While doing field work in Central America in the 1990's, biologist Karen Lips noticed the frogs she was studying were disappearing. Scientists in other parts of the world had documented the same thing - frogs and amphibians dying at an alarming rate. For years no one knew what was killing the animals until, finally, a bit of good luck helped solve the mystery. Follow host Maddie Sofia on Twitter @maddie_sofia. Email the show at shortwave@npr.org.

How can you tell if you have the flu, or the common cold? Why does your arm hurt after you get the flu shot? And can getting the flu shot actually give you the flu? This episode, we answer your flu-related listener questions with the help of Dr. Nicole Bouvier at the Icahn School of Medicine at Mount Sinai. Follow host Maddie Sofia on Twitter @maddie_sofia and reporter Emily Kwong @emilykwong1234. Email the show at shortwave@npr.org.

The private space company run by Elon Musk launched 60 satellites into orbit this week. Science correspondent Geoff Brumfiel explains why astronomers worry that kind of traffic — if it continues unabated — could permanently alter their ability to observe the night sky. Follow host Maddie Sofia on Twitter @maddie_sofia. Email the show at shortwave@npr.org.

NPR science correspondent Dan Charles explains why most of the dairy cows in America are descended from just two bulls, creating a lack of genetic diversity that can lead to health problems. He also visits a lab at Penn State University where scientists are trying to change that. Follow reporter/host Emily Kwong on Twitter @emilykwong1234. Email the show at shortwave@npr.org.

A lot of the stuff we buy in the U.S. comes by ship — ships that use a particularly dirty kind of fuel. Now a big shipping company says it wants to go zero carbon. Climate reporter Becky Hersher tells us how some old tech might play a role and where that tech falls short. Follow Maddie on Twitter @maddie_sofia. Email the show at shortwave@npr.org.

Helium is the second-most common element in the cosmos, but it's far rarer on planet Earth. As part of our celebration of the periodic table's 150th birthday, reporter Geoff Brumfiel shares a brief history of helium's ascent, to become a crucial part of rocket ships, MRI machines, and birthday parties. Follow host Maddie Sofia on Twitter @maddie_sofia. Email the show at shortwave@npr.org.

What happens after a whale dies? Their carcasses, known as "whale falls," provide a sudden, concentrated food source for organisms in the deep sea. Biologist Diva Amon is our guide through whale-fall ecosystems and the unique species that exist on the bones of these fallen whales. Follow host Maddie Sofia on Twitter @maddie_sofia and reporter Emily Kwong @emilykwong1234. Email the show at shortwave@npr.org.

The spotted lanternfly is eating its way through trees and crops in eastern Pennsylvania. NPR science correspondent Dan Charles explains how scientists hope to stop the spread of this invasive pest by importing a natural enemy from its home in China. Follow host Maddie Sofia on Twitter @maddie_sofia. Email the show at shortwave@npr.org.

It's official, but not a surprise. The U.S. has told the United Nations it wants to withdraw from the Paris Agreement, the global accord to fight climate change. President Trump announced his intention to leave it back in 2017. Climate reporter Becky Hersher tells us what the Paris Agreement is, why the Trump Administration wants out and what it means now that the U.S. has made it official. Follow host Maddie Sofia on Twitter @maddie_sofia. Email the show at shortwave@npr.org.

Victoria Gray has sickle cell disease, a painful and debilitating genetic condition that affects millions of people around the world. But an experimental gene-editing technique known as CRISPR could help her — and, if it does, change the way many genetic diseases are treated. Correspondent Rob Stein tells her story, an NPR-exclusive, and explains the science behind her treatment. Follow host Maddie Sofia on Twitter @maddie_sofia. Email the show at shortwave@npr.org.

It's our first-ever listener questions episode! On this Short Wave, Andy from Grand Rapids, Michigan, asks why some people seek out scary experiences. We reached out to Ken Carter, a psychology professor at Oxford College of Emory University, for answers. Turns out, some of us may be more wired to crave the thrill. Follow Maddie on Twitter @maddie_sofia. Email the show at shortwave@npr.org.

The idea of human zombies probably seems pretty far-fetched. But there are real zombies out there in the animal kingdom. Ed Yong of The Atlantic creeps us out with a couple of examples. Hint: they involve fungus. Follow Maddie on Twitter - she's @maddie_sofia. Email the show at shortwave@npr.org.

