It is the only absolute desert in North America, a four-hundred-square-mile dry lake bed so desolate that nothing ever grows there. Vast and featureless, Nevada's Black Rock Desert defies visual measurement much to the consternation of off-roaders who venture out onto this playa only to run out of gas before reaching the other side. It is the largest flat area on the continent, where the sound barrier was broken in a car. And it is a place of total silence not even birds or insects live here except when thousands of humans congregate for the Burning Man Festival on Labor Day weekend....