Science Friday
Science Friday

Science Friday is a weekly science talk show, broadcast live over public radio stations nationwide. Each week, the show focuses on science topics that are in the news and tries to bring an educated, balanced discussion to bear on the scientific issues at hand. Panels of expert guests join host Ira Flatow, a veteran science journalist, to discuss science and to take questions from listeners during the call-in portion of the program.

Airs on:
FRI 11am-1pm

Ocean Climate Solutions, Florida Corals, Climate Video Games. Sept 22, 2023, Part 2

Florida’s Reefs Are Vanishing. Can Scientists Save Them? This was a bad year for Florida’s coral reefs. Since the 1970s, reef cover in the Florida Keys has decreased by 90%. Those remaining reefs have been subjected to water temperatures higher than 100 degrees Fahrenheit, alongside other threats like disease and ocean acidification. This is a big problem for the largest reef in the continental U.S., which plays an important role in protecting the shorelines from erosion and storms. Scientists are scrambling to preserve as much of the reef as possible. One method marine biologists are focused on is selectively breeding corals in labs. Scientists look for the specimens most resilient to heat stress, then breed them together to create hardy offspring. Those spawn are then implanted into the reef, with hopes of bolstering the existing structure. Vox environmental reporter Benji Jones joins Ira to talk about his dives to Florida’s Pickles Reef, and the differences he saw between this year and last year. Then, Ira speaks with marine biologist Andrew Baker at the University of Miami about his efforts to bolster Florida’s reefs.    The Ocean Is A Climate Ally Did you know that the ocean absorbs about a quarter of all CO2 emissions? And about 90% of excess heat? It’s the largest carbon sink we have—and one of our biggest allies in the climate movement. Ira talks with Dr. Ayana Elizabeth Johnson, marine biologist and co-founder of the non-profit Urban Ocean Lab, as well as the climate initiative The All We Can Save Project. They chat about climate solutions—like the newly launched Climate Corps—the power of the ocean, and steps forward. Dr. Johnson is also the curator for Climate Futurism, an art exhibition at Pioneer Works in Brooklyn, New York.   Feeling Hopeless About Climate Change? Try Playing These Video Games This segment, originally from 2022, was re-aired this week. Five years ago, Stephanie Barish was tired of the public’s attitude about climate change. “Most people at that time were just so negative about climate,” she said. “It was doom and destruction, and I thought, wow, to make positive change, you have to really look at this from a solutions perspective.”  Stephanie is the founder and CEO of Indiecade, an organization that supports indie video game developers and hosts events like the Climate Jam—the goal of which was to change the gloomy public narrative around climate change. So, with the help of organizations like Earth Games, participants around the globe gather every year to make video games about climate change optimism, solutions, and justice. Teams can also consult with subject matter experts, like Dargan Frierson, an associate professor of atmospheric sciences at the University of Washington, and also a judge for the Climate Jam. If teams wonder what climate change would look like on a different planet, they can go to him for answers. “We always look for scientific accuracy,” he said. “I think it’s very important to keep things within the realm of possibility, even when you’re looking at fiction.” Read the rest at   To stay updated on all-things-science, sign up for Science Friday's newsletters. Transcripts for each segment will be available the week after the show airs on

