Lawrence Bragg discusses and demonstrates the competing theories of light.
Lawrence Bragg begins by outlining the two contesting theories of light held in the eighteenth century: the particles theory and the wave theory. This he follows with a description and demonstration of Thomas Young’s famous pinhole experiment; an experiment that validated the wave theory. Bragg then turns to diffraction, showing its effects with the use of Young’s original wave trough of 1800 and explaining interference fringes through a series of fascinating demonstrations.
Crown copyright information is reproduced with the permission of the Controller of HMSO and the Queen’s Printer for Scotland.