Aiming at the historical dilemma that the transverse wave model in classical electromagnetic theory requires the medium to have shear rigidity, this paper proposes a hypothesis on the nature of light based on the framework of classical fluid dynamics: the physical entity of light is a longitudinal-transverse composite wave in the space-filling medium (aether). The wave takes longitudinal compression-rarefaction vibration as the main body of energy propagation, corresponding to the dynamic pressure component; the periodic propagation of longitudinal compression and rarefaction segments induces symmetric alternating static pressure components in all lateral directions perpendicular to the propagation direction, presenting an overall axisymmetric distribution. This mechanism does not require the medium to have shear modulus, and can be carried by fluid media, which fundamentally resolves the contradiction between "solid aether" and "undamped celestial motion". This paper further proposes the transverse pressure squeezing redistribution mechanism of polarization: the polarizing structure achieves polarization not by absorbing components in a specific direction, but by constraining the static pressure energy in the perpendicular direction to transfer laterally and redistribute to the direction parallel to the slit. The process is approximately elastic with no significant total energy dissipation. Based on this hypothesis, two complementary verification schemes are designed: a physical ultrasonic polarization experiment and molecular dynamics numerical simulation, with key points of systematic error control and verification criteria clarified, providing a falsifiable experimental path for the model.
Jingyuan Guo (Fri,) studied this question.