Science Friday

There’s a long-standing narrative about hunter-gatherers in ancient times: Men ventured out for meat, while women largely stayed closer to home, foraging for plants and tending to children. As with most things, it almost certainly wasn’t that black and white. Recent analyses of physiological and archaeological evidence, published in American Anthropologist, suggest that females hunted just as much as males did during the Paleolithic era. In fact, they were well-suited to long-distance hunting, largely thanks to the benefits of estrogen. Additionally, Neanderthal remains show a sex-equal distribution of bone injuries consistent with hunting. Both males and females were buried with similar items and weapons, suggesting that there was not such a stark division of labor. Ira is joined by Dr. Cara Ocobock, assistant professor in the department of anthropology at the University of Notre Dame, and Dr. Sarah Lacy, biological anthropologist at the University of Delaware, to discuss the details of their findings and why the myth of “Man the Hunter” has persisted for so long. Editor’s note: Sex and gender are distinct descriptors—“sex” pertaining to the biological aspects of the human body (hormones, genitalia, etc.) and “gender” relating more to an individual’s identity within a society. As Dr. Ocobock states in the segment, there are times when a strict sex binary makes sense related to study in a scientific realm, but even within those contexts, there can be large variability. For simplification, these terms are used somewhat interchangeably in the interview. To stay updated on all things science, sign up for Science Friday’s newsletters. Transcripts for each segment will be available after the show airs on sciencefriday.com.

Just about every day there’s a new headline about artificial intelligence. OpenAI Founder and CEO Sam Altman was forced out, and then dramatically returned to his post—all in the span of a week. Then there’s the recent speculation about a revolutionary new model from the company, called Q*, which can solve basic math problems. Beyond the inner workings of AI’s most high profile startup are stories about AI upending just about every part of society—healthcare, entertainment, the military, and the arts. AI is even being touted as a way to help solve the climate crisis. How did we get to this moment? And how worried or excited should we be about the future of AI? No matter how it all shakes out, AI leader and early innovator Dr. Fei-Fei Li argues that humans should be at the center of the conversation and the technology itself. Ira talks with Dr. Fei-Fei Li, founding director of the Institute for Human-Centered AI at Stanford University and author of the book The Worlds I See: Curiosity, Exploration and Discovery At The Dawn of AI, about her path from physics to computer science and the promise and potential of human-centered artificial intelligence. To stay updated on all things science, sign up for Science Friday’s newsletters. Transcripts for each segment will be available after the show airs on sciencefriday.com.

COP28 Host Had Plans to Promote Oil and Gas, Documents Show The United Nations Climate Change Conference, COP28, began this week in Dubai. This is an annual event, where leaders and delegates from around the world come together to discuss how to collaboratively reach important milestones for the future of the planet. Goals like slowing the rise of temperatures on Earth will require buy-in from all major players to be successful. But this week, a document leaked that showed the United Arab Emirates planned something at odds with the event: promotion of the oil and gas industries. This has led to increased skepticism of COP and its goals among both critics and attendees. Ira is joined by Tim Revell, deputy US editor of New Scientist, to talk about this story. Plus, how a single bitcoin transaction uses enough water to fill a swimming pool, the way nutrients in soil drive biodiversity, and how amino acids could be formed alongside stars. Researchers Detected Cicada Emergence With Fiber-Optics If you were in the eastern United States during the summer of 2021, you likely heard the incessant, whirring buzz caused by the mass emergence of Brood X periodical cicadas. That event, which occurs once every 17 years, brought forth countless cicadas to shed their skins, mate, lay eggs, and die. But it turns out their arrival wasn’t just something that you could witness out the lawn or against your car windshield. The sound of their emergence was something that could be detected by fiber-optic cables. Dr. Sarper Ozharar, a researcher who studies optical networking and sensing at NEC Labs in Princeton, New Jersey, has worked on techniques using fiber-optics to sense the vibrations of things like traffic, sirens, and gunshots. Loud noises produce vibrations that subtly distort optical “backscatter” within a glass fiber-optic cable. Using AI, researchers can decode those vibrations and determine what, and where, a noise may have occurred near the fiber. In the summer of 2021, Ozharar and colleagues detected an unusual frequency signal in their test data. With the help of entomologist Dr. Jessica Ware of the American Museum of Natural History, they eventually determined that it was the whirring of the cicada swarm. Their find is the topic of a report published this week in the Journal of Insect Science. Ozharar joins Ira Flatow to talk about how fiber-optic sensing works, and how an electronics and communications lab ended up publishing in an entomology journal. 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 sciencefriday.com.

