The Missing Engine

Wegener's evidence was compelling, but he had a fatal problem: he could not explain what moved the continents. He suggested centrifugal force from Earth's rotation, which physicists quickly proved was far too weak.

Wegener died on a Greenland expedition in 1930, his theory still rejected. It took 30 more years and a completely different discovery to prove him right. The engine was convection currents in the mantle, slowly churning like a boiling pot.