The change of direction suffered by wavefront as it passes obliquely from one medium to another in which its speed of propagation is altered. The phenomenon occurs with all types of waves, but is most familiar with light waves. In optics the direction is changed in accordance with Snell’s law, i.e. n1sini=n2sinr, where i and r are the angles made by the incident beam of radiation and the refracted beam to the normal (an imaginary line perpendicular to the interface between the two media); n1 and n2 are the refractive indices of the two media. This law is also known as one of the laws of refraction. The other law of refraction is that the incident ray, the refracted ray, and the normal at the point of incidence lie in the same plane. The change of direction results from a change in the speed of propagation and the consequent change in wavelength.
Refraction.
The bending of a ray which travels obliquely from one medium to another, at the interface separating the two; it is caused by the contrast in velocities with which the ray travels in the two media, and described by Snell’s law. See also refraction survey.
- Halley's Comet
- Halley’s Comet
- Halley’s comet
- Halley’s method
- Hall, Granville Stanley (1846–1924)
- Hallian
- Hall, James (1761–1832)
- Hall, James (1811–98)
- Hall mobility(symbol: μH)
- halloysite
- Hall, Peter Gavin (1951–2016)
- Hall probe
- hallucination
- hallucinogen
- hallux
- Hall–Heroult cell
- Hall–Héroult smelting process
- Hall’s Theorem
- Halmos, Paul Richard (1916–2006)
- halmyrolysis
- halo
- haloalkanes
- halo, atmospheric
- halocarbons
- haloclasty