According to the big bang theory, radiation was created along with matter. The radiation is assumed to have been in equilibrium with matter and therefore exhibited the spectrum of a very hot black body. As the universe supposedly expanded, the wavelengths of the radiation were stretched so that the radiation is now observed in the microwave region of the electromagnetic spectrum.

The rest of the radiation that is currently observed has been created by a number of means such as the heating of matter or by nuclear and chemical reactions.

The conversion of mechanical work, electricity or chemical reactions into radiation is accepted as fact but the processes are not described further than to say atoms absorb and emit energy.

FET describes exactly how the first radiation was created by the accumulation of continuum energy by nuclear particles and how this was emitted in the form of photons with specific energies, shape and size all consistent with observations. It also describes how atoms absorb photons as kinetic energy that makes them move and in condensed matter breaks them into packets with an energy spread of black body radiation.

FET shows how photons are emitted from the surfaces of the solid cores of atoms and as these have a surface speed equal to c it explains why photons move at such a fast speed.