Spin around ten times as fast as you can.

Stop.

Now try to walk in a straight line.

You can't. The room is moving. You're not. And your brain has absolutely no idea what's real anymore.

But why? You stopped spinning. The room never moved in the first place. So what exactly is happening inside your body that makes everything feel like it's still going?

In this episode Daniel literally spins himself dizzy before asking the question — and what they figure out together is one of those answers that makes you look at your own body completely differently.

It starts in your ear. Not the part that hears things. Much deeper than that. Inside your inner ear there are three tiny curved tubes — so small you've never thought about them — and they're filled with liquid. Floating insid ...