"Hidden Variables" in QM are entangled with dipole elongation (ao) and linewidth (η). It turned out the quantity ao 2/η plays a dominant role. Rules of QM transition themself are not questioned. This quantity can be fixed for a "single" transition (no interaction with other atoms or molecules) as well as for an ensemble within a thermal bath, and when developed further unveils details of radiating matter especially when the linewidth of the radiating source is precisely known. In principle a "single" isolated local photon emanated by an adequate quantum transition is not detectable. Stepping towards non-thermal radiation sources (lasers) quantitative assertions can be made in regard of entanglement respectively the lateral dimension affected by such a process. Moreover, this concept applied to γ- radiation reveals inherent linewidths of γ-ray transitions fixes the dimension such emanation stems from and predominantly this lies within the influence sphere of one nucleon. A further aspect of this investigation makes it obvious: The Stefan-Boltzmann constant is not natural; in fact it is a composition of the constants of Planck and Boltzmann and the velocity of light as well. Exemplary analyzing a specific hydrogen line in the solar spectrum (λ= 486 nm) one must infer from its linewidth data this species shows photon entanglement, or alternatively substantial density fluctuations becomes obvious.