To create and observe vortexes
- Two empty liter bottles
- Two large bowls or sink
Fill both bottles with water. Place the bottles over the sink or bowls. Give one of the bottles a twist, turning the bottle in a circular motion while the bottle is still upright. This will form a vortex. Quickly turn the bottle upside down, allowing the water to flow out. Your partner should simply turn his or her bottle upside down, and allow the water to flow out. Keep in mind, in order for this to be a race, the bottles need to be turned upside down at the same time! Which bottle empties the fastest?
The bottle with the vortex wins the race. The opening of a vortex allows water to flow out of the bottle, while air molecules move inside the bottle to take the water’s place. The bottle without the vortex does not flow out of the bottle as quickly. The water and air molecules have to take turns passing through the opening of the bottle; this bottle comes in second place.