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
47 min

Endemic Diseases, Insects and Light, Opossum vs Aye-Aye. Sept 17, 2021

Nighttime Streetlights Are Stressing Out Urban Insects As insect populations—including bees, moths, and other pollinators—decline worldwide, researchers have established a variety of potential causes, including climate change, pesticides, and habitat loss. But now, new findings suggest yet another culprit may be part of the equation: night-time lighting, like street lights in populated areas. A team of entomologists in the United Kingdom looked at populations of moth caterpillars under street lights, compared to populations that lived in darkness all night. In conditions with night-time lighting, they found nearly half as many caterpillars, in some cases. In addition, caterpillars that grew up under street lights were bigger, suggesting that they might be stressed and attempting to rush into metamorphosis earlier than they should. Furthermore, the greatest threat seems to be coming from energy-efficient LED lights, whose bluer wavelengths may be more stressful than the warmer, redder light of older sodium bulbs. The team published their work in the journal Science Advanceslate last month. Guest host Umair Irfan talks to co-author Douglas Boyes about why nighttime lighting might be so bad for insects, and why ditching LED lights isn’t actually the best solution.     The Endemic End To The Pandemic Over the past year and a half, we’ve been talking about the COVID-19 pandemic. But there’s another stage of global virus spread to consider as well—the endemic stage. Instead of a sudden cacophony of viral noise, you can think of it as a constant low-level hum, with occasional bleeps.  Viruses such as the coronaviruses responsible for many colds, or the influenza virus, are already endemic worldwide. They’re pretty much everywhere, all the time—and sometimes make you ill. But they don’t usually threaten to overwhelm health systems the way COVID-19 is currently. Maureen Miller, an infectious disease epidemiologist and medical anthropologist at  Columbia University, joins guest host Umair Irfan to talk about pivoting from pandemic to endemic conditions, and what past outbreaks can teach us for future health decisions.       Charismatic Creature Carnival: Who Rules The Night? We’re in week two of our Charismatic Creature Carnival, our celebration of six overlooked or unfairly maligned species that deserve a closer look. Our audience submitted our candidates, but only one will be crowned the very first carnival inductee into the Charismatic Creature Corner Hall of Fame. This week’s friendly head-to-head battle is between the opossum and the aye-aye, submitted by listeners who remarked these creatures are cute, though unconventionally so. Defending the opossum is Lisa Walsh, postdoctoral researcher at the Donald Danforth Plant Science Center, based in Washington, D.C. Squaring up against them to support the aye-aye is Megan McGrath, education programs manager at the Duke Lemur Center in Durham, North Carolina. Find out how to participate in the final creature face-off and check out what you said about the last round between the mantis shrimp and the hellbender salamander!
46 min

Living With Wildfire, 7,000 Steps A Day Okay, Kids’ Mars Questions. Sept 17, 2021, Part 1

Scientists Potty Train Cows To Lower Greenhouse Gasses Scientists have known it for a long time: Cattle are a major source of nitrogen emissions, contributing to the global warming crisis. Alternatives have been tossed around for years: from eating less meat to feeding cows seaweed. Now, a new study out of Germany and New Zealand has a more outside-the-box solution: potty-training calves. Scientists trained cows to pee in just one spot—dubbed the “MooLoo”—so their urine can be cleaned before it seeps into the environment. Most calves got the hang of it within 20-25 pees. Joining guest host Umair Irfan to talk about this and other science stories of the week is Roxanne Khamsi, science journalist based in Montreal, Quebec. With Worsening Wildfire Seasons, How Can We Learn To Live With Them? It’s another record year for fire in the American West, with more than two million acres already burning in the state of California, and the Dixie Fire alone well on its way to a million acres—if it gets that big, it would be the second “gigafire” on record, after 2020’s August Complex fire. As climate change and human habitation collide in worsening fire seasons, what is the long-term outlook? Guest host Umair Irfan talks to fire scientist Crystal Kolden about the way fires are changing as we change the landscape, and what coexisting with fire can look like—including learning from the time-proven burning and forestry practices of Indigenous peoples of the West. Do I Really Need 10,000 Steps A Day? Scientists Say 7,000 Is Fine You’ve probably heard someone say that they have to “get their steps in.” But does the number of steps you take in a day actually matter? For years, there was a mythology around the health benefits of walking 10,000 steps a day. But it turned out that number wasn’t based on actual data—it grew out of a marketing effort in Japan from a pedometer company in the 1960s. Now, Amanda Paluch, an assistant professor of kinesiology at the University of Massachusetts Amherst, has published a paper—based on actual data—to help answer this question in the academic journal JAMA Network Open. Mining data collected by the CARDIA cohort study, they compared the overall health outcomes of people who walked less than 7,000 steps a day, those logging 7,000 to 10,000 steps, and those trekking over 10,000. They found that people who walked over 7,000 steps a day had a significant decrease in mortality, compared to people who took fewer steps. They’re still trying to tease out exactly what health benefits the steps may bring. Paluch joins guest host Umair Irfan to talk about the research, and what you should know about how walking might improve health. NASA Scientist Answers Kids’ Questions About The Mars Rover It was big news last week when the Mars rover Perseverance collected its first rock samples. And just in time, we invited young listeners in our audience to ask research scientist Katie Stack Morgan of NASA’s Jet Propulsion Laboratory some of their most pressing questions about the Mars 2020 mission. Questions like, “How do samples get back to Earth from Mars?” And, “How does Perseverance dust itself off … if it can?
46 min

