Tornado in a bottle

Monday, May 10th, 2010



We are talking a lot about water these days in school, what we use water
for, water safety, and now we are trying some water experiments. Today we got two empty drinks bottles and a blue bottle joiner (which joins 2 bottles together, but leaves a hole in the middle for the air/water to move from one bottle to another).

Teacher filled a 2litre bottle with water (the tornado is easier to see if you put a little food colouring in the water). We turned the bottles upside down, being careful not to knock the bottles, so that the full bottle was on top. Next the top bottle was swirled. This caused to water in the top bottle to spin near the edge of the bottle, leaving a space in the very middle of the bottle for the air to swirl up from below. This air, which had swirled up from the bottom bottle, now helped to push the remaining water into the bottom bottle. We could see the tornado really clearly. This tornado that we made works the very same way as real tornados do. We thought of the story "The wizard of Oz" and the way Dorothy's house was able to fly in the tornado.