Lightning is the doorknob spark scaled up beyond imagining: a storm cloud builds millions of volts against the ground, and eventually the air gives way.

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Giving the strike an easy road

How Does a Lightning Rod Protect a House?

A lightning rod repels nothing. It offers a strike a sharp, easy metal path to the ground, so the current goes around the house instead of through it.

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A sea breeze the size of a continent

What Is a Monsoon?

A monsoon is a continent-sized sea breeze that reverses with the seasons — summer heat drags in wet ocean air, and winter cold pushes it back out again.

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Too dry for forest, too wet for desert

Why Are Grasslands Treeless?

Grasslands sit between forest and desert on rainfall, and fire and grazing finish the job. All three keep an enormous belt of the world treeless.

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Ice you never see

Why Does Rain Begin as Snow?

Most rain starts as ice, because an ice crystal grows by stealing water vapour from the droplets around it — far faster than droplets can grow by bumping.

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Warm and windy beats damp and still

Why Do Puddles Dry Slower Some Days?

The same puddle can vanish by lunchtime or sit there all day, because molecules land back into it almost as fast as they escape.

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The sky letting go

Where Does Rain Come From?

Rain is water that rose off the ground invisibly, cooled into droplets far too light to fall, and then merged with its neighbours until gravity won.

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The air arrives empty

Why Is One Side of a Mountain Dry?

Air forced up a mountain cools and drops its rain on the way. It arrives on the far side dry and warm, and a desert is often the result.

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Raindrops as prisms

How Does a Rainbow Work?

Every raindrop bends sunlight, splits it and throws it back at a fixed 42-degree angle. The bow is a circle drawn on the sky opposite the Sun.

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Warm, wet, and never switched off

Why Does So Much Live in a Rainforest?

A rainforest has no winter, so growth never pauses and life stacks into layers — though the richness sits in the trees, not in the thin soil.

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An old rhyme, half right

Does a Red Sky Really Predict the Weather?

A red sunset means clean dry air off to the west. That predicts tomorrow only where the weather reliably arrives from the west — Britain included.

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Grass, lakes and cattle, 6,000 years ago

The Sahara Turns Green, and Will Again

A slow wobble in Earth's orbit swings the African monsoon north every twenty-odd thousand years, and last time it did the Sahara held lakes and herders.

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Land and sea disagree

Why Is It Windy at the Beach?

The risen air spreads out high up, drifts back over the water and sinks again: land, sky, sea and round, a slow wheel turning all afternoon.

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The ground is still catching up

Why Is the Hottest Month Not the Longest Day?

Midsummer is peak sunshine, but ground and sea keep taking in more heat than they lose, so the hottest weeks arrive some weeks afterwards.

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A flake's journey down

Why Does It Sometimes Rain and Snow at Once?

Almost all rain begins as snow. What lands on you is decided in the last kilometre, by the warm and cold layers the flake happens to fall through.

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Ice with air in it

Why Is Snow White and Fluffy?

A snowflake is ice grown into a six-armed crystal, and a snowdrift is mostly the air between them. The whiteness is countless surfaces bouncing light.

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Six arms, one journey

Why Is Every Snowflake Different?

Ice can only ever grow six ways, but the exact path a flake takes through the cloud — every temperature, every damp patch — makes its shape unrepeatable.

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Light not getting through

Why Do Storm Clouds Look Dark?

Every bounce costs a little light, so through kilometres of droplets almost none reaches the base. The grey is a measure of how much water is overhead.

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Counting between flash and bang

How Far Away Is the Storm?

Lightning and thunder leave together, but light arrives instantly and sound takes three seconds a kilometre. Count the gap and divide by three.

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Wind piling up water

Why Does the Sea Rise in a Storm?

A funnel-shaped bay gives the water nowhere to escape, and the same surge arriving at high spring tide instead of low is what overtops a sea wall.

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Air exploding

Why Does Thunder Rumble?

Lightning heats air so fast that it explodes outward. Thunder is that bang, and the rumble is one long bolt arriving in stages, nearest end first.

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A spin tipped upright

How Does a Tornado Form?

Winds at different heights roll the air into an invisible horizontal tube. A storm's updraught tips that tube upright and stretches it until it spins hard.

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A loop with no end

Where Does Water Go?

The water in your glass has been round the same loop for billions of years: sea to sky to land and back. None of it is ever new.

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Physics run forward

How Can Anyone Predict Tomorrow?

A forecast measures the atmosphere as it is now, cuts it into millions of boxes, and steps known physics forward until the errors grow too large to trust.

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Lines, triangles and half-circles

How Do You Read a Weather Map?

The lines join places of equal pressure. Crowded lines mean wind, highs mean settled air, lows mean rain, and fronts mark where air masses collide.

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Fire as a gardener

Why Do Some Forests Need to Burn?

Some cones are glued shut with resin that only a fire can melt, so the seeds drop exactly when the ground has been cleared and made fertile.

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Air evening things out

What Makes Wind Blow?

Every temperature difference becomes a pressure difference, and wind is crowded air pushing towards the emptier place. Earth's spin makes it spiral.

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Losing your warm coat of air

Why Does Wind Make You Colder?

Your body heats a thin layer of air around your skin, and wind keeps stealing it. That is why you lose heat far faster than the thermometer suggests.

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Named for where it starts

Where Does the Wind Come From?

A north wind blows from the north, and it brings whatever the north was like. Naming wind for its origin is really naming the air that is arriving.

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Space

Crashy night-sky stories — 4 stories.

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Life & body

Seeds, hearts, senses, and growing things — 2 stories.

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Physics

Invisible forces you can play with — 1 story.

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Animals

Creatures on land, in the sea, and in the air — 1 story.

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