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Mirror box

  1. Feb 2, 2013 #1
    If you had box where the inside was lined with mirrors and you closed the box in daylight, would inside of the box contain the light and be lit up? (Assuming no light was absorbed the edges or elsewhere).
  2. jcsd
  3. Feb 2, 2013 #2


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    Welcome to PF!

    Hi Juel! Welcome to PF! :smile:

    Yes, the light that was inside when you closed it would bounce around for ever (if it wasn't absorbed), and come out again when you re-opened the box.
  4. Feb 2, 2013 #3
    When light is reflected, I think it is actually absorbed and re-emitted by the surface, so your stipulation that it is not absorbed might need to be adjusted to say that all the light is totally reflected.
    It would have to a pretty special conditions type of box; if it was about a meter across the number of reflections for a single ray of light would be around 300 million times per second.

    Even if you could construct and isolate a box system that you thought might be able to support the on going reflection for a few minutes or hours, another question pops up... How would you propose verifying it? Any device - your eye, a camera, or other kind of photo-detector will operate by absorbing light. If you did have a box of light, how would you be able to tell?
  5. Feb 2, 2013 #4


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    this question comes up here every couple of months or so, so a forum search might turn up some discussion you would find interesting, although the previous 2 have pretty much said what's important.
  6. Feb 2, 2013 #5
    Re: Welcome to PF!

    What about the Compton effect?
  7. Feb 2, 2013 #6


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    what about it? :confused:
  8. Feb 2, 2013 #7
    Wouldn't the photon give up energy with each reflection?
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