DR. T.V. PADMA
Take out an atlas or globe and look again at the nearly perfect jigsaw puzzle fit of the South America and African coastlines on either side of the Atlantic Ocean. Were they once stuck together? If so, why did they separate and how did they move so far apart?
The first person we know of who explained the reason behind this was a German called Alfred Wegener. His idea was incorrect, but we still respect and remember it, because it opened a new way of thinking about the earth's continents.
Until Alfred Wegener put forward his ideas, most people assumed that continents were more or less fixed in position and could not move (except up and down in the case of earthquakes). Wegener paved the way for the future by suggesting an earth-shaking possibility: that continents could migrate or "float" on a fluid that lay beneath them.
Wegner thought that there was a fluid inside the earth and that the continental landmasses floated on this. The rotation of the earth could make the fluid spin, he decided, and as this movement could also propel the solid continents into motion. So America and Africa might have been like jigsaw pieces that were together at first, and then separated and pushed away from one another. The continents then floated on and ploughed through the fluid beneath them until they arrived at their present positions.
According to him, continents had a crust that was light, which floated above the ocean crust which was heavier. His idea was that the light continents could drift and push their way through the ocean. Wegener wasn't taken seriously at first. It took about half a century for scientists to replace their old ideas with his new theory of "continental drift".
Although this theory was wrong, it forced geologists (scientists who study the earth) to break out of their way of thinking (their "paradigm") and so it was an important breakthrough. Funnily enough, Wegener himself was not a geologist! In fact, he was a meteorologist (a scientist who studies weather).
This amazing man not only contributed his ideas to two different areas of science, he was also an active arctic explorer who prepared for his expeditions by skating, skiing, and hiking. He and his brother even established a world record in 1906 for the first uninterrupted 52-hour long balloon flight!
So, if Wegener's theory wasn't quite correct and continents don't float on a liquid that is underneath them, then what really happens? Answers to that in the weeks ahead.
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