Summer is the perfect time to learn about turbulent weather. During the next stormy day, when getting outside is impossible, be ready with this fun activity that is sure to intrigue.
The materials you’ll need:
- two 2-liter soda bottles; smaller children will enjoy using 10 or 12 oz. soda bottles
- a flat metal washer – one that’s the same size as the mouth of the bottles
- duct tape
- optional: food color, glitter; silicone caulk (water proofing)
A few notes about the materials:
First, this list will make one tornado tube. You can increase the fun by allowing each child to build their own.
Secondly, there is a little plastic connector that you can purchase through an educational supply store that makes the process a little easier but this old school method works wonderfully and children enjoy and learn through the building process.
Third – a sort of disclaimer – plan on these leaking a little. You can increase your chances of eliminating the leak by using the silicone caulk first to seal the bottles together, then wrapping tightly with duct tape. Using the smaller bottles will help too. If you choose to purchase a tornado connector, there will be no leakage.
How to build:
- Fill one of the bottles half-way with water. (If you like, add a little food coloring and/or glitter).
- Dry the mouth of the bottle well and place the washer over the mouth of the bottle.
- Place the second bottle (empty) upside down, on top of the washer.
- Tape the bottles together with the duct tape – don’t skimp on this – you want the connection between the two bottles to be very secure to prevent leakage.
To make your tornado:
- Turn the bottles upside down. With one hand on the top bottle and the other on the bottom, move the top bottle in a small circle several times.
- Set the bottles down and watch the tornado vortex form and repeat over and over again!!
The Science behind this:
Moving the top bottle around in circles causes the water inside to start circling. It then becomes a self-sustaining process which continues until the top bottle is emptied. If you don’t move the bottle around in circles, the water won’t form a vortex and as a result it won’t empty into the bottom bottle. The water would remain in the top bottle due to the air pressure in the bottom bottle which “pushes” up on the water. But when the water forms a vortex, air is allowed to enter the top bottle through the empty “hole” created by the center of the vortex. This allows the water to easily fall into the bottom bottle.
The tornado tube is similar to a real-life tornado. A real-life tornado forms when air in the atmosphere begins to rotate. This rotation is begun when warm and cold air streams encounter each other in the atmosphere, and due to the difference in densities of these air streams they can combine in such a way that the air rotates. It is this rotation which initiates a tornado.
Enjoy!
