A simple question. I though Maxwell said that : 1. The change of electric field generates magnetic field. 2. The change of Magnetic field generates Electric field. So, simple algorithm tells me there shall be a 90 degree of phase difference between the peaks of E field and B field,because the change amount of a sinuous wave is zero at its high and amximum at its zero. I am seeing a chart and equation showing that there is no phase difference between E field and B field. Why is that?