 Each of these terms in the sum is known as a harmonic, and the \(\tau\)th harmonic is given in terms of the time, \(t\), an amplitude, \(C_{\tau}\), and a frequency, \(\omega_{\tau}\), which is an integer multiple of the fundamental frequency, \(\omega_{\tau} = \tau \omega\) (these multiples of the fundamental frequency are referred to as the “overtones”). According to classical electrodynamics, the frequencies of the radiation emitted by this atom should just be given by the frequencies in the harmonics of the motion: \(\omega,\) \(2\omega,\) \(3\omega,\) etc.; hence the spectrum of this classical system should be a series of discrete evenly spaced lines.