Turn light into motion! When sun or bright light shines on the solar cells, they generate power to spin the propeller. This creates a forward force that enables the plane to rotate around the base. Challenge your students with a thought experiment: Think of at least five ways you could modify the variables to make the plane move faster. Wonderful addition to the science classroom. Great Gift! No batteries needed. 38 cm (15") dia., 19 cm (7.5") ht