What exactly waves in a light wave?

Good question. The things that wave are the electric and magnetic fields. Both are real physical fields that can be directly detected with a measuring device. read more

The thing that is waving, is the strength of an electric field, and the strength of a magnetic field that is perpendicular to the electric field. read more

Light waves are exactly a theoretical explanation of light radiation. Propagation of waves of electromagnetic fields is a good theory that works for low frequencies, but as Einstein showed (and was Nobel prized for) the photoelectric effect can only be explained if electromagnetic radiation is emitted as directed quanta of energy. read more

Best Answer: an electromagnetic field oscillates in a wave packet to give us the photon which is light. read more