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…
For example, very fine, leaded crystal glasses are more fragile than others. Thus, it may be easier to break such a glass than a thick water glass.
Volume is another key factor. The louder the sound, the more air it displaces. Singing more loudly thus results in sound waves hitting a glass with greater force.
Breaking glass with an amplified voice has been demonstrated many times. A human voice without amplification, though, will usually fail unless the glass is quite fragile.
In 2005, the Discovery Channel television show MythBusters proved that a voice alone could break glass. Rock singer Jamie Vendera shattered a wine glass with a 105-decibel wail. By comparison, normal speech is usually around 50 decibels.
So do you have to have natural talent to break glass with just your voice? Not necessarily… but it couldn’t hurt! Finding the right note to shatter a glass will be easier if you’re a naturally talented singer.
Sometimes people are born with certain talents. At other times, people work very hard to develop skills they have into true talents.
Even if singing isn’t your talent, you can still train and practice. If you set your mind to it, we believe you can achieve any goal you set for yourself.