Covid And Disabilities, Alzheimer’s And Inflammation, Ultrasonic Sound. Sept 10, 2021, Part 1

New Policies Emerge In The Wake Of Climate-Connected Disasters This week, people across the United States continued to be reminded of the results of a shifting climate—with people in the Gulf states still recovering from Ida, northeastern states dealing with the aftermath of Hurricane Ida-induced flooding, and western states battling wildfires and smoke. With climate-related disasters as a backdrop, President Biden announced a goal of shifting some 45% of U.S. energy production to solar power by 2050. Kendra Pierre-Louis, senior reporter for the Gimlet-Spotify podcast How to Save A Planet, joins Ira to talk about those stories and more, including new calculations of the importance of minimizing fossil fuel extraction, to a successful sample collection effort on Martian soil.   Is Inflammation In The Brain Causing Alzheimer’s Disease? The brain of a person with Alzheimer’s disease has a few hallmark traits. First, a buildup of plaques made of proteins called amyloid beta. Second, are tangles of another protein, called tau, within individual neurons. A third major indicator is inflammation. While researchers have long thought brain inflammation was a byproduct of the disease itself, there’s a growing hypothesis that it might actually be a driver of the disease’s progression. That would help explain why researchers have found people whose brains are full of tau tangles and amyloid plaques, but with no outward symptoms of Alzheimer’s. Research on animals has supported this theory. But finding the same evidence in human brains is harder. Now, a team of scientists, writing in the journal Nature Medicine, thinks they have it: time-lapsed images of patient brains showing tau tangles and inflammation spreading through the brain in the exact same pattern. Ira talks to Dr. Tharick Pascoal, assistant professor at the University of Pittsburgh and the study’s first author, about this finding, and what it means for future research into Alzheimer’s therapies.   The World According To Sound: Ultrasonics The mating calls of the katydid, a large insect, are ultrasonic, beyond the audible limit of human hearing. What if we could hear them? That’s the focus behind a collaboration between the abstract audio podcast The World According To Sound and scientist Laurel Symes, the assistant director of the Center for Conservation Bioacoustics at Cornell University. In this recording, you’ll hear the sounds of one of her study animals—a group of katydids in a forest in Panama. Bill McQuay, sound engineer and an audio producer at the Cornell Lab of Ornithology, slowed down Symes’ recording so you can hear a whole world of ultrasonic activity open up, from ultrasonic mating calls of katydids to the ultrasonic pings of bats echolocating their next meal. The World According to Sound is a live audio show, online listening series, and miniature podcast that focuses on sound, not story. Producers Chris Hoff and Sam Harnett create intentional, communal listening experiences as a way to “reclaim autonomy in a visually dominated world that is increasingly fracturing our attention.” This katydid recording and more are a part of their next listening series, an immersive listening party where audiences from all over the globe will be invited to experience a world of sound together, beginning in January 2022.   How COVID-19 Reveals Existing Biases Against The Disability Community In early July, I visit Ingrid Tischer at the Berkeley apartment she’s shared with her husband, Ken, for the past 10 years. When I arrive, she’s already sitting outside at the top of a gently sloping ramp that leads up to the door. We’re both vaccinated, but we’re still taking precautions: masks, outdoors, and social distancing. That’s because Ingrid has a severe disability. “I have muscular dystrophy,” she tells me, “which is a neuromuscular disorder that I’ve had my entire life because it’s genetic.” Muscular dystrophy is a progressive muscle wasting disease. It impacts her mobility, including her ability to walk unassisted. Ingrid says she’s most impacted by having a weak respiratory system and uses an oxygen device called a biPap to help her breathe. Earlier in the pandemic, her doctor told her that if she got COVID, it would likely be a death sentence. “I’d never heard my situation put in such stark, certain terms,” she says. Ingrid is in her mid 50s, with graying brown hair and bright blue eyes. She leads fundraising for DREDF, a disability rights and legal advocacy organization. She’s also a writer — she’s written a draft of a novel and has a blog called “Tales From the Crip.” In addition to a brilliant title, the blog is full of her personal reflections about navigating a world in which the needs and feelings of people with disabilities go mostly unseen and ignored. When COVID hit in the spring of 2020, Ingrid was terrified. Because of the risk of infection and smoke from the wildfires that summer, she stopped leaving her house entirely, developed severe anxiety and depression, and began noticing a host of new health issues. Her feet and legs began swelling and breathing became even more difficult than usual. Her doctor worried she might be developing congestive heart failure, but told her to stay home rather than come in for tests and risk infection. It’s a common story. A recent survey by the disability advocacy group #NoBodyIsDisposable found that many disabled people have delayed medical care for over a year due to concerns about COVID-19. Read more at sciencefriday.com.
47 min

