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Just wondering about frequencies

  1. Oct 19, 2006 #1
    Hey guys, long time no see. I was flipping through a book about black holes and gravity when i saw a chart about different frequencies and I came up with a little thought that would be nice to have explained.

    Why is it that lower frequencies (radio/microwave) and higher (x-ray/gamma ray) can pass easily through most solid objects but the visible/near-visible range is very easily reflected by most types of matter?

    ex: shoot radio at a wall, it goes through, shoot light, it bounces off, shoot x-rays it goes through
    Last edited: Oct 19, 2006
  2. jcsd
  3. Oct 21, 2006 #2
    actually it depends on the material in the wall, obviously. as a rule of thumb lower frequences pass through more readily because they have a lower energy and thus are less likely to succesfully interact with the particles in the wall. on the flip side xrays are so powerful and energetic they just 'wizz' through. i say that in inverted commas because according to an ol german dude with cool hair the speed of all EM waves is constant.

    reflection is actually a really cool area of physics, like edge physics. as far as i know reflection is an interaction and deformation of the electric fields of the EM wave and those generated by the electrons in the orbitals
  4. Oct 22, 2006 #3

    Claude Bile

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    Science Advisor

    Generally it is because photons that possess optical frequencies match electronic energy transitions, which means that these photons will strongly interact with most materials, though this interaction is usually absorption, not reflection.

    Last edited: Oct 22, 2006
  5. Oct 22, 2006 #4
    =] thanks guys
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