11.50 Topology: Classifying Surfaces Geometrically
Think of a surface. You can construct it with, at most. two special surfaces; take several copies, distort them, connect them.
12.15 am Instrumentation: Position Transducers and Counting
The Moire fringes you see when lace curtains move across each other are actually used to measure movement with great accuracy. The inventor of the Moire fringe counter, the late Dr L. Sayce. illustrates the method.