From our planet's underwater caves to its ancient soils, there are entire worlds right beneath our feet. This hour, we explore the subterranean forces that shape our lives above the ground. Guests include cave diver Jill Heinerth, death care advocate Katrina Spade, soil scientist Asmeret Asefaw Berhe, and paleontologist Nizar Ibrahim. Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy