Science Friday

In late September, firefighters in flame-resistant Nomex were strung out along a fireline. It ran midslope through a pine and hardwood forest above the Klamath River and the small northern California town of Orleans.

Several members of the Karuk tribe were laying down strands of fire with drip torches.

Aja Conrad, who runs the tribal natural resource department’s environmental education field institute, was the firing boss trainee. She kept a close eye as the strips burned together and smoke filled the air.

“Can you just keep an eye on that and maybe not put too much fire below it?” she told one of her burners.

“Copy that.”

Read the rest of this article on sciencefriday.com.

Transcript for this radio story will be available after the show airs on sciencefriday.com.

Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

The harms of smoking cigarettes are pretty clear. Smoking causes cancer as well as heart and lung diseases, and it’s the leading cause of preventable death in the United States.

When it comes to vaping, or electronic cigarettes, the risks are a bit more tricky to parse, especially if you read media reports about them. The outbreak of Vaping Use-Associated Lung Injury, also known as EVALI, in 2019 and 2020 made things even more confusing.

The founders of Juul, the company that mainstreamed vaping in the early aughts, said they wanted to help people kick their smoking habits. But can vapes really help people quit? And how bad are they for you, really? And if you’re addicted to vaping, what’s the best way to stop?

To answer those questions and more, Host Ira Flatow talks with one of the top researchers in the field, Dr. Jamie Hartmann-Boyce, assistant professor of health policy and management at the University of Massachusetts Amherst.

Transcripts for each segment will be available after the show airs on sciencefriday.com.

Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Scientists determined that Lucy, a human ancestor from 3.2 million years ago, couldn’t have beaten modern humans in a foot race. Also, the Chinese AI company DeepSeek startled industry observers with an efficient new system. But how does it compare with the leading tech?

Lucy is one of the most famous fossils—an Australopithecus afarensis who lived about 3.2 million years ago. Her skeleton is about 40% complete, and has been studied since its discovery in 1974. In a quest to learn more about what Lucy’s life may have looked like, scientists estimated what her leg and pelvic muscles were like based on her skeleton. They then put her on a treadmill—virtually, of course.

The findings? Lucy was likely not a natural runner, and the modern human body evolved for improved running performance. Host Flora Lichtman talks to Producer Kathleen Davis about these findings, and other news of the week.

Flora also speaks to Anil Oza, a Sharon Begley Science Reporting Fellow at STAT and MIT, about the latest news on the Trump administration taking down scientific data from the Centers for Disease Control website for mentioning topics like gender, DEI and accessibility. They also discuss the National Institutes of Health resuming grant reviews after two weeks of restrictions imposed by the president.

The Chinese company DeepSeek recently startled AI industry observers with its DeepSeek-R1 artificial intelligence model, which performed as well or better than leading systems at a lower cost. The DeepSeek product apparently requires less human input to train, and less energy in parts of its processing—though experts said it remained to be seen if the new model would actually consume less energy overall.

Will Douglas Heaven, senior editor for AI at MIT Technology Review, joins Host Ira Flatow to explain the ins and outs of the new DeepSeek systems, how they compare to existing AI products, and what might lie ahead in the field of artificial intelligence.

Transcripts for each segment will be available after the show airs on sciencefriday.com.

Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

The inner workings of our bodies, particularly what’s happening inside our cells, can be kind of a black box—with countless tiny molecules constantly working and churning to keep us alive. A new technology that blends bioluminescence with cellular machinery may shine some light on the details of their comings and goings and interactions that can be hazy.

Scientists had the bright idea to take that same enzyme that makes fireflies glow and tie it to RNA, the molecule that reads the genetic information in DNA. This developing technology has been used on mice, with the hope that these light-up molecules can help illuminate how viruses replicate or even how memories form in the brain.

Flora Litchtman talks with Dr. Andrej Lupták, professor of pharmaceutical sciences at the University of California Irvine and Dr. Jennifer Prescher, professor of chemistry at the University of California Irvine, about their research on the topic.

Transcripts for each segment will be available after the show airs on sciencefriday.com.

Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

It seems that every few months, there’s an exciting breakthrough in quantum computing, a kind of computing that takes advantage of quantum physics to perform calculations exponentially faster than our most advanced supercomputers. Last December, Google announced that its quantum computer solved a math problem in five minutes—a problem that would’ve taken a normal supercomputer longer than the age of the universe to solve. And earlier this month, Microsoft, coming off a quantum advance in the fall, told businesses to get “quantum-ready” for 2025, saying that “we are right on the cusp of seeing quantum computers solve meaningful problems.”

So, are we on the cusp? Flora Lichtman is joined by Dr. Shohini Ghose, a quantum physicist and professor at Wilfrid Laurier University in Waterloo, Canada and CTO of the Quantum Algorithms Institute, for a quantum computing check-in and a look at when this futuristic technology could start to have an impact on our lives.

Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

About four and a half years ago, a spacecraft called OSIRIS-REx touched down on the surface of an asteroid called Bennu. It drilled down and scooped up samples of rock and dust and, after several years of travel, delivered those samples back to Earth.

Since then, researchers around the world have been analyzing tiny bits of that asteroid dust, trying to tease out as much information as they can about what Bennu is like and where it might have come from. Two scientific papers published this week give some of the results of those experiments. Researchers found minerals that could have arisen from the drying of an icy brine, and a soup of organic molecules, including ammonia and 14 of the 20 amino acids necessary for life on Earth.

Dr. Danny Glavin and Dr. Dante Lauretta join Flora Lichtman to talk about the samples, what their analysis is revealing, and what those findings could mean for the hunt for life elsewhere in the solar system.

Transcripts for each segment will be available after the show airs on sciencefriday.com.

Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

After nearly four weeks of burning, the fires in Los Angeles are almost fully contained, and cleanup is underway. But as the dust literally settles, people in LA are left with major questions, like: What is actually in the ash? What’s in the air? And how do I stay safe?

Flora Lichtman talks with two experts in public health and toxic substance exposure about the chemicals left behind after an urban fire as well as what science needs to be done to fully understand the issue. She speaks with Dr. Rima Habre, associate professor of environmental health and spatial sciences at the University of Southern California in Los Angeles; and Dr. Mark Wilson, director of exposure science at Chemical Insights Research Institute (CIRI) in Marietta, Georgia.

Transcript for this segment will be available after the show airs on sciencefriday.com.

Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

The outbreak of H5N9 avian influenza occurred at a California duck farm in November 2024. Also, new research pinpoints 298 parts of the genome associated with higher risk of bipolar disorder. This could lead to better treatments.

This week, the World Organization for Animal Health reported that it had been notified by the USDA that a November outbreak of highly pathogenic avian influenza on a California duck farm was caused by a strain not before seen in the United States: H5N9. The dominant bird flu strain circulating currently, H5N1, has led to massive culling of bird flocks, has infected dairy cattle, and has killed almost 500 people around the world since 2003. The US reported its first human death from bird flu earlier this month.

Experts stressed that the new strain did not itself appear to be an immediate human threat. But the rise of a new strain is troubling and points to the risk of a viral phenomenon known as “reassortment,” in which different viruses mingled in a host can sometimes exchange bits of viral code, forming new strains.

SciFri’s Charles Bergquist joins Flora Lichtman to talk about H5N9 and other stories from the week in science, including a spacewalk that was meant to include a search for microbes on the outside of the International Space Station, a possible positive side effect of scratching an itch, and the discovery of 66 million-year-old fossilized vomit.

Bipolar disorder is one of the most common mental illnesses—it affects an estimated 40 million people worldwide, about 2.8% of the population. Bipolar disorder can cause extreme mood swings, and be debilitating without treatment.

In an effort to untangle the mysteries of where bipolar disorder originates, researchers studied the genomes of more than 40,000 people with the condition. When comparing these genomes to those of people without bipolar disorder, the researchers were able to pinpoint 298 different parts of the genome associated with the mental illness. With this better understanding of the genome, better, more targeted treatments for bipolar disorder may be possible.

Joining Flora to talk about this research is Dr. Niamh Mullins, assistant professor of psychiatric genomics at the Icahn School of Medicine at Mount Sinai in New York.

Transcripts for each segment will be available after the show airs on sciencefriday.com.

Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Health psychologist Dr. Kari Leibowitz traveled to some of the coldest, darkest places on earth to learn how people there don’t just survive, but thrive in winter. She says that one of the key ingredients is adopting a positive wintertime mindset by focusing on and celebrating the good parts of winter.

Flora Lichtman talks with Dr. Kari Leibowitz, author of How to Winter: Harness Your Mindset to Thrive on Cold, Dark, or Difficult Days, about saunas, cold plunges, candles, and other small ways to make winter a season to look forward to rather than dread. Plus, she responds to some of our audience’s own tips to make the season enjoyable.

What Would You Call The Fun Parts Of Winter?

Do you think “winter doldrums” needs a positive rebrand? Let us know what you would call the winter experience instead by leaving us a voicemail at 1-646-767-6532.

Transcripts for each segment will be available after the show airs on sciencefriday.com.

Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Birds are the master vocalists of the animal kingdom. They can make a remarkable variety of sounds.

But why is a barred owl more of a baritone, while a cedar waxwing is a soprano?

And what influences a bird’s vocal range, and the kinds of sounds it can make? Beak size? Body size? Geography?

To answer some of these questions, researchers analyzed over 140,000 bird vocalizations from all over the world to try to peck out some kernels of knowledge about bird calls and songs. Their research was recently published in Proceedings of the Royal Society B.

Flora Lichtman talks with Dr. Zuzana Burivalova, assistant professor of forest & wildlife ecology at the University of Wisconsin-Madison about her latest research.

Transcripts for each segment will be available after the show airs on sciencefriday.com.

Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.