Resonance: Why Bridges and Glass Can Shatter from Sound

Resonance happens when an object vibrates at its natural frequency, amplifying the motion.
Even small pushes, if timed right, can build into huge vibrations.
A child pumping their legs on a swing is a simple example of resonance in action.
Glass can shatter when sound waves match its natural frequency, making it vibrate uncontrollably.
Bridges can wobble or collapse if marching steps or winds hit their resonant frequency.
The famous Tacoma Narrows Bridge collapse in 1940 is a dramatic case of resonance.
Musical instruments use resonance to amplify sound, making notes louder and richer.
Buildings are engineered to avoid resonance with earthquakes and wind forces.
Resonance explains why singers can hold notes that make objects shake or rattle.
It’s both a danger and a design tool—resonance can destroy structures or create beautiful music.