Tornado in a Bottle

Materials

· Two plastic bottles

· Water (not included)

· Food coloring

· Glitter

· Beads

· Metal washer

· Duct tape

Procedure

1. Fill one of the plastic bottles with water.

2. Add glitter, food coloring, and beads to the bottle of water.

3. Place the metal washer on top of the bottle of water. Tear two small pieces of duct tape to secure it to the bottle. Make sure there is tape around the entire edge of the washer to prevent leaks, but don’t cover the hole in the middle.

4. Place the second (empty) bottle upside down on top of the full bottle. Use the remaining duct tape to secure the bottles together and create a seal so there are no leaks. Pull the duct tape tightly as you wrap it.

5. When your bottles are securely taped together, flip them over so that the empty bottle is at the bottom, and the full bottle is on top. Your goal is to make sure that the bottles are level so the liquid stays in the bottle on top.

6. Now hold on to the bottles securely and—without lifting them from the table—move them very quickly in a circular motion. It may take a few tries, but when you do it correctly, you will see a space from the top of the full bottle down to the hole in the washer—the glitter and beads will swirl around it and the liquid will drain into the empty bottle. Congratulations! You’ve created a tornado.

7. Repeat steps 5-6. Why doesn’t the water drain into the lower bottle when you flip them? How does your tornado in a bottle compare to a real tornado?

Science Behind it!

A tornado forms when air spins very fast during a storm—this is called a vortex. Tornadoes form when warm air mixes with cool air, causing the air masses to roll over each other. Rising warm air from the ground can cause the rolling air to tilt and touch the ground, creating a tornado.

When you flip your bottle upside down, the water doesn’t spill into the empty bottle. This is because water molecules are attracted to each other and create surface tension across the small hole in the washer—smaller surfaces of water have stronger surface tension. When you spin the water in the bottle, you are forcing the water to the sides and away from the center—this is called centrifugal force. This creates an empty column of air in the center of the water, which breaks the surface tension and allows the water to flow through the hole in the washer. This continues until the water drains due to surface tension as well as the fact that water is heavier than air!

Your tornado is very similar to a real one because it creates a vortex, but it is different because it is much smaller and made of water instead of air!