The discussion explores whether polarization bound charge density can be represented in vacuum using a wave function, noting that vacuum lacks bound charges. It focuses on the behavior of electromagnetic waves, particularly the electric field (E), magnetic field (B), and electric displacement field (D) in vacuum. The participants debate the existence of complex exponential solutions in the wave equations for E and B, questioning if D can accommodate such solutions. The conversation also distinguishes between disruptive and non-disruptive polarization, with an emphasis on linear harmonic polarization. Ultimately, the topic remains theoretical, with participants seeking clarity on definitions and the implications of these concepts.