A question
How do dolphins sleep?
A calm, true answer. Then, if the wondering keeps going, the whole episode.
The short answer
Half a brain at a time. A dolphin has to think about every breath it takes, so it can never switch off completely. Instead it rests one half of its brain while the other stays awake and keeps it rising to the surface.
One eye usually stays open, the one wired to the waking half. They drift like that near the surface, half asleep and still breathing, for hours.
Go deeper tonight
Dolphins: Riding the Waves
The full episode, in one calm voice, with nothing that startles.
Read the guide for this one in the morning.
This connects to
Sound and echoes Rest Finding the way
One idea turns up in many different nights. Follow one and the library starts to join up.
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