The discussion centers on the phase relationship between the electric (E) and magnetic (B) components of electromagnetic (EM) waves. Participants clarify that in plane waves, E and B fields oscillate in phase, meaning they reach their maximum values simultaneously, while their directions are perpendicular. However, in certain conditions, such as near the source of a spherical wave, E and B can be 90 degrees out of phase. This discrepancy is often misunderstood, leading to confusion in various forums and textbooks. Ultimately, the consensus emphasizes that for monochromatic plane waves in free space, E and B fields are indeed in phase, supported by Maxwell's equations.