Refraction
From ExoDictionary
Refraction
The process in which the direction of energy propagation is changed as the result of a change in density within the propagating medium, or as the energy passes through the interface representing a density discontinuity between two media. In the first instance the rays undergo a smooth bending over a finite distance. In the second case the index of refraction changes through an interfacial layer that is thin compared to the wavelength of the radiation; thus, the refraction is abrupt, essentially discontinuous. See atmospheric refraction. Compare reflection, diffraction, scattering.
References
This article is based on NASA's Dictionary of Technical Terms for Aerospace Use