Oyster Breeding, Climate Communication, Hellbender Vs Mantis Shrimp. Sept 10, 2021, Part 2

To Breed An Oyster In the ocean, climate change involves more than just warming temperatures. Water levels are shifting, and ocean chemistry is changing.  Changes to ocean salinity caused by shifting amounts of freshwater could have big effects on the health of oysters, who need a certain range of saltiness in the water to be happy.   As part of her doctoral work at Louisiana State University, researcher Joanna Griffiths bred hundreds of families of oysters, looking for clues to what makes an oyster more able to endure salinity changes. She found that there is a genetic component to an oyster’s salinity resilience.  Griffiths joins Scifri’s Charles Bergquist to talk about the work, and the challenges of conducting a laboratory oyster breeding program—in which it’s difficult convince an oyster that it’s time for romance, and often even hard to discern the sex of the oysters involved.     Talking Through The Tangled Terms Of Climate Change When scientists talk about climate change, there are certain words and phrases that get brought up often. Terms like “mitigation,” “carbon neutral” and “tipping point” are used frequently to explain how the climate crisis is unfolding. They’re often found in reports meant to educate the public on climate change, such as the latest report from the UN’s Intergovernmental Panel on Climate Change. It turns out a lot of words and phrases that scientists use to talk about climate change are not understood by the general public. That’s according to a recent study from the University of Southern California and the United Nations Foundation. This begs the question: if the public scientists are trying to reach don’t understand what’s being discussed, what’s the point? Joining Ira to talk about better communicating climate change is Wändi Bruine de Bruin, lead author of the study and provost professor of public policy, psychology and behavioral science at the University of Southern California in Los Angeles, California. Also joining Ira is Anthony Leiserowitz, founder and director of the Yale Program on Climate Change Communication in New Haven, Connecticut.      An Aquatic Charismatic Creature Showdown: Mantis Shrimp vs. Hellbender It’s time to kick off SciFri’s Charismatic Creature Carnival! Welcome to our celebration of creatures that are overlooked or unfairly maligned by the general public, which, if you look a little closer, have an undeniable charm. Six audience-suggested creatures were chosen, but only one will be crowned the very first carnival inductee into the Charismatic Creature Corner Hall of Fame. The first friendly head-to-head battle in this fall’s Charismatic Creature Carnival is between the mantis shrimp and the hellbender, a giant aquatic salamander. Defending the mantis shrimp is Jason Dinh, PhD candidate in biology at Duke University in Durham, North Carolina. And representing the hellbender is Lauren Diaz, PhD student in fisheries science at Oregon State University in Corvallis, Oregon. Find a list of upcoming carnival celebrations below!
47 min

COVID Fact Check, Ocean Circulation and Climate, Bread Culture. Sept 3, 2021, Part 2

Fact Check My Feed: Why Are People Taking Discredited Horse Medicine For COVID-19? If you’ve been online at all in the past few weeks, you’ve probably seen discussion about the drug ivermectin. It was originally developed as an antiparasitic treatment for livestock, and in 2015, the Nobel Prize in Medicine went to scientists who found that it helped control parasitic diseases in humans as well. But recently, non-medical groups have been incorrectly promoting the drug as a treatment for COVID-19—even though the coronavirus is a virus, not a parasite. Virologist Angela Rasmussen of the University of Saskatchewan joins Ira to look at the data behind sometimes hyperbolic COVID-19 claims, from the latest on booster shots to the emergence of a new coronavirus variant in South Africa.     What Happens If Atlantic Ocean Currents Cease To Churn? Early last month, the Intergovernmental Panel on Climate Change released its latest report. It was a grim document, concluding that global warming had already set in motion irreversible levels of sea level rise, along with other changes that are threatening lives and health around the globe. The report focused in part on climate tipping points, or phenomena that, if they occur, could lead to a long term re-setting of our global climate and cascades of dangerous changes. Included among tipping points like the loss of the Amazon rainforest and melting of the permafrost, was the potential shutdown of the Atlantic meridional overturning circulation—the AMOC, for short. That circulation, a set of currents that includes the Gulf Stream, ferries cold water from the poles toward the equator, and distributes heat from the equator to northern latitudes. And it’s powered by two things that are both changing as the climate warms: the temperature of ocean water, and the varying concentrations of salt in that water.  Climate models that use data from thousands of years ago can help us predict what might happen if the AMOC shuts down. Because the currents are a huge source of heat redistribution globally, a shutdown could have a complex array of consequences, from rainfall disruptions in the southern hemisphere, to even greater sea level rise on North America’s east coast. And if it shuts down completely, it may not come back on again in any of our lifetimes. Unfortunately, researchers have been finding evidence that the circulation is, in fact weakening, including a study published in the journal Nature Climate Change in early August. Ira talks to Levke Caesar, a researcher at Maynooth University’s ICARUS Climate Research Center. While not affiliated with the latest research, her work has helped map the ongoing pattern of weakening in the AMOC.       A Sourdough Saga, From Starter To Slice What makes sourdough taste sour? Was the first bread invented, or discovered? How did scientists eventually figure out that yeast and bacteria were the true master bakers? Will commercial bread ever be as good as that hand-baked loaf? Ira releases his inner breadmaking nerd in this conversation with Eric Pallant, author of the forthcoming book Sourdough Culture: A History of Breadmaking From Ancient to Modern Bakers.
47 min

Schools And The Delta Variant, Doubts For High-Tech Air Purifiers. Sept 3, 2021, Part 1

Nation Grapples With Several Climate Disasters At Once Hurricane Ida wreaked havoc on the eastern U.S. this week. It all started in Louisiana, leaving daunting damage and a long road to recovery for residents. Even though Ida was downgraded to a tropical storm after leaving the state, it left a trail of destruction through the eastern U.S. and mid-Atlantic, flooding cities and damaging homes. In the New York area, at least a dozen people died after the region was pummeled by more than half a foot of rain in just a few hours. This happened all while the western U.S. continues to battle wildfires, from Oregon to Colorado. In California, the extreme wildfire season led the state to close its National Forests through Labor Day weekend, a time where many people get outside and enjoy nature. If it feels like these apocalyptic-level events are happening more and more frequently, you’re correct. Extreme weather is inextricably tied to climate change, and the science backs that up. Joining Ira to talk about these climate stories and more is Maggie Koerth, science reporter for FiveThirtyEight based in Minneapolis, Minnesota. Florida Schools With Mask Mandates Lose Funding The state Department of Education said Tuesday it was investigating the school districts of Hillsborough, Sarasota and Orange counties over mask mandates that do not allow for a parental exemption. In a letter to district officials, Education Commissioner Richard Corcoran wrote the districts were in violation of a state Department of Health emergency rule triggered by Gov. Ron DeSantis’ executive order intended to block districts from enacting school mask mandates. On Friday, Leon County Circuit Judge John Cooper ruled the executive order was unconstitutional and cannot be enforced. However, DeSantis said an appeal is planned and his office has said it will continue to act in defense of parents’ rights until a signed judge’s order was issued. Corcoran’s letters were sent Friday, and the three districts were given until 5 p.m. Wednesday to respond. If they remain noncompliant, they could face financial penalties. All three counties have mandates that allow exemptions only for medical reasons with a medical professional’s note. Read more at sciencefriday.com. Back to School During The Delta Variant Back-to-school is usually an exciting time, with some nerves mixed in. But this year is a little different. All across the country, arguments about mask mandates are exploding in school board meetings and courtrooms. In places with no mask mandates, parents are weighing difficult decisions over how much risk is too much. But masks are just part of the equation for school safety. Air ventilation and distance are both important parts of the COVID-19 transmission equation, and many parents have questions about how their schools are preparing. With pediatric COVID-19 cases rising, and Delta’s high transmission rates, many are wondering how we’re going to keep our kids safe in schools. Joining Ira to mull over this question is Dr. Katelyn Jetelina, assistant professor at the University of Texas School of Public Health in Dallas, Texas. Many Schools Are Buying High-Tech Air Purifiers. Do They Actually Work? As students head back to school, parents are getting a lot of mail about what schools are doing to better protect kids in the classroom—from mask policies to spacing to lunch plans. One item on many administrators’ lists of protective measures is improving classrooms’ ventilation. Many studies have shown that better ventilation and air circulation can greatly reduce COVID-19 transmission. But rather than stocking up on HEPA filters, some districts are turning to high-tech air purification schemes, including untested electronic approaches and airborne chemicals. Christina Jewett, a senior correspondent for Kaiser Health News, has written extensively about school air filtration and purification. She joins Ira to explain why some air quality experts are less than convinced by the marketing claims made by many electronic air purifier companies.
46 min

Medieval Bones, Bird Ancestors And Dinosaurs. August 27, 2021, Part 2

A Skeletal Record Of Medieval England Society Whether you like it or not, a record of your life is constantly being chronicled. No, not through the internet or on social media—through your bones. If you’ve ever fractured a bone, that skeletal trauma stays with you forever, even after it heals. So researchers across the pond are using bones from medieval times to put together a picture of what life was like. The bones in the study came from ordinary people in medieval Cambridge in the United Kingdom, from between the 10th and 14th century. The researchers found that you can often guess who was working class, and who had more money based on what their bones looked like. In this re-broadcast, SciFri producer Kathleen Davis talks to Jenna Dittmar, a research fellow in osteoarchaeology at the University of Aberdeen in Scotland, about this new research.      Birds Are The Last Dinosaurs. Why Did They Survive? Sixty-six million years ago, thanks to the Chicxulub meteor—and possibly additional stressors like volcanic eruptions—85% of the species on Earth went extinct, and the Cretaceous period drew to a close. The loss of species included most dinosaurs, but not all. Today’s birds are the last of the dinosaurs, descendents of ancestors that didn’t just survive this mass extinction, but evolutionarily exploded into thousands of species distributed around the world.  Paleontologists are still searching for why birds didn’t die, and what traits their ancestors possessed that allowed them to inherit the planet, along with mammals and other survivors. Writing in the journal Science Advances last month, a team of researchers looked at a newly discovered fossil skull from a cousin of modern birds, a bird called Ichthyornis, which went extinct with the rest of the non-avian dinosaurs. Their logic was that if the brain of Ichthyornis was different from modern birds, that difference might explain why Ichthyornis died with the dinosaurs, while the ancestors of modern birds survived. Paleontologists Julia Clarke and Chris Torres, co-authors on the new research, join producer Christie Taylor for a conversation about the clues, the unknowns, and what fossils still can’t reveal. Plus, why studying the end-Cretaceous mass extinction could provide data for understanding what animals will survive modern global warming.
47 min

Pfizer Vaccine Approval, Making Solar Power For Everyone. August 27, 2021, Part 1

Pfizer’s Vaccine Is Now Fully Approved. What’s Next For The Pandemic? This week, the COVID-19 vaccine marketed by Pfizer finally received full FDA approval, moving out of the realm of “emergency use” to the status of a regular drug. In the wake of that change, many organizations—from the Pentagon to Ohio State University to the city of Chicago—are moving to require vaccinations against the coronavirus. It remains to be seen just how much the status change will move the needle on vaccination numbers—and more importantly, new cases and hospitalizations—in the U.S. Sarah Zhang, staff writer at The Atlantic, joins Ira to talk about what might be next for the pandemic, discussing the virus becoming endemic and how the Delta variant is changing people’s risk calculations. They also explore how different countries, from the U.K. to Vietnam to New Zealand, are coping. Plus, ways that the virus continues to upend business as normal—from SpaceX launches to water treatment.   How To Make Solar Power Work For Everyone If you follow Ira on social media, you may have noticed a trend in his posts over the last few months: They’ve become very joyful about the cost of his energy bill. Why? This year, he installed solar panels on his roof—and he’s not alone. The cost of solar panels has dropped nearly 70 percent since 2014, so more and more individuals and companies are jumping in. Even during COVID-19, solar installations in the U.S. reached a record high in 2020. For Ira and many others, solar panels turn homes into their own power generators. During some times of the day, the panels produce enough excess power that it’s fed back to the grid. As more and more people jump into solar power, big questions remain about how an energy grid designed for fossil fuels will be impacted. If everyone’s home is a utility, how do you best distribute power to a region? Accessibility is also a big concern. If there’s a need to retool how the country thinks about energy creation and use, how do we make sure it’s accessible to everyone? Joining Ira to talk through these big-picture solar energy quandaries are Joseph Berry, senior research fellow at the National Renewable Energy Laboratory in Golden, Colorado, and Sam Evans-Brown, executive director of Clean Energy New Hampshire based in Concord, New Hampshire.