Mental Floss

Can Opera Singers Shatter Glass?

By Editorial Staff
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Yes! But it isn’t easy. (And you don’t need to be an opera singer to do it. All you need is a good ear and powerful pipes.)

Next time you’re at a wedding and clink a wine glass for a toast, listen to the glass. It’ll ring at a specific pitch. If you circle a wet finger over the rim, the same tone will sing. That pitch is the glass’s “resonant frequency”—the speed at which the glass vibrates. Every object has a resonant frequency. The vibrations of a wine glass, though, are easier to hear since the bowl amplifies the sound.

Whenever you sing, the air molecules around you wiggle as the sound waves ripple. To break the glass, you need to sing the same pitch you hear after tapping the glass. Singing that pitch will make those air molecules vibrate, and, in turn, the glass will vibrate as well. If you sing loud and long enough, the glass can vibrate so much it shatters.

You’ll need serious lungpower, though. Volume makes a huge difference. The louder you sing, the harder you push those vibrating air molecules at the glass. If you’re singing into a crystal glass—which is weaker—your vocal chops could knock it dead. That’s why opera singers have the reputation of being glass-busters—they’re the loudest singers in the business.