Tag
Rocks & ground
Mountains, soil, caves, and what is underfoot — 60 tiny stories across 8 shelves.
Earth & sky
Weather, light, and the air around us — 37 stories.
All earth & sky →Water dissolving stone
How Do Caves Form?
Rainwater is faintly acidic, and over ages it dissolves limestone into rooms and tunnels — then the same water drips back in and decorates them.
Let’s go →Because it was one
Why Does the Map Look Like a Jigsaw?
South America and Africa fit together because they really were joined, and new sea floor forming between them has pushed them apart since.
Let’s go →Where a river puts down its load
Why Do Rivers Fan Out at the Sea?
A river carries dirt a thousand kilometres and drops nearly all of it in the last few, choking its own channel and fanning out sideways.
Let’s go →A wave made of sand
How Does a Sand Dune Move?
A dune crosses the desert without a single grain going the whole way: wind rolls sand up the gentle side and tips it down the steep one.
Let’s go →A bump of one part in seven hundred
Shrink Earth to a Marble and You Could Not Feel Everest
The tallest mountain on Earth is a rounding error against the planet's radius, which is why a scale model of Earth would feel smooth in your hand.
Let’s go →Rock finally slipping
Why Does the Ground Shake?
Earth's plates grind past one another, snag, and hold. The shaking is centuries of stored strain let go in seconds when the snag finally gives way.
Let’s go →Patience with sandpaper
How Do Rivers Carve Canyons?
A river carries grit, the grit grinds rock, and enough time turns a stream into a canyon — helped along by water undercutting its own banks.
Let’s go →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.
Let’s go →Rock replacing bone
How Does a Fossil Form?
A fossil is not the original bone. It is stone that grew into the bone's exact shape, and it takes fast burial plus real luck for any of them to exist.
Let’s go →A kettle with a narrow neck
Why Does the Ground Shoot Boiling Water?
Water works down through cracks to rock heated by magma two kilometres below, then waits there hotter than boiling for something to let the pressure go.
Let’s go →Ice that flows
How Do Glaciers Move?
Pile ice deep enough and it stops behaving like a solid: it deforms and creeps downhill under its own weight, carving U-shaped valleys as it travels.
Let’s go →A saw made of grit
How Does a River Cut a Gorge?
Water alone barely scratches rock. A river cuts a gorge with the grit it drags along, going down faster than its hard walls can fall inwards.
Let’s go →Soaked rock, not caverns
Where Is Water Underground?
There are no hidden lakes down there. Groundwater fills the microscopic pores between grains of rock like water in a sponge, and it moves very slowly.
Let’s go →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.
Let’s go →Atoms that tick
How We Know How Old a Rock Is
Certain atoms turn into other atoms at an utterly fixed rate, so the ratio between them in a rock says how long it has been sitting there.
Let’s go →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.
Let’s go →Nobody has been below 12 km
How We Know What Is Inside the Earth
Earthquake waves travel through the planet, and one kind of wave never comes out the far side — which is how we know the core is liquid.
Let’s go →Four different ways
How Does a New Island Appear?
Islands appear four different ways — a volcano building up, coral growing, land cut off by rising seas, or the sea dropping — and the shape shows which.
Let’s go →A bridge of land
What Is an Isthmus?
A strip of land a few kilometres wide is a bridge for everything that walks and a wall for everything that swims, and it redraws trade routes.
Let’s go →Sea, with a wall in front of it
How Does a Lagoon Form?
A lagoon is a piece of sea fenced off by a bar or a reef, and the still warm water behind that fence becomes something else entirely.
Let’s go →Building up and wearing down
Why Does Land Have Shapes At All?
Every hill and valley is a contest between forces shoving the land upwards and weather grinding it back down, settled by the rock underneath.
Let’s go →A slope losing an argument
Why Do Hillsides Slide?
Every slope is a slow argument between gravity and friction, and a landslide is the moment water, undercutting or shaking makes friction lose.
Let’s go →Sorted by weight
What Is Inside the Earth?
The young Earth was molten, so heavy iron sank and light rock floated. Earthquake waves passing through confirm the layers are still arranged that way.
Let’s go →Hot, and solid anyway
Why Is the Inside of the Earth Not Liquid?
The Earth's inside is hot enough to melt but held solid by pressure — so magma is made by dropping the pressure or adding water, not by adding heat.
Let’s go →Atoms in formation
What Is a Mineral?
A mineral is a natural solid with a fixed recipe and atoms stacked in a strict repeating lattice, and that hidden lattice shapes the crystal outside.
Let’s go →Crust crumpling
How Do Mountains Grow?
Mountains rise where colliding plates crumple the crust upward, and they last only as long as that uplift keeps ahead of the weather wearing them down.
Let’s go →Salt arrives and never leaves
Why Is the Sea Salty?
Rivers carry dissolved salt down to the sea, and evaporation lifts only the water back out. That one-way door has left seawater 3.5 per cent salt.
Let’s go →Land with sea on three sides
What Is a Peninsula?
Some are ridges of hard rock the sea never wore through, some are sandbars built by currents, and some are high ground the rising sea went around.
Let’s go →Lifted, not built
Why Are Some Mountains Flat on Top?
A plateau is not a mountain that lost its peak — it is flat land lifted as one block, keeping its surface until rivers cut in from the edges.
Let’s go →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.
Let’s go →Erosion on the outside
Why Do Rivers Bend?
Water runs fastest round the outside of a bend, so it cuts that bank and drops sand on the inner one. Every bend therefore makes itself a little sharper.
