Transcript: Every child who's stared at a map of the Earth has noticed that the continents seem to fit together like pieces of a jigsaw puzzle. Could this just be chance that they look this way? For many years scientists did not know. In the early 1900's German geophysicist Alfred Wegener speculated that the continents had drifted over a long period of time to their present positions. This was an outrageous hypothesis at the time. Nobody could understand possibly how continent size plates of the lithosphere could move around the surface of the Earth. Wegener was hounded, and his theory was not accepted. Unfortunately for Wegener he was right, but the evidence to show that plate tectonics occur and that continental drift was real only happened after his death. Now we have direct evidence that the continents move from very careful motion measurements that show that the continents move up to 10 centimeters per year. And we also have indirect measurement from the spreading of the sea floor to see that the plates are actually drifting, and the continents are actually moving due to geological activity within the Earth.