Turning a Sphere Inside Out

Visualizes the topological theorem of turning a sphere inside out using models and computer animation. Interviews Steve Smale, who originated the theorem; Charles Pugh, who designed and built the models; and Nelson Max who worked out the computer animation. Discusses the work of Bernard Morin, a blind mathematician who invented a homotopy that visualized the theorem, and explains the steps in the process using chicken wire models. Shows, in computer animation, intermittent and continuous surfaced spheres passing through themselves and twisting to turn inside out.