Becoming fluent in a second language is difficult. But for adults, is it impossible? Short Wave hosts Maddie Sofia and Emily Kwong dissect the "critical period hypothesis," a theory which linguists have been debating for decades — with the help of Sarah Frances Phillips, a Ph.D. student in the linguistics department at New York University. You can watch a related video about Emily learning Mandarin here. It's part of the Where We Come From series.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Maddie talks with physicist Chanda Prescod-Weinstein about her new book, The Disordered Cosmos: A Journey into Dark Matter, Spacetime, and Dreams Deferred. In the episode, we talk quarks (one of the building blocks of the universe), intersectionality and access to the night sky as a fundamental right.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

It is one of the Earth's great migrations: each year, millions of monarch butterflies fly some 3,000 miles, from their summer breeding grounds as far north as Canada to their overwintering sites in the central Mexico. It's one of the best-studied migrations and in recent years, ecologists like Sonia Altizer have been able to better answer how and why these intrepid butterflies make the journey. Short Wave brings this episode from the TED Radio Hour's episode with Sonia Altizer, with the University of Georgia.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

After hearing a vicious rumor on the internet that vegetables aren't real, Maddie goes looking for answers. Turns out, vegetables are a mere culinary construct. Still healthful and delicious, but a kinda mythic category of food. With the help of Harvard botanist Molly Edwards, Maddie and Emily break down our favorite foods from broccoli to zucchini. Take our survey! Tell us what you love and what you would love to see more of — on our show, and also other NPR podcasts.Email the show at [email protected] more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

(Encore episode.) Scientists have known for decades that one of the main causes of the smell of fresh rain is geosmin: a chemical compound produced by soil-dwelling bacteria. But why do the bacteria make it in the first place? Reporter Emily Vaughn answers this mystery.Read the paper on which this episode was based.Take our survey! Tell us what you love and what you would love to see more of — on our show, and also other NPR podcasts.Other scent mysteries driving your nose wild? Email the show at [email protected] and we might track down the answer.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

The Biden Administration is working to fight climate change in a way that also address the country's economic and racial disparities. Emily talks with NPR correspondent Dan Charles about why the ground work for a climate justice plan could be laid in the city of Cleveland. For more of Dan's reporting, follow him on Twitter @NPRDanCharles.You can email Short Wave at [email protected]. Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Nationwide, almost 65% of adults have had at least one vaccine shot, but vaccination rates vary significantly depending on the state. NPR health correspondent Allison Aubrey gives us the latest on the country's vaccination progress: which states are on track (and which are not), new research about why it's important teenagers get vaccinated, and what we know about the possibility of booster shots.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Paleontologist Yara Haridy looks at fossilized bones for a living. When she randomly walked by a scientific poster one day, she discovered an entirely new way to take pictures of her fossils. The results are shedding new light on how bones evolved.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

There's big change that's happening in the field of artificial limbs: artificial limbs that both move — and feel. NPR correspondent Jon Hamilton explains why touch is so important for people who are trying to control a state-of-the art robotic arm or a prosthetic limb.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Short Wave reporter Emily Kwong speaks with Janina Jeff, the host and executive producer of In Those Genes, a "science and culture podcast that uses genetics to decode the lost histories of African descendants." They discuss what a person's genetic ancestry test does and does not reveal, and the complicated intersection of genetics, history and race.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Researchers say the concept of achieving herd immunity threshold isn't the right finish line to end the pandemic. It's an elusive number to define in the first place, and it changes under various circumstances. Science correspondent Geoff Brumfiel talks with Maddie about the complexities in even defining the number and what the public should focus on instead.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Happy Pride, Short Wave Listeners! Here's a fun episode from our archives to celebrate the month!It's another "Back To School" episode where we take a concept you were maybe taught in school as a kid, but didn't really learn or just forgot. Short Wave producer Thomas Lu and host Maddie Sofia go on a journey to explore what a rainbow exactly is and how we see them! We all remember ROY G BIV, right?Email us your Back-To-School ideas at [email protected] more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Scientists and students with disabilities are often excluded from laboratories — in part because of how they're designed. Emily Kwong speaks to disabled scientist Krystal Vasquez on how her disability changed her relationship to science, how scientific research can become more accessible, and how STEMM fields need to change to be more welcoming to disabled scientists. Read Krystal's article in Chemistry World, 'Excluded From The Lab.' You can email Short Wave at [email protected] more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Juul Labs seemingly started out with the aim to reduce smoking, but the company's e-cigarettes came to symbolize something very different: a teen vaping epidemic. Host Maddie Sofia talks with Time health writer Jamie Ducharme about the science and marketing behind the rise and subsequent controversy surrounding Juul Labs. Plus, a look at what might be next in the future of e-cigarettes.Click here for links to studies mentioned in this episode.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Researchers report in the journal Science that they appear to have some clues about the origin of Earth's plutonium - which has been long debated. Correspondent Nell Greenfieldboyce explains that traces of rare forms of iron and plutonium have been found in extraterrestrial debris that had sunk to the bottom of the Pacific Ocean, hauled up by an oil company, then donated for research. By comparing the iron and the plutonium, scientists found the plutonium was likely forged in a cosmic cataclysm, perhaps a rare kind of supernova, and then rained down on Earth.Ever find yourself existentially musing? Wondering about the state of the cosmos? Drop us a line at [email protected] and we might jump into a wormhole with you.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Eight states have passed an important milestone: getting 70% of all adults vaccinated with at least one shot. That's a number President Biden wants the country to reach by July Fourth. As cases of COVID-19 in the U.S. continue to come down, host Maddie Sofia talks with NPR health correspondent Allison Aubrey about vaccination progress around the country. Have questions about the latest coronavirus headlines? Email us at [email protected] and we might cover it on a future episode.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

