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Can light produce darkness and can noise procude quiteness 4

  1. Nov 21, 2009 #1
    This is do with wave I think but i'm intrigued with this. As with waves sometimes they can cancel each other out but what about this:

    • Can light produce darkness?
    • Can noise produce quietness?
     
  2. jcsd
  3. Nov 21, 2009 #2
    due a to redistribution of energy as a result of interference , the light seems to produce darkness, when it is passed through slits
     
  4. Nov 21, 2009 #3
    Re: Can light produce darkness and can noise procude quiteness 4

    You can create just the right type of "anti-noise" to cancel some noise
    http://en.wikipedia.org/wiki/Noise-cancelling_headphones
    So in a way that is noise creating silence?

    Similarly for light in solids. Sometimes the process of absorbing or reflecting light can be seen as the electrons creating just the right "anti-light" to cancel any further propagation of the light waves.

    The trick is always to examine the signal that you want to cancel and produce a suitable anti-signal. Otherwise light or noise are not going to interfere destructively.
     
  5. Nov 21, 2009 #4
    Just as a side note, should light be cancelled out by interference, what happens to the energy?
     
  6. Nov 21, 2009 #5
    darkness is always there; light just covers it. also darkness is instantaineous
     
  7. Nov 21, 2009 #6
    The energy is redistributed. You cannot cancel light without creating more light somewhere else.
     
  8. Nov 21, 2009 #7
    oh by the way i'm new to this forum so how do you post questions?
    thanks
     
  9. Nov 21, 2009 #8
    also there in chemistry ther is a method to creat exp: metal to gold due to bombing the atoms and creat new atoms
     
  10. Nov 21, 2009 #9

    Redbelly98

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    Re: Can light produce darkness and can noise procude quiteness 4

    Very good question -- see Gerenuk's response. You cannot have destructive interference everywhere in the wave, at some locations there will be constructive interference. That is where the energy is.

    Go to a subforum page, like
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    Not sure I see the relevance to this discussion :confused:
     
  11. Nov 21, 2009 #10
    Thanks for all the answers guys. Would love some links would love to read more on this
     
  12. Nov 21, 2009 #11

    DrGreg

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    Re: Can light produce darkness and can noise procude quiteness 4

    For a start, try the Wikipedia article Interference (wave propagation) The animation shows areas that are permanently coloured cyan (pale blue) where there is no energy, and areas in between where there is more energy.
     
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