If a piece of conducting material has a temperature difference between its two ends, an electromotive force is observed between the ends with the hotter end being positive and the other negative. This is the Seebeck effect. The emf is dependent only on the temperature difference and the type of conductor material. Current physics only mentions the emf of the Seebeck effect, but has ignored another significant fact about the Seebeck effect. Besides the observed emf, the Seebeck effect causes a radiation energy current flow within the conductor from the hotter end towards the cooler end. The operation of a thermocouple electric cell relies on the Seebeck effect. An analysis the operation of such a cell shows that energy transmission by current-carrying conductors has nothing to do with the magnetic fields surrounding the conductor; the actual physical mechanism of energytransmission is by photon energy current within the body of the conductor.