The discussion centers on how charges in a wall interact with incoming electromagnetic waves, particularly focusing on whether these charges can cancel the waves and the implications for the existence of the waves on the other side of the wall. The scope includes conceptual understanding and technical explanations related to electromagnetic theory.
Participants express differing views on the nature of electromagnetic waves and the analogy of photons, indicating that multiple competing views remain without a clear consensus on the correct interpretation of these phenomena.
There are unresolved aspects regarding the definitions of electromagnetic wave behavior and the conditions under which photons interact with different materials, as well as the implications of energy levels on wave penetration.
k9b4 said:I think that a wall does not actually stop light, I think the electromagnetic waves exist on the other side of the wall, but the charges in the wall provide their own electromagnetic field, such that charges on the other side of the wall feel both forces at the same time and 'cancel out'.
Is this correct?
elegysix said:I would think of photons as bullets.
If you have a strong enough bullet (enough energy), it will go through the wall. otherwise, not so much.
Cool, thanks for explaining.Nugatory said:Not quite, but you have the right idea. The waves do not exist on the other side of the wall because the intensity of the electrical and magnetic fields there is zero - there is no wave, just as there are no water waves on the surface of a still pond. However, the intensity is zero for pretty much the reason that you give: the charges in the wall move around in response to the incoming wave in such a way that their electric fields always exactly cancel that of the incoming wave.