specular reflectors usually operate at the surface boundry atoms, in which electrons absorb the light wave energy, then reradiate such that the law of reflection holds.
https://upload.wikimedia.org/wikipedia/commons/thumb/2/21/Diffuse_reflection.gif/375px-Diffuse_reflection.gif
Diffusion occurs, when light passes thru the surface boundry, and there is not a coherent boundry that is reflecting in a uniform angle.
How can an object be a specular reflector for some electromagnetic waves yet be diffuse for others?
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