# Tippe Top

The tippe top is a spinning top that flips over after it's spun. You start off by spinning it, and a few seconds later it flips over completely and continues spinning in an upside-down orientation.

Check out a video of a tippe top:

As the top flips, the stem turns downward and touches the ground. The friction force between the stem and the ground causes the top to turn over completely.

The top falls down initially because it is dynamically unstable, but after flipping over (with the stem down), it becomes dynamically stable.

The top is a gyroscopic object, and such objects often exhibit non-intuitive behaviour. Unfortunately, the strange behaviour of the top cannot be simply explained in a few sentences. Its behaviour has puzzled many really smart scientists for many years. A detailed description of the top's behaviour is the stuff of advanced courses in physics.

You can see similar behaviour when spinning a hard-boiled egg, starting from its horizontal position. If you give the egg a fast enough spin it will turn upright. When the egg spins (in the horizontal position), the friction force with the bottom surface causes a secondary spin to occur along the egg's long axis. This secondary spin combined with the original spin, produces a gyroscopic force which causes the egg to turn upright with its long axis pointing up.

If the top is not spun fast enough it stops spinning and comes to rest. If it is spun fast enough it turns over on its side and then flips over completely.