When Alana Casanova-Burgess set out to make a podcast series about Puerto Rico, she struggled with what to call it. Until one word came to mind, a word that captures a certain essence of life in Puerto Rico, but eludes easy translation into English. We talk to Alana about her series, and that particular word, then turn to an old story about treating words as signals of something happening just beneath the surface.

Agatha Christie's clever detective novels may reveal more about the inner workings of the human mind than she intended. According to Dr. Ian Lancashire at the University of Toronto, the Queen of Crime left behind hidden clues to the real-life mysteries of human aging in her writing. Meanwhile, Dr. Kelvin Lim and Dr. Serguei Pakhomov from the University of Minnesota add to the intrigue with the story of an unexpected find in a convent archive that could someday help pinpoint very early warning signs for Alzheimer's disease and dementia. Sister Alberta Sheridan, a 94-year-old Nun Study participant, reads an essay she wrote more than 70 years ago.

La Brega update was produced by Maria Paz Gutierrez

Tuck your napkin under your chin. We’re about to serve up a tale of love, loss, and lamb chops - with a side of genetic modification.

Several years ago we told a story about Amy Pearl. For as long as she could remember, Amy loved meat in all its glorious cuts and marbled flavors. And then one day, for seemingly no reason, her body wouldn’t tolerate it. No steaks. No brisket. No weenies. It made no sense: why couldn’t she eat something that she had routinely enjoyed for decades?

It turned out Amy was not alone. And the answer to her mysterious allergy involved maps, a dancing lone star tick, and a very particular sugar called Alpha Gal.

In this update, we discover that our troubles with Alpha Gal go way beyond food. We go to NYU Langone Health hospital to see the second ever transplant of a kidney from a pig into a human, talk to some people at Revivicor, the company that bred the pig in question, and go back to Amy to find out what she thinks about this brave new world.

The original episode was reported by Latif Nasser, and produced by Annie McEwen and Matt Kielty. Sound design and scoring from Dylan Keefe, Annie McEwen, and Matt Kielty. Mix by Dylan Keefe with Arianne Wack.

The update was reported and produced by Sarah Qari. It was sound designed, scored, and mixed by Jeremy Bloom.

Support Radiolab by becoming a member today at Radiolab.org/donate.

In this hour of Radiolab, stories of cross-species communication.

When we gaze into the eyes of a wild animal, or even a beloved pet, can we ever really know what they might be thinking? Is it naive to assume they're experiencing something close to human emotions? Or is it ridiculous to assume that they AREN'T feeling something like that? We get the story of a rescued whale that may have found a way to say thanks, ask whether dogs feel guilt, and wonder if a successful predator may have fallen in love with a photographer.

In tape five, three stories: first, a tale of how the cassette tape supercharged the self-help industry. Second, cassettes filled with history make an epic journey across Africa with a group of Lost Boys. And finally, Simon meets up with fellow Radiolabber David Gebel to dig through an old box of mixtapes and rediscover the unique power of these bygone love letters.

Mixtape was reported, produced, scored and sound designed by me, Simon Adler, with music throughout by me. Unending reporting and production assistance was provided by Eli Cohen.

Special Thanks to: Shad Helmstetter, Vic Conan, Glenna Salisbury, Jerry Rosen, Richard Petty, Sharon Arkin, Angela Impey, William Mulwill for sharing his cassettes with me, and to the British library for sharing some of their recordings from their South Sudan collection, which is housed at the British Library Sound Archive.

Support Radiolab by becoming a member today at Radiolab.org/donate.

In 1983, Simon Goodwin had a strange thought. Would it be possible to broadcast computer software over the radio? If so, could listeners record it off the air and onto a cassette tape? This experiment and dozens of others in the early 80s created a series of cassette fueled, analog internets. They copied and moved information like never before, upended power structures and created a poisonous social network that brought down a regime.

In tape four of Mixtape, we examine how these early internet came about, and how the societal and cultural impacts of these analog information networks can still be felt today.

Mixtape is reported, produced, scored and sound designed by Simon Adler with original music throughout by Simon. Top tier reporting and production assistance was provided by Eli Cohen.

Special thanks to: Alex Sayf Cummings, Martin Maly, Piotr Gawrysiak, Joe Tozer, James Gleick, Jason Rezaian, Gholam Khiabany and Mo Jazi. And to Arash Aziz for helping us every step of the way with our story about Khomeini. And Simon Goodwin for making us that secret code. And to Micah Loewinger to tipping me off to these software radio broadcasts.

Support Radiolab by becoming a member today at Radiolab.org/donate.

As the Vietnam war dragged on, the US military began desperately searching for any vulnerability in their North Vietnamese enemy. In 1964, they found it. It was an old Vietnamese folktale involving a ghost, eternal damnation and fear - a tailor made weaponizable myth. And so, armed with tape recorders and microphones, the military set out to win the war by bringing this ghost story to life.

Today, the story of these efforts and their ghosts that still haunt us today.

Mixtape is reported, produced, scored and sound designed by Simon Adler with original music throughout by Simon. Indispensable reporting and production assistance was provided by Eli Cohen.

This episode was produced by Annie McEwen, with original music by Annie. Original reporting was contributed by Trung Dung Vo and Nguyễn Vân Hà.

Special thanks to: Allison Boccia, Jared Tracy and Herb Friedman. And to Mathew Campbell for introducing me to the Wandering Soul tape to begin with. And to Erik Villard for all his help pulling those tapes and voices for us.

Support Radiolab by becoming a member today at Radiolab.org/donate.

In 1946 Bing Crosby was the king of media. He was the movie star, the pop star and his radio show was reaching a third of American living rooms each week. But then, it all started to fall apart. His ratings were plummeting and his fans were fleeing. Bing however, was not going down without a fight.

Today, the story of how Bing Crosby and some stolen Nazi technology won his audience back, changed media forever and accidentally broke reality along the way.

Mixtape is reported, produced, scored and sound designed by Simon Adler with original music throughout by Simon Adler. Invaluable reporting and production assistance was provided by Eli Cohen.

Special thanks to: Michele Hilmes, Pete Hammer, Rich Flores, Mara Mills, Jonathan Sterne, Claudia Mewes. Though their voices weren’t in the piece, input certainly was.

And to Mary Crosby and Robert Bader, for opening up Bing’s archive for us, and enabling us to fill this episode with so much of Bing’s music.

Support Radiolab by becoming a member today at Radiolab.org/donate.

Through the 1980s, the vast majority of people in China had never heard western music, save for John Denver, the Carpenters, and a few other artists included on the hand-picked list of songs sanctioned by the Communist Party. But in the late 90s, a mysterious man named Professor Ye made a discovery at a plastic recycling center in Heping.In episode 1 of Mixtape, we talk to Chinese historians, music critics, and the musicians who took the damaged plastic scraps of western music, changed the musical landscape of China, and reimagined rock and roll in ways we never could’ve imagined.

Mixtape is reported, produced, scored and sound designed by Simon Adler with original music throughout by Simon. Invaluable reporting and production assistance was provided by Eli Cohen. Additional reporting by Noriko Ishigaki, Rebecca Kanthor and our amazing anonymous Chinese reporter.

Special thanks to: Paul de Gay, Juliette Kristensen, Rebecca Tuhus-Dubrow, Nick Lyons, Michael Bull, Jiro Ishikawa, Hayley Zhao, Megan Smalley and Deanne Totto.

This episode would not have happened without each and every one of them.

Support Radiolab by becoming a member today at Radiolab.org/donate.