Answering the question What is the relation between electromagnetic wave and photon? I wrote
The EM radiation of an antenna is measurable and it was found out that the nearfield of an antenna has two components, an electric field component and a magnetic field component. This two components get converted in each other, the induce each other.
@HolgerFiedler If the fields are a quarter-turn out of phase, the average value for the Poynting vector is zero and the wave is not transmitting any energy.
How does the energy transfer in the near field of an antenna work? And how does a standing EM wave inside a box work?