PBS News Hour - Science - The science behind exercise and why it’s good for our bodies

This will come as a surprise to no one, but exercise is really good for us. But why it works and how it works are far less understood. Horizons moderator William Brangham explores that with Stanford University's Euan Ashley. He's a professor of genomics and cardiovascular medicine and is part of a team trying to understand, at the very molecular level, how exercise changes our bodies, and why. PBS News is supported by - https://www.pbs.org/newshour/about/funders. Hosted on Acast. See acast.com/privacy

CrowdScience - Why don’t more animals have opposable thumbs?

On a recent kayaking trip, CrowdScience listener Lanier sliced through his right thumb, putting it out of action for a while. This made life difficult, as he couldn’t button his shirt, tie his shoelaces or type efficiently on his smartphone. Missing the use of his thumb made him wonder: since opposable thumbs are so advantageous to those of us who have them, why didn’t they evolve in more species?

Host Marnie Chesterton unpicks the evolution of our own unique thumbs with the help of paleoanthropologist Tracy Kivell, learning how our grip compares to that of other animals. We discover why mammals like horses and dogs have no use for thumbs, and why we humans don’t have opposable big toes.

Meanwhile, at Taronga Zoo in Sydney, Australia, senior keepers Tarryn Williams Clow and Bec Russell-Cook introduce us to two different marsupials. Humphrey the koala has not one but two thumbs on each hand. Why did koalas develop this anatomical quirk when their closest living relative, the wombat, has spade-like digits? Dr Mark Eldridge from the Australian Museum shares his hypothesis.

And what if we, too, had another thumb? Marnie tries on a robotic Third Thumb, built by designer Dani Clode. Dani has collaborated with neuroscientists from the Plasticity Lab at the University of Cambridge. She tells us what the Third Thumb has revealed about the human brain and how we control our digits.

Presented by Marnie Chesterton

Produced by Cathy Edwards and Margaret Sessa Hawkins for the BBC World Service

(Photo: Kung-Fu Koala - stock photo Credit: Alex BOISSY / Getty Images)

Unexpected Elements - Seeing double

Identical twins on trial for murder in France have left forensic experts unable to answer the question of which one pulled the gun’s trigger. With both having the same DNA, it got the Unexpected Elements team thinking, when do identical twins cease to be identical?

First, we look at how scientists have been confronting the possibility that they might soon be able to create an evil twin to life itself - mirror life. Also, we hear why the ‘Tatooine planets’ which orbit twin stars are so rare in our galaxy.

We’re then joined by professor of developmental psychology Nancy Segal, who explains why prosecutors should be able to distinguish between the French twins on trial. Plus, we hear how African farmers are struggling with a lack of data on pre-harvest crop loss.

And finally, why gorse flowers smell like pina coladas, and how the use of DNA evidence in court can still come down to interpretation. That’s all on this week’s Unexpected Elements.

Presenter: Marnie Chesterton, with Kai Kupferschmidt and Michael Kaloki Producers: Ella Hubber, with Lucy Davies, Sophie Ormiston, Imy Harper and Tim Dodd

Short Wave - The truth about intermittent fasting

From TikTok and Instagram influencers to celebrities like Hugh Jackman and Kourtney Kardashian, intermittent fasting has gotten a lot of hype. The diet restricts what time you eat rather than what or how much you eat. The idea is that short periods of fasting cause your body to burn through stored fat reserves. But is that conventional wisdom true? And can it really contribute to weight loss? Regina G. Barber and Rachel Carlson tackle those questions — plus why some researchers are rethinking how to protect people's mental health when talking to chatbots and how ultra-endurance running changes the human body.


Have a scientific question you want us to answer? Email us your question at shortwave@npr.org.


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Short Wave - The neuroscience of cracking under pressure

The 2026 Winter Olympics are unfolding in Milan and Cortina, and we can’t look away: We’re watching athletes fly down mountains on skis and glide — sometimes slipping and falling — on the ice. Vikram Chib studies performance and how the brain responds to rewards at Johns Hopkins University. And he says rewards aren’t just for Olympians; they’re baked into basically everything humans do. But those rewards and the pressure that comes with them can come at a cost to people’s brains. And even Olympians are human. Sometimes, we crack. So, today, Vikram dives into the science behind choking under pressure. 


Interested in more Olympics science? Email us your question at shortwave@npr.org – we may cover it in a future episode!


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Short Wave - Tea time… with an ape?

