I understand the EM spectrum is made up of photons at different energy levels (wavelengths); where, the higher the energy level the shorter the wavelength. What I do not understand is how collectively photons are created at a range of energy levels that produce a contiguous EM spectrum. (When I use the word gapped I do not mean absorption gaps; I mean the lack of a photons at that wavelength). I understand when an electron drops to a lower orbital shell it releases a photon at a specific wavelength; likewise, I understand there are multiple orbital shells each producing photons at their respective energy levels. I even understand electrons can drop down more than one level thus producing a photon of a different wavelength. However, the EM spectrum appears to be continuous even at infinitely small increments. Thus, it would appear there are more EM spectrum increments than electron shell combinations. Hopefully, someone can shed some light J on this question.