Ocean carry sound far

The ocean looks like it ought to be quiet. Big blue empty, like someone forgot to put the sound in.

But NOAA says sound travels very efficiently underwater. Ocean like this. Man think he is alone, then noise from miles off turns up for no reason.

That means a hydrophone can pick up whale songs from many kilometres away. Also manmade noise, which is less poetic but still gets the job done.

So the sea is not a blank hush. It is more like the world's largest hallway, with excellent acoustics and no carpet to help.

A sound can set off and keep going, sliding through water far better than most of us would guess. Brain like this. Ocean carry a message long after the thing that made it has gone.

That gives the water a strange, distant life. Not loud, not busy in a city way, just full of far-off chatter you cannot hear with normal ears.

Tiny win: next time you are by the sea, stand still for ten seconds and try to imagine all the noise moving under there. Man read this and need small sit down.