Ever eat a full meal ... and find you still have room for dessert? If so, you're not alone. Sugar is a quick form of energy that many people crave — even when they're full. Today, hosts Emily Kwong and Regina G. Barber dive into a new study on the neural origins of the "dessert brain."Want us to cover more neuroscience on the show? Let your voice be counted by emailing 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/adchoicesNPR Privacy Policy

What happens when a team of scientists and local Awajún guides go on a 38-day trip into the Alto Mayo region of Peru? Over 2000 species are identified, of course! Tucked in this lush landscape where the Amazon basin meets the Andes mountains, were 27 species of animals previously unknown to science. It makes us wonder, what else is out there that the scientific community hasn't seen? And who already knows about it? Check out photos of all the critters we mentioned — and more!Other ecosystems or critters you think would make a good episode? Let us know by emailing 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/adchoicesNPR Privacy Policy

Asked ChatGPT anything lately? Talked with a customer service chatbot? Read the results of Google's "AI Overviews" summary feature? If you've used the Internet lately, chances are, you've consumed content created by a large language model. These models, like DeepSeek-R1 or OpenAI's ChatGPT, are kind of like the predictive text feature in your phone on steroids. In order for them to "learn" how to write, the models are trained on millions of examples of human-written text. Thanks in part to these same large language models, a lot of content on the Internet today is written by generative AI. That means that AI models trained nowadays may be consuming their own synthetic content ... and suffering the consequences.View the AI-generated images mentioned in this episode.Have another topic in artificial intelligence you want us to cover? Let us know my emailing 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/adchoicesNPR Privacy Policy

Physics has a bit of a messy problem: There's matter missing in our universe. Something is there that we can't see but can detect! What could this mysterious substance be? A lot of astronomers are searching for the answer. And some, like theoretical particle physicist Chanda Prescod-Weinstein, think a hypothetical particle called the axion may make this problem a little ... tidier. That's right: hypothetical. Scientists have never seen one, and don't know if they exist. So today, we point our cosmic magnifying glasses towards the axion and ask how scientists could find one — and if it could be the neat solution physicists have been searching for. Help shape the future of Short Wave by taking our survey: npr.org/shortwavesurveyListen 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/adchoicesNPR Privacy Policy

For years, scientists have known that oxytocin is important in facilitating the feeling of love in humans. How do they know? Prairie voles. For years, scientists have relied on the cuddly rodents to help us humans understand how this protein works in our brains. But within the past few years, research has complicated that understanding, prompting the question: Can love prevail without the "love" hormone? (encore)Help shape the future of Short Wave by taking our survey: npr.org/shortwavesurveyListen 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/adchoicesNPR Privacy Policy

Rocky Mountain Spotted Fever is one of the deadliest tickborne diseases in the United States, often killing people within about a week if left untreated. At one point, the San Carlos Apache Reservation had rates of infection 150 times the national average. But now, they've achieved a huge milestone — no deaths from the disease in at least five years. NPR science correspondent Pien Huang and producer Megan Lim visited the reservation to see the program that led to their success.Read Pien's full story here.Interested in hearing more science success stories? 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.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

The U.S. tested nuclear weapons until the early 1990s. Since then, scientists have been using supercomputers and experiments to simulate nuclear test detonations, without detonating any nukes. But there are signs the world's nuclear powers may be readying to test again: Russia, China and the U.S. are all upgrading their nuclear test sites.NPR's science correspondent Geoff Brumfiel was among a small group of journalists allowed to tour an underground laboratory where this research happens. Read more of science correspondent Geoff Brumfiel's reporting here. Help shape the future of Short Wave by taking our survey: npr.org/shortwavesurveyListen 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/adchoicesNPR Privacy Policy

For people with two hands, one is usually dominant. On a molecular level, life takes this to the extreme. All of the DNA in earthly living things twists to the right, whereas the protein building blocks favor a kind of left-handed chemistry. But in recent years, scientists have worked toward a kind of mirror version of life. The technology to make mirror life likely won't exist for at least a decade. Still, a group of concerned scientists published a 299-page technical report calling for a stop to the science. New York Times science columnist Carl Zimmer explains how a mirror microbe could wreak havoc on life on Earth in the future. Check out the full technical report and Carl's full article.Curious about other controversial research? 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. Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

What do large crowds of people and water have in common? They both act like fluids. When crowds cheer, sway and clump together, the movements look like ripples of water. Researchers hope insights from physics like this one could help officials and engineers create safer crowds at festivals.Help shape the future of Short Wave by taking our survey: npr.org/shortwavesurveyListen 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/adchoicesNPR Privacy Policy

For a long time, microbes like the ones in Yellowstone's hot springs were studied in isolation. Molecular ecologist Devaki Bhaya says we should be studying them in community. Here's why.Help shape the future of Short Wave by taking our survey: npr.org/shortwavesurveyPlus, if you liked this episode, check out our episode on the last universal common ancestor in the tree of life. 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/adchoicesNPR Privacy Policy