Crows have gotten a bad rap throughout history. Think about it. A group of them is called a "murder." To get some insight into crows and perhaps set the record straight, we talked to Kaeli Swift. She's a lecturer at the University of Washington and wrote her doctoral thesis on crow "funerals."
In an earlier version of this episode, we used the word "spooky" to describe crows. Because that word has a history of being used as a racial slur, we chose to replace it with the words "scary" and "creepy." Thanks to our listeners who helpfully pointed this out to us, and we apologize. You can learn more about this from our friends at Code Switch.

Californians face a terrible new normal as wildfire season grows longer and more intense. Jennifer Montgomery, head of the California's Forest Management Task Force, explains three key factors at the heart of why the state is now at such high risk. It turns out, one of them goes all the way back to Spanish colonization. Follow host Maddie Sofia on Twitter: @maddie_sofia. Or email the show at shortwave@npr.org.

We meet two scientists working on opposite sides of the world, both thinking creatively about rising sea levels and our changing oceans. Andrea Dutton, a geologist at the University of Wisconsin-Madison, and Stacy Jupiter, a marine biologist and Melanesia Director with the Wildlife Conservation Society, were awarded MacArthur Fellowships this fall. Follow host Maddie Sofia on Twitter: @maddie_sofia. Or email the show at shortwave@npr.org.

NPR science correspondent Geoff Brumfiel shares the story of Nazi Germany's attempt to build a nuclear reactor — and how evidence of that effort was almost lost to history. It's a tale he heard from Timothy Koeth and Miriam Hiebert at the Department of Materials Science and Engineering at the University of Maryland in College Park. Read more on their original story in Physics Today. Follow host Maddie Sofia on Twitter @maddie_sofia. Email the show at shortwave@npr.org.

Artificial intelligence might not be as smart as we think. University and military researchers are studying how attackers could hack into AI systems by exploiting how these systems learn. It's known as "adversarial AI." Some of their experiments use seemingly simple techniques. Dina Temple-Raston has been looking into this for her special series, I'll Be Seeing You. Follow host Maddie Sofia on Twitter: @maddie_sofia. Or email the show at shortwave@npr.org.

The world's largest intact temperate rainforest is in a place you may not expect: southeast Alaska. The Trump administration wants to eliminate a longstanding rule protecting the Tongass National Forest from logging and road construction. Why? And what might this mean for one of the top carbon sinks in the world? Maddie talks with reporter Emily Kwong about the Tongass. Email the show at shortwave@npr.org.

NASA astronauts Christina Koch and Jessica Meir completed the first all-female spacewalk last week. The historic moment came 35 years after Kathryn Sullivan became the first American woman to spacewalk. We hear from Koch, Meir, and Sullivan. And former NASA chief scientist Ellen Stofan tells us why she says this moment is long overdue. Follow host Maddie Sofia on Twitter @maddie_sofia. Email the show at shortwave@npr.org.

Randall Munroe, the cartoonist behind the popular Internet comic xkcd, finds complicated solutions to simple, real-world problems. In the process, he reveals a lot about science and why the real world is sometimes even weirder than we expect. His new book is called How To: Absurd Scientific Advice for Common Real-World Problems. Follow host Maddie Sofia on Twitter: @maddie_sofia. Email the show at shortwave@npr.org.

Pioneering ecologist Nalini Nadkarni takes us up into the canopy — the area above the forest floor — where she helped research and document this unexplored ecosystem. Plus: the story of her decades-long effort to get more women into science, and how she found a surprising ally in the fight — Barbie. Video and more from Maddie's trip to the canopy is here. Follow Maddie on Twitter @maddie_sofia. Email the show at shortwave@npr.org.

The science is nascent and a little squishy, but researchers like Giulia Poerio are trying to better understand ASMR — a feeling triggered in the brains of some people by whispering, soft tapping, and delicate gestures. She explains how it works, and tells reporter Emily Kwong why slime might be an Internet fad that is, for some, a sensory pleasure-trigger. Follow Maddie on Twitter @maddie_sofia. Email the show at shortwave@npr.org.

Amid an outbreak of lung injury cases, there's a new spotlight on the dangers of vaping, a practice that's been marketed as an alternative to smoking. NPR health correspondent Allison Aubrey explains, with the story of one teenager whose vaping habit landed her in the ER. Follow host Maddie Sofia on Twitter @maddie_sofia. Email the show at shortwave@npr.org.

Magic mushrooms — they're not just for getting weird with your friends. Researchers are increasingly looking at psychedelics to treat conditions such as depression and addiction.

Short Wave, NPR's new daily science podcast, starts October 15th. Join host Maddie Sofia for new discoveries, everyday mysteries, and the science behind the headlines – all in about 10 minutes, Monday through Friday. Subscribe now.