Changes

==Description==

==Description==

In [[optics]], a '''ray''' is an [[idealized]] narrow beam of [[light]]. Rays are used to [[model]] the propagation of light through an optical [[system]], by dividing the real light field up into discrete rays that can be [[computationally]] propagated through the system by the [[techniques]] of ray tracing. This allows even very [[complex]] [[optical]] [[systems]] to be [[analyzed]] [[mathematically]] or [[simulated]] by computer. Ray tracing uses approximate solutions to [http://en.wikipedia.org/wiki/Maxwell%27s_equations Maxwell's equations] that are valid as long as the [http://en.wikipedia.org/wiki/Light_wave light waves] propagate through and around objects whose [[dimensions]] are much greater than the light's wavelength. Ray [[theory]] does not describe [[phenomena]] such as [[interference]] and [[diffraction]], which require wave theory (involving the [[phase]] of the [[wave]]).[http://en.wikipedia.org/wiki/Ray_(optics)]

In [[optics]], a '''ray''' is an [[idealized]] narrow beam of [[light]]. Rays are used to [[model]] the propagation of light through an optical [[system]], by dividing the real light field up into discrete rays that can be [[computationally]] propagated through the system by the [[techniques]] of ray tracing. This allows even very [[complex]] [[optical]] [[systems]] to be [[analyzed]] [[mathematically]] or [[simulated]] by computer. Ray tracing uses approximate solutions to [http://en.wikipedia.org/wiki/Maxwell%27s_equations Maxwell's equations] that are valid as long as the [http://en.wikipedia.org/wiki/Light_wave light waves] propagate through and around objects whose [[dimensions]] are much greater than the light's wavelength. Ray [[theory]] does not describe [[phenomena]] such as [[interference]] and [[diffraction]], which require wave theory (involving the [[phase]] of the [[wave]]).[http://en.wikipedia.org/wiki/Ray_(optics)]

[[Category: Physics]]

[[Category: Physics]]