The Aggregate Effect Is Controlled by Wave Equations, Right?

The aggregate effect that's controlled by the wave equations. What happens when light hits a mirror, for example? Sure, it gets absorbed by the atoms and the surface of the mirror. But how do those atoms know what direction to send the light out? We can't really answer that question from the particle point of view because, you know, they don't really know. It's just like an average process for many, many possible paths.