# Is there any optical phenomenon can't be explained without magnetic field?

Almost all optical phenomenon can be explained considering a fluctuating electric field. Is there any optical phenomenon which can't be explained without considering two fluctuating fields, electric and magnetic?

• what you mean by "fluctuating" ? and "optical" by definitions relates to light, which is both electric and magnetic fields together.
– TMS
Jul 28 '13 at 8:57
• well, lets think about Young's experiment. If you want to calculate the fringe width or other quantities, you will add two sine term representing the disturbance of electric field. You don't need to think about the magnetic field. Jul 28 '13 at 10:02

$$E_0e^{ikx}e^{-i\omega t} \hat E$$ Where $\hat E$ depends on the polarization. What we see or what we record in optics is Intensity, which is $|\Phi_{TOT}(x,t)|^2$
$$\nabla \times \vec E=- \frac{\partial \vec B} {\partial t}$$ $$\nabla \times \vec B=\mu_0 \vec J+\mu_0\epsilon_0 \frac {\partial \vec E} {\partial t}$$
So I am not completely sure what you mean by can't be explained without considering two fluctuating fields but whenever you have the electric field, you will have a magnetic field related by maxwells equations.