Whirligig

To fall or not to fall?

Difficulty:
Danger:
Duration:
15 minutes

Safety

  • Carefully review the general safety advice on the back of the box cover before starting the experiment.
  • Disassemble the setup after the experiment.

Disposal

Dispose of solid waste together with household garbage.

Scientific description

We’ve already seen how the gyroscopic effect keeps a rotating object upright even when you lightly push it to the side. Now, what happens if this rotating object has a force acting on it constantly?

The non-rotating whirligig cannot stand upright, it falls because the earth pulls it. This attraction is called gravity. As the top rotates/spins , there is a gyroscopic effect that keeps it upright. Gravity tries to pull the spinning top to the side, just as it starts to tilt to the right, the gyroscopic effect immediately tilts it forward. As soon as the top starts to fall forward, the gyroscopic effect immediately pushes it to the left, and so on. Because of this constant influence of gravity and the gyroscopic effect, the axle  of the whirligig begins to rotate. This complex phenomenon, when the axle  around which the object rotates begins to rotate, is called precession. When the gyroscope is rotating quickly, precession is inconspicuous. As the rotation of the gyroscope speed decreases, the axle rotation becomes noticeable.