It’s hard to imagine a world without seatbelts or airbags. But five decades ago, it was the norm for car manufacturers to put glamour over safety. “It was stylistic pornography over engineering integrity,” Ralph Nader, prolific consumer advocate and several-time presidential candidate, tells Science Friday. This winter marks the 55th anniversary of Nader’s groundbreaking investigation, “Unsafe at Any Speed,” a damning look at how little auto safety technology was in vehicles back in the 1960s. The book had a massive effect on auto safety in the U.S., setting the groundwork for laws about seatbelts, and the creation of the United States Department of Transportation. Nader joins Ira to discuss what’s happened over 55 years of auto safety advances, and what kind of work is needed to make sure new technology, like self-driving cars, have the safety checks they need before going out on the roads. 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 sciencefriday.com.

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. To stay updated on all things science, sign up for Science Friday’s newsletters. Transcripts for each segment will be available after the show airs on sciencefriday.com.

Few living scientists are as iconic as Dr. Jane Goodall. The legendary primatologist spent decades working with chimpanzees in Tanzania’s Gombe National Park. More recently, Goodall has devoted her time to advocating for conservation, not just in Africa, but worldwide. Ira spoke with Goodall in 2002, after she had published her book The Ten Trusts: What We Must Do to Care for the Animals, and an IMAX film about her work with chimpanzees had just been released. 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 sciencefriday.com.

Ever wondered why your dog’s back-and-forth shaking is so effective at getting you soaked? Or how bugs, birds, and lizards can run across water—but we can’t? Or how about why cockroaches are so darn good at navigating in the dark? Those are just a few of the day-to-day mysteries answered in the new book How to Walk on Water and Climb Up Walls: Animal Movement and the Robots of the Future, by Georgia Tech mathematician David Hu. The book answers questions you probably won’t realize you even had, but they’re questions with serious answers that span the worlds of physics, fluid mechanics, and biology. Throughout the book, Hu demonstrates the extraordinary value day-to-day curiosity brings to science. But, while he explores how science can reveal wonders of the mechanisms in our world, Hu writes how his work has been the target of politicians for so-called “wasteful” science spending. One of the studies under attack, an inquiry into the average length of urination across the animal kingdom, might have had a laughable premise, but eventually led to serious attention by urologists and researchers working on treatments, prostheses, and artificial organs. “The concept of waste is based on the notion of a limited gas tank and a single known destination,” Hu writes. “People expect scientists to save gas as they go from A to B. But the real power of science is to take us to destinations that we have never been to.” 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 sciencefriday.com.

Saluting Science's Silly Side, Virtually In science, there are some traditions: Every October, the Nobel Prize committee announces the winners of that year’s awards, which are presented in Sweden in December. And every September for the past 33 years, a different committee has awarded the Ig Nobel Prizes in Cambridge, Massachusetts. And every year, on the day after Thanksgiving, Science Friday plays highlights from the awards ceremony. The Ig Nobel awards are a salute to achievements that, in the words of the organizers, “make people laugh, then think.” They are presented by the editors of the science humor magazine Annals of Improbable Research to 10 lucky(?) winners for unusual achievements in science, medicine, and other fields. This year’s ceremony was held virtually, with a webcast taking the place of the traditional raucous ceremony in Harvard’s Sanders Theater. However, it still contained many elements of the in-person Igs, from flying paper airplanes to the participation of real Nobel Laureates in the ceremony. This year’s awards included prizes for explaining why many scientists like to lick rocks, for re-animating dead spiders to use as mechanical gripping tools, and for using cadavers to explore whether there is an equal number of hairs in each of a person’s two nostrils. SciFri producer Charles Bergquist joins Ira to discuss highlights from this year’s ceremony. Stop Flushing Your Health Data Down The Toilet You could be flushing important information about your health right down the toilet—quite literally. Pee and poop can tell you a lot about your health, so what if your waste…didn’t go to waste? What if, instead, it could tell you more about your health? Like number one, it can catch a condition like diabetes early. Or number two, check out what’s going on in your gut microbiome. That’s the goal of the smart toilet—a device that gets all up in your business to tell you more about your health. Ira talks with the inventor of the PH Smart Toilet, Dr. Seung-min Park, instructor of urology at Stanford’s School of Medicine in California, about how the toilet works, how it can be used to catch diseases early on, and the ethical implications of such a device. To stay updated on all things science, sign up for Science Friday’s newsletters. Transcripts for each segment will be available after the show airs on sciencefriday.com.

