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What happens with a 'Light in a box theory'

  1. Sep 12, 2009 #1
    I have no background in physics, but I have a question about light.

    Might consider it the 'Light in a box theory'.

    What would happen if you could make a box or sphere of mirrors that would constantly accept incoming light and focus the light into an infinite loop with little or no difraction?

    If this could be done, what would it achieve, or how could it be useful?
  2. jcsd
  3. Sep 12, 2009 #2


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    How would you make a box that would let light in but not let light out?
  4. Sep 13, 2009 #3
    I just wrote a very detailed response, and when I posted the reply, the forum page had timed out. *!#%* I hate when that happens! What sense does that make!!

    Why does every forum time out after about 10 or so minutes of writing, and then lose everything you just wrote to tell you to login, again?!?

    Seems pretty stupid that I have to copy my text everytime I write something and then re-login in order to post it.... (Wait... let me copy before I hit the post button and lose this too).
    Last edited: Sep 13, 2009
  5. Sep 13, 2009 #4
    I would focus the incoming light using a converging lens. The light would be directed onto a perfect convex mirror that would help to further focus the light.
    I hope using this method in series, an infinite loop of sorts could be created.

    If this were possible, how would the light behave?
    Would the particle become more and more charged as more light enters the loop?
    Or would the waves cause an interference pattern ruining my loop?
  6. Sep 13, 2009 #5


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  7. Sep 13, 2009 #6
    I have thought about this as well- I believe one factor is the fact that as light refracts or is focused you will lose energy to heat through the mirror or lens, so a truly infinite loop is impossible. A long lasting refracted beam may be possible though...
  8. Sep 14, 2009 #7
    As far as i can tell this is the optical analog of the carnot heat engine sort of thing, ie looking for 100% efficiency, which of course does not exist.
  9. Sep 14, 2009 #8
    Carnot's heat engine had to do with the transfer of hot & cold in order to produce mechanical work... not sure how that relates to this idea to capture light.
  10. Sep 24, 2009 #9
    Smokee77, it's a good question. What I think you'll find is that there's no "perfect reflector" similar to no "prefect conductor" of electricity. There's always some resistance, which ends up converting to heat.

    (Of course, someone will point out superconductors, those nearly perfect conductors which operate at very cold temperatures.)
  11. Sep 24, 2009 #10
    Good point about the perfect reflector.
    Maybe this experiment experiment would only result in producing heat.
    Could it be used to create a flameless heat source, or possibly even drive a steam turbine?
    I guess my idea is now sounding alot more like a light engine.
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