Broken Symmetry

Music and the Brain

From an interview of Oliver Sacks:

Using loud music as torture draws on these qualities of music, as well as simple sensory overload. I personally find the assault of loud public music—in stores, restaurants, airports–a minor form of torture. One wants to listen to one’s own music, in one’s own way, not to have it force-fed, especially at great volume.

One of the things I found remarkable about Beijing when I visited in 1998 was the ubiquity of public address speakers, which were usually playing some kind of music in the background in between and during public announcements. One had the sense that people there were uncomfortable without these sounds, since one could have observed these speakers installed even in improbable locations. Here's another quote from the interview:

Rhythm, actual or imagined, activates areas of the motor cortex, crucial in synchronizing and energizing movemen... There is a great deal of debate about the relationship between music and language, and speculation about which capacity evolved first. It has often been suggested that music emerged as a by-product of linguistic capacities. But musical rhythm, with its regular pulse, is very unlike the irregular stressed syllables of speech.

Musicophilia may be worth a look.

Acoustically driven programmable liquid motion using resonance cavities

From Sean M. Langelier, Dustin S. Chang, Ramsey I. Zeitoun and Mark A. Burns:

Performance and utility of microfluidic systems are often overshadowed by the difficulties and costs associated with operation and control. As a step toward the development of a more efficient platform for microfluidic control, we present a distributed pressure generation scheme whereby independently tunable pressure sources can be simultaneously controlled by using a single acoustic source. We demonstrate how this scheme can be used to perform precise droplet positioning as well as merging, splitting, and sorting within open microfluidic networks.

Via Technology Transfer Tactics

Resonance and Neural Networks

A demonstration courtesy of Bobby McFerrin:

Via Cosmic Variance. Don't miss the earlier post (and linked PDF) on music and quantum mechanics here.

What do Music and Quantum Mechanics Have in Common?

Time and frequency are a Fourier pair:

The key to using music to teach modern physics, in my mind, is harmonic analysis. Harmonic analysis is nothing other than Fourier analysis, a tool which is highly valued in physics and engineering. It is not widely known by the non-scientist, yet it is easy to explain in the musical context—when someone looks at a graphic equalizer on their stereo they are looking at a real-time Fourier amplitude analysis of the music that is being played. One can explain how the synthesis of harmonics affects the timbre of musical sound—how the coefficients in a Fourier series can describe different real functions. A very simple example is the comparison between the organ pipe and the piano string. The ‘stopped’ organ pipe has only odd-numbered harmonics and the piano has all harmonics. (Because the ‘stopped’ organ pipe has a pressure node at one end and a pressure antinode at the other, whereas a string has nodes at both ends.) The different symmetry of the boundary conditions accounts for a major aspect of the difference in the timbre of the organ and the piano.

That's from The birth of the blues: how physics underlies music by J.M. Gibson. Via Physics and Physicists

If you're a regular Broken Symmetry reader, then you should know already that it is not only music that can be understood better with Fourier Analysis, but any time-series that can be decomposed into ocillations of different frequency, including cash-flows. The balance sheet is sort of like the graphic equalizer, except that the frequency of the accounts is not rigorously ordered in terms of liquidity. If it were, then the analogy would be complete.