The story
Bragg diffraction was first proposed by Lawrence Bragg and his father William Henry Bragg in 1913.
Etymology from Wiktionary, CC BY-SA 4.0.
Bragg's law
Today it means: A law that equates the angle (θ) between the incident and scattered ray to the spacing (d) between the crystal planes and the wavelength (λ) of the radiation - nλ=2d sin (θ), Full definition →