Physics Hub on Instagram: "This experiment demonstrates electrostatic propulsion using two lightweight metal blades mounted on a central shaft. When connected to a high-voltage source (such as a Tesla coil), strong electric fields build up at the sharp ends of the blades. Because electric charge concentrates at sharp points, the air around the tips gets ionized. The ionized air particles are rapidly accelerated away from the blade tips, creating a small reactive force in the opposite direction.