Considered a grade school throwback for us parents, there’s a reason why the “tornado in a bottle” activity is mainstay favorite. It’s easy to put together, mesmerizing for all ages, and a perfect example of centripetal force in a vortex…the perfect storm for scientific discovery!
What is a tornado?
A real tornado, however, is considered the most violent of all atmospheric storms. It is a rotating column of air formed beneath a large thunderstorm system. Tornadoes are hard to spot because wind is, after all, invisible. Once the funnel begins to form, dust, debris, and water droplets make a tornado very distinct.
Facts about tornadoes:
- Most tornadoes have between a 73-112 mph wind speed and typically only travel a few miles before they exhaust themselves.
- The highest rate of tornadoes in the world occur in the United States’ “Tornado Alley”, which includes Texas, Oklahoma, Kansas, South Dakota, Iowa, Illinois, Missouri, Nebraska, Colorado, North Dakota, and Minnesota.
- Funnels can grow to 660 feet wide.
- The average warning time for a tornado is 13 minutes, and can often be identified by a greenish-sky, large hail, and a roar sounding like a freight train.
- About 1,200 tornadoes hit the United States yearly
- Most tornadoes occur between 4-9 p.m.
To appreciate these incredible weather occurrences by making your own tornado at home, grab:
2 empty, clear soft drink or water bottles
A pitcher of water
A “vortex connector”, or a metal washer and duct tape
First, take off the tops of your liter bottles and cut the plastic ring that is left around the neck of the bottle.
The “vortex connector” is the most crucial part in this exercise. This piece of plastic can be purchased online or at a teacher supply store. If you’d prefer, use a metal washer from the hardware store, and place it on top of one of the bottles. As shown, the vortex connector and washer both do the job of narrowing the water as it transfers from bottle to bottle.
Fill one of the plastic bottles three quarters full. The addition of glitter provides a great visual representation of a tornado’s water droplets and debris.
Lastly, screw on the vortex connector to the bottom bottle, and connect the top bottle. If you are using a washer, get a second pair of hands to help you steady the second bottle as you use duct tape to secure the bottles together.
Once all is secure and not leaking (this might take a few turns up and down), whip your bottom bottle up and quickly rotate the top in clockwise motion.
The science behind it
Spinning the bottle in this circular motion creates a water vortex. The centripetal force, or the inward force directing the water toward the center of its circular path, is the same principle of how tornadoes for during a storm. Gravity is what pulls the water down the hole.
Discuss the importance of severe weather safety!
Mother Nature can be quite powerful, so the sooner children learn to appreciate her, the better. Perhaps take this opportunity to talk about your family’s plan for when severe weather strikes. Older kids might like to map out an action plan for their families. The little ones can help put together a preparedness kit. A plan and kit help make kids feel ahead of the storm, which might empower them to keep a cool head if things get severe.
Sources: nationalgeographic.com, nssl.noaa.gov, sciencekids.co.nz