David Johnson is a man in a hurry. Carrying a battered leather shoulder bag and sweating profusely in the searing desert heat, he chatters nonstop as he scrambles up a stony, barren hill in the Nasca region of southern Peru. Johnson, a retired high school social studies teacher from Poughkeepsie, New York, thinks he has discovered the secret behind one of the world's most enduring archaeological mysteries, and he can't wait to show off how he got the idea. He tops the hill and stops, sets his feet, purses his lips, and hitches up his pants with his elbows to signal he is ready to make his point. The sun is low, the shadows sharp. Johnson steps aside theatrically. "That's what I saw," he announces, and points.
Below, a parched pampa, or desert, stretches southward for miles toward a distant peak in the Andes Mountains. On the valley floor, a ...
