Antiresonance Antiresonance In the physics of coupled oscillators, antiresonance, by analogy with resonance, is a pronounced minimum in the amplitude of one oscillator at a particular frequency, accompanied by a large shift in its oscillation phase. Such frequencies are known as the system's antiresonant frequencies, and at these frequencies the oscillation amplitude can drop to almost zero. Antiresonances are caused by destructive interference, for example between an external driving force and interaction with another oscillator. Antiresonances can occur in all types of coupled oscillator systems, including mechanical, acoustic, electromagnetic and quantum systems. They have important applications in the characterization of complex
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