Demonstrate Bernoulli’s Principle in one breath.With a simple science secret you can amaze your students and friends by blowing up your Windbag in one breath. If you don’t believe it, try this amazing science activity. Windbags are so light and strong that even the smallest scientist can demonstrate the amazing properties of air! Use this air-mazing experience to learn about the properties of air molecules and how they move. It’s a sure-fire way to engage your students and teach them how mind-boggling air really is when it’s moving!