What you need
- a glass jar with lid
- a big squirt of dishwashing liquid
Fill the jar with water, nearly to the top. Leave about a 2cm gap for shaking room.
Squirt in a good amount of dishwashing liquid.
Shake the jar vigorously in a circular motion then set it down. You should see a cyclone forming in the centre of the jar.
Why is it so?
A tornado forms when cold and hot air combine and spin very quickly. Inside the jar, the fluid on the outside starts spinning before the fluid at the centre. When you set the jar down, you see the fluid on the outside slowing down as the fluid on the inside continues to spin. What you are seeing is the formation of a vortex: the water spins rapidly around the vortex due to centripetal force.
A centripetal force is an inward force that directs an object or fluid towards the centre of its circular path.
Vortexes found in nature include tornadoes, hurricanes and waterspouts.