Making a tornado in a bottle is easy, and you can easily entertain yourself and kids with this trick. All you need is a tall bottle, preferably one with a neck. Water bottles, beer bottles, and also soda bottles work. Fill the bottle ¾ full. If you’re doing this as a science experiment, add a squirt of dish soap and some glitter or food coloring to make the vortex easier to see. Be sure to seal the bottle tightly before moving the bottle in a circular motion. The faster you go, the stronger the centripetal forces that make the tornado. Stop the circular motion and watch the swirl.