Spin yourself around and watch water reveal the Coriolis effect

The Coriolis Force Demonstrator is a small acrylic device you fill with water and hold in your hand. Rotate your whole body while holding it steady, and the water streaming from the discharge hole traces a path that bends away from a printed reference line on the surface, the same effect that curves hurricane winds and ocean currents on a rotating Earth.

There's no motor and nothing to calibrate. The rotation comes from the student's own body turning, not a motorized turntable, so each student can hold their own unit, refill it, and run the trial again immediately. Reversing the direction of rotation flips which way the water bends, letting students compare Northern and Southern Hemisphere deflection side by side.

Works for Earth science and meteorology units covering global wind patterns, as well as physics units on motion in rotating reference frames.

Why Teachers Love It

• Hands-On, Individual Trials – Compact and lightweight enough for every student to run their own trial and refill for repeat attempts, instead of watching a single demo from the back of the room.

• No Motor, No Setup – Entirely mechanical, no batteries, wiring, or calibration; ready as soon as the tank is filled.

• Models Both Hemispheres and the Equator – Reversing rotation direction shows Northern versus Southern Hemisphere deflection, and moving the device in a straight line instead of rotating shows why the Coriolis force disappears at the equator.