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The Sounds of Silence

© Linda Bond

Now that we've spent considerable time discussing the philosophical nature of physics, let's turn our attention to its scientific aspects. Come with me now to days of yore, when hippies roamed the earth in great hoards, engaging in sit-ins, listening to standup comics, and going on long freedom walks.

It was a time of new ideas -- new looks -- new acts -- of new definitions. It was the SIXTIES! And out of this turmoil and con-fusion came many a troubadour to tell the tales of a new era. One such pair was Paul Simon and Art Garfunkle, who put out a shipload of songs which did not sink like the Titanic, but rather, rose to the top of the charts on waves of popularity.

Now I don't know if they shared my awe at God's intricate design of creation, nor do I know exactly what they had in mind when they gave birth to "The Sounds of Silence," but that song has had a tremendous impact on me from the first time I heard it. "Sounds of Silence?" How can that be? I mean, if you have sounds, you can't have silence, right? And where there is silence (something I have thankfully NEVER experienced), there can be no sounds, right? Well, as it turns out, it depends on how you look at it.

The Wave of the Future

First, let's look at what sound is and what it is not. Sound is not an actual material thing. Rather, it is the effect of energy being transferred from "point A" to "point B" in the "form" of a wave. For instance, if I bang on a tin can with a spoon (ouch!) the energy from my action is translated into a vibration in the can, which then begins its journey outward through the air. As the energy passes through the air, it alternately bunches up the air molecules (compression) and leaves sections of thinner amounts of molecules between the bunches (rarefaction). It's a sort of pushing (compressing) and pulling (rarefying) of the molecules of the material through which the energy is traveling; in this case, air.

You have probably seen graphs of sound waves (hospital TV shows are great ones for this) which look like rolling hills (or jagged ones) moving along a baseline. It is important to note that such graphs are not "pictures" of a sound wave itself. Rather, they are graphs of the pressure (density) changes produced by the sound wave. The "peaks" on the graph (highest point) represent the bunched up (compressed) molecules or high pressure. The "valleys" of the graph (lowest point) represent the thinned out molecules (rarefaction) or low pressure.

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