UBC Mathematics Department
This talk will present an explanation of the following experiment: Take a tennis racket and mark its faces so that they can be distinguished. Call one rough and the other smooth. Hold the racket horizontally so that the smooth face is up. Toss the racket attempting to make it rotate about the intermediate principal axis (which is perpendicular to the handle in the face of the racket passing through its center of mass). After one rotation catch the racket by its handle. The rough face will almost always be up! Thus the racket has made a near half twist around its handle.