I searched for similar questions but most of them treated the problem in a optic or quantum/energetic interpretation while I'm interested in an electromagnetic interpretation. I was wondering why light can't pass through some materials, since matter cannot block electromagnetic field or the force between two charged particles this must be something related to the variation of the field (which if I'm not wrong is what light actually is). So I thought that in some cases electromagnetic waves stimulates charged particle in such a way that they produce an opposed waves that cancels the first, but I still don't understand how this can happen so exactly to perfectly cancel the waves and why this happen only in the direction that goes through the material. I hope the question is not too confusing, thanks for the help. (I have physics and math rudiments, vectors, fields and calculus but I'm interested much in the physical interpretation)

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    $\begingroup$ I'm not sure but I believe it has to do with energy that the atoms is capable of "consuming" by changing the atoms excited state. If an atom cant change the excited state by the energy that is in the photon, it wont "consume" it. So low freq. waves has to little energy to excite the atoms, and a high freq. wave will ionize. $\endgroup$
    – Gjert
    May 12, 2017 at 21:29
  • $\begingroup$ This goes in the quantum/energetic interpretation I mentioned, but explaining it like this means that we require quantum mechanics to explain why light don't pass through wall and that electromagnetism is not powerful enough, I don't know enough to tell if this is the case but I would be surprised that it cannot at least in some sort of abstraction. $\endgroup$
    – Claudio P
    May 12, 2017 at 21:34
  • $\begingroup$ I looked it up as well out of curiosity and I it seems that it can be explained by how a particle has limitations on what frequency it can move. Therefor certain materials cant produce opposing waves, and that is why certain waves can pass the material. Also explains why conducting materials are better at absorbing EM waves. $\endgroup$
    – Gjert
    May 12, 2017 at 21:51


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