Levitate a Soda Can

Did you know that Bernoulli’s principle is a statement of conservation of energy? The sum of kinetic and potential energy is constant in every closed system. In fluid dynamics, potential energy is an expression of the pressure within a volume of liquid or gas. When a fluid moves faster (its kinetic energy increases), pressure (potential energy) must decrease to compensate.
Image credit: University of Oregon
This coupling of behaviors creates fun scientific results! We’ve explained before how to levitate a beach ball with a leaf blower. Today, we’re scaling Bernoulli’s principle down to tabletop size for a super-doable DIY experiment. All you need is an empty soda can and a mug big enough to contain it.
Place the can inside the mug and blow air into the gap between the two containers. Your breath moves faster than the surrounding air, so it creates an area of low pressure around the sides of the can. Stagnant air trapped underneath the can expands to fill the partial vacuum, pushing the can upwards. With a little practice, you’ll be able to jump the can from one mug to another!
Written By: Caela Barry