They bounce to a higher level than they are dropped from, seeming to defy conservation of energy. It shows that energy can be stored in many ways besides potential and kinetic energy. They are made from a rubberized material that allows them to release the power of natural tension after they are turned inside out. This natural tension is the energy that makes it soar, dropping it is the "activation" energy. This is a fun activity for any Physics or Chemistry Class. Your glitter poppin hoppers will be chosen randomly from the assortment of 6, although if you buy more that one, we will send different colors.