Our Fragile Moment, Climate Comedy. Sept 22, 2023, Part 1

A Week Of Climate Protests, Meetings, Pledges, And Action Climate Week NYC is wrapping up, where hundreds of events took place across the city (including one from Science Friday), all with the goal of encouraging conversation and action around our climate crisis. The weeklong event takes place alongside the UN General Assembly meeting, where world leaders discussed climate change, alongside other topics, including the war in Ukraine and universal health coverage. While President Biden emphasized the importance of reducing the use of fossil fuels to combat climate change, there was a notable absence of leaders from the world’s biggest polluters, including Biden and president Xi Jinping of China, from the meeting’s Climate Ambition Summit. UN Secretary-General António Guterres said that in order to participate, governments need to come with “credible, serious and new climate action.” Large demonstrations also took place across the city, pressuring leaders and companies to take bigger action to end gas, oil, and coal use. Swapna Krishna, a journalist based in Philadelphia, talks with Ira about these stories and more, including a new climate jobs program from the White House, a lawsuit from California against the five big oil companies, new battery recycling rules from the EU, and data from the Parker Solar Probe’s recent flight through a sun explosion.   Can Earth’s Past Climate Help Us Understand Today’s Crisis? A combination of factors led to Earth’s climate being able to support life. And changes in the climate some 6,000 years ago created the conditions for human civilization to flourish. It’s a delicate balance on the verge of collapse, due to our reliance on burning fossil fuels. Ira talks with paleoclimatologist Dr. Michael Mann about his forthcoming book Our Fragile Moment: How Lessons from Earth’s Past Can Help Us Survive the Climate Crisis, about the importance of understanding our planet’s climate history, and strategies to get policymakers to take action before it’s too late to reverse some of the worst consequences of climate change. Mann is a professor of earth and environmental science and director of the Penn Center for Science, Sustainability and the Media at the University of Pennsylvania, based in Philadelphia, Pennsylvania.  Read an excerpt of the book on   The Climate Movement Should Be Funnier How do you know that climate change is funny? Even the Antarctic ice sheets are cracking up. The climate crisis is no joke, but that doesn’t mean we can’t laugh about it. Research suggests that comedy is a powerful way to connect people and get them to empathize with a cause—and the climate crisis is a pretty big one. So what does science say about the power of a good laugh? And how does that fit into the climate movement? Ira talks with Esteban Gast, comedian in residence at the clean energy non-profit Generation 180, and Dr. Caty Borum, executive director of the Center for Media & Social Impact at American University.   To stay updated on all-things-science, sign up for Science Friday's newsletters. Transcripts for each segment will be available the week after the show airs on

New Covid Vaccine, Moroccan Earthquake, Native Bees. Sept 15, 2023, Part 2

New COVID Boosters Arrive Amid Rise In Infections This past week, the FDA and CDC recommended new COVID vaccines from Pfizer and Moderna for anyone over the age of six months. They’re expected to be in larger pharmacies by the end of the week. It’s welcome news for some, as cases have ticked up over the summer, accompanied by higher hospital admissions and deaths. The boosters join a suite of other vaccines to combat respiratory illness this fall, including this year’s flu shot and the new RSV vaccine, recommended especially for children and the elderly. Dr. Katelyn Jetelina, epidemiologist, adjunct professor at UTHealth School of Public Health, and author of the Your Local Epidemiologist newsletter, joins Ira to talk about the details of the new boosters, how long you should wait to get one if you were recently infected, masking recommendations, and if you can get all three shots at once.   The Science Behind Devastating Earthquakes On September 8, 2023 at 11:11 PM local time, a 6.8 magnitude earthquake struck Morocco’s High Atlas mountains. So far, more than 2,500 people died and thousands more were injured or lost. Other natural disasters usually give off warning signs; we can predict when a volcano will explode, ring the alarms when a tsunami starts to build, or evacuate before a hurricane makes landfall, but we still can’t detect earthquakes before they strike. And victims are left to face “the particular trauma that comes from watching the world around you crumble in an instant,” writes science journalist Robin George Andrews for The Atlantic. Ira talks with Andrews about the specifics of this earthquake, where the science stands with earthquake detection, and the particular kind of trauma that comes from watching the world crumble.   The Buzz On Native Bees In Your Neighborhood When you think ‘bees,’ you probably think of a neat stack of white hive boxes and the jars of honey on the store shelves.  But there’s a lot more to bees than the agricultural staple, the European honey bee. Around the world there are over 20,000 known bee species, and around 4,000 of them are native to the United States. While these native bees play a key role in pollinating our plants and ensuring the health of ecosystems, they don’t get a ton of recognition or support.  Around three-quarters of flowering plant species rely on insects for pollination, and some native plants have evolved a partnership with specific native bee pollinators. Squashes, pumpkins, gourds, and the annual sunflower all have specific species of native bees as part of their life cycles. Native plants such as blueberries, cherries, and cranberries all developed without the European honeybee, which arrived in North America in 1622.  Dr. Neal Williams, a professor of entomology at the University of California, Davis, joins Ira to talk about native bees, bee behavior and pollination.   To stay updated on all-things-science, sign up for Science Friday's newsletters. Transcripts for each segment will be available the week after the show airs on

Radioactive Wildlife, Bus Stop Heat, Football Jersey Numbers. Sept 15, 2023, Part 1

