Many people, when they encounter the words “quantum mechanics,” go on the alert for esoteric paradoxes. And there are certainly plenty of those on offer. But sometimes, as my brilliant friend the physicist Sidney Coleman put it in a famous lecture at Harvard, quantum physics is “in your face.”
To hear, we sense pressure waves, commonly called sound waves, which impinge on our eardrums. Channeled through some impressive natural mechanical engineering, sound waves set off vibrations on the membranes of our inner ears. Those membranes work like the keyboards of a pair of inverse pianos: The sounds play the keys! Neurons fire in response to the keys’ motion, generating the signals that our brains interpret as music, speech or whatever.
Two things are noteworthy in this process. First, we naturally deconstruct the incoming wave pattern into its component of pure tones. Mathematicians learned how to use equations to perform that feat in the 19th century and they call it Fourier analysis. It is similar to what spectrometers, ranging from Isaac Newton’s prisms to sophisticated modern instruments—but not our eyes—do to separate light into its component frequencies. [Continue reading…]