Light is M in E=MC2 meaning it is more than a wave but all waves are more than a wave or all waves would be the same, right?
I am an itinerate(sp?) on all such subjects, but the matter of light is like the matter of pixels on a screen. A single pixel cannot describe the details of an image. The pixels are in groups, or packets, in order to display the on/off states and
Frequencies and contrast and color levels necessary to create the illusion of a picture.
And levels now. Consider that a standard light bulb produces light by heating a filament which then basically builds its energy level to saturation of the filaments mass until the filament's capacity to retain the heat is filled, at which point the heat energy creates harmonics in the visible spectrum.
The filament has valence rings and levels and as they fill, they create higher rates of groups/packets of energy identified as harmonics or as higher frequencies.
The first working laser was achieved by taking a cut Ruby, hooking up electrodes to it in a tube which delivered high velocity pulses of electricity while at the same time exposing the gem to a very high level of light, so that the combination of forces filled the valence rings of the atoms in the ruby and then caused release of those combined energies as a lasing pulse of light. This was in 1959.
So, the valence rings of atoms appear to relate to the ability to absorb or release energy at various frequencies, from very low physical waves due to physical pressure all the way to illumination when the object is set afire.
If my memory of science class serves me, and it Probably Doesn't, the valence rings of an atom run something like a ring of 8 electron positions immediately surrounding the proton at the center, while the second ring surrounding the first ring also has a set of 8 electron positions. The next outer ring has 16(maybe?), and the next outer ring has 52 (not sure), and so on.
The greater the density of the element, the more electron valence rings it has, I THINK??? It's been a loong time since I studied it.