Dylan talks with journalist and author Ed Conway about three materials that our entire civilization depends on: salt, copper, and sand. They visit the biggest man-made hole on Earth, a salt mine large enough to fit the Eiffel Tower inside it, and a single mine in North Carolina that is essential to nearly all the world’s computer chips. 

If you want to learn more, check out Ed’s book: Material World: The Six Raw Materials That Shape Modern Civilization.