On a moss-covered log, in the middle of the Hoh Rain Forest, in Olympic National Park in Washington State, there's reddish, square-ish stone. This stone may be the smallest, least noticeable marker ever for a really big idea. This stone marks one square inch of silence.

To understand this unique yet ever-so-ordinary marker, you have to understand Gordon Hempton, the man behind the project that is One Square Inch of Silence. Hempton is an acoustic ecologist—that is to say, he travels around the world recording the sounds of nature. Here's what he said in an interview with Newsweek about how he came to such an odd career:

I was driving from Seattle to Madison, Wis., and decided to sleep in a cornfield for the night. I didn't want to pay for a hotel. As I lay there I heard crickets, and rolling thunder in the background, which captivated me. The thunderstorm came, and I truly listened. The storm passed on, and as I lay there, drenched, the only thought in my mind was, how could I be 27 years old and never have truly listened before? I then took my microphone and tape recorder and went everywhere, obsessively listening—freight trains, hobos—it was a flood of sensation. I realized how we need to hear to survive.

For Gordon Hempton, silence isn't the complete absence of any sound. It's natural quiet, undisturbed by any mechanical, human-made sounds, so that all you hear is the natural world. When Hempton started trying to identify quiet places in 1984, he found just 21 places where you could go for 15 minutes without hearing a single human-made sound. In 2007 he could find only three.

One of those three places is the square inch of silence marked by the little red stone. Hempton and other volunteers are trying to preserve the silence of that small spot, knowing that keeping it completely undisturbed by noise pollution can protect 1000 square miles around it. They are trying to get airlines to agree not to fly over the park, and are trying to get the National Park Service to recognize quiet as a feature of our national parks that needs to be preserved.

Why bother to try to preserve this natural quiet? This is how Hempton put it, in the introduction to the book One Square Inch of Silence:

Silence is not the absence of something, but the presence of everything. ... It is the presence of time, undisturbed. It can be felt within the chest. Silence nurtures our nature, our human nature, and lets us know who we are. Left with a more receptive mind and a more attuned ear, we become better listeners not only to nature, but to each other... . Silence can be found, and silence can find you. Silence can be lost, and also recovered. But silence cannot be imagined, although most people think so. To experience the soul-swelling wonder of silence you must hear it.

If you sat on the log by that stone, you wouldn't hear the sounds of your everyday life. You wouldn't hear cars or leaf blowers, or the hum of computers or refrigerators. But you might hear wind moving the leaves of trees 300 feet above you, or the distant call of an elk, or the hollow knock of a woodpecker searching for bugs, or the patter of rain sifting through branches. And maybe you would experience the soul-swelling wonder of silence.