Ringward: Q Factor Resonance
Optics, Waves & Sound arc, page 123 of 193. Back to The Pixelated Physics Universe
Who they are
Ringward has one line, and says it often: “High q. still ringing from that question.”
Ringward is a character of the Optics, Waves & Sound arc: drawn in pixels, ruled by one piece of real physics, and never allowed to break it.
The physics
Quality factor Q = ω₀/Δω; a resonator's stored energy rings down as e−ω₀t/Q, so high-Q rings for many cycles.
$$ \begin{gathered} Q = \frac{\omega_0}{\Delta\omega} \\ E(t) \propto e^{-\omega_0 t / Q} \end{gathered} $$
| Symbol | Meaning | SI unit |
|---|---|---|
| $Q$ | quality factor | — |
| $\omega_0$ | resonant angular frequency | rad/s |
| $\Delta\omega$ | resonance width (FWHM) | rad/s |
| $E(t)$ | stored energy | J |
Sources
- A. P. French, Vibrations and Waves (Norton, 1971), chs. 3–4
Crossovers
Ringward meets Sloshwyn (Coffee Sloshing Resonance). Sloshwyn's coffee is a lightly damped oscillator. Ringward measures how lightly with Q: the higher the Q, the more cycles it rings and the bigger the resonant response.
Ringward meets Murmura (Whispering Gallery). Murmura's whisper clings to the curved wall and travels round it. Optical whispering-gallery resonators do the same with light and can reach very high Q, which is Ringward's measure of how long they ring.
Ringward meets Rijka (Singing Heat). Rijka's tube rings at its natural acoustic mode. Ringward points out that heat input must outrun the losses that set the Q, or the tone dies away.
Wear the lore
Concept keywords: Q Factor Resonance, Ringward, Optics, Waves & Sound, physics lore, Pixelated Physics