Earth & Weather

The planet's own machinery — engines that build weather out of sunlight and seawater.

How a Cyclone Works — A hurricane is a heat engine that builds itself out of warm seawater. It burns about 6 x 10^14 watts of evaporated ocean — 200 times the electrical output of the United States — and turns roughly a tenth of it into wind.
How a Rainbow Works — A rainbow is not an object and it is not in the sky — it is an angle, about 42 degrees, measured from the shadow of your own head. Every drop sprays the whole spectrum everywhere; you only ever catch one colour from any one drop.
How an Earthquake Works — The ground under a fault is moving all the time — about 3.5 cm a year — but friction holds the fault shut, so the rock bends instead. An earthquake is that bend snapping back in seconds, and the waves it throws off.
How the Seasons Work — Earth is closest to the Sun in early January, in the middle of northern winter. The seasons come from a 23.4° lean that tips each half of the planet toward the Sun and then away, and the same lean steers the monsoon rains and the snow line.
What’s Inside the Earth — The deepest hole ever drilled stopped at 12 km, 0.2% of the way down. Yet we know the centre is a solid iron ball as hot as the Sun’s surface, because earthquakes X-ray the planet and the liquid core casts a shadow.