Qualitative description of photon from faraway star

[Q-reeus]

Either I completely misunderstand you or we are talking past each other. My usage of thermal broadening is that a line is broadened because the emission comes from many atoms/ions/emitters/whatever that have very different velocities. This spread in the velocities causes the line to broaden. The recoil does not alter this. The cool thing Mössbauer achieved was rather the possibility of resonance fluorescence - absorption and emission (if one can even call it that way) of indistinguishable photons.

Err, yes - my mia culpa there. Meant frequency down-shift owing to either single-or-two emitter recoil would be much greater than if a collective many-particle sharing recoil were in effect. I was crossing that over in head with that value of thermal line broadening is consistent with more or less free single particles which then in a way comes back to nature of recoil processes going on. Never mind.

Hmm, you can shoot weak emission or even single photons at whatever you like. You may do experiments like antibunching (two detectors never fire simultaneously when you fire a single photon at them) to test loading theory, I think. The joint detection rate should have some dependence on the threshold energy.

An area I know next to nothing about, but may try and chase up. There is one person who has apparently solid evidence for 'funny business' in this matter involving very high energy EM radiation - gamma rays in fact. But I say no more.

Anyway, I thought loading theory is dead anyway?

Pretty sure there are at least one or two proponents lurking here. Again I say no more.

It is not too clear to me, why the detection rate should depend on the photon model. In the statistical ensemble, the results will be the same. A purely point-like photon will, however, always create problems when you try to explain interference experiments. Especially two-photon interference gets non-intuitive using a bullet-photon model.

Yes understand the appeal of wave model and would much otherwise prefer it. And as stated earlier, certainly don't subscribe to a bullet-photon concept. Have no idea if D-B theory or something else holds all the answers interpretation wise. Anyway I'm about done on this but thanks for some stimulating feedback. I had not considered the aspect of environmental decoherence before. Cheers. :zzz: