A question
Where does rain come from?
A calm, true answer. Then, if the wondering keeps going, the whole episode.
The short answer
From the sea, mostly, by way of the sky. The sun warms water until it rises invisibly as vapour, the vapour cools high up and gathers into droplets, and when the droplets grow heavy enough they fall.
None of the water is new. It has been going round for billions of years, so the water in your glass tonight has been a cloud and a river and an ocean before, and may well have drifted over a dinosaur.
Go deeper tonight
The Water Cycle: The Journey of a Droplet
The full episode, in one calm voice, with nothing that startles.
Read the guide for this one in the morning.
This connects to
One idea turns up in many different nights. Follow one and the library starts to join up.
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