Why do you feel dizzy after spinning?

The answer is in your ear. The inner ear has three semicircular canals filled with fluid and lined with fine sensory hairs. When your head turns the fluid moves, the hairs bend, and the brain reads that signal as rotation.

The trouble comes at the moment you stop. The fluid has inertia — it keeps rotating for a while after your head has stopped. The hairs stay bent and keep signalling rotation, while your eyes insist everything is still.

That contradiction between eyes and ears is what dizziness is. The same conflict causes motion sickness in a car or a boat, where the ear senses movement while the eyes see a stationary interior. Once the fluid settles, the feeling passes within seconds.

Dancers get around this with technique. While turning they fix their eyes on one point and whip the head round at the last instant — a move called spotting. It keeps the visual input relatively steady, which reduces the conflict between eyes and ears and with it the dizziness.