1. Damping“ and ”dissipation“ usually refer only to conversion of mechanical energy into heat. These terms are generally not applied to energy losses that occur as a result of reflection at discontinuities (see Chapter V), which process is usually described as ”attenuation“.
2. Meyer, 0. E.: J. reine u. angewandte Math. 78 (1874) 130–135.
3. Boltzmann, L.: Ann. Physik, Erg. Bd. 7 (1876) 624–654.
4. For molecular vibrations, these times obviously are very short, but the times r corresponding to changes in molecular structure may be very long. Relaxation times may be of the order of hours and days, but also of the order of nanoseconds.
5. Tamm, K., Weis, O.: Acustica 9 (1959) 275.