Short Wave

The evolutionary purpose of kissing has long eluded scientists. Smooching is risky, given things like pointy teeth, and inherently gross, given an estimated 80 million bacteria are transferred in a 10 second kiss. And yet, from polar bears to humans, albatrosses and prairie dogs, many animals kiss. So, what gives? Evolutionary biologist Matilda Brindle tells us the sordid details driving this behavior, what distinguishes different kinds of kissing and whether culture has anything to do with why people kiss. Interested in more of the science behind love and connection? Email us your question at shortwave@npr.org. Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave. Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy

It seems like artificial intelligence is everywhere in our virtual lives. It's in our search results and our phones. But what happens when AI moves out of the chat and into the real world? NPR science editor and correspondent Geoff Brumfiel took a trip to the Intelligence through Robotic Interaction at Scale Lab at Stanford University to see how scientists are using AI to power robots and the large hurtles that exist for them to perform even simple tasks. (encore) Read Geoff's full story. Interested in more AI stories? Email us your ideas at shortwave@npr.org.Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave. Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy

Watching a ski jumper fly through the air might get you wondering, “How do they do that?” The answer is – physics! That’s why this episode, we have two physicists – Amy Pope, a physicist from Clemson University and host Regina G. Barber – break down the science at play across some of the sports at the 2026 Winter Olympics. Because what’s a sport without a little friction, lift and conservation of energy? They also get into the new sport this year, ski mountaineering - or “skimo” as many call it - and the recent scandal involving the men’s ski jump suits. Interested in more science behind Olympic sports? Check out our episodes on how extreme G-forces affect Olympic bobsledders, the physics of figure skating and the science behind Simone Biles' Olympic gold. Also, we’d love to know what science questions have you stumped. Email us your questions at shortwave@npr.org – we may solve it for you on a future episode! Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave. Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy

In 1928, a chance contaminant in Scottish physician Alexander Fleming’s lab experiment led to a discovery that would change the field of medicine forever: penicillin. Since then, penicillin and other antibiotics have saved millions of lives. With one problem: the growing threat of antibiotic resistance. Today on Short Wave, host Regina G. Barber talks to biophysicist Nathalie Balaban about the conundrum — and a discovery her lab has made in bacteria that could turn the tides. Check out our episodes on extreme bacteria in Yellowstone and the last universal common ancestor. Interested in more science behind our medicines? Email us your question at shortwave@npr.org. Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave. This episode was produced by Berly McCoy, edited by our showrunner Rebecca Ramirez and fact checked by Tyler Jones. Jimmy Keeley was the audio engineer. Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy

Rhythm is everywhere. Even if you don’t think you have it, it’s fundamental to humans’ biological systems. Our heartbeat is rhythmic. Speech is rhythmic. Even as babies, humans can track basic rhythm. Researchers wanted to find out if there were more layers to this: Could babies also track melody and more complicated rhythms? So they played Bach for a bunch of sleeping newborns and monitored the babies’ brains to see if they could predict the next note. What they found offers clues about whether melody and rhythm are hard-wired in the human brain or learned over time. We also get into what powers the eating habits of some snakes and chameleons, and insights into the role of sleep in problem-solving. Have a scientific question you want us to answer? Email us at shortwave@npr.org. Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave. Listen to Short Wave on Spotify and Apple Podcasts. This episode was produced by Jordan-Marie Smith and Rachel Carlson. It was edited by Rebecca Ramirez and Christopher Intagliata. Tyler Jones checked the facts. The audio engineers were Jimmy Keeley and Hannah Gluvna. Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy

Olympic sliding sports – bobsled, luge and skeleton – are known for their speed. Athletes chase medals down a track of ice at up to 80 or 90 mph. With this thrill comes the risk of “sled head.” Athletes use the term to explain the dizziness, nausea, exhaustion and even blackouts that can follow a brain-rattling run. Untreated, this can turn into concussions and subconcussions. But there’s still a lot more to learn about this condition. So today, host Emily Kwong speaks with two experts about the medical research into sled head – and how the sport would need to change to protect athletes’ brain health. Check out more of NPR’s Olympics coverage. Interested in more Olympic science? Email us your question at shortwave@npr.org. Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave. Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy

Autism has a long history of misinformation that continues to today. The Trump administration has perpetuated some of this misinformation in the last year. Among other things, officials have claimed certain groups of people don’t get the condition and that taking Tylenol while pregnant causes autism to later develop in children. Today, NPR Science Correspondent Jon Hamilton sets the record straight with host Emily Kwong on what scientists do and don’t know about autism. If you liked this episode, check out our episodes on an Autism researcher’s take on Trump’s claims about Tylenol and a Fragile X treatment that may be on the horizon. Interested in more science in the news? Email us your question at shortwave@npr.org. Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave. This episode was produced by Berly McCoy. It was edited by Rebecca Ramirez. Tyler Jones checked the facts. The audio engineer was Damian Herring. Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy

PFAS make pans nonstick, clothes waterproof and furniture stain resistant. They're so ubiquitous, they're even inside of us. Now, researchers are looking for more insights in firefighters' blood. Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy

On Jan. 28, 1986, NASA’s 25th space shuttle mission, Challenger, left the launchpad in Cape Canaveral, Florida. Seventy-three seconds into flight, Challenger exploded over the Atlantic Ocean as millions of people watched. All seven people on board died. Now, forty years later, journalist Adam Higginbotham chronicles what went wrong. His book Challenger: A True Story of Heroism and Disaster on the Edge of Space pieces together stories from key officials, engineers and the families of those killed in the explosion – and details how its legacy still haunts spaceflight today. Consider checking out our episode speaking to an astronaut while she’s in space. Have a scientific question you want us to answer? Email us at shortwave@npr.org. Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave. Listen to Short Wave on Spotify and Apple Podcasts. Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy

This past weekend, Winter Storm Fern struck the States. Sleet, snow and ice battered Americans all the way from New Mexico to New York. Scientists predicted its arrival in mid-January, and in anticipation of the storm, more than 20 state governors issued emergency declarations. But how did scientists know so much, so early, about the approaching storm? NPR climate reporter Rebecca Hersher says it has to do with our weather models… and the data we put into them. Which begs the question: Will we continue to invest in them? Interested in more science behind the weather? Check out our episodes on better storm prediction in the tropics and how the Santa Ana winds impact the fire season this time of year. Have a question we haven’t covered? Email us at shortwave@npr.org. We’d love to consider it for a future episode! Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave. This episode was produced by Hannah Chinn. It was edited by our showrunner Rebecca Ramirez. Tyler Jones and Rebecca Hersher checked the facts. The audio engineer was Robert Rodriguez. News clips were from CBS Boston, Fox Weather, Fox 4 Dallas-Fort Worth, and PBS Newshour. Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy

Listener Shabnam Khan has a problem: Every time she works in her garden, she’s visited by lizards and frogs. Shabnam has lived in the metro Atlanta area for decades, and she says this number of scaly, clammy visitors has exploded over the past few years. Frogs croak at night; lizards sun on the cement. And she wants to know, where did all of these animals come from? It turns out, there are a number of potential answers – from small-scale environmental changes like natural plants and new water sources to large-scale shifts like urbanization and development displacing local wildlife. On this month’s Nature Quest, host Emily Kwong and producer Hannah Chinn discuss the possibilities – and impacts – of these changes. If you live in the Atlanta area and are interested in volunteering with MAAMP (the Metro Atlanta Amphibian Monitoring Program), you can sign up for training here. This episode is part of Nature Quest, our monthly segment that brings you a question from a fellow listener who is noticing a change in the world around them. Send a voice memo to shortwave@npr.org telling us your name, location and a question about a change you’re seeing in nature – it could be our next Nature Quest episode! Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave. Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy

There’s an ongoing, near-total blackout of the internet in Iran. The shutdown is part of a response by the government to ongoing protests against rising inflation and the value of the nation’s currency plummeting. Since protests began more than two weeks ago, only an estimated 3% of Iranians have stayed online through the satellite internet system Starlink. Doing so is a crime. So, today on the show: Iran offline. We get into how the internet works, how a government can shut it down and how scientists are monitoring the nation’s connectivity from afar. Check out more of NPR's coverage of Iran: - Iran Protests Explained - There's an internet blackout in Iran. How are videos and images getting out? - Iran blocked the internet amid deadly protests. Some voices are still getting through Interested in more science behind the headlines? Email us your question at shortwave@npr.org – we may tackle it in a future episode! Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave. This episode was produced by Berly McCoy, edited by Rebecca Ramirez and fact checked by Tyler Jones. Robert Rodriguez was the audio engineer. Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy

A new study shows penguins are breeding earlier than ever in the Antarctic Peninsula. This region is one of the fastest-warming areas of the world due to climate change, and penguins time their breeding period to environmental conditions. That’s everything from the temperature outside and whether there’s ice on the ground to what food is available. Changes in those conditions could contribute to mating changes. Plus, answers to a debate about how ice melts and how dirty diapers train parents in the art of disgust. Have a scientific question you want us to answer? Email us at shortwave@npr.org. Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave. Listen to Short Wave on Spotify and Apple Podcasts. This episode was produced by Jason Fuller and Rachel Carlson. It was edited by Rebecca Ramirez and Christopher Intagliata. Tyler Jones checked the facts. The audio engineers were Kwesi Lee and Hannah Gluvna. Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy

