Resonance (Physics)
Definition
When pushes timed to a system's natural rhythm build enormous motion — a singer shattering a glass hits the glass's resonant note.
Technical definition
Driving at ω ≈ ω₀ maximizes the steady-state amplitude; the response curve's width is set by damping and the Q factor.
Example
The Tacoma Narrows Bridge collapsed in 1940 when wind vortices matched its torsional resonance — a permanent lesson in engineering.
Common confusion
Resonance needs a periodic driver near the natural frequency. A single hard push is not resonance — that is just a large impulse.