Science Friday

The concept of math has been around for a long time, developing independently in many different cultures. In 1650 BC, the Egyptians were creating math textbooks on papyrus, with multiplication and division tables. Geometry, like the Pythagorean theorem, was used in ancient Greece. And negative numbers were invented in China around 200 BC.

Some mathematical concepts are easier to understand than others. One apple plus one apple equals two apples, for example. But when it comes to complex equations, negative numbers, and calculus, concepts become abstract. All that abstraction prompts some to wonder: Is math even real?

Mathematician Dr. Eugenia Cheng has heard this question many times over her career. The quandary is the basis of her latest book, Is Math Real?: How Simple Questions Lead Us to Mathematics’ Deepest Truths. She joins Ira from Chicago, Illinois.

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

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Don’t let owls’ cute faces fool you—they’re deadly predators. This duality is part of what makes them so mysterious to humans. And their contradictions don’t end there: Their hoots are among the most distinctive bird sounds, yet owls are nearly silent when gliding through the air to catch their prey.

Scientists are learning more about why owls are such good predators—how their hearing and night vision are so sharp, and their flight so silent. With new technology, researchers are also decoding owl communications, increasing our understanding of their social structures and mating habits.

John Dankosky talks about all things owls with Jennifer Ackerman, author of the new book, What An Owl Knows: The New Science of the World’s Most Enigmatic Birds.

When you eat a piece of good chocolate, chances are you don’t just bite down and chew away. There’s a good chance you hold the chocolate in your mouth for a moment, feeling the silkiness as it softens, melting into a molten mass and mixing with your saliva. That gradual phase change process—as fats in the chocolate melt from solid to liquid—is a big part of the chocolate mouthfeel experience.

Researchers at Leeds University in the UK have constructed an artificial tongue that doesn’t focus on the taste of a food, but rather its texture, and how that texture changes over time. Using the artificial tongue, they explored the textures of materials that can change phase in the mouth, such as chocolate, butter, and ice cream. 

They reported their findings in the journal ACS Applied Materials & Interfaces. The researchers found that in dark chocolate, the sensation in the mouth is governed largely by the fat content, as the surface of the chocolate begins to soften. A few moments later, as the chocolate melts completely and mixes with saliva, the fat content of the treat is less important to the mouthfeel experience.

Dr. Anwesha Sarkar, an author of the report, joins Ira to talk about the research, the challenge of designing a lower-fat chocolate that might exploit these findings, and the importance of learning about textures to determine why people like—and don’t like—certain foods. 

Transcripts for each segment are available on sciencefriday.com.

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The editors of this year’s The Best American Science and Nature Writing anthology—and special guest journalists and writers—took to the virtual stage to reflect on their favorite stories from 2023, the biggest news from this year in science, and the future of scientific discovery and journalism.

The guests:

This event was a part of the SciFri Book Club read for December 2023. 

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Chances are you don’t give much thought to seaweed unless you’re at the beach, or perhaps when you’re considering a dinner menu. But the thousands of seaweed species around the world are a key part of our coastal ecosystems.

Seaweeds photosynthesize, provide food and shelter for marine animals, stabilize the coastlines, and even contribute to making your ice cream creamier (through an ingredient called carrageenans, extracted from red seaweeds in the Rhodophyceae family). Increasingly, they’re also being investigated as a source of biofuels and as biological factories, due to their fast-growing nature.

Dr. John Bothwell, a phycologist at Durham University in the UK, has written a book in praise of seaweeds. In Seaweeds of the World: A Guide To Every Order, he highlights beautiful, unusual, and important species from each of the three seaweed lineages—green, red, and brown. In this segment, he talks with SciFri’s Charles Bergquist about some of his favorite species, where the seaweeds fit into the web of life, and the importance of seaweeds to the global ecosystem.

Scientists have collected DNA samples of thousands of new fungus species over the past several decades. These fragments of fungal DNA are found nearly everywhere—in soil, decomposing logs, water, and even in the air. Mycologists have enough data to place these new species within the fungal family tree, but haven’t collected physical samples of them or been able to grow them in a lab. This means that according to the International Code of Nomenclature for algae, fungi, and plants, these new species cannot receive scientific names.

How can you understand a fungus that has no name? SciFri producer Shoshannah Buxbaum talks with fungal taxonomist Dr. David Hibbett, professor of biology at Clark University, about a proposal to give these “dark fungi” scientific names, and why naming living things might help us better protect the Earth’s biodiversity.

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

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In 1972, pandas arrived at the Smithsonian’s National Zoo in Washington, DC, to huge fanfare. Since then, pandas have been some of the city’s most beloved residents.

