Propagation constant a conductor. The skin effect causes R along the conductor to be approximately dependent on frequency according to Losses in the dielectric depend on the loss tangent (tan "δ") of the material divided by the wavelength of the signal. Thus they are directly proportional to the frequency. The attenuation constant for a particular propagation mode in an optical fiber is the real part of the axial propagation constant. In electromagnetic theory, the phase constant, also called phase change constant, parameter or coefficient is the imaginary component of the propagation constant for a plane wave. It represents the change in phase
A Brief History of Time chapter. Some theories say that light acts like particles even though it really is made of waves; one theory that says this is Planck's quantum hypothesis. A different theory also says that light waves also act like particles; a theory that says this is Heisenberg's uncertainty principle. Light waves have "crests" and "troughs". The highest point of a wave is the crest, and the lowest part of the wave is a trough. Sometimes more than one of these waves can interfere with each other - the crests and the troughs line up. This is called "light interference". When light waves