Astronomers Find Exoplanet That May Be Covered In Water Scientists using the James Webb Space Telescope made an exciting discovery this week: Exoplanet K2-18 b, 120 light years away from our solar system, could be covered by a water ocean, similar to Earth. Astronomers say this could be a big leap in our exploration of life on other planets. This news comes amid another JWST discovery: The earliest black holes seem to be much larger than black holes today. This news also provides evidence that black holes can form without stars, a theorized phenomenon that has never been directly observed. Joining Ira to talk about these and other science stories of the week is Tim Revell, Deputy U.S. Editor of New Scientist, based in New York, New York.   What Radioactive Animals Teach Us About Nuclear Fallout When you hear the words “radioactive wildlife,” your brain probably jumps to Chernobyl’s wolves, which—despite the odds—are still thriving at the site of the nuclear disaster. Or maybe you’ve heard of the rat snakes in Fukushima that pick up radioactive contamination as they slither around. Well, it’s time to add two more to that list of radioactive critters: turtles and wild boar. They’re the subjects of two new studies that looked at radioactivity in wildlife and mapped out where it came from.  Ira talks with Dr. Cyler Conrad, archaeologist at Pacific Northwest National Lab in Richland, Washington who worked on the turtle study, and Dr. Georg Steinhauser, professor of applied radiochemistry at the Vienna University of Technology in Austria, who studied boar. They chat about the two studies, how wildlife can clue us into radioactive contamination, and what we can learn from critters in nuclear fallout zones.   Waiting for the Bus in Houston is Hot. And Dangerous. It was a hot summer day and Glory Medina and her daughter Jade, who was 3 at the time, were running a quick errand at the grocery store near their apartment in Gulfton. They had taken the bus and once they arrived, the two of them faced a giant unshaded parking lot, the black asphalt radiating heat into their faces as they walked across it. The blast of AC felt cool as they entered the store, and Medina bent down to lift her daughter into the grocery cart. That’s when she noticed Jade’s face was red, almost purple. “I got scared,” Medina said in Spanish, remembering that day four years ago. Read more at   The Psychology Behind Wide Receivers’ Jersey Numbers Football season is officially here, with the NFL’s first game kicking off last Sunday. And if you’ve been watching the sport for a long time, you may have noticed some changes: better-padded helmets meant to reduce serious brain injury, new “sticky” gloves that make it easier for players to hold the ball, and lighter-weight jerseys that make it harder for other players to grab onto. But you’ll also notice the numbers on those jerseys are different, too. For most of the NFL’s history, wide receivers could only pick jersey numbers between 80 and 89. But in 2004, the league relaxed this policy, allowing players to also pick numbers between 10 and 19. Many players preferred these smaller values explaining that the 1 looked slimmer than the 8, and made them feel thinner and faster. As of 2019, 80% of wide receivers made the switch. But is there an actual association between smaller numbers and perception of body size? To investigate whether this was fact or superstition, Dr. Ladan Shams, professor of psychology, bioengineering, and neuroscience at UCLA, ran a study that found those wide receivers were onto something: the results suggest there is a correlation between smaller numbers and perceived body size. Her team’s research was published in PLOS One. She joins Ira to talk about the study and what it could tell us about implicit bias.   To stay updated on all-things-science, sign up for Science Friday's newsletters. Transcripts for each segment will be available the week after the show airs on

Tree Soil, Rodent Biologist, Soundscape Artist. Sept 8, 2023, Part 2

Where Soil Grows Above The Trees You might be used to the feeling of Earth under your feet, but did you know that there’s soil high above your head? Way up in the treetops, where ferns, mosses, flowers, and even trees grow on top of the forest. A new study in Geoderma describes the factors that contribute to how canopy soil is formed. Ira talks with lead author Jessica Murray, an ecologist and PhD candidate at Utah State University in Logan, Utah. They discuss the importance of canopy soil, what we do and don’t know about it, and what it’s like to study it. Check out views from Murray’s field sites at! ‘I Will Not Be Vole Girl’—A Biologist Warms To Rodents The path to becoming a scientist is not unlike the scientific process itself: Filled with dead ends, detours, and bumps along the way. Danielle Lee started asking questions about animal behavior when she was a kid. She originally wanted to become a veterinarian. But after being rejected from veterinary school, she found a fulfilling career as a biologist, doing the type of work she always wanted to do—but never knew was possible for her. Science Friday producer Shoshannah Buxbaum talks with Dr. Danielle Lee, a biologist, outreach scientist, and assistant professor in biology at Southern Illinois University Edwardsville in Edwardsville Illinois about what keeps her asking questions, what rodents can help us understand about humans, and the importance of increasing diversity in science. This Soundscape Artist Has Been Listening To The Planet For Decades Jim Metzner is one of the pioneers of science radio—he’s been making field recordings and sharing them with audiences for more than 40 years. He hosted shows such as “Sounds of Science” in the 1980s, which later grew into “Pulse of the Planet,” a radio show about “the sound of life on Earth.” Over the decades, Metzner has created an incredible time capsule of soundscapes, and now, his entire collection is going to the Library of Congress. John Dankosky talks with Metzner about what he’s learned about the natural world from endless hours of recordings and what we can all learn from listening. Plus, they’ll discuss some of his favorite recordings. To hear the best audio quality, it might be a good idea to use headphones if you can. To stay updated on all-things-science, sign up for Science Friday's newsletters. Transcripts for each segment will be available the week after the show airs on