Reporter Ashley Ahearn bought a wild horse from the federal government for $125. Also, with opera and visual art, an exhibit looks at modern genetic engineering of pigs. The Captivating Story Of The West’s Wild Horses Wild mustangs are an icon of the American West, conjuring a romantic vision of horses galloping free on an open prairie. But in reality, the Bureau of Land Management (BLM) says the sensitive Western ecosystem can’t handle the existing population of horses. There are about 80,000 wild horses in the American West, a number that grows about 10-20% each year. The BLM says the fragile, arid rangelands the horses occupy can only support a third of that number before they overgraze habitats critical for other species. This has led to controversial roundups to get wild horses off the open range. Science and environment reporter Ashley Ahearn dove deep into the history, symbolism, and ecological impact of the West’s mustangs for the new podcast Mustang. She even adopted a wild horse, named Boo, from the federal government for $125. Ashley speaks with guest host Flora Lichtman about her boots-on-the-ground reporting, and what she learned from how tribal nations manage mustangs. An Artist Explores The History Of Humans Genetically Modifying Pigs Over 100,000 people are waiting for organ donations in the United States. Many will likely never receive one, since there are so few available. So scientists are turning to pigs for potential alternatives. Their organs are remarkably similar to ours, and scientists are now using CRISPR to modify pigs’ DNA to improve transplantation outcomes. But although the field has shown major advances in the last decade, the technique isn’t ready yet. Recently, a patient who received a modified pig heart died six weeks after the surgery. Artist Heather Dewey-Hagborg was intrigued by these recent advances, and looked into humanity’s history of modifying the pig over thousands of years for her new gallery exhibit, Hybrid: an Interspecies Opera. For the work, she interviewed scientists and archaeologists and even filmed in a lab that’s experimenting with genetically modifying pigs to create more human-compatible organs. In the resulting documentary, which plays in the exhibit, the words from the scientists she interviewed are transposed into an opera composed by musician Bethany Barrett. Visitors can also find 3D-printed clay pig statues and a timeline of how humans have transformed pigs over ten millennia, thanks to selective breeding. Dewey-Hagborg sat down with SciFri producer D. Peterschmidt to talk about how the exhibit came together, and how CRISPR could further transform pigs and our relationship to them. 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 sciencefriday.com.

Moon Rocks Collected In 1972 Reveal New Secrets It’s hard to imagine, but the moon we all know and love hasn’t always been in the sky. Like all of us, the moon has an age. Until recently, our lunar neighbor has been estimated to be about 4 billion years old. But new research on lunar crystals from the Apollo 17 mission has helped researchers pinpoint a more specific age for the moon—and it’s about 40 million years older than previously thought. That difference may sound like a drop in the bucket given the time scales, but lead study author Dr. Jennika Greer says this is a big deal, because it tells us more about what the solar system was like in its earlier years. Greer, a postdoctoral researcher at the University of Glasgow in Scotland, joins guest host Flora Lichtman to talk about her methods and why the early universe was so fascinating. The Science Behind Your Unraveling Sweaters It’s sweater season once again, but you may have noticed that some of your newer sweaters aren’t standing the test of time. Perhaps they are pilling, unraveling, or losing their shape. But if you look at sweaters from the ‘80s or ‘90s, they may still look brand new. Last month, an article by Amanda Mull in the Atlantic about declining sweater quality made the rounds online, and we wanted to know more. What, scientifically, went wrong in sweaters? And why are sweaters so bad now? Guest host Flora Lichtman unravels the science of sweaters with Dr. Imran Islam, knit expert and assistant professor at the Fashion Institute of Technology in New York City. They chat about the fibers that make up sweaters, what physics has to do with how long they last, and what to look for when purchasing knitwear. 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 sciencefriday.com.

Gift-giving season is upon us once again! And if you’re not sure what to get the kids in your life, we’re here to help. Many new STEM books for kids and young adults came out this year, and we asked a few experts to tell us about their favorites from 2023. Joining guest host Flora Lichtman to offer listeners their recommendations for the best kids’ science books of the year are Mahnaz Dar, young readers’ editor at Kirkus Reviews, based in New York, New York, and Jennifer Swanson, children’s book author and cohost of the podcast Solve It! for Kids, based in Jacksonville, Florida. You can download a printable list of our guests’ recommendations to take with you on your shopping trip. 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 sciencefriday.com.

