Mechanical resonance Mechanical resonance Mechanical resonance is the tendency of a mechanical system to respond at greater amplitude when the frequency of its oscillations matches the system's natural frequency of vibration (its "resonance frequency" or "resonant frequency") than it does at other frequencies. It may cause violent swaying motions and even catastrophic failure in improperly constructed structures including bridges, buildings and airplanes. This is a phenomenon known as resonance disaster. Avoiding resonance disasters is a major concern in every building, tower and bridge construction project. The Taipei 101 building relies on a 660-ton pendulum—a tuned mass damper—to modify the response at resonance.
Boat anchor (metaphor) Boat anchor (metaphor) In amateur radio and computing, a boat anchor or boatanchor is something obsolete, useless, and cumbersome – so-called because metaphorically its only productive use is to be thrown into the water as a boat mooring. Terms such as brick, doorstop, and paperweight are similar. In amateur radio, a "boat anchor" or "boatanchor" is an old piece of radio equipment. It is usually used in reference to large, heavy radio equipment of earlier decades that used tubes. The use of the term in a disparaging way is unusual. An early use of the term appeared in a 1956