Tornado in a Bottle
Watch and make your own tornado using two two-liter bottles, a washer, and some duct tape.
- Two 2-liter plastic bottles
- One washer
- Duct tape
- Food coloring (optional)
- Fill one of the 2-liter plastic bottles two-thirds full with water. If you’d like, add a few drops of food coloring to the water.
- Place the metal washer on top of the bottle opening.
- Take the second bottle and place it upside down on top of the first one, so that the bottle openings perfectly line up to each other.
- Tape the bottles together at their openings using duct tape. Make sure to tape tightly so that no water will leak out when you turn the bottle over.
- Turn the bottles upside down so that the bottle with water is on top. Swirl the bottle in a circular, counterclockwise motion.
- Watch what happens. What shape does the water take as it moves from the upper bottle to the lower one?
This simple activity lets you see the structure of a vortex. A vortex is an area where the flow of a fluid (such as water or air) revolves around an axis. In the bottle, water flows in a circle and creates a funnel shape. In a supercell thunderstorm, a tornado is an example of a vortex that can form from air that moves in a deep and continuous circular updraft.