I am reading QED by Richard Feynman and he explains how changing the thickness of glass results in a change in the probability of photons reflecting off the glass back to the photomultiplier.
However, he states that:
The situation today is, we haven't go a good model to explain partial reflection by two surfaces; we just calculate the probability that a particular photomultiplier will be hit by a photon reflected from a sheet of glass.
So is there still no model to explain the partial reflection of light by two surfaces? Are there any developing theories that seem promising?
