An Etymological Dictionary of Astronomy and Astrophysics

A wave property of light which allows it to curl around obstacles whose size is about that of the wavelength of the light. As a → wavefront of light passes by an opaque edge or through an opening, secondary weaker wavefronts are generated, apparently originating at that edge. These secondary wavefronts will interfere with the primary wavefront as well as with each other to form a → diffraction pattern.

Related terms:
→ diffusion; → dispersion; → distribution; → scatter; → scattering.

Etymology (EN): From Fr. diffraction, from Mod.L. diffractionem, from L. diffrac-, stem of diffringere “break in pieces,” from → dis- “apart” + frangere “to break.”

Etymology (PE): Parâš “dispersion, scattering,” variant of pâš, pâšidan, → dispersion.