X-ray crystallography (William and Lawrence Bragg)

X-ray crystallography is a method of determining the atomic structure of crystals using x-rays. It was discovered and experimented with by father and son, Sir William Henry and Sir William Lawrence Bragg.

William Henry Bragg was appointed to the professorship of mathematics and experimental physics at the University of Adelaide in 1885, at the age of 23. At the time mathematics, not physics, was his area of expertise, although he would later become one of the most eminent physicists of all time. William Lawrence (known as Lawrence) was born in Adelaide in 1890. In 1896 William began experimenting with x-rays. When six-year-old Lawrence fell and broke his elbow, William photographed it with his crude x-ray equipment. From 1904 William concentrated on the study of x-rays and contended that x-rays were streams of neutral particles rather than electro-magnetic waves, which was the accepted theory at the time. In 1912, the German physicist Max von Laue proved that x-rays were waves of light with a very short wavelength by diffracting them through crystals. Lawrence had just received his degree from Cambridge University and, following up on von Laue's work, he began his own experiments with x-rays and crystals. He found that when x-rays passed through a crystal they created a diffraction pattern that showed the atomic structure of the crystal. He formulated Bragg's law, which can be used to determine the arrangement of atoms inside the crystals. Meanwhile, William had perfected a piece of equipment called an x-ray spectrometer with which father and son could conduct their x-ray crystallography experiments.

William and Lawrence Bragg were jointly awarded the Nobel Prize for physics in 1915. Lawrence was 25, the youngest ever recipient of the prize.