[Detour] LIGO | If two black holes collide in the universe, do they make a sound?

Redwood National and State Parks | How do the world’s tallest trees hold each other up?

Redwood trees have roots only ten feet deep. For a tree that grows as tall as the statue of liberty, that should be a problem…This episode is about why it isn't. We explain how redwoods manufacture the fog that feeds them, what a banana slug actually does for a forest, and what the Yurok people understood about these trees long before anyone else was paying attention. And we tell the story of four women — Laura Mahan, Lady Bird Johnson, Julia Butterfly Hill, and Amy Cordalis — who have spent the last century making sure these forests survived.

[Detour] LIGO | If two black holes collide in the universe, do they make a sound?

This episode explains how scientists built a machine so sensitive that your heartbeat standing next to it would ruin the experiment...and why they put it in the middle of the Washington desert. We walk through the control room where gravitational wave detections happen, with a working LIGO scientist as our guide. We explain what it means that space itself can stretch and squeeze, and why the signal they caught in 2015 had been traveling for 1.3 billion years before anyone caught it. We talk about Einstein getting fact-checked by a journal reviewer, refusing to believe it, and eventually being proven right sixty years after he died. And we look at what's coming next: a detector in space with arms two and a half million kilometers long that might — just might!!!— let us hear the echo of the Big Bang.

Joshua Tree National Park | How does anything survive in a desert this dry?

Joshua Tree isn't just about weird trees and cool rocks. This episode tells you why those "trees" are not actually trees and what a rain shadow actually does to a landscape. We explain why the Oasis of Mara—the place where Serrano and Chemehuevi people had lived peacefully for generations—got claimed by the state of California in 1875 and sold to the Southern Pacific Railroad without their consent. We meet Minerva Hamilton Hoyt, the wealthy socialite who shipped seven freight cars of desert plants across the country to convince people this place was worth saving. And we talk about what's happening right now: animals so desperate for water they're showing up in people's backyards, and what that means for the future of the desert.