I'll describe what I "think" a photon is and once any misunderstanding I have has been corrected then any problems I have following the correction should probably be ignored as I will have to re-evaluate from that point. So here goes. Its an electromagnetic wave that's emitted from an atom when it loses energy, its self propagating and expands as a spherical shell at speed c. It travels through space as a wave but interacts with other atoms as a particle, once an interaction takes place the entire expanding shell vanishes and the total amount of energy is passed to the host atom. It would be like a stone thrown into a pond and as the ripples spread outwards the ripple comes into contact with something (like my finger) but instead of a slight tickle my finger gets hit with the total energy of the stone that was thrown into the water and the ripples instantly vanish. This view has got to be catastrophically wrong for the following reasons. Say I was looking at a star to the left of the moon and it was 10 million miles away, by the time the photon reaches my eye its a 20 million mile wide spherical shell. Its too big to squeeze past the moon and so the moon should absorb it and it would never reach my eye. But I do see the star so the moon doesn't absorb it (at least not all of it) So maybe in proportion to the size of the photon shell the moon is tiny so it only takes a tiny amount of energy, but even this idea sounds stupid because I could make a star look dimmer just by building a (big) wall behind the star that would absorb some of the photons. Where have I gone wrong?