The publication is indicating that there is a fundamental coincidence existing between the dynamics being inherent to acoustic and electromagnetic fields. This entails that the wave propagation speed in both media is related to an identical physical background. The particles in the electromagnetic field are vibrating at a celerity being lower than the light propagation speed c. Energy conservation considerations indicate that both the acoustic and electromagnetic fields need to be extended by a rotational field. The energy inherent to this rotational field is related to the thermodynamic ¿inner energy¿ of the medium. The validation of the developed theoretical fundamentals is based on the so-called ¿black body radiation specträ. Thereby also an explanation as to the non-existence of the ¿ultraviolet catastrophe¿ will be given. The mass of the electromagnetic particle, being at 2,04¿10-40 kg, will be derived from a thermodynamic approach.