Comment on 'An investigation of nonlinear transmission lines and shock waves'

A recent paper by Freeman and Karbowiak (see ibid., vol.10, p.633 (1977)) analyses shock wave structure in waves propagating along a periodic nonlinear LC ladder. They conclude: 'The energy paradox, first noted by Lord Rayleigh in 1910, has therefore been resolved'. It is believed that energy dissipation in shock waves, whether electrical or not, has long been understood. This letter does not attempt to discuss that in detail, but only points to some earlier publications in the field.