The Bedtime Scientist

A question

Why does the ocean glow at night?

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

The short answer

Because living things in it are making light. Bioluminescence is a chemical reaction inside an animal's body, producing light with no wires and almost no heat.

In some bays, tiny plankton flash when the water is disturbed, so a hand trailed through leaves a glowing wake behind it. Most deep-sea animals can make light of some kind, usually a soft blue, because blue travels furthest through water.

Go deeper tonight

Bioluminescence: Nature's Living Light

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

The episode

Bioluminescence: Nature's Living Light

0:00 11:02
Sleep timer

Read the guide for this one in the morning.

This connects to

Light

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