Was recently re-reading QED and wondered whether there was any "simple" explanation of partial reflection? How does the thickness of glass affect reflection if it's a particle?
Actually, nobody knows the answer to this one. For a basic exposition, I would highly recommend that you read "QED-The Strange theory of light and Matter by R.P Feynman".
The stuff you learn about matching up boundary conditions to retrace the path of the reflected and refracted rays (Classical Electrodynamics approach) does not answer the question why? It gives the answer, but not at the fundamental level.
Yeh, I've read QED, very good treatment, not enough math for me to really understand things. Odd that a problem that is so simple to demonstrate, and known about since Newton's time, has yet to be solved. Maybe it's Fermats last theorem for physicists?