From the icy lakes of Sweden to the cliffs of California, wind athletes move in the space where earth and air converge. They fly. They flip. They zip. They skim. And, like a surfer to the swell or a skier to the snow, they're beholden to nature's mercurial rhythm. Sitting in the cubicle on a weekday afternoon, wind addicts get goose bumps just from seeing the trees in the parking lot shake.

As dramatically as wind-driven movement has evolved, the ancient sail—that same simple motor the early Egyptians took out on the Nile—remains largely unchanged. With a sheet of cloth and a gust of air, the wind seeker's thrills are always close by.

Above, three paragliders descend along the curvy flanks of Mt. Tamalpais in Marin County, California, overlooking the Pacific Ocean. They cruise down in tight turns, intermittently gaining lift on rising columns of wind called thermals.