Embryo Model, Sweat, Whale Vocal Fry. September 8, 2023, Part 1

Scientists Develop Human Embryo Model Without Sperm Or Eggs This week, research published in the journal Nature detailed a model of a 14-day old human embryo created without using sperm or eggs. The hope is to shine a light into a previously unavailable window of an embryo’s development, potentially helping to better understand miscarriages and side effects of medications taken during pregnancy.  Ira talks with Casey Crownhart, climate and energy reporter at MIT Technology Review to talk about that and other top science news of the week including Japan’s rocket launch to the moon, zinc batteries, and newly discovered toxic bird species. Sweating Is Our Biological Superpower Sweat may feel like a constant summer companion, whether or not you exercise frequently. Being damp can feel uncomfortable, but the smells that follow—thanks to the lives and deaths of sweat-munching bacteria—are often socially stigmatized as well. (Deodorant itself is actually a very recent invention!) But sweat isn’t just a cosmetic embarrassment: It’s crucial to keeping us cool, as the evaporating liquid pulls heat energy from our bodies. If you look at animals that don’t sweat, many have evolved alternate adaptations like peeing or even pooping on body parts to achieve that vital evaporative effect. People who are born unable to sweat run a constant risk of heatstroke. Ira talks to Sarah Everts, author of the new book, The Joy Of Sweat, about what makes sweat useful, the cool chemistry of this bodily fluid, and why it’s our evolutionary superpower. Vocal Fry Serves Up Treats For Toothed Whales Toothed whales—species like orcas, bottlenose whales, and dolphins—use echolocation to zero in on prey about a mile deep into the ocean. Until now, scientists couldn’t quite figure out how the whales were making these clicking sounds in the deep ocean, where there’s little oxygen. A new study published in the journal Science, finds the key to underwater echolocation is vocal fry. Although in whales it might not sound like the creaky voice that some people love to hate, the two sounds are generated in a similar way in the vocal folds. Ira talks with the study’s co-author, Dr. Coen Elemans, professor of bioacoustics and animal behavior at the University of Southern Denmark based in Odense, Denmark.  To stay updated on all-things-science, sign up for Science Friday's newsletters. Transcripts for each segment will be available the week after the show airs on

An AI for Smell, Heat and Agricultural Workers, Golden Lion Tamarin, Y Chromosome. Sept 1, 2023, Part 2

