Billions of years ago, Mars probably hosted many water features: streams, rivers, gullies, etc. But until recently, water detected on the Red Planet was either locked up in ice or flitting about as a gas in the atmosphere. Now, researchers analyzing radar data from the Mars Express mission have found evidence for an enormous salty lake under the southern polar ice cap of Mars. Daniel Clery joins host Sarah Crespi to discuss how the water was found and how it can still be liquid—despite temperatures and pressures typically inhospitable to water in its liquid form. Read the research. Sarah also talks with science journalist Katherine Kornei about her story on changing athletic performance after gender transition. The feature profiles researcher Joanna Harper on the work she has done to understand the impacts of hormone replacement therapy and testosterone levels in transgender women involved in running and other sports. It turns out within a year of beginning hormone replacement therapy, transgender women plateau at their new performance level and stay in a similar rank with respect to the top performers in the sport. Her work has influenced sports oversight bodies like the International Olympic Committee. In this month’s book segment, Jen Golbeck interviews Andrew Lawler about his book The Secret Token: Myth, Obsession, and the Search for the Lost Colony of Roanoke. Next month’s book will be The Book of Why: The New Science of Cause and Effect by Judea Pearl and Dana Mackenzie. Write us at sciencepodcast@aaas.org or tweet to us @sciencemagazine with your questions for the authors. This week’s episode was edited by Podigy. Download a transcript of this episode (PDF) Listen to previous podcasts. [Image: Henry Howe; Music: Jeffrey Cook]

We now live in the Meghalayan age—the last age of the Holocene epoch. Did you get the memo? A July decision by the International Commission on Stratigraphy, which is responsible for naming geological time periods, divided the Holocene into three ages: the Greenlandian, the Northgrippian, and the Meghalayan. The one we live in—the Meghalayan age (pronounced “megalion”)—is pegged to a global drought thought to have happened some 4200 years ago. But many critics question the timing of this latest age and the global expanse of the drought. Staff writer Paul Voosen talks with host Sarah Crespi about the evidence for and against the global drought—and what it means if it’s wrong. Sarah also talks to staff writer Kelly Servick about her feature story on what happens when biocontrol goes out of control. Here’s the setup: U.S. Department of Agriculture researchers wanted to know whether brown marmorated stink bugs that have invaded the United States could be controlled—aka killed—by importing their natural predators, samurai wasps, from Asia. But before they could find out, the wasps showed up anyway. Kelly discusses how using one species to combat another can go wrong—or right—and what happens when the situation outruns regulators. This week’s episode was edited by Podigy. Download a transcript of this episode (PDF) Listen to previous podcasts. [Image: Melissa McMasters/Flickr; Music: Jeffrey Cook] 

Several thousand years ago the volcano under Santorini in Greece—known as Thera—erupted in a tremendous explosion, dusting the nearby Mediterranean civilizations of Crete and Egypt in a layer of white ash. This geological marker could be used to tie together many ancient historical events, but the estimated date could be off by a century. Contributing Correspondent Lizzie Wade joins host Sarah Crespi to talk about a new study that used tree rings to calibrate radiocarbon readings—and get closer to pinning down a date. The findings also suggest that scientists may need to change their standard radiocarbon dating calibration curve. Sarah also talks to Tony Belpaeme of Ghent University in Belgium and Plymouth University in the United Kingdom about his Science Robotics paper that explored whether people are susceptible to peer pressure from robots. Using a classic psychological measure of peer influence, the team found that kids from ages 7 to 9 occasionally gave in to social pressure from robot peers, but adults did not. This week’s episode was edited by Podigy, with help from Meagan Cantwell. Download a transcript of this episode (PDF) Listen to previous podcasts. About the Science Podcast [Image: Softbank Robotics; Music: Jeffrey Cook]

Small satellites—about the size of a briefcase—have been hitching rides on rockets to lower Earth orbit for decades. Now, because of their low cost and ease of launching, governments and private companies are looking to expand the range of these “sate-lites” deeper into space. Host Sarah Crespi talks with Deputy News Editor Eric Hand about the mods and missions in store for so-called CubeSats. And our newest podcast producer Meagan Cantwell interviews Quentin Grafton of Australian National University in Canberra and Brad Udall of Colorado State University in Fort Collins about something called the “irrigation efficiency paradox.” As freshwater supplies dry up around the world, policymakers and farmers have been quick to try to make up the difference by improving irrigation, a notorious water waster. It turns out that both human behavior and the difficulty of water measurement are plaguing water conservation efforts in agriculture. For example, when farms find they are using less water, they tend to plant ever-more-water-intensive crops. Now, researchers are trying to get the message out about the behavioral component of this issue and tackle the measurement problem, using cheap remote-sensing technology, but with water scarcity looming ahead, we have to act soon. This week’s episode was edited by Podigy. Download a transcript of this episode (PDF) Listen to previous podcasts. About the Science Podcast [Image: John A. Kelley, USDA Natural Resources Conservation Service; Music: Jeffrey Cook]

A new project out of the Center for Open Science in Charlottesville, Virginia, found that of all the experimental social science papers published in Science and Nature from 2010–15, 62% successfully replicated, even when larger sample sizes were used. What does this say about peer review? Host Sarah Crespi talks with Staff Writer Kelly Servick about how this project stacks up against similar replication efforts, and whether we can achieve similar results by merely asking people to guess whether a study can be replicated. Podcast producer Meagan Cantwell interviews Emily Brodsky of the University of California, Santa Cruz, about her research report examining why earthquakes occur as far as 10 kilometers from wastewater injection and fracking sites. Emily discusses why the well-established mechanism for human-induced earthquakes doesn’t explain this distance, and how these findings may influence where we place injection wells in the future. In this month’s book podcast, Jen Golbeck interviews Judea Pearl and Dana McKenzie, authors of The Book of Why: The New Science of Cause and Effect. They propose that researchers have for too long shied away from claiming causality and provide a road map for bringing cause and effect back into science. This week’s episode was edited by Podigy. Download a transcript of this episode (PDF) Listen to previous podcasts. About the Science Podcast [Image: Jens Lambert, Shutterstock; Music: Jeffrey Cook]

We are in the middle of what some scientists are calling the sixth mass extinction and not all at-risk species can be saved. That’s causing some conservationists to say we need to start thinking about “species triage.” Meagan Cantwell interviews freelance journalist Warren Cornwall about his story on weighing the costs of saving Canada’s endangered caribou and the debate among conservationists on new approaches to conservation. And host Sarah Crespi interviews Hope Michelsen, a staff scientist at Sandia National Laboratories in Livermore, California, about mysterious origins of soot. The black dust has been around since fire itself, but researchers never knew how the high-energy environment of a flame can produce it—until now. Michelsen walks Sarah through the radical chemistry of soot formation—including its formation of free radicals—and discusses soot’s many roles in industry, the environment, and even interstellar space. Check out this useful graphic describing the soot inception process in the related commentary article. This week’s episode was edited by Podigy. Download a transcript of this episode (PDF) Listen to previous podcasts. About the Science Podcast [Image: Darren Bertram/Flickr; Music: Jeffrey Cook]

Meta-analyses—structured analyses of many studies on the same topic—were once seen as objective and definitive projects that helped sort out conflicts amongst smaller studies. These days, thousands of meta-analyses are published every year—many either redundant or contrary to earlier metaworks. Host Sarah Crespi talks to freelance science journalist Jop de Vrieze about ongoing meta-analysis wars in which opposing research teams churn out conflicting metastudies around important public health questions such as links between violent video games and school shootings and the effects of antidepressants. They also talk about what clues to look for when trying to evaluate the quality of a meta-analysis. Sarah also talked with three other contributors to our “Research on Research” special issue. Pierre Azoulay of the Massachusetts Institute of Technology (MIT) in Cambridge, Ben Jones of Northwestern University in Evanston, Illinois, and MIT’s Heidi Williams discuss the evidence for some hoary old scientific home truths. See whether you can guess who originally made these claims and how right or wrong they were: Do scientists make great contributions after age 30? How important is it to stand on the shoulders of giants? Does the truth win, or do its opponents just eventually die out? Read the rest of the package on science under scrutiny here. This week’s episode was edited by Podigy. Download a transcript of this episode (PDF) Listen to previous podcasts. About the Science Podcast [Image: Davide Bonazzi/@SalzmanArt; Show music: Jeffrey Cook; additional music: Nguyen Khoi Nguyen]

Science has often treated Indigenous people as resources for research—especially when it comes to genomics. Now, Indigenous people are exploring how this type of study can be conducted in a way that respects their people and traditions. Meagan Cantwell talks with contributing correspondent Lizzie Wade about a summer workshop for Indigenous scientists that aims to start a new chapter in genomics. We’ve known for decades that PCBs—polychlorinated biphenyls—are toxic and carcinogenic. In the 1970s and 1980s, these compounds were phased out of use in industrial and electronic applications, worldwide. But they are still in the environment—in soil and air—and in animal tissues, particularly those of killer whales. These toxic compounds start out at minute levels in tiny organisms, but as the small are eaten by the slightly larger, the PCB concentration increases—from plankton, to fish, to seals—until you are at killer whales with PCB-packed blubber. Ailsa Hall, director of the Sea Mammal Research Unit at St. Andrews University in the United Kingdom, talks with host Sarah Crespi about her group’s work measuring PCB levels in different killer whale populations and calculating the effect of PCBs on those populations 100 years from now. In this month’s book segment, Jen Golbeck interviews Damon Centola about his book How Behavior Spreads: The Science of Complex Contagions. You can listen to more books segment and read more reviews on our books blog, Books et al.  This week’s episode was edited by Podigy. Download a transcript of this episode (PDF) Listen to previous podcasts About the Science Podcast [Image: Public domain; Music: Jeffrey Cook] 

Hoping to spot subatomic particles called neutrinos smashing into Earth, the balloon-borne Antarctic Impulsive Transient Antenna (ANITA) detector has circled the South Pole four times. ANITA has yet to detect those particles, but it has twice seen oddball radio signals that could be evidence of something even weirder: some heavier particle unknown to physicists’ standard model, burrowing up through Earth. Science writer Adrian Cho joins host Sarah Crespi to discuss the possibility that this reading could lead to a big change in physics. Next, host Meagan Cantwell asks researcher Ben Dalziel what makes a bad—or good—flu year. Traditionally, research has focused on two factors: climate, which impacts how long the virus stays active after a sneeze or cough, and changes in the virus itself, which can influence its infectiousness. But these factors don’t explain every pattern. Dalziel, a population biologist in the Departments of Integrative Biology and Mathematics at Oregon State University in Corvallis, explains how humidity and community size shape the way influenza spreads. This week’s episode was edited by Podigy. Download a transcript of this episode (PDF) Listen to previous podcasts. About the Science Podcast [Image: Stuart Rankin/Flickr; Music: Jeffrey Cook]

A small isolated town in Colombia is home to a large cluster of people with fragile X syndrome—a genetic disorder that leads to intellectual disability, physical abnormalities, and sometimes autism. Spectrum staff reporter Hannah Furfaro joins host Sarah Crespi to discuss the history of fragile X in the town of Ricaurte and the future of the people who live there. Also this week, we talk about greening up grass. Lawns of green grass pervade urban areas all around the world, regardless of climate, but the cost of maintaining them may outweigh their benefits. Host Meagan Cantwell talks with Maria Ignatieva of The University of Western Australia in Perth and the Swedish University of Agricultural Sciences in Uppsala about how lawns can be transformed to contribute to a more sustainable future. This week’s episode was edited by Podigy. Download a transcript of this episode (PDF) Listen to previous podcasts. About the Science Podcast [Image: Adam Kerfoot-Roberts/Flickr; Music: Jeffrey Cook]

A group of children is suing the U.S. government—claiming their rights to life, liberty, and property are under threat from climate change thanks to government policies that have encouraged the use and extraction of fossil fuels. Host Meagan Cantwell interviews news writer Julia Rosen on the ins and outs of the suit and what it could mean if the kids win the day.    Also this week, host Sarah Crespi talks with Andrew Moeller of Cornell University about his work tracing the gut microbes inherited through 10 generations of mice. It turns out the fidelity is quite high—you can still tell mice lineages apart by their gut microbes after 10 generations. And horizontally transmitted microbes, those that jump from one mouse line to another through exposure to common spaces or handlers, were more likely than inherited bacteria to be pathogenic and were often linked to illnesses in people. This week’s episode was edited by Podigy. Download a transcript of this episode (PDF) Listen to previous podcasts. About the Science Podcast [Image: Bob Dass/Flickr; Music: Jeffrey Cook] 

For a long time, Parkinson’s disease was thought to be merely a disorder of the nervous system. But in the past decade researchers have started to look elsewhere in the body for clues to this debilitating disease—particularly in the gut. Host Meagan Cantwell talks with Viviane Labrie of the Van Andel Institute in Grand Rapids, Michigan, about new research suggesting people without their appendixes have a reduced risk of Parkinson’s. Labrie also describes the possible mechanism behind this connection. And host Sarah Crespi talks with Peter Fratzl of the Max Planck Institute of Colloids and Interfaces in Potsdam, Germany, about what materials scientists can learn from nature. The natural world might not produce innovations like carbon nanotubes, but evolution has forged innumerable materials from very limited resources—mostly sugars, proteins, and minerals. Fratzl discusses how plants make time-release seedpods that are triggered by nothing but fire and rain, the amazing suckerin protein that comprises squid teeth, and how cicadas make their transparent, self-cleaning wings from simple building blocks. Fratzl’s review is part of a special section in Science on composite materials. Read the whole package, including a review on using renewables like coconut fiber for building cars and incorporating carbon nanotubes and graphene into composites. This week’s episode was edited by Podigy. Download the transcript (PDF) Listen to previous podcasts. About the Science Podcast [Image: Roger Smith/Flickr; Music: Jeffrey Cook]

First, we hear from science writer Joshua Sokol about his trip to the Cambrian—well not quite. He talks with host Megan Cantwell about his travels to a remote site in the mountains of British Columbia where some of Earth’s first animals—including a mysterious, alien-looking creature—are spilling out of Canadian rocks.   Also on this week’s show, host Sarah Crespi talks with James Hazel a postdoctoral research fellow at the Center for Genetic Privacy and Identity in Community Settings at Vanderbilt University in Nashville about a proposal for creating a universal forensic DNA database. He and his co-authors argue that current, invasive practices such as law enforcement subpoenaing medical records, commercial genetic profiles, and other sets of extremely detailed genetic information during criminal investigations, would be curtailed if a forensics-use-only universal database were created.     This week’s episode was edited by Podigy.   Read a transcript (PDF) Listen to previous podcasts.   About the Science Podcast  

A new Science investigation reveals several major private research funders—including the Wellcome Trust and the Robert Wood Johnson Foundation—are making secretive offshore investments at odds with their organizational missions. Host Meagan Cantwell talks with writer Charles Piller about his deep dive into why some private funders choose to invest in these accounts. In the United States, gun injuries kill more children annually than pediatric cancer, but funding for firearm research pales in comparison. On this week’s show, host Sarah Crespi talks with Staff Writer Meredith Wadman and emergency physician Rebecca Cunningham about how a new grant will jump-start research on gun deaths in children. This week’s episode was edited by Podigy. Listen to previous podcasts. About the Science Podcast [Image: Bernard Spragg; Music: Jeffrey Cook] *Correction, 27 December, 5 p.m.: The interview on studying gun deaths in children in the United States incorrectly says that NIH spent $3.1 million on research into pediatric gun deaths. The correct figure is $4.4 million.

First, we hear Online News Editor David Grimm and host Sarah Crespi discuss audience favorites and staff picks from this year’s online stories, from mysterious pelvises to quantum engines. Megan Cantwell talks with News Editor Tim Appenzeller about the 2018 Breakthrough of the Year, a few of the runners-up, and some breakdowns. See the whole breakthrough package here, including all the runners-up and breakdowns. And in her final segment for the Science Podcast, host Jen Golbeck talks with Science books editor Valerie Thompson about the year in books. Both also suggest some last-minute additions to your holiday shopping list. This week’s episode was edited by Podigy. Download the transcript (PDF) Listen to previous podcasts. About the Science Podcast [Image: NASA Scientific Visualization Studio; Music: Jeffrey Cook]

Plan S, an initiative that requires participating research funders to immediately publish research in an open-access journal or repository, was announced in September 2018 by Science Europe with 11 participating agencies. Several others have signed on since the launch, but other funders and journal publishers have reservations. Host Meagan Cantwell speaks with Contributing Correspondent Tania Rabesandratana about those reservations and how Plan S is trying to change publishing practices and research culture at large. Some 1.7 million Jewish people were murdered by the Nazis in the 22 months of Operation Reinhard (1942–43) which aimed to eliminate all Jews in occupied Poland. But until now, the speed and totality of these murders were poorly understood. It turns out that about one-quarter of all Jews killed during the Holocaust were murdered in the autumn of 1942, during this operation. Meagan talks with Lewi Stone, a professor of biomathematics at Tel Aviv University in Israel and mathematical science at RMIT University in Melbourne, Australia, about this shocking kill rate, and why researchers are taking a quantitative approach to characterizing genocides. This week’s episode was edited by Podigy. Download the transcript (PDF) Listen to previous podcasts. About the Science Podcast [Image: Michael Beckwith; Music: Jeffrey Cook]

Massive Open Online Courses (MOOCs) provide free lectures and assignments, and gained global attention for their potential to increase education accessibility. Plagued with high attrition rates and fewer returning students every year, MOOCs have pivoted to a new revenue model—offering accredited master’s degrees for professionals. Host Meagan Cantwell speaks with Justin Reich, an assistant professor in the Comparative Media Studies Department at the Massachusetts Institute of Technology in Cambridge, about the evolution of MOOCs and how these MOOC professional programs may be reaching a different audience than traditional online education. Archaeologists were flummoxed when they found a brilliant blue mineral in the dental plaque of a medieval-era woman from Germany. It turned out to be lapis lazuli—an expensive pigment that would have had to travel thousands of kilometers from the mines of Afghanistan to a monastery in Germany. Host Sarah Crespi talks to Christina Warinner, a professor of archaeogenetics at the Max Planck Institute for the Science of Human History in Jena, Germany, about how the discovery of this pigment shed light on the impressive life of the medieval woman, an artist who likely played a role in manuscript production. This week’s episode was edited by Podigy. Download the transcript (PDF) Listen to previous podcasts. About the Science Podcast [Image:Oberlin.edu/Wikimedia Commons; Music: Jeffrey Cook]

Orla Smith, editor of Science Translational Medicine joins host Sarah Crespi to talk about what has changed in the past 10 years of microbiome research, what’s getting close to being useful in treatment, and how strong, exactly, the research is behind those probiotic yogurts. When you’re sick, sleeping is restorative—it helps your body recover from nasty infections. Meagan Cantwell speaks with Amita Sehgal, professor of neuroscience at the University of Pennsylvania and an investigator at Howard Hughes Medical Institute in Chevy Chase, Maryland, about the process of discovering a gene in fruit flies that links sleep and immune function. This week’s episode was edited by Podigy. Download the transcript (PDF) Listen to previous podcasts. About the Science Podcast [Music: Jeffrey Cook]

Because of its genetic complexity, the potato didn’t undergo a “green revolution” like other staple crops. It can take more than 15 years to breed a new kind of potato that farmers can grow, and genetic engineering just won’t work for tackling complex traits such as increased yield or heat resistance. Host Sarah Crespi talks with Staff Writer Erik Stokstad about how researchers are trying to simplify the potato genome to make it easier to manipulate through breeding. Researchers and companies are racing to perfect an injector pill—a pill that you swallow, which then uses a tiny needle to shoot medicine into the body. Such an approach could help improve compliance for injected medications like insulin. Host Meagan Cantwell and Staff Writer Robert F. Service discuss a new kind of pill—one that flips itself over once it hits the bottom of the stomach and injects a dose of medication into the stomach lining. This week’s episode was edited by Podigy. Download the transcript (PDF) Listen to previous podcasts. About the Science Podcast [Image: Michael Eric Nickel/Flickr; Music: Jeffrey Cook]

In the wake of a devastating earthquake, assessing the extent of damage to infrastructure is time consuming—now, a cheap sensor system based on the accelerometers in cellphones could expedite this process. Host Sarah Crespi talks with Contributing Correspondent Lizzie Wade about how these sensor systems work and how they might assist communities after an earthquake. In another Earth-shaking study, scientists have downgraded the height of the ancient Tibetan Plateau. Most reconstructions estimate that the “rooftop of the world” reached its current height of 4500 meters about 40 million years ago, but a new study suggests it was a mere 3000 meters high during this period. Host Meagan Cantwell speaks with Svetlana Botsyun, a postdoctoral researcher at Tübingen University in Germany, about her team’s new approach to studying paleoelevation, and how a shorter Tibetan Plateau would have impacted the surrounding area’s climate. This week’s episode was edited by Podigy. Download the transcript (PDF) Listen to previous podcasts. About the Science Podcast [Image: Martin Luff/Flickr; Music: Jeffrey Cook]

New archaeological evidence suggests the same black plague that decimated Europe also took its toll on sub-Saharan Africa. Host Sarah Crespi talks with Contributing Correspondent Lizzie Wade about diverse medieval sub-Saharan cities that shrank or even disappeared around the same time the plague was stalking Europe. In a second archaeological story, Meagan Cantwell talks with Gustavo Politis, professor of archaeology at the National University of Central Buenos Aires and the National University of La Plata, about new radiocarbon dates for giant ground sloth remains found in the Argentine archaeological site Campo Laborde. The team’s new dates suggest humans hunted and butchered ground sloths in the late Pleistocene, about 12,500 years ago. This week’s episode was edited by Podigy. Download the transcript (PDF) Listen to previous podcasts. About the Science Podcast [Image: Ife-Sungbo Archaeological Project; Music: Jeffrey Cook]

Host Sarah Crespi talks with Staff Writer Daniel Clery about the many, many theories surrounding fast radio bursts—extremely fast, intense radio signals from outside the galaxy—and a new telescope coming online that may help sort them out. Also this week, Sarah talks with Staff Writer Jennifer Couzin-Frankel about her story on researchers’ attempts to tackle the long-term effects of pediatric cancer treatment. The survival rate for some pediatric cancers is as high as 90%, but many survivors have a host of health problems. Jennifer’s feature is part of a special section on pediatric cancer. This week’s episode was edited by Podigy. Download a transcript (PDF) Listen to previous podcasts. About the Science Podcast [Image: ESO/L. Calçada; Music: Jeffrey Cook] 

A single factory in Malaysia supplies about 10% of the world’s rare earth oxides, used in everything from cellphones to lasers to missiles. Controversy over the final resting place for the slightly radioactive byproducts has pushed the plant to the brink of closure. Host Meagan Cantwell talks with freelance writer Yao Hua Law about calls to ship the waste back to where it was originally mined in Australia, and how stopping production in Malaysia would mean almost all rare earth production would take place in China.  In another global trade story, host Sarah Crespi talks with freelance writer Sam Kean about close links between the slave trade and early naturalists’ efforts to catalog the world’s flora and fauna. Today, historians and museums are just starting to come to grips with the often-ignored relationships between slavers and scientists. This week’s episode was edited by Podigy. Download the transcript (PDF) Ads on this show: Kolabtree and MagellanTV Listen to previous podcasts. About the Science Podcast [Image: James Petiver, 1695; Music: Jeffrey Cook]

The ancient humans also known as the “hobbit” people (Homo floresiensis) might have company in their small stature with the discovery of another species of hominin in the Philippines. Host Sarah Crespi talks to Contributing Correspondent Lizzie Wade about what researchers have learned about this hominin from a jaw fragment, and its finger and toe bones and how this fits in with past discoveries of other ancient humans. Also this week, host Meagan Cantwell speaks with Florian Schiestl, a professor in evolutionary biology at the University of Zurich in Switzerland, about his work to understand the rapid evolution of the flowering plant Brassica rapa over the course of six generations. He was able to see how the combination of pollination by bees and risk of getting eaten by herbivores influences the plant’s appearance and defense mechanisms. This week’s episode was edited by Podigy. Ads on this week's show: Kolabtree.com and Magellan TV Listen to previous podcasts. About the Science Podcast [Image: Florian Schiestl; Music: Jeffrey Cook]

This week we have two interviews from the annual meeting of AAAS in Washington D.C.: one on the history of food and one about our own perceptions of food and food waste.  First up, host Sarah Crespi talks with Christina Warinner from the Max Planck Institute for the Science of Human History in Jena, Germany, about the history of dairying. When did people first start to milk animals and where? It turns out, the spread of human genetic adaptations for drinking milk do not closely correspond to the history of consuming milk from animals. Instead, evidence from ancient dental plaque suggests people from all over the world developed different ways of chugging milk—not all of them genetic. Next, Host Meagan Cantwell speaks with Sheril Kirshenbaum, co-director of the Michigan State University Food Literacy and Engagement Poll, about the public’s perception of food waste. Do most people try to conserve food and produce less waste? Better insight into the point of view of consumers may help keep billions of kilograms of food from being discarded every year in the United States. This week’s episode was edited by Podigy. Download the transcript (PDF) Ads on the show: Columbia University and Magellan TV Listen to previous podcasts. About the Science Podcast [Image:  Carefull in Wyoming/Flickr; Music: Jeffrey Cook]

Up until this year, most U.S. graduate programs in the sciences required the General Record Examination from applicants. But concerns about what the test scores actually say about potential students and the worry that the cost is a barrier to many have led to a rapid and dramatic reduction in the number of programs requiring the test. Science Staff Writer Katie Langin joins host Sarah Crespi to talk about this trend and how it differs across disciplines. Also this week, Sarah talks with DeepMind’s Max Jaderberg in London about training artificial agents to play a video game version of capture the flag. The agents played approximately 4 years’ worth of Quake III Arena and came out better than even expert human players at both cooperating and collaborating, even when their computer-quick reflexes were hampered. And in this month’s book segment, new host Kiki Sanford interviews Marcus Du Satoy about his book The Creativity Code: Art and Innovation in the Age of AI. This week’s episode was edited by Podigy. Ads this week: KiwiCo.com Download a transcript (PDF) Listen to previous podcasts. About the Science podcast. [Image: DeepMind; Music: Jeffrey Cook]

Cheap and easy to make, perovskite minerals have become the wonder material of solar energy. Now, scientists are turning from using perovskites to capture light to using them to emit it. Staff Writer Robert Service joins host Sarah Crespi to talk about using these minerals in all kinds of light-emitting diodes, from cellphones to flat screen TVs. Read the related paper in Science Advances. Also this week, Sarah talks with Caitlin Thurber, a biologist at Nassau Community College in Garden City, New York, about a hard limit on human endurance. Her group used data from transcontinental racers—who ran 957 kilometers over the course of 20 weeks—and found that after about 100 days, their metabolism settled in at about 2.5 times the baseline rate, suggesting a hard limit on human endurance at long timescales. Earlier studies based on the 23-day Tour de France found much higher levels of energy expenditure, in the four- to five-times-baseline range. Download a transcript (PDF) This week’s episode was edited by Podigy. Ads on the show: KiwiCo.com Listen to previous podcasts. About the Science Podcast [Image: N. Zhou et al., Science Advances 2019; Music: Jeffrey Cook]

Researchers have been making animal embryos from two different species, so-called “chimeras,” for years, by introducing stem cells from one species into a very early embryo of another species. The ultimate goal is to coax the foreign cells into forming an organ for transplantation. But questions abound: Can evolutionarily distant animals, like pigs and humans, be mixed together to produce such organs? Or could species closely related to us, like chimps and macaques, stand in for tests with human cells? Staff Writer Kelly Servick joins host Sarah Crespi to discuss the research, the regulations, and the growing ethical debate. Also this week, Sarah talks with Yossi Yovel of the School of Zoology and the Sagol School of Neuroscience at Tel Aviv University in Israel about his work on sensory integration in bats. Writing in Science Advances, he and his colleagues show through several clever experiments when bats switch between echolocation and vision. Yossi and Sarah discuss how these trade-offs in bats can inform larger questions about our own perception. For our monthly books segment, Science books editor Valerie Thompson talks with Lucy Jones of the Seismological Laboratory at the California Institute of Technology in Pasadena about a song she created, based on 130 years of temperature data, for an instrument called the “viola de gamba.” Read more on the Books et al. blog. Download a transcript (PDF) This week’s episode was edited by Podigy. Ads on the show: MagellanTV; KiwiCo Listen to previous podcasts. About the Science Podcast [Image: The Legend Kay/Flickr; Music: Jeffrey Cook]

Chemists have long known how to convert carbon dioxide into fuels—but up until now, such processes have been too expensive for commercial use. Staff Writer Robert Service talks with host Sarah Crespi about using new filters and catalysts to close the gap between air-derived and fossil-derived gasoline.   Also this week, host Sarah Crespi talks with Nitish Padmanaban of Stanford University in Palo Alto, California, about replacing bifocals with “autofocals.” These auto-focusing glasses track your eye position and measure the distance to the visual target before adjusting the thickness of their liquid lenses. The prototype glasses have an onboard camera and batteries that make them particularly bulky; however, they still outperformed progressive lenses in tests of focus speed and acuity. This week’s episode was edited by Podigy.   Download a transcript (PDF) Listen to previous podcasts.   About the Science Podcast  

Imagine having a rat clinging to your back, sucking out your fat stores. That’s similar to what infested bees endure when the Varroa destructor mite comes calling. Some bees fight back, wiggling, scratching, and biting until the mites depart for friendlier backs. Now, researchers, professional beekeepers, and hobbyists are working on ways to breed into bees these mite-defeating behaviors to rid them of these damaging pests. Host Sarah Crespi and Staff Writer Erik Stokstad discuss the tactics of, and the hurdles to, pesticide-free mite control. Also this week, Sarah talks to Philip Kragel of the Institute of Cognitive Science at the University of Colorado in Boulder about training an artificial intelligence on emotionally charged images. The ultimate aim of this research: to understand how the human visual system is involved in processing emotion. And in books, Kate Eichorn, author of The End of Forgetting: Growing Up with Social Media, joins books host Kiki Sanford to talk about how the monetization of digital information has led to the ease of social media sharing and posting for kids and adults. This week’s episode was edited by Podigy. Download a transcript (PDF)  Listen to previous podcasts. About the Science Podcast [Image: Steve Baker/Flickr; Music: Jeffrey Cook]

After two mysterious earthquake swarms occurred under the Sea of Galilee, researchers found a relationship between these small quakes and the excessive extraction of groundwater. Science journalist Michael Price talks with host Sarah Crespi about making this connection and what it means for water-deprived fault areas like the Sea of Galilee and the state of California. Also this week, Sarah talks with graduate student Adrian Baez-Ortega from the University of Cambridge in the United Kingdom’s Transmissible Cancer Group about the genome of a canine venereal cancer that has been leaping from dog to dog for about 8000 years. By comparing the genomes of this cancer from dogs around the globe, the researchers were able to learn more about its origins and spread around the world. They also discuss how such a long-lived cancer might help them better understand and treat human cancers. This week’s episode was edited by Podigy. Ads on this week’s show: Science Sessions podcast from the Proceedings of the National Academy of Sciences Download the transcript (PDF) Listen to previous podcasts. About the Science Podcast

In recent months, telecommunications companies in the United States have purchased a new part of the spectrum for use in 5G cellphone networks. Weather forecasters are concerned that these powerful signals could swamp out weaker signals from water vapor—which are in a nearby band and important for weather prediction. Freelance science writer Gabriel Popkin joins host Sarah Crespi to talk about the possible impact of cellphone signals on weather forecasting and some suggested regulations. In other weather news this week, Sarah talks with Pengfei Yu, a professor at Jinan University in Guangzhou, China, about his group’s work using a huge smoke plume from the 2017 wildfires in western Canada as a model for smoke from nuclear bombs. They found the wildfire smoke lofted itself 23 kilometers into the stratosphere, spread across the Northern Hemisphere, and took 8 months to dissipate, which line up with models of nuclear winter and suggests these fires can help predict the results of a nuclear war. This week’s episode was edited by Podigy. Ads on this week’s show: KiwiCo.com Download the transcript (PDF)  Listen to previous podcasts. About the Science Podcast

Researchers, regulators, and the chicken industry are all united in their search for a way to make eggs more ethical by stopping culling—the killing of male chicks born to laying hens. Contributing Correspondent Gretchen Vogel talks with host Sarah Crespi about the many approaches being tried to determine the sex of chicken embryos before they hatch, from robots with lasers, to MRIs, to artificial intelligence, to gene editing with CRISPR. Also this week, Sarah talks with Melanie Bergmann, a marine biologist at the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven, Germany, about finding microplastic particles in snow all the way up at the Fram Strait, between Greenland and the Svalbarg archipelago in Norway. This week’s episode was edited by Podigy. Download a transcript (PDF) Ads on this week’s show: Science Sessions podcast; National Highway Traffic Safety Administration Listen to previous podcasts. About the Science Podcast [Image: fruchtzwerg’s world/Flickr; Music: Jeffrey Cook]

Changing the National Suicide Prevention Lifeline from 1-800-273- 8255 (TALK) to a three-digit number could save lives—especially when coupled with other strategies. Host Meagan Cantwell talks to Greg Miller, a science journalist based in Portland, Oregon, about three effective methods to prevent suicides—crisis hotlines, standardizing mental health care, and restricting lethal means. Greg’s feature is part of a larger package in Science exploring paths out of darkness. With more solutions this week, host Sarah Crespi speaks with A. R. Siders, a social scientist at the Disaster Research Center at the University of Delaware in Newark, about her policy forum on the need for “managed climate retreat”—strategically moving people and property away from high-risk flood and fire zones. Integrating relocation into a larger strategy could maximize its benefits, supporting equality and economic development along the way. This week’s episode was edited by Podigy. Ads on this show: KiwiCo; Kroger Download a transcript (PDF) Listen to previous podcasts. About the Science Podcast [Image: Scott Woods-Fehr/Flickr; Music: Jeffrey Cook] 

This week’s show starts with Contributing Correspondent Lizzie Wade, who spent 12 days with archaeologists searching for a lost Maya city in the Chiapas wilderness in Mexico. She talks with host Sarah Crespi about how you lose a city—and how you might go about finding one. And Sarah talks with Christophe Coupé, an associate professor in the department of linguistics at the University of Hong Kong in China, about the information density of different languages. His work, published this week in Science Advances, suggests very different languages—from Chinese to Japanese to English and French—are all equally efficient at conveying information. This week’s episode was edited by Podigy. Ads on this week’s show: Kroger’s Zero Hunger, Zero Waste campaign; KiwiCo Download a transcript (PDF) Listen to previous podcasts. About the Science Podcast  

On this week’s show, Senior News Correspondent Jeffrey Mervis talks with host Sarah Crespi about a stalled Facebook plan to release user data to social scientists who want to study the site’s role in elections. Sarah also talks with Jennifer Gruhn, a postdoctoral research fellow at the University of Copenhagen Center for Chromosome Stability, about counting chromosomes in human egg cells. It turns out that cell division errors that cause too many or too few chromosomes to remain in the egg may shape human fertility over our reproductive lives. Finally, in this month’s book segment, Kiki Sanford talks with Daniel Navon about his book Mobilizing Mutations: Human Genetics in the Age of Patient Advocacy. Visit the books blog for more author interviews: Books et al. This week’s episode was edited by Podigy. Ads on this week’s show: MOVA Globes; The Tangled Tree by David Quammen Download a transcript (PDF) Listen to previous podcasts. About the Science Podcast  

Most historical accounts of slavery were written by colonists and planters. Researchers are now using the tools of archaeology to learn more about the day-to-day lives of enslaved Africans—how they survived the conditions of slavery, how they participated in local economies, and how they maintained their own agency. Host Sarah Crespi talks with Contributing Correspondent Lizzie Wade about a Caribbean archaeology project based on St. Croix in the U.S. Virgin Islands and launched by the founders of the Society for Black Archaeologists that aims to unearth these details. Watch a related video here. Sarah also talks with Jonathan Schulz, a professor in the Department of Economics at George Mason University in Fairfax, Virginia, about a role for the medieval Roman Catholic Church in so-called WEIRD psychology—western, educated, industrialized, rich, democratic. The bulk of psychology experiments have used participants that could be described as WEIRD, and according to many psychological measures, WEIRD subjects tend to have some extreme traits, like a stronger tendency toward individuality and more friendliness with strangers. Schulz and colleagues used historical maps and measures of kinship structure to tie these traits to strict marriage rules enforced by the medieval Catholic Church in Western Europe. Read related commentary. This week’s episode was edited by Podigy. Ads on this week’s show: Bayer; KiwiCo Download a transcript (PDF) Listen to previous podcasts. About the Science Podcast

The National Institutes of Health’s largest loan repayment program was conceived to help scientists pay off school debts without relying on industry funding. But a close examination of the program by investigative correspondent Charles Piller has revealed that many participants are taking money from the government to repay their loans, while at the same time taking payments from pharmaceutical companies. Piller joins Host Sarah Crespi to talk about the steps he took to uncover this double dipping and why ethicists say this a conflict of interest.   Sarah also talks with Nate Lindsey, a Ph.D. candidate at the University of California, Berkeley, about turning a 50-kilometer undersea fiber optic cable designed to move data into a sensor for activity in the ocean and the land underneath. During a 4-day test in Monterey Bay, California, the cable detected earthquakes, faults, waves, and even ocean-going storms. For this month’s books segment, Kiki Sandford talks with Dan Hooper about his book At the Edge of Time: Exploring the Mysteries of Our Universe’s First Seconds.   You can find more books segments on the Books et al. blog.   This week’s episode was edited by Podigy.   Ads on this week’s show: McDonalds; Salk’s Where Cures Begin podcast   Download the transcript (PDF) Listen to previous podcasts.   About the Science Podcast

After their life as research subjects, what happens to lab monkeys? Some are euthanized to complete the research, others switch to new research projects, and some retire from lab life. Should they retire in place—in the same lab under the care of the same custodians—or should they be sent to retirement home–like sanctuaries? Online News Editor David Grimm joins host Sarah Crespi to discuss recently penned legislation that pushes for monkey retirements and a new collaboration between universities and sanctuaries to create a retirement pipeline for these primates. Sarah also talks with Dante Lauretta, principal investigator for NASA’s Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer (OSIRIS-REx) and a professor at the University of Arizona in Tucson, about the latest news from the asteroid Bennu. Within 1 week of beginning its orbit of the asteroid, OSIRIS-REx was able to send back surprising images of the asteroid ejecting material. It’s extremely rocky surface also took researchers by surprise and forced a recalculation of the sample return portion of the craft’s mission. This week’s episode was edited by Podigy. Ads on this week’s show: McDonalds; Parcast’s Natural Disasters podcast; KiwiCo Download the transcript (PDF) Listen to previous podcasts. About the Science Podcast

Getting into an MRI machine can be a tight fit for just one person. Now, researchers interested in studying face-to-face interactions are attempting to squeeze a whole other person into the same tube, while taking functional MRI (fMRI) measurements. Staff Writer Kelly Servick joins host Sarah Crespi to talk about the kinds of questions simultaneous fMRIs might answer. Also this week, Sarah talks with Igor Grossman, director of the Wisdom and Culture Lab at the University of Waterloo, about his group’s Science Advances paper on public perceptions of the difference between something being rational and something being reasonable. This week’s episode was edited by Podigy. Read a transcript (PDF) Listen to previous podcasts. About the Science Podcast

As part of a special issue on chemicals for tomorrow’s Earth, we’ve got two green chemistry stories. First, host Sarah Crespi talks with contributing correspondent Warren Cornwell about how a company came up with a replacement for the popular can lining material bisphenol A and then recruited knowledgeable critics to test its safety. Sarah is also joined by Beate Escher of the Helmholtz Centre for Environmental Research and the University of Tübingen to discuss ways to trace complex mixtures of humanmade chemicals in the environment. They talk about how new technologies can help detect these mixtures, understand their toxicity, and eventually connect their effects on the environment, wildlife, and people. Read more in the special issue on chemicals for tomorrow’s Earth. This week’s episode was edited by Podigy. Listen to previous podcasts. About the Science Podcast Download a transcript (PDF)

Structural biologists rejoiced when cryo–electron microscopy, a technique to generate highly detailed models of biomolecules, emerged. But years after its release, researchers still face long queues to access these machines. Science’s European News Editor Eric Hand walks host Meagan Cantwell through the journey of a group of researchers to create a cheaper, more accessible alternative. Also this week, host Joel Goldberg speaks with psychiatrist and researcher Goodman Sibeko, who worked with the Xhosa people of South Africa to help illuminate genetic details of schizophrenia. Though scientists have examined this subject among Western populations, much less is known about the underlying genetics of people native to Africa. This week’s episode was edited by Podigy. Download a transcript (PDF) Listen to previous podcasts. About the Science Podcast

On this week’s show, Staff Writer Jennifer Couzin-Frankel joins host Sarah Crespi to talk about a Science paper that combines two hot areas of research—CRISPR gene editing and immunotherapy for cancer—and tests it in patients. Sarah also talks with Damien Finch, a Ph.D. candidate in the School of Earth Sciences at the University of Melbourne, about the Kimberly region of Australia and dating its ice age cave paintings using charcoal from nearby wasp nests. This week’s episode was edited by Podigy. Listen to previous podcasts. About the Science Podcast Download a transcript (PDF).

On this week’s show, senior correspondent Jeffrey Mervis joins host Sarah Crespi to discuss a new National Institutes of Health (NIH) grant program that aims to encourage diversity at the level of university faculty with the long-range goal of increasing the diversity of NIH grant recipients. Sarah also talks with Pierre Gagnepain, a cognitive neuroscientist at INSERM, the French biomedical research agency, about the role of memory suppression in post-traumatic stress disorder. Could people that are better at suppressing memories be more resilient to the aftermath of trauma? This week’s episode was edited by Podigy. Listen to previous podcasts. About the Science Podcast Download a transcript (PDF).

This week on the podcast, Contributing Correspondent Lizzie Wade joins host Sarah Crespi to discuss a turning point for one ancient Mesoamerican city: Tikal. On 16 January 378 C.E., the Maya city lost its leader and the replacement may have been a stranger. We know from writings that the new leader wore the garb of another culture—the Teotihuacan—who lived in a giant city 1000 kilometers away. But was this new ruler of a Maya city really from a separate culture? New techniques being used at the Tikal and Teotihuacan sites have revealed conflicting evidence as to whether Teotihuacan really held sway over a much larger region than previously estimated. Sarah also talks with Rashid Sumaila, professor and Canada research chair in interdisciplinary ocean and fisheries economics at the University of British Columbia, Vancouver’s Institute for the Oceans and Fisheries. You may have heard of illegal fishing being bad for the environment or bad for maintaining fisheries—but as Sumaila and colleagues report this week in Science Advances, the illegal fishing trade is also incredibly costly—with gross revenues of between $8.9 billion and $17.2 billion each year. In the books segment this month, Kiki Sanford interviews Gaia Vince about her new book Transcendence How Humans Evolved through Fire, Language, Beauty, and Time. This week’s episode was edited by Podigy. Listen to previous podcasts. About the Science Podcast Download a transcript (PDF).

On this week’s show, Online News Editor David Grimm joins host Sarah Crespi to discuss how dogs’ cold noses may be able to sense warm bodies. Read the research. International News Editor Martin Enserink shares the latest from our reporters covering coronavirus. And finally, from a recording made at this year’s AAAS annual meeting, host Meagan Cantwell talks with Jill Tarter, chair emeritus at the SETI Institute, about the newest technologies being used to search for alien life, what a positive signal would look like, and how to inform the public if extraterrestrial life ever were detected. This week’s episode was produced with help from Podigy. Listen to previous podcasts. About the Science Podcast Download a transcript (PDF).

On this week’s show, freelance writer Christa Lesté-Lasserre talks with host Sarah Crespi about the scientists working on the restoration of Notre Dame, from testing the changing weight of wet limestone, to how to remove lead contamination from four-story stained glass windows. As the emergency phase of work winds down, scientists are also starting to use the lull in tourist activity to investigate the mysteries of the cathedral’s construction. Also this week, Felipe Quiroz, an assistant professor in the biomedical engineering department at the Georgia Institute of Technology and Emory University, talks with Sarah about his paper on the cellular mechanism of liquid-liquid phase separation in the formation of the tough outer layer of the skin. Liquid-liquid phase separation is when two liquids “demix,” or separate, like oil and water. In cells, this process created membraneless organelles that are just now starting to be understood. In this work, Quiroz and colleagues create a sensor for phase separation in the cell that works in living tissue, and show how phase separation is tied to the formation of the outer layers of skin in mice. Read the related Insight. This week’s episode was produced with help from Podigy. Listen to previous podcasts. About the Science Podcast Download a transcript (PDF). [Image: r. nial bradshaw/Flickr; Music: Jeffrey Cook]

On this week’s show, host Joel Goldberg talks with science journalist Andrew Curry about archaeological finds from thousands of years ago along the shores of Northern Europe. Curry outlines the rich history of the region that scientists, citizen scientists, and energy companies have helped dredge up. Also this week, from a recording made at this year’s AAAS annual meeting in Seattle, host Meagan Cantwell speaks with Elizabeth Margulis, a professor at Princeton University, about musical memory. Margulis explains what research tells us about how our brains process music, and dives into her own study on how Western and non-Western audiences interpret the same song differently. This week’s episode was edited by Podigy. Download a transcript (PDF) Listen to previous podcasts. About the Science Podcast [Image: Sebastian Reinecke/Flickr; Music: Jeffrey Cook] 

Contributing Correspondent Kai Kupferschmidt talks with host Sarah Crespi about countries planning a comeback from a coronavirus crisis. What can they do once cases have slowed down to go back to some sort of normal without a second wave of infection? See all of our News coverage of the pandemic here. See all of our Research and Editorials here. As part of a drought special issue of Science, Contributing Correspondent Lizzie Wade joins Sarah to talk about water management and the downfall of the ancient Wari state. Sometimes called the first South American empire, the Wari culture successfully expanded throughout the Peruvian Andes 1400 years ago. Also this week, Yon Visell of the University of California, Santa Barbara, talks with Sarah about his Science Advances paper on the biomechanics of human hands. Our skin’s ability to propagate waves along the surface of the hand may help us sense the world around us. This week’s episode was produced with help from Podigy. Listen to previous podcasts. About the Science Podcast Download a transcript (PDF).

Staff Writer Jocelyn Kaiser joins Sarah to talk about a recent Science paper describing the results of a large study on a blood test for multiple types of cancer. The trial’s results suggest such a blood test combined with follow-up scans may help detect cancers early, but there is a danger of too many false positives. And postdoctoral researcher Timo Reinhold of the Max Planck Institute for Solar System Research joins Sarah to talk about his paper on how the Sun is a lot less variable in its magnetic activity compared with similar stars—what does it mean that our Sun is a little bit boring? This week’s episode was produced with help from Podigy. Listen to previous podcasts. About the Science Podcast Download a transcript (PDF).