Hi Can anyone tell me the differences between normal light (waves of the EM spectrum, i.e. visible light, gamma ray, radio waves, etc.) and magnetic field? I know that both, light and magnetic fields, consist of photons and i know that magnetic and electric fields are perpendicular to each other. And I know that Maxwell's equations describe both, normal light and em-fields, too. But what i can't understand is why one time photons are perceived as light and always go straight out (we are ignoring gravity and there are no obstacles in the way which may cause diffraction and refraction effects, light means here full em-spectrum) and another time photons behave like a magnetic field and go from north pole to south pole and transmit magnetic and electrostatic forces. And I've got another little question: How does the spin of the photon affect a magnetic field? For normal light, one can interpret the spin as the polarization AFAIK.