At one time or another, most of us have seen a cartoon in which an opera singer uses her powerful voice to shatter glass. But can a human being really do that? The answer might surprise you because science says yes!
The laws of physics show that every piece of glass — actually, every material on Earth — has a natural resonant frequency. That frequency is the speed at which it will vibrate if struck.
For example, wine glasses are especially resonant because of their hollow, tubular shape. If you flick a wine glass with your finger, you will hear a ringing sound.
The resonant frequency of a glass could be any particular musical note. It just depends on the glass and how it was made.
If a singer sings the same musical note that matches the resonant frequency of the glass, the sound waves will vibrate the air particles around the glass at its resonant frequency. This will make the glass begin to vibrate, too. If a singer sings loudly enough, the vibrations can cause the glass to vibrate so hard that the glass shatters under the strain.
So can just about anyone break a glass with a song? Not quite. It’s much harder to do than it sounds.
Experts believe a singer has to be both very good and very lucky to break a glass with the voice alone. But it can be done
