A communication on electrical charge relaxation in metals

The correction of an erroneous textbook derivation on electrical charge relaxation in conductors is discussed. The actual decay in a good conductor is damped oscillatory instead of the simple exponential decay that is often claimed, while short wavelength disturbances spread through the medium much like particles of mass m=ℏωp/〈v2〉, where ωp is the plasmon frequency and 〈v2〉 is the mean-square electron velocity.