Tornado in a Bottle - Tornado Tube You'll amaze your dinner guests with this cool trick. email to friend
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1. Fill the soda bottle to the top with water. If you do not have access to a sink nearby or you don't want to move the dinner party to the kitchen, use a large pitcher to fill the bottle.
2. Here's the challenge: How long will it take to empty all of the water in the bottle into the pitcher on the table? Record your prediction on a piece of paper.
3. Without squeezing the sides of the bottle, time how long it takes to empty all of the water. You might want to repeat this several times to validate your time.
4. Fill the bottle to the top with water just as you did before. However, this time swirl the water by moving the bottle in a clockwise or counter-clockwise motion while the water is pouring out. Keep swirling the water until you see the formation of what looks to be a tornado! The water begins to swirl in shape of a vortex and flows out of the bottle very quickly. To everyone's amazement, you are the Quick-Pour Soda Bottle Master.

How does it work?

Swirling the water in the bottle while pouring it out causes the formation of a vortex. The vortex looks like a tornado in the bottle. The formation of the vortex makes it easier for air to come into the bottle and allows the water to pour out faster. If you look carefully, you will be able to see the hole in the middle of the vortex that allows the air to come up inside the bottle. If you do not swirl the water and just allow it to flow out on its own, then the air and water have to essentially take turns passing through the mouth of the bottle.

Additional Info

The "Tornado Tube" is a very popular science toy that connects two soda bottles, one filled with water, the other filled with air. Simply swirl the liquid in the bottles and in seconds a twisting, turning, spiraling vortex appears.

Twist of Color - Try adding 2 ounces of colored lamp oil to the water. Lamp oil is available at most department stores were oil lamps are sold. The oil will float on the surface of the water since oil is less dense than water. When the oil and water swirl together, the less dense oil travels down the vortex first and creates a "colored tornado" effect.