Lex Fridman Podcast

Podbit · Lex Fridman Podcast

#489 – Paul Rosolie: Uncontacted Tribes in the Amazon Jungle

Explore episode Jan 13, 2026
Science
The Mist River Moment

#489 – Paul Rosolie: Uncontacted Tribes in the Amazon Jungle · Jan 13, 2026 Science

Scientists describe an invisible 'flying river' above the Amazon that carries more moisture than the Amazon River itself. Rosolie had heard about it his whole life. Bleeding and exhausted at 120 feet up a millennium ironwood at dawn, he finally saw it: golden mist flowing over the canopy as macaws took flight beneath him. He cried.

Where this was said

Climbing the giant tree

At 2:01:30 · chapter starts 1:58:45

Rosolie's telling of climbing the giant ironwood is equal parts adventure story and spiritual experience. The tree's trunk goes vertical for 70 feet before the first branch appears; the only route up is a single vine, climbed gorilla-style in the dark at 4 AM with JJ belaying from below. At every 30-foot interval Rosolie places a webbing anchor — meaning a fall before the next anchor doubles his fall distance and slams him into the tree trunk. Wasps, venomous snakes, and complete darkness are the ambient threats. After more than an hour, he reaches the canopy — branches as thick as mature oaks — and ascends to about 120 feet just as the howler monkeys begin their morning call and macaws start taking flight beneath him. The sun's first rays hit the canopy and begin lifting moisture: the atmospheric river scientists call the 'flying river,' carrying more water above the Amazon than flows in the river below. Rosolie sees it in the golden morning light, tears streaming, feeling what he can only describe as 'the gift of the tree.' Lex reads the passage from the book — some of the most beautiful nature writing of the conversation.

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