I understand that a stationary charge has an electric field by the equation: E = kq1q2/r^2 When the charge starts to move, it has an electric field and a magnetic field: B = ui/(2pi)r where i is the current and u the permeability of free space. What I don't understand is the cause of electromagnetic waves. More specifically, how does a changing magnetic field cause a change in electric field, and a changing electric field cause a change in the magnetic field. I don't understand how. Can someone show it to me using the eqations.