But for the first time in more than 50 years, DC is panda-free—indefinitely. Mama panda Mei Xiang, papa bear Tian Tian, and their youngest cub Xiao Qi Ji returned to China in November when their leases ended. This is possible because all but a few pandas residing outside of China are on loan through agreements with the country.

It’s not just the National Zoo waving its pandas goodbye—the Memphis Zoo’s single panda returned to China in April, and Zoo Atlanta’s pandas will go later in 2024. The news of the pandas’ departure seemed sudden, and it stirred up some questions: Why are the pandas leaving? And why now?

The news resurfaced the idea of panda diplomacy—how China introduced pandas to the world by loaning them out to other countries and using them as a symbol of cooperation.

SciFri producer Rasha Aridi and freelance journalist Aja Drain look back at 80 years of panda conservation, and how panda diplomacy paved the way for groundbreaking science. And they try to answer the multi-million dollar question: Was it all worth it?

This story was produced by Rasha Aridi, with help from Aja Drain. Edited by John Dankosky, with help from D. Peterschmidt and Emma Gometz. All our music and sound design is by D. Peterschmidt.

Special thanks to the experts we spoke with: Dr. Chee Meng Tan, Dr. Pierre Comizzoli, Dr. Mel Songer, Michael Brown-Palsgrove, Dr. Rich Bergl, Dr. Jack Liu, Dr. Binbin Li, as well as Dr. E. Elena Songster, environmental historian at Saint Mary’s College of California, and Dr. Carolyn Lin, professor of communication at the University of Connecticut.

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

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It can be hard to avoid the chime of classic Christmas songs at this time of year. Certain songs may even bring up potent memories, transporting a person to a specific moment in the past, like an afternoon baking cookies as a child, or warming up after playing in the snow.

Music, when coupled with emotion, has the ability to create powerful memories. And listening to songs associated with specific memories can almost feel like going back in time.

Better understanding how this mechanism works is the work of Assistant Professor Dr. David Clewett and PhD candidate Mason McClay, both in UCLA’s cognitive psychology department. They talk with SciFri producer Kathleen Davis about how this method could be used to improve therapies for PTSD and other memory disorders.

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

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As the year comes to a close, we wanted to reflect on some of the top science stories of 2023: Scientific breakthroughs that will shape our lives in 2024 and beyond. Research that’s shifted how we understand the universe. And even a story or two that put a smile on our faces.

In 2020, the story of the year was the rapid development of COVID-19 vaccines. And while there are now updated versions of those, vaccine development has gone much further. This year we saw approval of two exciting new vaccines, for RSV and malaria.

SciFri’s director and senior producer Charles Berquist talks with Sophie Bushwick, incoming senior news editor at New Scientist about this years vaccine breakthroughs and other top science news of the year, including a new generation of weight loss drugs, record high temperatures, completion of the human pangenome, an asteroid sample’s arrival on Earth, ripples in space-time, AI to understand pets’ emotions and T. rex’s new smile.

Cape Cod is home to one of the largest historic districts in the country. In the 80 square miles that make up the Old Kings Highway Historic District, the goal of preservationists is to maintain a certain look. So from Sandwich to Orleans, some 45,000 people who live north of Route 6 are required to get approval from local historic committees for solar installations that are visible from a public way. Over the last few decades, many property owners who’ve had their solar plans challenged or denied have described the committees’ decisions as inconsistent, arbitrary, and subjective.

But the committees remain steadfast: tourists and locals alike love seeing historic buildings preserved. And solar panels on the front of a house can read like billboards for modernity.

“When you start messing with the street view of your house, we have a legal right, on behalf of the public, to make a judgment of the appropriateness of it,” said Jim Wilson, administrative counsel for the Old Kings Highway Regional Historic District Committee, which sets standards and hears appeals of rulings by town committees.

The preservationists’ mandate is only to approve solar panels on homes when they present a minimal visual impact on the neighborhood. And that standard is often the source of the argument: what defines a minimum visual impact?

Read the full story at sciencefriday.com

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

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Pennsylvania is one of 12 states that do not implicitly or explicitly authorize syringe services programs through statute or regulation, according to a recent analysis. They are widely considered to be illegal outside of Allegheny County and Philadelphia, where officials have for decades used local health power to grant legal protection to people who operate syringe services programs.

These programs have widespread support in the medical community, and expanding them is listed as one of nine “Core Strategies” for the tens of billions of dollars coming to states as part of settlements with drug companies for their role in allegedly fueling the opioid epidemic. A coalition of state attorneys general reached the agreements with the companies.

