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Thread: shattering glass with your voice

  1. #1 shattering glass with your voice 
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    Some say this is a myth, some say its true. So, leave it to the mythbusters to solve it! I saw the show a while a go and I can't remember whether they said it was plausible or confirmed, but it definatly was not busted. Anyways, they said it had to do with the resonant(i think) frequency of the glass. If you sing at the frequency the glass shakes violently and shatters.
    My question is, how does the sound wave interact in that way with particles? If you have 2 waves of opposite frequencies they balance each other out and are destroyed, does this mean that wave-particle duality can be applied to all particles to some extent? Maybe all particles have wave like properties and as they reach higher speeds they become more dominant and that is why we can observe them easily when they are photons.


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  3. #2  
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    Yes, you can do it – although it’s practically impossible to do it with your voice, since you would have to be very loud and at exactly the right frequency. But I have seem demonstrations of it with speakers hooked up to a tone generator.

    I'm not sure what the rest of your post had to do with breaking glass, though.


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  4. #3  
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    Yes, it can be done. The principle is mechanical resonance -- a steady series of small pushes can make a swing go ever higher or a potter's wheel turn faster and faster. *I have no idea why you think of this as either wave interference or wave-particle duality. Where did that come from??
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  5. #4  
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    Shawn, quantum mechanics is for atomic and subatomic particles. Don't try to use it for macroscopic objects like a vibrating wine glass. The sound wave is just a pressure wave in the air and it interacts with the glass by the pressure of the air against the glass.

    There is no such thing as opposite frequencies. I think you mean two waves that are 180 degrees out of phase will cancel each other out. That is not the case here though. Where would the out of phase wave be coming from?

    As far as I can find out there is no documented case of somebody breaking a glass with their voice.
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  6. #5  
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    Where did that come from? Well, I was thinking what's so special about the frequency? How does the frequency of the voice interact with glass?
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  7. #6  
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    Quote Originally Posted by Harold14370
    As far as I can find out there is no documented case of somebody breaking a glass with their voice.
    Then you didn't see the Mythbusters epsiode in which they actually filmed it happening.
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  8. #7  
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    Quote Originally Posted by shawngoldw
    Where did that come from? Well, I was thinking what's so special about the frequency? How does the frequency of the voice interact with glass?
    What is special about it is that it is the frequency at which the glass naturally vibrates. It is like when you push someone on a swing. you time your pushes so that they go higher on each successive swing.

    The sound waves cause the glass to vibrate, if the sound frequencies is right, each sound wave will hit the glass at just the right timing to cause the vibration of the glass to grow in ampitude. Eventually the vibration become large enough that the glass can't hold together and it breaks.

    What makes it diffucult to do with a human voice is that you have to find that correct pitch and hold it long enough for the vibrations to build up.
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  9. #8  
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    oooo ok. Thanks, and it was probably the same episode. That's why I said I couldn't remember if they said plausible or confirmed. It was a while a go.
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