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Can we visually detect sound?

  1. Jun 27, 2013 #1
    I hear that sound is waves in a medium (ie air). So, like, the source of sound is something which creates waves in air? If this is the case, could be detect sound visually with a colored gas (similar to how aerodynamics is studied in wind tunnels)?
     
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  3. Jun 27, 2013 #2

    mfb

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    I guess colored gas is possible, but small particles in the air are easier. It is possible to detect sound by their motion, but most sound sources will give a really tiny motion.
     
  4. Jun 27, 2013 #3

    Bobbywhy

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    Cymatics (from Greek: κῦμα "wave") is the study of visible sound and vibration
    http://en.wikipedia.org/wiki/Cymatics

    Sound Waves Visualized with a Chladni Plate and Colored Sand [Video]
    http://www.howtogeek.com/131159/sound-waves-visualized-with-a-chladni-plate-and-colored-sand-video/

    'Seeing sound': 5 remarkable examples of cymatics and beyond
    Summary: The application of cymatics is wide-reaching and includes artists and DIY experimenters alike looking to uncover the nature of sound--often resulting in great eye candy. The following is a mixed bag of 5 remarkable sound visualizations from around the world.
    http://www.zdnet.com/blog/emergingt...markable-examples-of-cymatics-and-beyond/2126

    European Journal of Physics Volume 28 Number 4
    F Elias et al 2007 Eur. J. Phys. 28 755 doi:10.1088/0143-0807/28/4/014
    Visualization of sound waves using regularly spaced soap films
    F Elias1, S Hutzler2 and M S Ferreira2
    Abstract
    “We describe a novel demonstration experiment for the visualization and measurement of standing sound waves in a tube. The tube is filled with equally spaced soap films whose thickness varies in response to the amplitude of the sound wave. The thickness variations are made visible based on optical interference. The distance between two antinodes is easily measured using a ruler and the determined wavelengths of the modes of the standing wave are in excellent agreement with the theory.”
    http://iopscience.iop.org/0143-0807/28/4/014
     
  5. Jun 27, 2013 #4

    f95toli

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    You can also map out sound "fields" in 3D using lasers, this is e.g. used to study sound propagation from speakers.
     
  6. Jun 27, 2013 #5

    CWatters

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    Most sound waves you encounter in daily like are not standing waves so even if you could see them in the air they would move past you very fast.

    If you look on youtube you can see shock waves travelling outwards from various explosions. These are essentially very loud sound impulses.
     
  7. Jun 27, 2013 #6

    f95toli

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  8. Jun 27, 2013 #7

    boneh3ad

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    Given a sufficient amplitude you can see sound waves using schlieren photography.
     
  9. Jun 28, 2013 #8

    Andy Resnick

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    Last edited by a moderator: May 6, 2017
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