Poynting energy flow is considered to be the energy flow of electromagnetic waves, but the author found that such conclusions are not accurate enough. The author once proposed the mutual energy theorem. After careful study, the mutual energy theorem is actually the law of energy conservation, including all energy exchange. If the mutual energy represents all the energy, the self energy flow, that is, the energy flow corresponding to the Poynting vector, should not transfer energy to space. However, the calculation of the antenna radiates active power. In this way, the self energy flow also radiates energy, so the mutual energy flow + self energy flow is more than the total energy flow should be. When studying the transformer, the author notes that a current element can be calculated according to both inductance and antenna. If it is calculated according to the inductance, it produces reactive work, and if it is calculated according to the antenna, it produces active work, which is contradictory. It is found that the problem lies in the definition of magnetic field. At present, the definition of magnetic field in classical electromagnetic theory only takes into account the retarded effect of magnetic vector potential, but does not take into account the retarded effect of magnetic field itself. In other words, the current electromagnetic theory is the retarded potential theory, while Poynting’s theorem and mutual energy flow theorem all need a retarded field theory. The authors propose a retarded magnetic field. This magnetic field and electric field maintain a phase difference of 90 degrees. Unlike the classical electromagnetic theory, the magnetic field and electric field in the distance of the antenna maintain the same phase. According to the definition of the new magnetic field and the electromagnetic mutual energy theory proposed by the author, the author finds that the two components of the mutual energy flow between the primary coil and the secondary coil of the transformer and the two components of the mutual energy flow between the transmitting antenna and the receiving antenna are very close to the description of the wave of particles in John Cramer’s interpretation of quantum mechanics. Therefore, the author believes that electromagnetic mutual energy flow is photon, and other particles are also composed of mutual energy flow. The theory of electromagnetic mutual energy can be regarded as the concrete realization of the transactional interpretation of quantum mechanics.

maxwell equation, reciprocity theorem, conservation of energy, poynting theorem, energy flow, transformer, primary coil, secondary coil, transmitting antenna, receiving antenna, retarded wave, retarded potential, advanced wave, advanced potential, absorber, radiator, emitter, photons, quantum, electromagnetic wave, electromagnetic field, transactional interpretation