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Crazy theories that turned out to be true

By Rachel J. Dickinson / November 9, 2004

Now that the weather has turned cold in the northern part of the Northern Hemisphere, our thoughts are turning to snow and ice. Many of us take advantage of the winter weather by ice skating, skiing, or snowboarding. But what if we had more snow or ice - let's say about 5,000 feet of snow and ice - rising above where your house stands today?

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Does that sound crazy? It sure sounded crazy to people in the early 1800s, when the Ice Age theory was first proposed. But like many radical theories about Earth's past, it was later proved to be true.

Let's take a look at three "crackpot" theories that have changed the way we look at Earth's past:

Baby, it's coooold outside: The Great Ice Age

Many years ago - 167 years ago, to be exact - a Swiss naturalist named Louis Agassiz (AG-uhs-see) proposed the theory of the Great Ice Age. Agassiz grew up in the Swiss Alps and was very familiar with alpine (mountain) glaciers and their effects on the landscape. One day two of his friends took him to see an alpine glacier and pointed out big boulders (called erratics) strewn across a valley well below the glacier. Agassiz and his friends recognized that these huge boulders must have been carried into the valley by a strong force - a glacier. But how could that be? The glacier was way up the mountainside.

Then Agassiz's friends pointed to ridges of gravel, sand, and boulders that marked the front edge of where a glacier had once stood. At that time, naturalists who studied glaciers knew that these very slow moving "ice rivers" scoured the land beneath them. They also picked up and carried everything in their path. And because of the way the ice in a glacier moves, any debris that a glacier has picked up will be deposited at the front edge of a glacier. That's what creates these ridges of material, called moraines.

This was a "Eureka!" moment for Agassiz. Suddenly, everywhere he looked he saw evidence that glaciers had been there. He saw erratics where they shouldn't be, far from the bedrock from which they had broken off. He saw glacial moraines where others just saw gravel banks. In places like Scotland, which is thousands of miles from the nearest glacier, Agassiz saw rocks with long striations - scratches or gouges - on them. The striations indicated the presence of a once flowing glacier.

Agassiz collected his thoughts and presented them in a lecture in 1837. Three years later, his book "Studies on Glaciers" was published. In it, he proposed that "a huge ice sheet ... extended beyond the shorelines of the Mediterranean and of the Atlantic Ocean, and even completely covered North America and Asiatic Russia."

Scientists hotly debated the idea of glaciers the size of continents for decades. Eventually, though, they came to accept Agassiz's theory. Not only that, but other scientists concluded that there had been not just one, but many Ice Ages in our past.

Continents adrift on an ocean of magma

Alfred Wegener was an early 20th-century German meteorologist. He had a PhD in astronomy, but dropped it to study meteorology, the new science of weather. During the school year he was a popular lecturer on meteorology at the University of Marburg in Germany. For several summers he joined or led expeditions to Greenland. (Exploring Greenland was his lifelong passion.)

In 1910, Wegener happened to notice on a map that the coastlines of South America and Africa looked as though they had once fitted together, like pieces of a jigsaw puzzle. He was not the first to notice this; it was first noted by a 16th-century mapmaker. Perhaps you've noticed it, too. But Wegener became obsessed with the idea of explaining how this could be. He gave his first lecture on the topic in January 1912. That's where he put forth the idea of "continental displacement" or what later was called "continental drift." (That same year, incidentally, he returned to Greenland and set a record for the longest crossing of the ice cap on foot.)