This week my kids finally got to speak to my parents in Chennai. The monsoon was on hold giving a much-needed respite from the heavy rain. They have electricity and the phones have started working. I realized that we’d all been talking a lot about the cyclone and flooding after I heard D shouting, “Wait, my boat is coming.” She and her friends were busy rescuing their pets (stuffed animals) from the floods!
The kids had heard a lot about the effects of the cyclone and seen a lot of the pictures. They were very curious about why there was so much rain. That evening my husband decided to do the cyclone in a bottle experiment with them. They are really too young (6 and 4) to understand all the physics behind it but the experiment gave them something concrete to connect the idea of fast moving, swirling air carrying lots and lots of water vapor. It was quite simple and easy because we used materials lying around our home.
You will need:
Two clear plastic bottles
Remove the label from the bottle so you can see the vortex forming.
Pour water in one of the bottles. Add food coloring to the water.
Tape the mouth of the two bottles together with duct tape. Just make sure the seal is airtight and the water doesn’t leak out.
Flip the bottles so that the water flows from the bottle on top into the empty bottle. Swirl the bottle on top, to create a circular motion. The rotating movement will create a vortex as the water rushes down.
In this experiment, we see the water creating a vortex. In cyclones, it is the air that creates a vortex because of the differences in air pressure created on the surface of the ocean.