Bragg’s law is a diffraction effect expressed mathematically as nl=2d sinq in 1913 to describe the angles of incidence associated with X-ray reflections that occurs when parallel rays encounter crystal structures.
Bragg’s law is known after Sir Lawrence Bragg (1890-1971), who jointly with his father Sri William Bragg (1862-1942) won the Nobel Prize in Physics in 1915 for their work on the elucidation of crystal structures using X-ray diffraction.
The use of the term ‘reflection’ for a diffracted beam comes from the optical analog. In an optical mirror the angle of reflection is not restricted. Lawrence realized the principle by which X-rays can be used to reveal the arrangement of atoms in a crystal and he has spent his life using his technique ox X-ray crystallography to study the architecture of matter.
Bragg’s law and the study of diffraction have since been applied to many other theoretical and practical fields of study beyond X-rays and crystals.
Bragg’s Law by Lawrence Bragg