Pennsylvania expects to receive more than $1.6 billion in opioid settlement funds, but the state’s ban makes it significantly harder for the money to directly support expanding syringe services in many places.

Some supporters of syringe services programs operate underground. Carla Sofronski, executive director of the Pennsylvania Harm Reduction Network, said she’s not aware of anyone ever facing criminal charges for doing so in the state, but noted the threat hangs over them, and they are taking a “great risk.”

Read more at sciencefriday.com.

The fields of science, technology, engineering, and math (also known as STEM) are not particularly diverse. And despite a gradual uptick in diversity over the last decade, a 2023 report from the National Science Foundation showed that only 24% of people in these industries are Hispanic, Black, or Native American.

Dr. Carlotta Berry is working to change that, taking an untraditional approach to encourage people from marginalized backgrounds to enter the sciences. She is, as she puts it, an engineering professor by day and romance novelist by night. Working under the pen name Carlotta Ardell, she writes youth-friendly romance novels featuring Black protagonists who work in STEM fields.

SciFri producer and host of the Universe Of Art podcast D. Peterschmidt sat down with Dr. Berry, who is a professor of electrical and computer engineering at the Rose Hulman Institute of Technology, to talk about how she got started on this journey and why she wants to make STEM a little steamier.

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

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On cocoa farms around the world, cocoa beans are pulled from their pods, and the hard husks are discarded, leaving 20 million tons of plant waste to biodegrade and potentially harm future crops. These husks are a source of lignin, a substance that gives plants their rigidity. It’s extremely abundant—but often wasted.

A new study published in the journal ACS Sustainable Chemistry and Engineering found that the lignin processed from leftover cocoa pod husks could have a new use as an ingredient in flame retardant.

“Lignin is pretty special, as it is very soluble in organic solvents,” said study co-author Dr. Nicholas Westwood, a professor of chemistry and chemical biology at St. Andrews University in Scotland, in an email. This means lignin can be chemically manipulated to create a number of useful substances relatively easily.

Because of lignin’s malleability, Westwood and his coauthors were able to add a flame-retardant molecule to the processed substance, and found that the modification increased its already naturally high ability to smother flames.

That’s just one possible application. While lignin hasn’t found widespread industrial use yet, scientists hold hope for it to become a greener alternative for fuel and a biodegradable plastic instead of just being leftovers. Processing biomass for food or fuel also produces a massive amount of lignin as a byproduct, which has been converted to materials like activated charcoal or carbon foam. “There are endless possibilities,” Westwood said.

​​Joining Ira to talk about lignin and its potential uses is Dr. Rigoberto Advincula, a materials scientist with the Oak Ridge National Laboratory and the University of Tennessee in Knoxville.

You may be familiar with a common science demonstration done in classrooms: If you mix cornstarch and water together in the right proportions, you create a gooey material that seems to defy the rules of physics. It flows like a liquid, but when you try to handle it quickly, it stiffens up.

This kind of material is called an oobleck, and it’s a type of non-Newtonian fluid, meaning its viscosity changes under pressure or stress. Oobleck-like materials include human-made things like Silly Putty and paint, but are also found in nature; blood and quicksand are both non-Newtonian fluids.

For a long time, it’s been hard to prove exactly why these materials act the way they do. But recently, scientists developed a better understanding of the underlying physics. A new study conducted in collaboration between the James Franck Institute and Pritzker School of Molecular Engineering at the University of Chicago was able to demonstrate this mechanism.

“The findings from this study are important because they provide direct experimental evidence for one of the mechanisms proposed for strong shear thickening,” says Dr. Heinrich Jaeger, professor of physics at the University of Chicago. “Namely, frictional interactions as the particles in the liquid are sheared into contact.” Jaeger is a co-author of the study, which was led by postdoctoral researcher Dr. Hojin Kim.

Jaeger and Kim speculate that a better understanding of non-Newtonian fluids could help in the development of new, advanced materials. The potential ranges from flexible speed bumps to impact-resistant clothing. Jaeger joins Ira to talk about it.

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

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Between supplying fuel to military bases, planes, and ships, making and using weapons, and clearing land, militaries around the world account for almost 6% of global greenhouse gas emissions.

A new report calculated how much the militaries of the United States and the United Kingdom would hypothetically “owe” if they paid for the damage caused by their carbon emissions. The total came up to $111 billion. So what can the military do about its emissions? And what does militarism in the context of the climate crisis look like?

Ira talks with two of the report’s authors, Khem Rogaly, a senior researcher at London-based think tank Common Wealth, and Dr. Patrick Bigger, research director at the Climate and Community Project, a progressive climate policy think tank in the US.

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

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