The Bedtime Scientist

A question

How does a steam train work?

A calm, true answer. Then, if the wondering keeps going, the whole episode.

The short answer

By boiling water. A fire heats a boiler, the water becomes steam, and steam takes up far more room than the water it came from, so it pushes hard on anything in its way.

That push drives a piston back and forth, and the piston turns the wheels. The chuff-chuff you hear is the used steam being let go, once for each turn.

Go deeper tonight

Steam Train: The Rhythm of Sleep

The full episode, in one calm voice, with nothing that startles.

The episode

Steam Train: The Rhythm of Sleep

0:00 12:04
Sleep timer

Read the guide for this one in the morning.

This connects to

Sound and echoes Force and machines

One idea turns up in many different nights. Follow one and the library starts to join up.