Inside Planet Earth: Past Scientific Beliefs

About the early scientific beliefs about the inside of Planet Earth, the past belief the earth was hollow.

WHAT SCIENTISTS ONCE THOUGHT

The Eggshell Mountains. Dr. Edmund Halley, Astronomer Royal for England in the 18th century, thought that beneath its 500-mi.-thick crust, the earth was hollow. In the hollow, he said, were 3 planets.

Leonard Euler, an 18th-century mathematical genius, also thought that the earth was hollow. He maintained that it was inhabited and had a central sun.

In 1738, French mathematician Pierre Bouer, was in the Andes on a scientific expedition. While making measurements, he noticed that the gravitational attraction of the mountains was less than would be expected from such a mass. He thought that the reason for this was the relatively light weight of granite, but, by some strange leap of logic, the French press extrapolated from his findings the idea that the mountain was hollow and inhabited. (Later scientists conjectured that lighter rock had formed on the heavy basalt mantle, like cream on milk, and that it floats there like a raft.)