What’s That Smell? An AI Nose Knows If you want to predict the color of something, you can talk about wavelengths of light. Light with a wavelength of around 460 nanometers is going to look blue. If you want to predict what something sounds like, frequencies can be a guide—a frequency of around 261 Hertz should sound like the musical note middle C. Predicting smells is more difficult. While we know that many sulfur-containing molecules tend to fall somewhere in the ‘rotten egg’ or ‘skunky’ category, predicting other aromas based solely on a chemical structure is hard. Molecules with a similar chemical structure may smell quite different—while two molecules with very different chemical structures can smell the same. This week in the journal Science, researchers describe developing an AI model that,  given the structure of a chemical compound, can roughly predict where it’s likely to fall on a map of odors. For example, is it grassy? Or more meaty? Perhaps floral? Dr. Joel Mainland is one of the authors of that report. He’s a member of the Monell Chemical Senses Center and an adjunct associate professor in the department of neuroscience at the University of Pennsylvania in Philadelphia. Mainland joins Ira to talk about the mystery of odor, and his hope that odor maps like the one developed by the AI model could bring scientists closer to identifying the odor equivalent of the three primary colors—base notes that could be mixed and blended to create all other smells.     As Temperatures Rise, Farmworkers Are Unprotected Juan Peña, 28, has worked in the fields since childhood, often exposing his body to extreme heat like the wave that hit the Midwest last week. The heat can cause such deep pain in his whole body that he just wants to lie down, he said, as his body tells him he can’t take another day on the job. On those days, his only motivation to get out of bed is to earn dollars to send to his 10-month-old baby in Mexico. To read more, visit   The Golden Lion Tamarin Rebounds From The Brink Of Extinction The Golden Lion Tamarin is a small, charismatic monkey with a mane of red fur that’s a local celebrity in Brazil’s Atlantic Forest. This pint-sized primate was on the brink of extinction back in the 1970s, with only about 200 left in the wild. After decades of concentrated conservation efforts, an estimated 4,800 golden lion tamarins are now living in the wild. The multi-pronged effort involved reconnecting parts of the forest that had disappeared due to deforestation, vaccinating monkeys against yellow fever, and reintroducing zoo-bred primates to the wild. Ira speaks to Carlos Ruiz Miranda, associate professor of conservation and behavior at Northern Rio de Janeiro State University in Campos dos Goytacazes, Brazil. Dr. Ruiz Miranda has worked on restoring golden lion tamarin populations for decades, and was involved in every facet of this effort.    Unraveling the Mysteries Of The Y Chromosome Last week, we briefly mentioned the sequencing and analysis of the human Y chromosome, which was recently reported in the journal Nature. It’s an important achievement—the small Y chromosome is filled with repeated segments of genetic code that make reconstructing the full sequence difficult. Think of trying to put together a jigsaw puzzle—the unique parts of the picture are easy, but areas with repeated colors, like sky or waves, are more challenging.     In addition to the complete sequence of one individual’s Y, other researchers compared the Y chromosomes of 43 different individuals—and found that the structure of the chromosome can vary widely from one person to another. The Y chromosome plays a key role in sex determination and sperm production, making it of interest to fertility researchers. It’s also linked to some diseases and health conditions. Adam Phillippy, a senior investigator in the computational and statistical genomics branch of the National Human Genome Research Institute at the National Institutes of Health, and Kateryna Makova, a professor of biology at Penn State University, join Ira to talk about the challenges of sequencing the Y chromosome, and what doing so might mean for medical research.   To stay updated on all-things-science, sign up for Science Friday's newsletters. Transcripts for each segment will be available the week after the show airs on

US Surgeon General On Mental Health, Tracking Tick Bites. Sept 1, 2023, Part 1

What To Expect From Hurricane Season We’re approaching the peak of hurricane season, which is usually around mid-September. It’s that time of year when it feels like there’s a new storm every week, and we blow through the alphabet trying to name them. This week, Hurricane Idalia made landfall around Florida’s Big Bend as a Category 3 storm, which caused a few fatalities, left hundreds of thousands of people without power, and some without homes. So what do we know about Idalia, and what can we expect from the rest of the hurricane season? Ira talks with Rachel Feltman, editor at large at Popular Science, about hurricane season and other science news of the week. They chat about what we’re learning from India’s lunar rover, a three-inch roundworm pulled out of someone’s brain, a new study about public health and air pollution, heavy metals in marijuana products, what an ancient Egyptian mummy smells like, and a turtle named Tally, who is far from home.   The Surgeon General Warns About An Epidemic Of Loneliness The early days of the COVID-19 pandemic were lonely for many, upending their social lives. But loneliness pre-dates COVID, especially among young people. In a recent advisory, the United States surgeon general, Dr. Vivek Murthy warned that the negative health effects of loneliness and isolation are comparable to smoking daily. Despite being more technologically connected than ever before, the Surgeon General’s Office is also raising concerns about the harms of social media on youth mental health. Ira sits down for a conversation with the United States surgeon general, Dr. Vivek Murthy, about the intersection of youth mental health, social media, and loneliness. Dr. Murthy outlines both public policy and community interventions that can help strengthen America’s emotional well being and social connections.   Keeping Tabs On Tick Bites If you live in the Midwest or Northeast, you’re probably aware of an issue that’s gotten worse over the years: ticks, and the illnesses they can spread, including Lyme Disease and Alpha-gal syndrome. Scientists are still trying to learn more about how and where ticks are spreading. That’s where The Tick App comes in. It’s a community science effort where you can log your tick encounter and help scientists learn more about tick-borne disease. Science Friday digital producer Emma Gometz sat down with Ira to talk about her recent article profiling the app, and the scientists behind forms of tick monitoring research.   To stay updated on all-things-science, sign up for Science Friday's newsletters. Transcripts for each segment will be available the week after the show airs on