A devastating tornado
How to make a tornado in a bottle
Safety precautions
None.
Equipment
- glass bottle;
- water;
- bowl.
Step-by-step instruction
Take a bottle of water, turn it upside down, and pour the water into the bowl. Note that the water flows slowly and fitfully. Repeat the experiment, swirling the bottle before beginning to pour. Note the formation of a “tornado” funnel and the rapid flow of water.
Process description
When we turn the bottle over, water wants to leave the bottle, while air wants to enter. The water’s flow is interrupted by air bubbles trying to enter the bottle. When the bottle is spun, the resulting centrifugal force pushes the water against the walls. The effect is enhanced when we open the bottle. An air channel is created in the central “axis” around which the liquid vortex rotates. As a result, the water leaving and air entering can occur in parallel. The stream becomes uninterrupted, letting the water flow faster.