World Basics: The Earth’s Shell Has Cracked, and We’re Drifting on the Pieces December 18, 2018December 18, 2018NATALIE ANGIERComments Off on Basics: The Earth’s Shell Has Cracked, and We’re Drifting on the Pieces Plate tectonics helped make our planet stable and habitable. But the slow shifting of continents is still a mysterious process.