**Heads up. This episode discusses addiction and alcoholism.**Some doctors are seeing a disturbing spike in lethal alcoholic liver disease, especially among young women. The recent trend has been supercharged, they say, in the pandemic. Emily Kwong speaks to NPR science correspondent Yuki Noguchi about this and some of the challenges to getting proper treatment. To read more on the story, check out Yuki's reporting here. You can email us at [email protected] more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Solar geoengineering--the human attempt to cool the planet by reflecting sunlight away from Earth--is fraught with technological and ethical challenges. Maddie discusses some of these with contributor Ariela Zebede.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

During the Great Depression, President Franklin Delano Roosevelt created the Civilian Conservation Corps to improve the country's public lands, forests, and parks. Now, nearly a hundred years later, President Biden is trying to bring a similar version of it back. He wants to launch the Civilian Climate Corps to address the threat of climate change. NPR's White House correspondent Scott Detrow and National Desk Correspondent Nathan Rott report on Biden's plan and how it could play out.Click here to see photos and read more on this story.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

In general, there are more men in STEMM fields than women. Representation in science, technology, engineering, math, and medicine is even lower for women of color — facing racial discrimination on top of gender discrimination. And then, the pandemic hit. Short Wave reporter Emily Kwong speaks with Dr. Eve Higginbotham about our earliest understandings of how the pandemic has impacted women in STEMM, and what support institutions can offer to make it easier for women in stay in the workforce and progress in their careers. You can download a free PDF of the 2021 study here.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Many Americans are baring their faces in public again, following new CDC recommendations that fully vaccinated people don't need them in most settings. But there are critics who question the CDC's decision and say it's too soon. Maddie Sofia talks with NPR health correspondent Allison Aubrey about this latest mask guidance and the questions it raises for businesses, essential workers, and the most vulnerable. If you'd like help finding a vaccination site, you can dial 1-800-232-0233 or go to vaccines.gov (English) or vacunas.gov (Spanish) for more information. Have questions about the latest coronavirus headlines? Email us at [email protected] and we might cover it on a future episode.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

(Encore.) Drug overdose deaths are on the rise all around the country, including in Chicago, Illinois. ProPublica Illinois reporter Duaa Eldeib explains how the coronavirus pandemic has exacerbated the opioid epidemic, and the challenges that public health officials are facing as they work to reduce opioid-related deaths.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

It's the latest installment of our series, "Animal Slander," where we take a common saying about animals and see what truth there is to it. The case before the Short Wave court today: "badgering." We look at the dark origins of the word and explore the wild world of badger biology with University of Oxford scientist Tanesha Allen.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

