Summary

The book starts by describing the flow of energy. Then we told of the great discovery of seafloor spreading, that led to the general realization that the interior of the Earth was moving. The motion took the form of great plates that spread apart and plunged back into the Earth. The structure of the motion resembles to a limited extent a form of fluid motion called cellular convection that had been studied by physicists and engineers. The suggestion is advanced that these giant forms of flow are driven and maintained by the flow of energy.