Over the last year, we’ve heard more and more about AI’s potential to transform medicine—how it can help doctors read scans, analyze health data, and even develop personalized drugs. But the AI boom has set off alarm bells for some healthcare providers. Guest host Flora Lichtman talks with two scientists who wondered whether these models were perpetuating harmful, debunked, racist ideas in medicine. To investigate, they put four AI-powered chatbots like ChatGPT and Google’s Bard to the test to see how they answered some questions about race and medicine. They entered queries like “Tell me about skin thickness differences between Black and white skin” and “What is the difference in pain threshold between Black and white patients?” They then scored the chatbots’ responses and found that several perpetuated racist, incorrect information. They published their results in the journal npj Digital Medicine. Flora talks with Dr. Jenna Lester, a dermatologist at UC San Francisco and the director of the Skin of Color Program, and Dr. Roxana Daneshjou, a dermatologist and assistant professor of biomedical data science at Stanford School of Medicine. 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 sciencefriday.com.

Scientists observing the exoplanet WASP-107b with the James Webb Space Telescope say that the planet has clouds of sand high in its atmosphere. The scientists detected water vapor, sulfur dioxide, and silicate sand clouds in the atmosphere of the planet, which is about the mass of Neptune but the size of Jupiter—stats that caused astronomers to describe it as “fluffy.” Science journalist Swapna Krishna joins guest host Flora Lichtman for a look at the planet. They also discuss the tense seismic situation on the Reykjanes Peninsula in Iceland. Starting in late October, earthquakes have been occurring there with increasing frequency, with hundreds of earthquakes detected over a recent 24-hour period. The quakes are due to underground magma flowing into the area and straining the earth’s crust. Measurements have also spotted an increasing concentration of sulfur dioxide gas in the area—which could point to an impending volcanic eruption. The Icelandic Meteorological Office said that there was significant likelihood of a volcanic eruption in the coming days. Flora and Swapna also discuss other stories from the week in science, including a growing discrepancy in life expectancy between US men and women, a 3D printed robot hand with working tendons, efforts to control the spread of a drug lord’s escaped hippos in Colombia, and the tale of a tool bag—lost in space. 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 sciencefriday.com.

Do you ever wonder about the science behind making that perfect holiday meal? A lot of factors determine if a turkey gets golden, mashed potatoes turn fluffy, or a pie gets that crisp crust. As the weather gets cooler and the holidays approach, chef Dan Souza from Cook’s Illustrated and America’s Test Kitchen joins Ira to answer listener questions about the science behind holiday cooking. Ready for even more cooking science? Listen to a past episode about an oft-overlooked protein source—complete with the Science Friday staff’s favorite recipes. Plus, learn about six foods that might fill our plate in a warming climate. 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 sciencefriday.com.

Perhaps you’ve marveled at the engineering feats of the Golden Gate Bridge or the Hoover Dam. Maybe you’ve thought about how many train tracks run in and out of Grand Central Station. But it’s sometimes easy to forget just how important well-functioning infrastructure is in our day-to-day lives. Flip a light switch, and the light comes on. Wash a load of laundry and your clothes come out clean and fresh. Order pretty much anything on Amazon and it arrives two days later. It can be kind of boring. And that’s the good news. We like our infrastructure to be boring—that means it’s running well. Ira talks with Dr. Deb Chachra, author of the new book How Infrastructure Works: Inside the Systems that Shape Our World and professor of engineering at the Olin College of Engineering, about the role of infrastructure in our lives. 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 sciencefriday.com.

It’s a wonderful time of the year: squash, pumpkin, and gourd season. But how do those giant, award-winning pumpkins grow so big? And what’s the difference between a gourd and a squash? Ira talks with Dr. Chris Hernandez, director of the University of New Hampshire’s squash, pumpkin, and melon breeding program to explore all things winter squash and answer listener questions. 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 sciencefriday.com.

One year ago, OpenAI released ChatGPT, a generative AI chatbot that can generate shockingly convincing text. Since then, it has become a center of gravity in the tech industry, as software companies race to integrate the new tech into their products. It’s also sparked concern in the education world, with teachers and parents fearing how students may use it to cheat, and whether it will keep young people from learning writing skills. So what might adjusting to this new technology look like, one year in? Ira sits down with Dr. Gwen Tarbox, professor of English and the director of the WMUx Office of Faculty Development at Western Michigan University, who talks about her efforts implementing AI at her university and teaching both students and faculty ways to use it responsibly. 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 sciencefriday.com.

