1880-1930

German geophysicist whose theory of continental drift preceeded the current understanding of plate tectonics. Born in Berlin, the son of an orphanage director, Wegener earned a doctorate in astronomy, and went on several harrowing expeditions to Greenland to study polar air circulation. While recovering from a World War II injury, Wegener studied the strange coincidences of identical plant and animal life existing on continents separated by oceans. He theorized the Earth had once consisted of a single land mass, which he called Pangaea (Greek for "all earth"), that broke into pieces some 200 million years ago. His "continental drift" theory was widely challenged at the time, but proved basically true after geophysicists established the idea of plate tectonics, several decades later.