It is my understanding that a photon is absorbed when the photon's energy is sufficient to excite an electron into a higher energy state. So if I shine a light unto a light absorbing material, let's say a thin black metal, then why the surface never reaches a saturated state? I mean, if we keep the light pointing continuously on the black surface for years, the color never varies. To put it in another way. If the light excites every available electron on that surface, what happens when there are no more electrons to excite? Shouldn't the light be then 100% reflected or the light simply goes through the material like a glass? Moreover, if photons do not stay at an excited energy level for more than a nanosecond, where does all that photon energy go? Is it lost as kinetic energy? Or radiated as another form of energy? This makes me think that the current understanding of photon interaction with atoms is partially wrong. The frequency (energy level) of the photons DOES have a direct relation to the electron's energy transition. This electron "exciting" and "emission" cannot be true. I am thinking that the behavior of photons striking a surface is more akin to the behavior of radio waves as they strike surfaces. Which is better described as kinetic interactions. After all, light is an EM wave. I think that light is absorbed by the atoms acquiring more momentum, thus the material gets hotter. Not this explanation of electron absorption.