Alfred Wegener (1880-1930) is best known as the father of continental drift, the precursor to the theory of plate tectonics. His Ph.D. work at the University of Berlin was in astronomy, but his attention soon turned to meteorology. He maintained a boyhood fascination for Arctic exploration and participated in four research expeditions to Greenland. Another example of his adventurous spirit is that he and his brother set a world ballooning record in 1906 with one trip lasting fifty-two hours.