Let’s go →Nothing is permanent
Can a Rock Turn Into a Different Rock?
Weather grinds rock to grains, burial presses the grains back into stone, and deeper heat cooks that stone into something new without ever melting it.
Let’s go →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.
Let’s go →Mountains, eventually
Where Does a Beach Come From?
Sand is what is left when rock has been broken down for ages and everything softer has washed away. Tropical sand is often ground-up coral instead.
Let’s go →A page for every year
How Do Rocks End Up in Stripes?
Layered rock is a stack of old surfaces: material settles flat, gets buried and pressed, and each band records a different time.
Let’s go →Rock, remains and life
What Is Dirt Actually Made Of?
Half of good soil is empty space where roots find air and water, and one handful holds billions of bacteria and the fungal threads binding it.
Let’s go →Pressure finding a way out
Why Do Volcanoes Erupt?
Molten rock is lighter than the rock above it, so it rises. Dissolved gas expanding on the way up is what turns that rise into an eruption.
Let’s go →Space
Crashy night-sky stories — 8 stories.
All space →Leftover bricks
What Are Asteroids?
Asteroids are the bricks left over from planet-building — the rubble of a world that never managed to form, mostly parked between Mars and Jupiter.
Let’s go →A dirty snowball
What Is a Comet?
The ice never melts — it goes straight from solid to gas and blasts off the surface. Halley's comes round every 76 years, so most people see it once.
Let’s go →Nothing rubs them out
Why Is the Moon Covered in Holes?
Earth is hit just as often as the Moon. The difference is that the Moon has no air, water or moving crust to rub the scars out afterwards.
Let’s go →A rusty planet
Why Is Mars Red?
Mars is red for the same reason an old nail is: its iron-rich dust has rusted. A whole planet the colour of something left out in the rain.
Let’s go →Not a star at all
What Is a Shooting Star?
A grain of dust hits our air at tens of kilometres a second and burns out 80 km up. The glow is not friction — air squeezed that hard gets white hot.
Let’s go →A true space story
Where the Moon Came From
The Moon is the piece of Earth that got knocked loose and never fell back, thrown into the sky by one enormous crash into the young planet.
Let’s go →A definition, not a demotion
Why Is Pluto Not a Planet Any More?
Finding Eris, heavier than Pluto, forced a choice: name a tenth planet or redraw the line. Pluto now leads a category instead of trailing one.
Let’s go →Billions of orbiting snowballs
What Are Saturn's Rings Made Of?
The rings are billions of separate ice chunks, each on its own orbit. They only look solid from far away, and the sheet is astonishingly thin.
Let’s go →What things are made of
Atoms, metal, glass, plastic, and every kind of stuff — 5 stories.
All what things are made of →Fire welds the grains together
Why Does Baking Mud Make Stone?
Firing clay drives out the water locked inside and heats the grains until their edges fuse. Soft mud comes out behaving, for all purposes, like stone.
Let’s go →A cliff of tiny shells
What Is Chalk Made Of?
Drop a stick in vinegar and it fizzes, the same reaction acid rain runs on limestone — though most sticks sold today never came near an ancient sea.
Let’s go →Flat plates with water between them
Why Can You Shape Clay but Not Sand?
Clay holds a shape because its grains are flat plates sliding on a film of water, which then pulls them together wherever you leave them.
Let’s go →Sunlight from a very long time ago
What Is Crude Oil?
Crude oil is the squashed remains of tiny sea creatures, cooked under rock — so burning it releases sunlight caught a hundred million years ago.
Let’s go →The metal that will not change
Why Is Gold So Special?
Almost every metal dulls or rusts. Gold sits unchanged for thousands of years, bends easily, is genuinely rare, and was made in dying stars.
Let’s go →Animals
Creatures on land, in the sea, and in the air — 5 stories.
All animals →The steadiest place around
Why Do Animals Dig Burrows?
A metre of soil holds one temperature through a heatwave and a frost alike, and the door is narrow — both worth an enormous amount of digging.
Let’s go →Both, in a way
Is Coral a Rock or an Animal?
A reef is not rock. It is millions of tiny animals living in stone cups they built themselves, fed by algae farmed inside their own tissue.
Let’s go →Reading bones
How Do We Know About Dinosaurs?
Everything we know about dinosaurs comes from bones, teeth and footprints, read against animals alive today — birds and crocodiles above all.
Let’s go →By about sixty million years
Sharks Are Older Than Trees
Sharks appear in the fossil record 65 million years before the first true trees — and they are older than Saturn's rings and older than the North Star.
Let’s go →Free soil engineering
Why Are Earthworms Useful?
Worms eat dead leaves and pass them out enriched, drill the soil full of air and drainage, and quietly mix its layers year after year without stopping.
Let’s go →Life & body
Seeds, hearts, senses, and growing things — 2 stories.
All life & body →Being eaten by the invisible
Why Do Dead Things Rot?
Rotting is countless microbes digesting what has died from the outside in, unlocking nutrients that would otherwise stay stuck in the body forever.
Let’s go →Anchor and straw
What Do Roots Do?
Roots do three jobs at once: hold the plant down, drink water and minerals through microscopic hairs, and trade sugar with fungi for nutrients underground.
Let’s go →Physics
Invisible forces you can play with — 1 story.
All physics →Everyday wonders
Kitchen, bubbles, echoes, and odd little magic — 1 story.
All everyday wonders →How things work
Everyday machines, taken apart — 1 story.
All how things work →