Why Opera Singers Can Break Glass With Their Voice

Every glass has a natural frequency at which it prefers to vibrate.
An opera singer can match that frequency with a sustained, powerful note.
When the voice and the glass’s frequency align, resonance occurs.
Resonance makes the glass vibrate with increasing intensity.
If the vibrations grow strong enough, tiny cracks in the glass expand rapidly.
Thin, crystal glasses are easier to shatter than thick, sturdy ones.
The singer must deliver enough amplitude (loudness) to pump energy into the glass.
The phenomenon is rare—most voices don’t have the power or precision to break glass.
High-speed cameras show glasses vibrating dramatically just before they shatter.
It’s a spectacular example of physics in action: resonance + energy = breakage.