Re: So . . . . .
I'm well out of date here (and the memory is foggy) but this analogy may be helpful (or completely wrong).
If you drop something into a pool the ripples spread out until they hit a boundary, then they reflect, rinse and repeat until the energy has been evenly distributed around the pool, the boundary, etc. No more ripples.
These waves haven't hit any boundary, they haven't reflected. They suffer from the dissipation of energy as they move from a 'point' source into a larger and larger volume but they are not absorbed, reflected or otherwise homogenated (word?) before reaching us.