Alfred Lothar 1880–1930
German physicist, meteorologist, and explorer who introduced the theory of continental drift in 1915. His hypothesis was controversial and remained so until the 1960s, when new scientific understanding of the structure of the ocean floors provided evidence that his theory was correct.
See more at plate tectonics
Biography A look at a map shows that the eastern coast of South America and the western coast of Africa have roughly the same outline. By the early twentieth century scientists observing this similarity speculated that the two continents must have once been joined together with the other continents as one large landmass. But they were unable to come up with a satisfactory model to explain how this giant landmass could become the modern continents positioned around the globe. In 1912 Alfred Wegener proposed a radical new idea, called continental drift, claiming that the primeval supercontinent (which he named Pangaea) had slowly broken apart, its pieces separating over millions of years into the locations observed today. In the geological record he found corroborating evidence in the form of identical rock strata and fossil remains in eastern South America and western Africa and in other locations that would align if the continents fit together. Wegener's theory was soon rejected because he could not propose a suitable mechanism to account for the supposed drifting of continents. It was not until the 1960s that a mechanism would appear—the theory of plate tectonics, stating that the Earth's lithosphere is divided into plates on top of which the continents ride, slowly carried along by huge convection currents within the Earth's mantle. Sadly, Wegener did not live to see the vindication of his theory, having died on an expedition to Greenland in 1930.