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Can light enegry or waves affects sound waves?

  1. May 6, 2004 #1
    is there any relations for light waves to affects sound waves? :biggrin:
  2. jcsd
  3. May 7, 2004 #2

    Chi Meson

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    Light can indirectly affect sound: since sound must travel through a medium (air) made of particles, those particles could absorb energy from light. WHen the particles absorbe energy, the temperature of the medium goes up. THis will increase the speed of sound through the medium. This will in turn change the refractive index of the substance and could cause a change in direction of propagation of the sound.

    So since light interacts with matter, and sound must travel through matter, light will affect sound. This effect would be hard to notice under normal atmospheric conditions, but might be significant under some experimental procedure. I can't think of any use for it, what are you thinking of doing?
  4. May 7, 2004 #3
    oh thanks meson. i have been reading up on GR and hyperspace for a while. But i have not touched much on the calculations part yet, but i am considering the idea of using sound as a point of view instead of light. Simply means that even we humans used light as an reference point, what will it be for sound? ..weird idea of mine..thanks again. :rolleyes:
  5. Jul 30, 2011 #4
    So when you have light in a room with sound waves coming from somthing, would you be able to hear the sound better, or would it be harder to hear?
  6. Jul 30, 2011 #5
    aeros, although the light affects sound, it will only affect it a tiny amount, so no audible difference will be heard :D
  7. Jul 31, 2011 #6
    Ok thank you for the answer. If light has no mass wouldnt it not affect sound at all? I would think itd have mass becasue when you close your eyes it still exerxts pressure on them, or at least it feels like it to me, and wouldnt the mass of light be the area that is covering? Sorry if im asking redundant questions, but if dark is before light wouldnt that mean that it travels faster than it?
  8. Jul 31, 2011 #7
    Light has no mass, but carries momentum, which obvious is not related to its speed by [itex]p=mc[/itex] like classical massive particle. So light can exert pressure, which is just rate of momentum exchange per area as light (or particle) bounding off a surface. The claim that you can feel it is completely baloney though.

    No idea what you just said here.
  9. Aug 1, 2011 #8
    As in feel i ment when I close my eyes I can still feel the light penetrating my eye lids im sure we all can, and the dark coming before light is just a theory of mine just seeing if anyone would concur, but since no one seems to know much about dark energy its not perplexing.
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