Unexpected Elements - Ancient warmth in Greenland

Two-million-year-old molecular fossils reveal flourishing woodlands and widespread animals in Greenland's pre-Ice-Age past, and give hints to the Arctic’s future under global warming. We hear from a molecular palaeontologist and a climate modeller.

DNA also reveals the enduring genetic influence of our extinct Denisovan cousins on disease immunity in modern Island Southeast Asians.

And the art and science of 3D-printing violins

If your home is drafty, filling in holes and cracks can help tackle rising energy bills, and lower your carbon footprint. But is there a limit to how airtight we should make our homes? That’s what CrowdScience listeners Jeff and Angie wondered when weatherproofing their doors and sealing up cracks for the winter. Once every last gap is blocked, will enough air get in for them to breathe properly? How would they know if they’ve gone too far?

With Covid-19 making us more aware than ever of the importance of good ventilation, CrowdScience investigates how to make your home cosy and energy-efficient without sacrificing fresh air in the process. And we find out how, in hotter climates, you can carefully tap into your drafts, to reduce energy-intensive air conditioning.

With contributions from Kimble Smith, Professor Nicola Carslaw, Dr Iain Walker, Marion Baeli and Dr Yashkumar Shukla.

(Image credit: Beth Zaiken/bethzaiken.com)

CrowdScience - Could my house run out of air?

If your home is drafty, filling in holes and cracks can help tackle rising energy bills, and lower your carbon footprint. But is there a limit to how airtight we should make our homes? That’s what CrowdScience listeners Jeff and Angie wondered when weatherproofing their doors and sealing up cracks for the winter. Once every last gap is blocked, will enough air get in for them to breathe properly? How would they know if they’ve gone too far?

With Covid-19 making us more aware than ever of the importance of good ventilation, CrowdScience investigates how to make your home cosy and energy-efficient without sacrificing fresh air in the process. And we find out how, in hotter climates, you can carefully tap into your drafts, to reduce energy-intensive air conditioning.

With contributions from Kimble Smith, Professor Nicola Carslaw, Dr Iain Walker, Marion Baeli and Dr Yashkumar Shukla.

Presented by Marnie Chesterton Produced by Cathy Edwards for the BBC World Service

Short Wave - DART: The Impacts Of Slamming A Spacecraft Into An Asteroid

If an asteroid were hurling through space, making a beeline straight to Earth, how would humans prevent it from doing what it did to the dinosaurs? Would we bomb it? Would we shoot lasers at it like a scene from Hollywood's latest sci-fi flick? Well, the folks at NASA have designed and tested a theory.

"The DART mission, the Double Asteroid Redirection Test, is essentially our first test of a kinetic impact for planetary defense." says Cristina Thomas, assistant professor of Astronomy and Planetary Science at Northern Arizona University.

Put simply, scientists at NASA took a spacecraft and crashed it into an asteroid — hoping the little nudge, like bumper cars, would be enough to push the asteroid off course.

Today on the show, Short Wave's scientist-in-residence Regina G. Barber talks to Cristina Thomas about what it was like watching the success of the DART mission and what this means for science and planetary defense.

Email Short Wave at ShortWave@NPR.org. Or, follow us on Twitter at @NPRShortWave.

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Science In Action - Ancient warmth in Greenland

Two-million-year-old molecular fossils reveal flourishing woodlands and widespread animals in Greenland's pre-Ice-Age past, and give hints to the Arctic’s future under global warming. We hear from a molecular palaeontologist and a climate modeller.

DNA also reveals the enduring genetic influence of our extinct Denisovan cousins on disease immunity in modern island South East Asians.

And the art and science of 3D-printing violins

Producer: Roland Pease Assistant producer: Sophie Ormiston

(Image: Landscape illustration with three elephants. Credit: Beth Zaiken/bethzaiken.com)

Short Wave - The Biologist Who Talks With Cells

The human body is made up of more than 30 trillion cells, but how do they all work together? It's all about communication! "They talk through molecules going from one cell to the adjacent cell," says Dr. Sandra Murray, a professor of cell biology and physiology at the University of Pittsburgh who studies how cells communicate with each other to do complex tasks, like close a wound or deliver a baby.

