Dispersion Relation
In physics and electrical engineering, dispersion relations describe the interrelations of wave properties like wavelength, frequency, velocities – including phase velocity and group velocity – and refractive index. Besides geometry- and material-dependent dispersion relations, there are the overarching Kramers–Kronig relations that connect the frequency dependences of propagation and attenuation.
Dispersion may be caused either by geometric boundary conditions (waveguides, shallow water) or by interaction of the waves with the transmitting medium. Elementary particles, considered as matter waves, have a nontrivial dispersion relation even in the absence of geometric constraints and other media.
In the presence of dispersion, wave velocity is no longer uniquely defined, giving rise to the distinction of phase velocity and group velocity.
Read more about Dispersion Relation: Dispersion, Plane Waves in Vacuum, Frequency Versus Wavenumber, History
Famous quotes containing the words dispersion and/or relation:
“The slogan offers a counterweight to the general dispersion of thought by holding it fast to a single, utterly succinct and unforgettable expression, one which usually inspires men to immediate action. It abolishes reflection: the slogan does not argue, it asserts and commands.”
—Johan Huizinga (1872–1945)
“Science is the language of the temporal world; love is that of the spiritual world. Man, indeed, describes more than he explains; while the angelic spirit sees and understands. Science saddens man; love enraptures the angel; science is still seeking, love has found. Man judges of nature in relation to itself; the angelic spirit judges of it in relation to heaven. In short to the spirits everything speaks.”
—Honoré De Balzac (1799–1850)