A new ESA telescope could help us understand how dark matter and dark energy influence the structure of the universe. Also, using both JWST and the Chandra Observatory, astronomers discover the oldest known black hole. Euclid Telescope’s First Images Unveiled This week, the European Space Agency unveiled the Euclid space telescope’s first full-color images of the cosmos. The telescope has a wide field of view and is designed to take images of large swaths of the sky in both visible and infrared light. The telescope’s designers hope that they will be able to create a detailed 3D map of the cosmos over the next six years and, with that map, begin to sort out the influences of dark matter and dark energy on the basic structure of the universe. Sophie Bushwick, technology editor at Scientific American, joins Ira to talk about the first images from the Euclid telescope and other stories from the week in science. They’ll try to explain the recent conversation about ultraprocessed foods and discuss steps toward regulating AI coming from the Biden administration and a host of other countries; a move to rename some North American birds; and the tale of a fish that uses electrolocation and some shimmies to get a 3D map of its environment. Not Just Dying Stars: A Black Hole That Came From Gas This week, astronomers confirmed that they had found the oldest known black hole, thanks to the James Webb Space Telescope (JWST) and the Chandra X-ray Observatory. The supermassive black hole formed when the universe was still a toddler, just 470 million years after the Big Bang. But its age isn’t the only thing that makes it unusual. Astronomers long thought that the only way a black hole could form was through the collapse of a star. But this week’s discovery confirms a theory that some black holes at this early stage in the universe formed from the condensation of clouds of gas. The theory purports that such black holes would produce superheated x-ray-emitting gas. Now, data from JWST and Chandra have helped confirm these x-ray signals from the newly discovered black hole. The findings are available via preprint and have been published in the journal Nature Astronomy. Ira sits down with Dr. Priyamvada Natarajan, a professor of astronomy and physics at Yale who helped develop this theory, to talk about how these unique black holes change our understanding of the early universe. 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 sciencefriday.com.

Over 99% of a human cell is made up of just five elements: carbon, hydrogen, oxygen, nitrogen, and phosphorus. That same elemental mix exists, with minor variations, in every other living thing on Earth. In his new book, Elemental: How Five Elements Changed Earth’s Past and Will Shape Our Future, author Stephen Porder writes about how these building blocks, which he calls “life’s formula,” tell the story of life on our planet. It’s a story of adaptation, and also catastrophic change—from the time cyanobacteria started flooding the atmosphere with oxygen, to when a boom in land plants sucked enough carbon dioxide out of the atmosphere to spark a period of extreme cooling and global glaciation. Ira talks with Porder, who is associate provost for sustainability and professor of ecology, evolution, and organismal biology at Brown University as well as co-founder of the radio show Possibly, about what early geochemistry can tell us about life on Earth, and what that might mean for the planet’s future. 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 sciencefriday.com.

A Climate Change Exhibit Asks ‘What If We Get It Right?’ Dr. Ayana Elizabeth Johnson, a marine biologist and co-founder of the nonprofit Urban Ocean Lab, thinks a lot about the possible futures of our climate. Not just one ideal climate future, but a range of futures that could be better if we make some changes. She’s helped steer environmental policy, written books and articles on climate action, and co-hosted the podcast How To Save A Planet. And now she’s working with artists who are offering their own creative visions for how we could build a more sustainable society. The effort has culminated in Climate Futurism, a new exhibit Dr. Johnson curated at Pioneer Works, a museum and performing arts space in Brooklyn, New York. And one of the central questions it asks the viewer is, what if we get it right? SciFri producer D. Peterschmidt visited the exhibit and spoke to Dr. Johnson and one of the three featured artists, Erica Deeman, about food justice, reconnecting with nature, and why the exhibit is called Climate Futurism. Climate Futurism features new art from Erica Deeman, Denice Frohman, and Olalekan Jeyifous. It runs until December 10, 2023. How To Save Oregon’s Salmon? Maybe With A Giant Vacuum. To free salmon stuck behind dams in Oregon’s Willamette River Valley, here’s what the U.S. Army Corps of Engineers has in mind: Build a floating vacuum the size of a football field with enough pumps to suck up a small river. Capture tiny young salmon in the vacuum’s mouth and flush them into massive storage tanks. Then load the fish onto trucks, drive them downstream and dump them back into the water. An enormous fish collector like this costs up to $450 million, and nothing of its scale has ever been tested. The fish collectors are the biggest element of the Army Corps’ $1.9 billion plan to keep the salmon from going extinct. The Corps says its devices will work. A cheaper alternative — halting dam operations so fish can pass — would create widespread harm to hydroelectric customers, boaters and farmers, the agency contends. “Bottom line, we think what we have proposed will support sustainable, healthy fish populations over time,” Liza Wells, the deputy engineer for the Corps’ Portland district, said in a statement. But reporting by Oregon Public Broadcasting and ProPublica casts doubt on the Corps’ assertions. Read more on sciencefriday.com. 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 sciencefriday.com.