THE DRIFTING WORLD: ALFRED WEGENER AND MOVING CONTINENTS

In January 1912 a thirty-one-year-old meteorologist stood up in Frankfurt and told a room of geologists that the continents move. He was right. He was also, on the question that mattered most to his audience, spectacularly wrong - and the men who threw him out were not fools. They asked what force could shove a continent through the floor of an ocean, and the best answer he had was far too weak to move anything at all. Harold Jeffreys did the arithmetic. It was not close. This is the story of what happens when somebody measures a pattern he cannot explain. Alfred Wegener assembled evidence that has never been overturned - the fit of the coasts at the edge of the shelf, the same fossil fern on five continents, glacial scratches running inland from the sea on three of them - and bolted it to a mechanism that was rubbish. His profession treated the pattern and the mechanism as one claim and discarded both. It took half a century, a world war's worth of naval instruments and a magnetic barcode on the sea floor to pull them apart again. And here is the part that never makes it onto the poster. The force is still being argued about. Geophysicists have not settled what actually drives the plates - sinking slabs, spreading ridges, rising plumes, some conspiracy of all three. The standard Wegener was held to is a standard the winning theory has never met either. What ended the argument was not an explanation. It was a measurement: stripes of reversed magnetism on the ocean floor, and then satellites that simply watch the Atlantic widen while you read this sentence, at roughly the rate your fingernails grow. He did not live to see any of it. He died on the Greenland ice cap in November 1930, in the week of his fiftieth birthday, hauling food to two men at a weather station in the middle of nothing. They buried him with his skis planted upright in the snow, and that is still where he is, somewhere under a great deal more snow, moving very slowly west. >Keywords: Alfred Wegener; continental drift; plate tectonics; history of science; Pangaea; geology; scientific consensus