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If light hits a mirror and then switches direction

  1. Nov 21, 2011 #1
    if light hits a mirror and then switches direction....

    if light hits a mirror at a 90 degree angle, wouldn't it HAVE to travel slower than the speed of light when it hit the mirror?
     
  2. jcsd
  3. Nov 21, 2011 #2

    Vanadium 50

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    Re: if light hits a mirror and then switches direction....

    No. Why?
     
  4. Nov 21, 2011 #3

    HallsofIvy

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    Re: if light hits a mirror and then switches direction....

    When light reflects from a mirror, it is absorbed by the mirror and re-emited. It does not "stop" and change direction.
     
  5. Nov 21, 2011 #4
    Re: if light hits a mirror and then switches direction....

    Perhaps you are thinking of REFRACTION when light is abosrbed in a medium??

    That involves a change in phase velocity:

    http://en.wikipedia.org/wiki/Refraction
     
  6. Nov 21, 2011 #5
    Re: if light hits a mirror and then switches direction....

    I meant more what hallsofivy guessed. That is interesting though. Would the angles of reflection the same for a solid object bouncing off a wall? it seems odd that light's angle of reflection wouldn't be jumbled around somehow while it was absorbed by the mirror.
     
  7. Nov 21, 2011 #6

    turbo

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    Re: if light hits a mirror and then switches direction....

    Just a niggle, here. If light hits a conventional rear-surface silvered mirror it will travel slower than its normal speed in air when it hits the glass, until it is reflected by the silvering and re-exits the glass and re-enters air. This is not situation with a front-surface silvered mirror like those used in telescopes or the larger flat mirrors that are used to allow optometrists/ophthalmologists to test your visual acuity in small exam rooms. In such cases, the light is reflected right back into the air and does not have to traverse any glass.
     
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