According to the Centers for Disease Control and Prevention (CDC), the proportion of emergency department visits by children in mental health crises went up significantly during the pandemic — about 30% for kids ages 12-17 and 24% for children ages 5-11 between March and October of last year, compared to 2019. For psychiatrists like Dr. Nicole Christian-Brathwaite, this is evident in her practice and personal life. We talk to her about how this past year has taken a toll on children and their mental health, as well as her advice for helping the kids in your life cope better.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Mud and dirt have often been treated as waste products from excavation or dredging sites. But these days, coastal communities need massive amounts of mud and dirt to protect their shorelines from rising seas. This is leading to a dirt shortage, where the demand for it is higher than supply. NPR climate correspondent Lauren Sommer gives us the scoop — including why one federal agency that has dirt often disposes of it instead of reusing it for these projects.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Some colleges and universities have announced that COVID vaccination will be mandatory (with some exemptions) and the FDA has authorized the Pfizer COVID-19 vaccine for kids ages 12 to 15. While coronavirus infections are declining in the United States, vaccination rates also appear to be slowing down, so pediatricians and public health officials say they're trying to spread the word to overcome hesitancy, and get the vaccine out to people where they go to school and shop. Emily talks with NPR health correspondent Allison Aubrey about this and other topics in the pandemic news. If you'd like to assistant on finding a vaccination site, you can dial 1-800-232-0233 or go to vaccines.gov (English) or vacunas.gov (Spanish) for more information. Have questions about the latest coronavirus headlines? Email us at [email protected] and we might cover it on a future episode.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

The Pfizer-BioNTech and Moderna COVID-19 vaccines are the first authorized vaccines in history to use mRNA technology. The pandemic might've set the stage for their debut, but mRNA vaccines have been in the works for more than 30 years. Host Maddie Sofia chats with Dr. Margaret Liu, a physician and board chair of the International Society for Vaccines, about the history and science behind these groundbreaking vaccines. We'll also ask, what we can expect from mRNA vaccines in the future?Have a question for us? Send a note to [email protected] — we'd love to hear it.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

The numbers are staggering. India has been reporting more than 300,000 COVID-19 cases each day for the past two weeks, and recently topped more than 400,000 cases in a single day, a global record. Many more cases are likely unreported. NPR International Correspondent Lauren Frayer shares the latest from India. Email the show at [email protected] more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Katie Clapp and Michael Tranfaglia's son was born with a genetic disorder that affects brain development. It makes it hard to learn language and basic daily tasks and often is accompanied by a host of other disorders. To help find a cure, they started a foundation and raised research money. After several setbacks, one treatment is showing promise. NPR neuroscience reporter Jon Hamilton tells Emily Kwong the story.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

We've been talking a lot about COVID in the US. Now, we want to look at how things are going in some other countries. NPR's correspondents — Jason Beaubien, Phil Reeves, and Anthony Kuhn — talk with Morning Edition's Noel King about why most of the world is struggling to get even a small percentage of their population vaccinated.Have questions about the latest coronavirus headlines? Email us at [email protected] and we might cover it on a future episode.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

The rate of vaccination in the U.S. continues to slow. Maddie Sofia talks with NPR health correspondent Allison Aubrey about that and what can be done to get more people vaccinated. Also, making sense of the CDC's latest mask guidance. Have questions about the latest coronavirus headlines? Email us at [email protected] and we might cover it on a future episode.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Today, NPR's mental health correspondent Rhitu Chatterjee guests hosts Short Wave. She talks to Dr. Arghavan Salles about burnout among health care workers — what it looks like, what it's doing to the mental health of doctors and nurses and how institutions can address it. Have a scientific question you can't stop thinking about? Drop us a line at [email protected] — we'd love to hear it.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

We at Short Wave are sometimes a little too aware of how difficult it can be to explain science to a general audience. So when we came across Vick Krishna's viral TikTok breaking down how the mRNA vaccine works, we were impressed and immediately like, "We've got to get him on the show!" Today's that show. Vick breaks down the inspiration, the science and his newfound responsibility as an accidental science communicator.Know someone else bringing science to the masses? Send us an email at [email protected] more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

In 2011, villages and towns around the Fukushima Daiichi Nuclear plant in Japan were evacuated because of a series of meltdowns caused by a tsunami. Ten years later, some of the villages and towns are slowly reopening. Geoff Brumfiel talks with producer Kat Lonsdorf about the Fukushima nuclear accident, its lasting effects on Japan, and the future of nuclear power. You can read and listen to more of Kat's reporting about Fukushima and Japan here.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Feeling green? If you'd like to do something to slow down climate change, even if it's just a small thing, you can get started in your own apartment or house. With the help of our friends over at Life Kit, NPR correspondent Dan Charles shares five ways to cut carbon emissions in your own home. This episode was adapted from an earlier Life Kit. To hear the full version, check out npr.org/lifekit.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Short Wave's Emily Kwong talks with NPR health correspondent Allison Aubrey about some of the latest coronavirus news, including the return of the Johnson & Johnson vaccine in the U.S. and vaccine outreach in harder to reach communities.Have questions about the latest coronavirus headlines? Email us at [email protected] and we might cover it on a future episode.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

