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Light and mirrors

  1. Sep 27, 2008 #1
    i want to know if any scientists have ever done these-literally shoot a beam of light through
    a small hole in a "ball" of sorts, and close the hole. the inside surface of the ball would have a mirrored surface and the light beam would bounce around forever. would the ball glow inside due to the beam of light bouncing around perpetually?

    also, have they ever tried perfectly aligning two mirrors-one of the mirrors would have a black hole, a beam of light would be bounced off that hole, towards the opposite mirror. the hole is then shut, with the surface of the hole then being mirrored as the rest of the mirror. then the beam of light would bounce back and forth between the two mirrors in a perfectly straight line, for infinity.

    i prefer a professional answer these questions-a physicist or graduate if possible.
  2. jcsd
  3. Sep 27, 2008 #2


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    Yes, you can do both these experiments. In practice the mirrors are not 100% reflective and the light is soon absorbed and turned into heat in the mirror.

    Gravitational wave detectors bounce the light between pairs of mirrors 1000s of times to allow very small movements of th emirrors to be detected, in a slightly different configuration hey also have a practical application as a gyroscope.
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