How can singing break glass

Invisible cracks and chinks cover every material's surface but their size and location can vary wildly, according to Kysar. Wine glasses that look identical to the naked eye could have radically different fracture strengths, enabling some to withstand much higher levels of volume than others. Volume is a key player in the glass shattering game, because the loudness of a sound is directly related to the extent it displaces air molecules.

In essence, the sound passes from molecule to molecule until it hits the glass. As Brunhilde sings louder, she is, in effect, pushing air at the glass harder. The effect is much like pushing a kid on a swing—the harder each shove, the sooner the kid will go over the top. But a strong shove has little effect unless it is timed so it matches the natural oscillation of the swing—just as a hopeful glass breaker must sing a note that matches the glass's resonant frequency.

The physics involved in the art of vocal destruction seem straightforward enough. But although stories of powerful singers shattering wine goblets, vases and eyeglasses abound, real instances of this feat are suspiciously missing from the historical record.

The famous tenor Enrico Caruso was said to have had the ability, but after he died his wife denied these rumors. What gives? It turns out that most pieces of glass, including most wine glasses, are the equivalent of a kid on a swing who weighs hundreds of pounds. Push away, but that baby probably won't get anywhere close to the top. Only the finest leaded crystal is dainty and resonant enough to break at volumes that some people can produce without amplification—upward of decibels.

A famous commercial from the s showed Ella Fitzgerald shattering a wine glass with ease through Memorex speakers, and the trick has been repeated many times with amplification.

The principle of directing sound at a brittle object is used, for example, to break up kidney stones—except doctors don't bother to find the resonant frequency, preferring just to blast the stone with lots of sound energy and if a singer were as loud as, say, an explosion, she wouldn't have to find the resonant frequency to break a glass, either.

Yet, it seems that until a couple of years ago there was no proof that any person had ever broken glass with his or her voice alone. Then in the Discovery Channel television show MythBusters tackled the question, recruiting rock singer and vocal coach Jamie Vendera to hit some crystal ware with his best shot. CMoG One of many wine glasses in The Corning Museum of Glass collection that we take great care not to break by any means! Toggle action bar FAQ Actions. Print Tweet Share on Facebook Was this helpful?

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Which of the following BEST describes your question? Selected Files:. Finding the resonant frequency of a wine glass, which is especially resonant because it's tubular and hollow, is easy.

Our ears and brain interpret these waves as sound, with the pitch of the sound determined by the frequency of the waves. If you've got a good ear or the appropriate computer program, you can find out what that note is and match the pitch of your voice to the to the glass's resonant frequency. Singing that tone will get the air around the glass, and then the glass itself, vibrating. And if you can sing loud enough and long enough, the glass will basically vibrate itself to death.

Loud and long are important for glassware destruction. The volume of a sound is related to the amplitude of the sound wave and the extent that it displaces air.