Picture this: You’re at a pretend tea party, but instead of sitting across from toddlers in tiaras, you’re clinking cups with Kanzi—an ape with the incredible ability to communicate with humans. NPR science correspondent Nate Rott talked to some scientists who did exactly that. But these scientists weren’t just having pretend tea parties with Kanzi for fun, they were trying to test the limits of his imagination – because humans’ ability to play out “pretend” scenarios in our heads and guess at the potential consequences of our actions is key to how we live our lives. And we might not be the only animals to do it!

For more of Nate’s reporting, plus videos of Kanzi, check out the full story on NPR here. Chris Krupenye’s study can be found here.


If you liked this episode, you might also like our episode on bonobos and the evolution of niceness, and what insights monkeys offer us for the evolution of human speech


Interested in more science about our brains and their abilities? Email us your question at shortwave@npr.org.


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Short Wave - Could this vaccine trial mean a future without HIV?

Early last year, a hundred researchers, clinicians and other experts on HIV discussed the development of an innovative vaccine that could prevent the disease. But just as the meeting was about to wrap up, the mood darkened. A new executive order signed by President Trump on Inauguration day had frozen all foreign aid, pending a review. Soon, DOGE would begin its decimation of USAID — and with it, this vaccine trial. That is – until the South African researchers came up with a new plan. 

Read more of freelance science reporter Ari Daniel’s story here.

Interested in more on the future of science? Email us your question at shortwave@npr.org.

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CrowdScience - Can we cancel light waves?

Noise cancelling headphones filter out sound waves that we don’t want to hear. Listener Ahmed in Libya loves wearing his and, as he was listening to them, he had a thought: ‘Could we cancel out light waves in a similar way to how noise cancelling headphones do it?’

He sent his question to CrowdScience and now presenter Alex Lathbridge is getting deep into the physics, to find out if light cancelling devices could replace curtains and shutters.

Alex starts at the Ray Dolby Centre in Cambridge in the UK, built to honour Ray Dolby’s invention of noise cancelling technology. In this amazing building he meets Jeremy Baumberg, Professor of Nanophotonics at Cambridge University. With the help of a tuning fork and a laser beams, Jeremy shows Alex that manipulating light is no easy feat.

Undeterred, Alex tracks down Stefan Rotter, Professor of Theoretical Physics at Vienna Technical University in Austria. Stefan and his colleagues around the world have been pushing forward the development of a device called the ‘anti-laser’. Alex and Stefan explore whether this could be the light-cancelling device of Ahmed’s imagination.

And once we've created a light-cancelling device, what do we do with it? Mary Lou Jepsen is an inventor and the founder of health tech firm Openwater. She tells Alex about how she’s using light wave manipulation to open up new possibilities for medical imaging, and even treatment.

This programme includes clips from: Surrounded by Sound: Ray Dolby and the Art of Noise Reduction https://www.bbc.co.uk/programmes/m002bswq CrowdScience: Can we trap light in a box? https://www.bbc.co.uk/programmes/w3cswvwy

Presenter: Alex Lathbridge

Producer: Tom Bonnett

Editor: Ben Motley

(Photo: Eyesight and vision concept - stock photo Credit: J Studios / Getty Images)

Unexpected Elements - Are you lucky?

K-pop fans in Taiwan have been turning to the God of love in the hope it will boost their luck in getting concert tickets. It got the Unexpected Elements team thinking, are some people just lucky?

First, we look at how music resonates in the brain and why listening to it live can feel more emotional. Also, can we measure how lucky we are? We look at a possible formula, and how you can increase your chances of striking on a lucky event.

We’re then joined by Professor of Marketing Marco Bertini, who explains the wild west of dynamic pricing and gives us some tips and tricks along the way. Plus we hear about Kenya’s ambitious plans to integrate traditional medicine into its health system.

And finally, why we dance when we pee and the Great British art of queuing. That’s all on this week’s Unexpected Elements.

Presenter: Marnie Chesterton, with Phillys Mwatee and Imaan Moin Producers: Margaret Sessa-Hawkins, with Ella Hubber, Lucy Davies, Imy Harper and Tim Dodd

Short Wave - Why do we kiss? It’s an evolutionary conundrum

The evolutionary purpose of kissing has long eluded scientists. Smooching is risky, given things like pointy teeth, and inherently gross, given an estimated 80 million bacteria are transferred in a 10 second kiss. And yet, from polar bears to humans, albatrosses and prairie dogs, many animals kiss. So, what gives? Evolutionary biologist Matilda Brindle tells us the sordid details driving this behavior, what distinguishes different kinds of kissing and whether culture has anything to do with why people kiss.

Interested in more of the science behind love and connection? Email us your question at shortwave@npr.org.


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