William Lawrence Bragg (1890-1971), British physicist. Bragg, the son of William Henry Bragg, was born in Australia. While a research student at Cambridge University he worked on the diffraction of X-rays by crystals (1912) and developed Bragg's Law concerning this diffraction. He discussed this work with his father, who went on to develop the X-ray spectrometer. In 1915, they shared the Nobel Prize in Physics for this work. From 1953, Bragg worked at the Royal Institution, London, starting the annual public lectures for schoolchildren.