Black holes are notorious for gobbling up, well, everything. They're icons of destruction, ruthless voids, ambivalent abysses from which nothing can return — at least, according to pop culture. But black holes have another side: Astrophysicists have seen powerful jets, sometimes millions of light-years long, shooting out of supermassive black holes – including the one at the center of our own galaxy. So today, we're getting to know the other side of black holes, and the powerful role they may play in creating and shaping the cosmos. Read more about the Blandford-Znajek process.Got other cosmic curiosities? Email us at shortwave@npr.org.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Ecologist Gergana Daskalova moved back to the small Bulgarian town of her childhood. It's a place many people have abandoned — and that's the very reason she returned. At the same time as land is being cleared around the world to make room for agriculture, elsewhere farmland is being abandoned for nature to reclaim. But what happens when people let the land return to nature? This episode, science reporter Dan Charles explains why abandoned land has conservationists and researchers asking: If we love nature, do we tend it or set it free?Read more of Dan's reporting for Science Magazine and NPR.Want us to cover other about ecology, biodiversity or land science stories? Let us know by emailing 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/adchoicesNPR Privacy Policy

In a world brimming with innovation and limited time, it can be hard to tell what technology has the potential to really shift life. Yet, every year, MIT Technology Review undertakes this very task and puts out an annual list to magazine readers of 10 Breakthrough Technologies. Today, host Regina G. Barber hops through highlights from the list with Amy Nordrum, an executive editor at the publication.Check out the full list here.Another tech topic on your mind that you want us to discuss on an upcoming episode? Let us know by emailing 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/adchoicesNPR Privacy Policy

Farts are funny and sometimes smelly. But are they a legitimate topic of research? More than 40% of people worldwide are estimated to suffer from some kind of functional gut disorder — from acid reflux, heartburn, indigestion, constipation and irritable bowel syndrome to inflammatory bowel disease. So, yes, freelance science writer Claire Ainsworth thinks so. Claire speaks with Emily about two teams of scientists studying intestinal gases, who she profiled in a recent New Scientist article — and why understanding people's gut microbiome through a fart-shaped window may help treat these conditions at the source. Read more of Claire's reporting for New Scientist.Have another bodily function you want us to explore or just want to report to us about a funny time you passed gas? 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.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Bird flu, or avian influenza, is spreading among livestock and other mammals in the United States, raising concerns that another pandemic may be looming. Last month, California declared a state of emergency due to rising cases in dairy cattle, and there have been over 65 human cases in the U.S. during this outbreak. While cases have been largely mild and risk to the public is still considered low, scientists warn it could evolve and become more dangerous. Curious about other health updates? Email us at shortwave@npr.org.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Put on your headphones. 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 Short Wave 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/adchoicesNPR Privacy Policy

At least, it's contagious among a group of captive chimpanzees at the Kumamoto Sanctuary. How do researchers know? A very dedicated grad student at Kyoto University. In the quest for scientific knowledge, Ena Onishi logged over 600 hours in the field! This episode, host Regina G. Barber and special guests Jonathan Lambert and Ari Shapiro get into the nitty gritty of the research and their hypotheses for why this is happening in this episode.Read Jonathan's full reporting about contagious peeing in chimps.Delighted by other scientific discoveries you think we should share with the whole class (the rest of our audience)? Let us know by emailing 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/adchoicesNPR Privacy Policy

Around the turn of the century, 3.8 million people banded together in a real-time search for aliens — with screensavers. It was a big moment in a century-long concerted search for extraterrestrial intelligence. So far, alien life hasn't been found. But for people like astronomer James Davenport, that doesn't mean the hunt is worthless — or should be given up. No, according to James, the search is only getting more exciting as new technology opens up a whole new landscape of possibilities. So today on the show: The evolving hunt for alien life.Want more space content? Let your opinion be heard by dropping us a line 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/adchoicesNPR Privacy Policy

Forests are the lungs of our planet. Not only do they absorb carbon dioxide and create oxygen, they also regulate temperature, absorb rainwater to help prevent flooding, and provide critical habitat for the majority of the world's land-based plant and animal species.But due to land conversion for agriculture and road construction, timber harvesting, and increasing wildfires, the trees that make up our forests are increasingly endangered. That's why we need reforestation: replanting new forests to replace the old ones.For the past century, the United States Forest Service has helped to replant new forests and manage existing ones. But as scientists face the ongoing threat of climate change, they're developing new strategies... including one that tries to literally predict the future.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

On Wednesday, the Food and Drug Administration announced it is banning the dye called Red No. 3, a food dye additive in many processed foods, like sodas, sweets and snacks. Recently, it and other dyes were linked to behavior issues in children. But high levels of Red No. 3 were linked to cancer in rats decades ago. So why is the ban happening now? Senior editor and science desk correspondent Maria Godoy answers our questions about Red No. 3 and other dyes that may replace it. Plus, how should parents think about feeding their kids products that may contain Red No. 3 before the ban takes affect.Questions, story ideas or want us to dig into another food science issue? Email us at shortwave@npr.org — we'd love to hear from you! 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/adchoicesNPR Privacy Policy