Galaxies on Instagram: "The Dzhanibekov Effect, also known as the tennis racket theorem, is a phenomenon in classical mechanics that occurs during the rotation of an object with three distinct momenta of inertia. When such an object, like a T-handle, wingnut or tennis racket, is tossed in the air with a spin around its intermediate axis, it unexpectedly flips its orientation. This surprising behaviour, most powerfully observed in microgravity, is due to the instability inherent in rotation aroun