William Lawrence Bragg. Portrait of Sir William Lawrence Bragg (1890-1971), British physicist and pioneer of X-ray crystallography. Following von Laue's discovery of X-ray diffraction, Bragg and his father, William Henry Bragg, investigated the reflection of X-rays by crystals. W.L. Bragg developed the Bragg Law" which relates the angle of diffraction, the X-ray wavelength and spacing of the crystal planes. They refined the technique and used it to discover the crystal structures of a number of materials. They published their work in X-rays and Crystal Structure in 1915. W.L.Bragg shared the 1915 Nobel Prize for physics with his father; aged 25 he was the youngest-ever winner."