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Why do objects reflect light (microscopic point of view)

  1. Jul 3, 2013 #1
    I can explain why objects reflect, absorb or transmit light by referring to the objects' refractive index (differnece of the refractive index of two media).

    I'd like to know if there is a microscopic point of vue that can explain why objects reflect light?
    For example
    * Light is transmitted if the band gap of molecules (LUMO - HOMO) in the object is larger than the energy of the incident light (hv)
    * Light is absorbed if the energy of the incident light (hv) correspond to specific energy levels of the electrons in the molecule.
    * And what is the condition for light to be reflected? And can anyone recommend me some books or websites that I could read to get more informations about this?
  2. jcsd
  3. Jul 4, 2013 #2

    Simon Bridge

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    Light interacts with "surface" electrons (i.e. in a metal) and get scattered.
    Light scattered into the object you don't get the see. Light scattered back may contribute to a reflection.

    ... one of the examples is the QED description of reflection ... how the arbitrary scattering ends up as the law of reflection, in terms of photons, source, mirror and detector.
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