How does electromagnetic radiation get absorbed by an object (like a black body) in the classical regime?
In the classical picture, electromagnetic radiation is produced by the movement of charges, which produce a change in the electromagnetic field in space, which propagates as a wave. But, this change in the electromagnetic field can't be absorbed. If an electron wiggles, it's disturbance will permeate all space.
The only way radiation seems to be getting absorbed is by the following process:
The charges in the body absorbing the radiation start wiggling when they feel the radiation, and their motion in turn produces a second radiation. The original and the newly produced radiation interfere by superposition, and the resulting wave is weaker, i.e., attenuation.
So far so good, but then how do distinguish between the absorbed and emitted radiation from a blackbody?
P.S. This is the classical regime, and hence there are no photons.