Decibel, It Was You

I found a fascinating Wikipedia article recently. It reads, in part,

The National Radio Quiet Zone (NRQZ) is a large area of land in the United States in which radio transmissions are strictly restricted by law to facilitate scientific research and military intelligence. It is located in the states of West Virginia, Virginia, and a tiny part of Maryland. ...

Most broadcast transmitters in the Quiet Zone are forced to operate at reduced power and use highly directional antennas. This makes cable and satellite all but essential for acceptable television in much of the region. Restrictions on transmissions are tightest within ten miles of the NRAO and Sugar Grove facilities, where most omnidirectional and high-power transmissions are prohibited.

There was more, of course, but this was enough to convince me that it must be a great place to live. I value peace and quiet and it sounded like the place for me. And I'm old-fashioned. A quiet area with a minimum of noise and electronic devices sounded great. So I sent a link to my children, and got back the following from my older son who noted that his Rabbi had mentioned it in a sermon. It's from an article in The Smithsonian Magazine.

Earth’s Quietest Place Will Drive You Crazy in 45 Minutes

… Inside the room it's silent. So silent that the background noise measured is actually negative decibels, -9.4 dBA. Steven Orfield, the lab's founder, told Hearing Aid Know [an on-line site]: “We challenge people to sit in the chamber in the dark – one person stayed in there for 45 minutes. When it’s quiet, ears will adapt. The quieter the room, the more things you hear. You’ll hear your heart beating, sometimes you can hear your lungs, hear your stomach gurgling loudly. In the anechoic chamber, you become the sound. ...

I admit to being an amateur when it comes to physics, so I was amazed. At least until I thought about it. (I never read the article, however, hence I'm not corrupted by facts.) The whole idea of negative sound is one that I find confusing. If, for example, there is a -9.4 dBA reading, there must be a -4.7 and a -14.3 dBA. The possibility that there are degrees of soundlessness – and, therefore, that one “non-sound” is greater than another – is totally beyond me. (Are there degrees of perfection, uniqueness, and infinity?) And how would you measure it anyway?

I tried to use negative pressure and the vacuum cleaner as analogies, but that didn't really work. The “negative pressure” involved is simply a pressure relative to those around it, rather than an absolute.

Indeed, we know of no temperature below absolute zero, nor a humidity below 0%. At least not yet (unless it just hasn't made it to the media yet). And what tools would provide us with the information? Being a scientist is a great profession. You don't have to explain anything to anyone – only to amaze them. They wouldn't understand the explanation anyway. I know I wouldn't.

I'm a hermit. And I like it quiet. But there are limits. At least I thought there were.

November 13, 2016

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Subsequent to writing this I was informed (by the same son who gave me the initial information) that 0 dBA reflects not soundlessness, but the lowest level of sound that the human ear can hear and that “it seems that the dB scale is more like Celsius or Fahrenheit, not Kelvin.” Facts are nasty things. That's why I try to avoid them and not let myself be corrupted.



November 14, 2016