Cloud 9 is a failed galaxy. It’s a clump of dark matter, called a dark matter halo, that never formed stars. But this failure could be the key to a mystery almost as old as the universe itself: dark matter. Scientists don’t know what dark matter is, but Cloud 9 could offer new clues. Three researchers weigh in on this new discovery and why it could be a missing piece to the story on how the universe formed. Check out our episode with astrophysicist Jorge Moreno on the mysterious Great Attractor and our summer series on space. Have a scientific question you want us to answer? Email us at shortwave@npr.org. Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy

Medical drama The Pitt is winning Golden Globes… and health care workers’ hearts. Medical experts say the show, which chronicles a fictional Pittsburgh hospital emergency department, is perhaps the most medically accurate show that’s ever been created. But what about The Pitt makes it so accurate… and does the second season hold up as well as the first? Stanford Global Health Media Fellow (and fourth-year medical school student) Michal Ruprecht joins Short Wave to discuss. Have a question about YOUR favorite show and whether science supports it? Email us at shortwave@npr.org. Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave. This episode was produced by Hannah Chinn. It was edited by Rebecca Ramirez. Tyler Jones checked the facts. The audio engineer was Maggie Luthar. Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy

In today's episode, host Emily Kwong leads us on a night hike in Patuxent River State Park in Maryland. Alongside a group of naturalists led by Serenella Linares, we'll meet a variety of species with unique survival quirks and wintertime adaptations. We'll search out lichen that change color under UV light and flip over a wet log to track a salamander keeping warm under wet leaves. Emily may even meet the bioluminescent mushrooms of her dreams. Plus, we talk about community events to get outside, such as the City Nature Challenge and Great American Campout. Do you have a question about changes in your local environment? Email a recording of your question to shortwave@npr.org — we may investigate it as part of an upcoming Nature Quest segment! Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave. Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy

Wanna know where tech is headed this year? MIT Technology Review has answers. They compile an annual list called "10 Breakthrough Technologies". Today, host Regina G. Barber speaks with executive editor Amy Nordrum about the list, and they get into everything from commercial space stations and base-edited babies to batteries that could make electric vehicles even more green. We also do a lightning round of honorable mentions you won't want to miss out on! Check out the full list from MIT Technology Review. Interested in more science? Check out our episode on last year’s top 10 technologies to watch and our episode on building structures in space. Email us your questions at shortwave@npr.org. Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave. This episode was produced by Berly McCoy. It was edited and fact-checked by Rebecca Ramirez. The audio engineer was Robert Rodriguez. Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy

There’s this idea that something happens in the human brain when we turn 25. Suddenly, we can rent a car without fees. Make rational decisions. We may even regret some of our past… indiscretions. All because we’re developed…right? Well, a recent paper in the journal Nature suggests that may not be the case. Neuroscientists found four distinct turning points in brain development across the human lifespan – and that the brain may be in its “adolescent” phase until about the age of 32. Interested in more of the science inside your brain? Email us your question at shortwave@npr.org. Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave. This episode was produced by Rachel Carlson. It was edited by Rebecca Ramirez. Tyler Jones checked the facts. The audio engineer was Kwesi Lee. Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy

In the mid-1980s, scientists published a startling finding–a giant hole in the ozone layer over Antarctica. That’s the protective shield that blocks large amounts of harmful UV radiation. And without it, the rate of cancer, cataracts and crop failure would skyrocket. Today on the show, we dive into ozone science and examine how scientists successfully sounded the alarm and solved an Antarctic mystery. Check out our episode on an Antarctic plankton mystery. And, listen to our monthly series Nature Quest. Interested in more atmospheric science? Email us your question at shortwave@npr.org. Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave. This episode was produced by Berly McCoy. It was edited by Rebecca Ramirez. Tyler Jones checked the facts. The audio engineer was Becky Brown. Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy

Microbes are little alchemists that perform all manner of chemical reactions. A team of microbiologists co-founded a non-profit to try to harness those abilities to solve some of the world’s big problems — from carbon capture to helping coral reefs to cleaning up waste. Recently, the team turned their attention to the microbes living in people’s homes — on and in shower heads, drip pans, and hot water heaters. These rather extreme environments may have pressured microorganisms into surviving in ways that could be advantageous to humans. Science reporter Ari Daniel takes us on a treasure hunt in miniature. This episode was produced by Hannah Chinn. It was edited by Rebecca Ramirez. Tyler Jones checked the facts. The audio engineer was Robert Rodriguez. Interested in learning more about the weird and wonderful world of microbes? Email us your question at shortwave@npr.org. Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave. Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy