Science Friday

Sunscreen has been on the shelves of drugstores since the mid-1940s. And while new kinds of sunscreens have come out, some of the active ingredients in them have yet to be determined as safe and effective. A recent study conducted by the FDA showed that the active ingredients of four commercially available sunscreens were absorbed into the bloodstream—even days after a person stops using it. Ira talks to professor of dermatology and editor in chief of the Journal of the American Medical Association Dermatology Kanade Shinkai about what the next steps are for sunscreen testing and what consumers should do in the meantime. Often called the planet’s lungs, the trees of the Amazon rainforest suck up a quarter of Earth’s carbon and produce a fifth of the world’s oxygen. The National Institute for Space Research in Brazil has been using satellite images of tree cover to monitor the Amazon’s deforestation since the 1970s—and new data shows a potentially dangerous spike in deforestation. In the first seven months of 2019, the rainforest lost 50% more trees than during the same period last year. That spike in tree loss has coincided with Brazil’s new president, Jair Bolsanaro, taking office in January and slashing environmental protections. Bolsanaro even called the new data a lie. But climate scientists warn deforestation is pushing the Amazon rainforest to a tipping point that would disrupt both its ecosystem and the global climate. Ira talks to Carlos Nobre, a climate scientist at the University of Sao Paulo’s Institute of Advanced Studies, about the new data and why deforestation in the Amazon is so risky for the planet. When you think of algae, one of the first images that might come to mind is the green, fluffy stuff that takes over your fish tank when it needs cleaning, or maybe the ropy seaweed that washes up on the beach. But the diversity of the group of photosynthetic organisms is vast—ranging from small cyanobacteria to lichens to multicellular mats of seaweed. Author Ruth Kassinger calls algae “the most powerful organisms on the planet.” She talks about how this ancient group of organisms produces at least 50% of the oxygen on Earth, and how people are trying to harness algae as a food source, alternative fuel, and even a way to make cows burp less methane. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Mauna Kea is the tallest mountain in Hawaii, towering over the Pacific at nearly 14,000 feet. That high altitude, combined with the mountain’s dry, still air and its extreme darkness at night, make it an ideal place for astronomy. There are already 13 observatories on the summit plateau. Now, astronomers want to build another, called the Thirty Meter Telescope, or TMT, which would become the largest visible-light telescope on the mountain.  But many native Hawaiians don’t want it there, for a multitude of reasons. Science Friday talked with Kawika Winter, a multidisciplinary ecologist at the Hawaii Institute of Marine Biology and the He'eia National Estuarine Research Reserve, who summed it up this way:  "The notion of pursuit of knowledge is an important one here. But is it pursuit of knowledge at all costs? Is it pursuit of knowledge at the expense of our humanity?  From the native Hawaiian perspective this is just the same thing that's happened before. It's preventing people from accessing sacred places. It's desecration of sacred places through construction. It's all of these issues, but this time it's for a ‘good reason.’ This time it's for science, this time it's for knowledge, so now it should be ok, right? But it's the same thing that's been happening for 200 years. It doesn't matter what the reason is. Engaging native Hawaiians is not a box to check off in the process. And you check it off at the end, say 'yeah, we checked with native Hawaiians.' That's not the proper way to engage in science in indigenous places. So we're trying to advocate for a different model for approaching science, and integrating native peoples, indigenous peoples, and indigenous cultures into the process. And that's how we can make sure the science we conduct doesn't come at the expense of our humanity."  Many native Hawaiians say the way this fight has been portrayed in the media—as Hawaiian culture versus science—is disrespectful of their culture, ignorant of their motives, and oblivious to the fact that science has long been an important part of traditional Hawaiian culture. Nearly a thousand scientists and astronomers have now signed an open letter in solidarity with those who would like to see a halt in construction.  When a baby human learns to talk, there’s a predictable pattern of learning: First, they listen to the language spoken around them, then they babble and try to make the same sounds, and then they eventually learn the motor skills to shape that babble into words and meaning. Researchers who study songbirds know this is also the process by which a baby male zebra finch learns the unique songs that as an adult he will use to mate and defend territory. The same holds true for canaries, nightingales, warblers, and beyond. And for many birds, like humans, the window where they learn their “language” best is a short one that closes early in life. In fact, bird song is studied closely as an analogy for human speech—an example of sophisticated brain machinery for learning that evolved separately in birds and humans.  Alaska governor Mike Dunleavy’s budget cuts to the University of Alaska total about $136 million, or roughly 41 percent of state support. As a result, the University of Alaska Board of Regents voted 8 to 3 to move towards consolidating the entire university system to a single accredited university. UA president Jim Johnsen says under any plan, it’s likely that the cuts will have a ripple effect on enrollment and research. He says both are avenues that could result in less money for the university as a whole. A task force has been put together to determine how to move forward with the single university model.   Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Have you ever tried to make your favorite rocky road flavored ice cream at home, but your chocolate ice cream turns out a little crunchier than you hoped? And your ribbons of marshmallow are more like frozen, sugary shards? Chemist Matt Hartings and ice cream maker Ben Van Leeuwen, co-founder of Van Leeuwen Artisan Ice Cream in New York City, talk about the science behind how milk, sugar, and eggs turn into your favorite frozen desserts. They’ll chat about the sweet science behind other frozen delights, too—like how the size of water crystals affect texture and how you can make a scoopable vegan ice cream.  Are you a fluent texter? Are you eloquent with your emoji? DOES WRITING IN ALL CAPS SOUND LIKE SCREAMING TO YOU? Maybe you’ve become accustomed to delivering just the right degree of snark using ~~sparkly tildes~~… Or you feel that slight sense of aggression when someone ends a simple text to you with a period.     In her new book Because Internet: Understanding the New Rules of Language, internet linguist Gretchen McCulloch explores some of the ways that online communication has changed the way we write informally, from the early days of computer bulletin boards to today’s Facebook and Twitter memes. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

The Science Friday Book Club is buckling down to read Jennifer Ackerman’s The Genius of Birds this summer. Meanwhile, it’s vacation season, and we want you to go out and appreciate some birds in the wild. But for beginning birders, it may seem intimidating to find and identify feathered friends both near and far from home. Audubon experts Martha Harbison and Purbita Saha join guest host Molly Webster to share some advice. They explain how to identify birds by sight and by ear, some guides that can help, and tips on photographing your finds. Plus the highlights of summer birding: Shore bird migration is already underway, and baby birds are venturing out of the nest. We challenge you to get outside to see your local clever birds in action! Join the Science Friday Bird Club on the citizen science platform iNaturalist.  In this era of the Equifax breach and Facebook’s lax data privacy standards, most people are at least somewhat anxious about what happens to the data we give away. In recent years, companies have responded by promising to strip away identifying information, like your name, address, or social security number.  But data scientists are warning us that that isn’t enough. Even seemingly harmless data—like your preferred choice of cereal—can be used to identify you. In a paper from Nature Communications out this week, researchers published a tool that calculates the likelihood of someone identifying you after offering up only a few pieces of personal information, like your zip code and your birth date.  Dr. Julien Hendrickx, co-author of the study out in Nature Communications, joins guest host Molly Webster to discuss the risk of being discovered among anonymous data. And Joseph Jerome, policy council for the Privacy and Data project at the Center for Democracy and Technology, joins the conversation to talk about whether data can ever truly be anonymous. Plus, the Ebola crisis in the D.R.C. is now the second biggest outbreak on record. That, and other science stories in the news this week.  Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Our Lunar Muse Most of us remember that iconic photograph of the Apollo 11 moon landing: Buzz Aldrin standing on a footprint-covered moon, one arm bent, and Neil Armstrong in his helmet’s reflection taking the picture.  But there’s a much longer, ancient history of trying to visually capture the moon that came before the 1969 photo—from Bronze Age disks with crescent moons to Galileo’s telescope drawings to 19th-century photos and modern photographs. For millennia, we’ve been obsessed with the moon’s glow, its craters and blemishes, its familiar, but mysterious presence in the sky. The moon has mesmerized experts from all fields of study, from scientists, historians, curators, to artists, including this segment’s guest, Michael Benson. Benson is a filmmaker, artist, and author of Cosmigraphics: Picturing Space Through Time, a history of humanity’s quest to visualize the moon and space. In his own art, he uses raw data from space missions to create lunar and planetary landscapes.  Benson isn’t the only person who’s thinking about how science and art has impacted how we see the moon. Mia Fineman recently curated Apollo’s Muse: The Moon in the Age of Photography at the Metropolitan Museum of Art in New York City. The exhibit explores how humanity has interpreted the moon through drawings, paintings, and photographs for the last 400 years. Preserving Space History We’ve all heard the iconic stories of the early space program—from   Kennedy’s “We choose to go to the moon” speech, to The Right Stuff, to Armstrong’s “one small step,” to the dramatic story of Apollo 13.  But how do we find new stories to tell, locate hidden figures of history, or even know they exist? The answer may lie in museum collections, old paper archives, and in the memories of ordinary people. Ed Stewart, the curator of the U.S. Space and Rocket Center, and Reagan Grimsley, head of Special Collections and Archives at the University of Alabama-Huntsville, join Ira to talk about preserving artifacts of the early space program, and the importance of the archival record in telling the tales of historic space flight. NASA's Megarocket Bet The Trump administration says it wants to go back to the moon—but how will we get there? You’ve seen the advances in spaceflight from private companies like SpaceX and Blue Origin. But a big part of the current U.S. plan for returning to the moon involves something called SLS, the Space Launch System—a megarocket assembled from a combination of parts repurposed from the Shuttle program, and new hardware.  John Blevins, deputy chief engineer for the Space Launch System, and Erika Alvarez, lead systems engineer for the Space Launch System Vehicle, join Ira to talk about the rocket’s design, capabilities, and NASA’s plans to use it to go back to the moon and beyond.  Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Celebrating Apollo's 'Giant Leap' July 20, 1969 was a day that changed us forever—the first time humans left footprints on another world. In this segment, Ira Flatow and space historian Andy Chaikin celebrate that history and examine the legacy of the Apollo program. Apollo ushered in a new age of scientific discovery, with lunar samples that unlocked the history of how the moon and the solar system formed. It accelerated the development of new technologies, like the integrated circuit. And most of all, says Chaikin, it taught us how to work together, to achieve seemingly impossible goals.  We also take a look at what comes next for NASA’s historic launchpads. Science Friday producers Alexa Lim and Daniel Peterschmidt went to NASA Kennedy Space Center at Cape Canaveral, Florida a few months ago. They got to see how the space agency is upgrading some of its storied launchpads—and leaving others behind to rising sea levels. Take Flight With Science Friday's Book Club Called anyone a “bird brain” recently? There was a time when we thought this meant “stupid,” deceived by the small size and smooth surface of birds’ brains into thinking they were mere mindless bundles of feathers. But researchers are finding out what birds themselves have always known: Our feathered friends come with mental skills that might stump even humans. Be it tool-making, social smarts, navigation across vast distances, or even the infinitely adaptable house sparrow, Jennifer Ackerman writes of dozens of examples in this summer’s SciFri Book Club pick, The Genius of Birds. Take homing pigeons, which can be released hundreds of miles from the roof and still eventually wing their way home. Or mockingbirds, who can memorize and mimic, with astonishing accuracy, the songs and calls of as many as 200 different other birds. And birds have other kinds of genius: Bowerbirds craft intricate displays to lure their mates, each species with its own particular aesthetic preferences, like the satin bowerbird’s penchant for blue. Ira, Book Club captain Christie Taylor, and bird brain researchers Aaron Blaisdell and Lauren Riters convene for the summer Book Club kickoff, and a celebration of avian minds everywhere. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

If you’ve ever tried brewing your own beer or raising your own sourdough, then you know that the process of fermentation isn't easy to get right. How do you control the growth of mold, yeast, or bacteria such that it creates a savory and delicious new flavor, and not a putrid mess on your kitchen counter? David Zilber is Director of Fermentation at the restaurant Noma, and he tells his fermentation secrets. The human scent is made up of a combination of 100 odor compounds. Other mammals such as guinea pigs also emit the same odor compounds—just in different blends. And even though human odor can also differ from person to person, mosquitoes can still distinguish the scent of a human from other mammals. We'll talk about how mosquitos have evolved to hunt for the prey of their choice. Next week marks the 50th anniversary of the Apollo moon landing. But before astronauts could take that one small step on the moon, they had to take off from Earth. On Tuesday, July 16, in commemoration of the 9:32 am launch of the Saturn V rocket carrying the Apollo 11 crew, model rocketeers from around the world will conduct a global launch event—by firing off thousands of rockets planet-wide. Plus, download the SciFri VoxPop app for iPhone or Android and contribute to the show all week long. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

A quarter of the world’s greenhouse gas emissions come from putting food on the table. From the fossil fuels used to produce fertilizers, to the methane burps of cows, to the jet fuel used to deliver your fresh asparagus, eating is one of the most planet-warming things we do. In our latest chapter of Degrees of Change, we're looking at how to eat smarter in a warming world. Plus, we’ve launched a new way for you to add your voice to the show: the SciFri VoxPop app. Download now for iPhone or Android. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Much has been written about the Manhattan Project, the American-led project to develop the atomic bomb. Less well known is Nazi Germany’s “Uranium Club”—a similar project started a full two years before the Manhattan Project. The Nazis had some of the greatest chemists and physicists in the world on their side, including Werner Heisenberg, and the Allies were terrified that the Nazis would beat them to the bomb—meaning the Allies were willing to try anything from espionage to assassination to bombing raids to stop them. Science writer Sam Kean joins Ira to tell the high-stakes story written in his new book The Bastard Brigade: The True Story of the Renegade Scientists and Spies Who Sabotaged the Nazi Atomic Bomb.  Plus, "spontaneous generation" was the idea that living organisms can spring into existence from non-living matter. In the late 19th century, in a showdown between chemist Louis Pasteur and biologist Felix Pouchet put on by the French Academy of Sciences, Pasteur famously came up with an experiment that debunked the theory. He showed that when you boil an infusion to kill everything inside and don’t let any particles get into it, life will not spontaneously emerge inside. His experiments have been considered a win for science—but they weren’t without controversy. In this interview, Undiscovered’s Elah Feder, Ira Flatow, and historian James Strick talk about what scientists of Pasteur’s day really thought of his experiment, the role the Catholic church played in shutting down “spontaneous generation,” and why even Darwin did his best to dodge the topic. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Summer is here—and that means it’s time for a road trip! Dylan Thuras and Ella Morton, co-authors of Atlas Obscura: An Explorer’s Guide to the Hidden Wonders of the World, join Ira to share some suggestions for sciencey things to see and do around the country, from unusual museum exhibits to outstanding natural wonders. Plus, we asked you for YOUR travel ideas—and did you deliver! We’ll share tourist tips from some regular Science Friday guests, and highlight some of your many suggestions. Speaking of summer trips... You might consider skipping the large urban centers, like Paris or Madrid, for something a little older—like Pompeii. The ancient city in Italy is one of the country’s largest tourist attractions, receiving over 4 million visitors a year. Perhaps it's because archaeology is inspiring tourism around the world. From Egypt, China, South America to India, archaeologists are experiencing a golden era of discovery thanks to new tools that help uncover buried civilizations. Sarah Parcak, professor of anthropology at the University of Alabama Birmingham and author of the new book Space Archaeology joins Ira to talk about what past civilizations can teach us about our current moment in time.  Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.