On April 15, at four o'clock in the morning, a small group of scientists found their way to a secret location. A light wintry mix of rain and snow was falling. The lousy weather was a relief because it meant even less of a chance that someone might randomly pass by.Today on the show, NPR science correspondent Nell Greenfieldboyce unearths why a new generation of scientists is digging up seeds under the cover of night buried 142 years ago.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

President Biden is hosting dozens of world leaders for a virtual climate summit on Thursday and Friday. The administration is trying to regain ground lost by pulling out of the Paris climate agreement during the Trump administration. The Biden team is promising dramatic cuts in greenhouse gas emissions in the next several decades. Rhitu Chatterjee talks with NPR climate reporters Rebecca Hersher and Lauren Sommer.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Horseshoe crabs have been around for 450 million years — nearly unchanged. And their blood has helped the medical world make some fascinating discoveries. Emily Kwong talks with Ariela Zebede about these living fossils and their role in making medicine safer. Get in touch! You can email Short Wave at [email protected] more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Why does hair turn gray? Stress? Age? Genetics? We turn to dermatologist Dr. Jenna Lester for answers.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Today, NPR Health Correspondent Allison Aubrey offers perspective on how to think about the latest coronavirus news. On one hand, half of U.S. adults have been vaccinated and as of this week, everyone 16 years old and up is eligible to be vaccinated. At the same time, the administration of the Johnson & Johnson vaccine has been paused and many are still hesitant to get vaccinated.Coronavirus on your mind? Email us at [email protected] — with your questions about the latest developments.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

When you think of mathematicians, do you think of lone geniuses scribbling away at complex equations? This myth is one mathematician Ranthony Edmonds actively tries to dispel in her classroom as a post-doc at The Ohio State University. Instead, Ranthony focuses on the community aspects of math — the support systems behind each mathematician and the benefits of a collaborative, inclusive environment for math innovation. Think we should consider math more? Let us know by emailing [email protected] more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

(Encore episode.) Archival records may help researchers figure out how fast the sea level is rising in certain places. Millions of people in coastal cities are vulnerable to rising sea levels and knowing exactly how fast the water is rising is really important. But it's a tough scientific question. NPR climate correspondent Lauren Sommer explains how scientists are looking to historical records to help get at the answer. If you'd like to help transcribe old tidal data, you can get started here.For more of Lauren's reporting, follow her on Twitter @lesommer. Email us at [email protected] more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

(Encore episode.) Earlier this year, the Supreme Court heard arguments in a case brought by the city of Baltimore against more than a dozen major oil and gas companies including BP, ExxonMobil and Shell. In the lawsuit, BP P.L.C. v. Mayor and City Council of Baltimore, the city government argued that the fossil fuel giants must help pay for the costs of climate change because they knew that their products cause potentially catastrophic global warming. NPR climate reporter Rebecca Hersher has been following the case.Read Rebecca's digital piece about the Supreme Court case here.Email the show at [email protected] more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

(Encore episode.) Global Witness documented that 212 environmental and land activists were murdered in 2019. Over half of those documented murders took place in Colombia and the Philippines, countries where intensive mining and agribusiness has transformed the environment. NPR Short Wave reporter Emily Kwong speaks with three activists about the intersection between natural resource extraction and violence, and what keeps them going in their work.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

(Encore episode.) As sea levels rise from climate change, coastal communities face a greater risk of chronic flooding. Climate scientist Astrid Caldas and her colleagues have looked at where it's happening now and where it could happen in the future as the tides keep getting higher.Follow host Maddie Sofia on Twitter @maddie_sofia. Email the show at [email protected] more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Humans have changed the Earth in such profound ways that scientists say we have entered a new geological period: the Anthropocene Epoch.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Psychedelics like ketamine and psilocybin are getting a second look as a way to treat psychiatric problems like depression, anxiety, substance use disorders, even PTSD. NPR neuroscience correspondent Jon Hamilton explains how these drugs are helping brain scientists understand what causes mental illness and find new ways to treat it. Email the show at [email protected] more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy