How to Make a Tornado in a Bottle

Co-authored by Jessie Antonellis-John

Last Updated: January 31, 2023 References

With water, dish soap, and a bit of spinning, you can make a tornado in a bottle! This can be a great way to learn how tornadoes work.^{[1]
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Research source} For a basic experiment, try making a tornado in a single bottle. If you want to get more advanced, try putting two bottles together. Read on to learn how to get started!

Part 1

Part 1 of 3:

Filling the Bottle(s)

1
Fill a plastic bottle with water. Leave two inches of air at the top of the bottle. The size of the bottle doesn't matter – but the bigger the bottle, the bigger the tornado. The bigger the tornado, the easier it will be to observe the effects on the water.^{[2]
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- If you are only making a one-bottle tornado, you can use a plastic water bottle or a clear glass canning jar.^{[3]
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  Research source} If you are making a larger two-bottle tornado, try using a pair of two-liter soda bottles.
- Try experimenting with more or less water. Record whether the amount of water has any effect on the size and speed of the tornado.
2
Add dish soap. Two squirts from a bottle of concentrated soap will do. You can also use oil, or anything hydrophobic (that repels water).^{[4]
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- Don't try to use other cleaning products like bleach or non-liquid soap. Do not use laundry detergent: it is designed to interact differently with water than dish soap.^{[5]
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- Try experimenting the amount of dish-washing soap, or the brand of dish-washing soap. See if a particular brand works better than another, or if more or less soap makes a difference.
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3
Add a pinch of glitter. This step is optional, but it may make it easier to see the tornado in action. Alternately, add food coloring for flair. If you're using a large bottle, try putting a few plastic Monopoly houses into the water to simulate the "houses" that are being picked up the tornado.^{[6]
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4
Seal the bottle. If you are making a one-bottle tornado, you just need to twist the cap and seal it shut. If you are making a two-bottle tornado, you'll need to find a watertight way to fix the openings so that they face one another. Try using superglue, caulk, duct tape, or a large rubber band.^{[7]
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Part 2

Part 2 of 3:

Making a One-Bottle Tornado

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Make sure that the bottle is sealed. The trick won't work well unless the container is completely airtight. Test the cap with your hand.
2
Spin the bottle. Hold it by the top or the bottom, and use your wrist to shake the water in a loose circular vortex. After a few seconds of spinning, you should see the water begin to swirl in the center. This is your "tornado." Ask questions:
- Why is it spinning?^{[8]
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- Is the tornado spinning clockwise or counterclockwise?
- How does the glitter interact with the tornado?
3
Experiment. Try spinning the bottle slower or faster. Try spinning it upside down. Observe whether changing the spin pattern has any effect on how the tornado looks.
4
Learn why the water is spinning. It is responding to "centripetal force" – an inward-facing force that pulls an object or liquid toward the center of its circular path.^{[9]
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Research source} In this case, the water is spinning around the "center" of the vortex, which happens to be the center of the bottle because the bottle defines the size of the "body of water."^{[10]
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Part 3

Part 3 of 3:

Making a Two-Bottle Tornado

1
Make sure that the two bottles are attached at the mouth. The connection should be airtight and watertight. Set the bottles upright so that the bottom of the full bottle is sitting on the ground or table, and the bottom of the empty bottle is sticking straight up into the air. Be sure to leave an inch or two of air at the top of the "full" bottle.
2
Flip the bottles upside-down. Think of it like the motion of flipping an hourglass. The bottom bottle should now be empty of water, and the top bottle should be full of water. Hold the bottles for support – the contraption will be top-heavy!
3
Watch the water trickle down. The air pressure in the now-top bottle is lower than the air pressure in the now-bottom bottle, so there should not be much water flowing between the mouths of the bottles.
4
Swirl the water-filled bottle in circles. If you gently spin the water-filled bottle on top, water should begin to pour again. This should create a vortex or "tornado" in the center of the water-filled bottle as the liquid flows from a space of low pressure to a space of high pressure.

Community Q&A

Question

How can I connect the two bottles without leakage?

Community Answer

You can seal it with a glue gun. If not, you can always use duct tape.
Question

What type of dishwasher soap do you use?

Community Answer

You use dish soap, not dishwasher soap. But you can use any kind of dish soap.
Question

Can you use oil instead of dish soap?

Community Answer

No. You cannot.