How to Make a Tornado in a Bottle With Your Kids
Want to observe a tornado vortex without getting anywhere near a real tornado?
Make your own mini tornado!
In this article I’ll show you how to make a tornado in a bottle, using two bottles and duct tape. You and your kids will see how a tornado is formed by creating one yourselves. It’s easy!
Why Make a Tornado in a Bottle?
But how do they work? How does the sky start twisting around itself and become something so powerful and destructive?
Explore the science behind this terrifying and amazing weather phenomenon with your kids and create your own tornado in a bottle.
Tornadoes form quickly—without a lot of warning—when different temperatures and humidity meet. For example, when a cold front moving from the north hits warm humidity traveling from the south, a vortex will form as they connect.
Check out this video that explains how wind, clouds and pressure combine in nature to create tornadoes.
Learn how tornadoes occur before creating your own tornado in a bottle.
Although there is a distinct “tornado season” in spring and summer and the storms occur most frequently in “Tornado Alley” (an area of the central U.S.), tornadoes can happen anywhere in the world at any time of year.
You can learn more tornado facts here.
A tornado in a bottle is a fun experiment you can do with your kids for a science fair or just to create and explore this fascinating natural occurrence as a family.
Ready to make your own tornado in a bottle?
Before you start, sit down with your kids and have a tornado tête-à-tête. Talk about tornados.
Ask how long they think it will it take to empty all of the water in the bottle into the pitcher on the table. Record everyone’s prediction (including your own) on a piece of paper.
Here’s a quick summary of the tornado in a bottle experiment.
Remember, if you’re doing this as a science experiment for school, have your kids write down their hypotheses (what they think is going to happen) and take lots of notes throughout the process.
#1: Prep Your Experiment
The setup for this experiment is easy. Just gather your materials and set up your workspace.
You and your kids can do this experiment in the kitchen where you have a sink nearby, or outside near the garden hose. You can also fill a large pitcher with water and do this experiment anywhere: dining room table, craft or science room, etc.
Remove the labels from the soda bottles so you have a clear view of the inside, and you’re ready to get started.
#2: Test the Glug-Glug Method
You’ll want to keep a table of all of your results. Call this one the Glug-Glug method.
Fill a soda bottle to the top with water.
Without squeezing the sides of the bottle, turn it over. Time how long it takes to empty all of the water. You might want to repeat this several times to validate your results. Note: If you have more than one child, they can take turns timing and turning over the bottle.
Watch the Glug-Glug method and the Vortex method in action.
Be sure to use the same amount of water for each of the trials. Note: Empty the water into a tub or bowl so you can reuse the water.
Do the test 3 times, and write down the results each time. Average the results (add them up and divide by 3).
#3: Test the Vortex Method
Take a new sheet of paper for the results of this test. Call this one the Vortex method.
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 like a tornado! The water begins to swirl in the shape of a vortex and flows out of the bottle very quickly.
Time this method as you did before, and write down the results of the Vortex method. Taking turns, repeat the test several times, and again average the results.
Compare your results. Which method allows the water to exit the bottle more quickly? Why do you think so? This is another opportunity to talk tornados with your kids before moving on to the next step.
#4: Make a Tornado in a Bottle
Now that you’ve tested the Glug-Glug and Vortex methods, it’s time to create a tornado in a bottle.
Fill a one-liter bottle to the top with water.
Put a metal washer that fits flush (or as closely as possible) onto the mouth of the one-liter bottle.
Place another one-liter bottle on top of the water-filled bottle, so that the washer sits in place between the two.
Use duct tape and tape the two bottles and washer in place. Make sure that the connection is as sturdy as possible and that the duct tape does not allow any bending.
Turn the apparatus over so that the filled bottle is on top and swirl the water. The water will form a tornado and drain into the other bottle.
You and your kids can test different motions—clockwise vs. counterclockwise—and see if it times out differently.
Plus, this tornado in a bottle is one you never have to refill.
#5: Test it Further With Variations
Spice up your tornado in a bottle with these variations. Before you try my ideas, ask your kids if they have ideas of their own.
Twist of Color: Add 2 ounces of colored lamp oil to the water. Note: Lamp oil is available at most department stores where oil lamps are sold. The oil will float on the surface of the water because 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.
Bubbly Vortex: For a fizzy effect, add a squirt of dish soap to the water. As the twister drains from one bottle to the other, the top bottle will fill with soapy bubbles!
This is cool and shows that as the bottom bottle fills with water, the top bottle is filling with air.
Styrofoam Storm: Add some debris to your twister for a dramatic effect. You can use small items like confetti or glitter or even Monopoly houses and hotels, but our personal favorite is tiny Styrofoam balls.
The balls float but are sucked into the bottom bottle from the power of the spinning vortex. It’s really cool to look at!
This variation lends itself to lots of creativity. What items can you put into your vortex? What is the story behind it?
How Does it Work?
If you’ve ever seen a dust devil on a windy day or watched the water drain from the bathtub, you’ve seen a vortex.
A vortex is a type of motion that causes liquids and gases to travel in spirals around a centerline. A vortex is created when a rotating liquid falls through an opening. Gravity is the force that pulls the liquid into the hole and a continuous vortex develops.
If you swirl the water in the bottle while pouring it out, it causes a vortex to form. That 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.
Look carefully and you’ll be able to see the hole in the middle of the vortex that allows the air to come up inside the bottle. If you don’t 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, thus the glug-glug sound.
Some Final Thoughts…
While the tornado in a bottle is a fun experiment, it’s also an excellent learning experience. Discuss with your kids ways you can you take this experiment even further.
What happens when you narrow or open up the washer between the bottles? What other things can you do to alter the results? Test different openings and see what happens.
What do you think? What did you do to spice up your vortex? We want to see your tornado in a bottle. Please share your experiment and photos in the comments.
Steve Spangler is an author, teacher, toy designer, Emmy award-winning television personality and creator of a huge soda mess. His appearances on television demonstrate his passion for making learning fun. Other posts by Steve Spangler »