This year, Dr. Murray became the first person of color elected as president of the American Society for Cell Biology. She talks with host Aaron Scott about the beautiful language of cells, how she made her way as a Black woman in STEM, and what gives her hope in her field today.

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Short Wave - What Makes Hawaii’s Erupting Volcanoes Special

Just after Thanksgiving, for the first time in almost 40 years, Hawaii's Mauna Loa volcano erupted. It's one of several ongoing eruptions – including Kilauea, also on Hawaii, and Indonesia's Mount Semeru. At just over half the size of the big island of Hawaii, Mauna Loa is the world's biggest active volcano.

Today, volcanologist Alison Graettinger talks to Scientist in Residence Regina G. Barber about what makes Mauna Loa's eruption different than Indonesia's and others around the Pacific, and what it reveals about planet Earth.

Watch the U.S. Geological Survey's live video of the eruption here.

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Short Wave - ‘One Mississippi…’ How Lightning Shapes The Climate

When lightning strikes a giant tree in the tropical rainforest, there's usually no fire, no blackened crater — you might not even notice any damage. But come back months later, as Evan Gora does, and you may find that tree and dozens around it dead. Gora, a forest ecologist who studies lightning in tropical forests, says we are just beginning to understand how lightning actually behaves in these forests, and what its implications are for climate change. On today's episode, Evan Gora tells Aaron Scott about shocking discoveries in lightning research, and why Evan has developed a healthy respect for the hazards it poses – both to individual researchers and to the forests that life on Earth depends on.

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Short Wave - Don’t Call It Dirt: The Science Of Soil

It's easy to overlook the soil beneath our feet, or to think of it as just dirt to be cleaned up. But soil wraps the world in an envelope of life: It grows our food, regulates our climate, and makes our planet habitable. "What stands between life and lifelessness on our planet Earth is this thin layer of soil that exists on the Earth's surface," says Asmeret Asefaw Berhe, a soil scientist at the University of California-Merced.

Just ... don't call it dirt.

"I don't like the D-word," Berhe says. Berhe says soil is precious, taking millennia to regenerate. And with about a third of the world's soil degraded, according to a UN estimate, it's also at risk. Prof. Berhe, who is also serving as Director of the U. S. Dept. of Energy's Office of Science, marks World Soil Day by telling Aaron Scott about the hidden majesty of soil and why it's crucial to tackling the climate crisis.

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Unexpected Elements - COVID spreads in China

Hong Kong health expert Professor Malik Peiris relates the lessons from the devastation there earlier this year.

UK virologist Dr Tom Peacock reveals the unusual origins and evolution of omicron, and explains the risks of dangerous new variants.

New studies from China are revealing further SARS-like viruses in the wild; Professor Eddie Holmes says they underline the risk of further pandemics.

What are the clouds like where you are? When you look upwards can you see great tufts of cotton wool, or do they stretch off into the distance, flat like sheets. Are they dark greys and purples, bringing the promise of rain or maybe there aren’t any at all. For listener John from Lincolnshire in the UK clouds looking up at the clouds is a favourite pastime and he wants to know why they look the way they do and why they are so different from one day to the next.

Join Presenter Marnie Chesterton as we turn our gaze skyward to discover what gives clouds their shape. Join us for a cloud spotting mission with Gavin Pretor-Pinney, founder of the cloud appreciation society as he helps us de-code the shapes across the sky to reveal what they can tell us about our atmosphere. Dr Claire Vincent at the University of Melbourne introduces us to one of the superstars of the cloud world, Hector the Convector to explain where thunderstorms come from. And we learn how people like you can help NASA to understand the clouds better with Marilé Colón Robles project scientist at the GLOBE programme.

(Photo: Kevin Frayer/Getty Images)

CrowdScience - What gives clouds their shapes?

What are the clouds like where you are? When you look upwards can you see great tufts of cotton wool, or do they stretch off into the distance, flat like sheets. Are they dark greys and purples, bringing the promise of rain or maybe there aren’t any at all. For listener John from Lincolnshire in the UK clouds looking up at the clouds is a favourite pastime and he wants to know why they look the way they do and why they are so different from one day to the next.

Join Presenter Marnie Chesterton as we turn our gaze skyward to discover what gives clouds their shape. Join us for a cloud spotting mission with Gavin Pretor-Pinney, founder of the cloud appreciation society as he helps us de-code the shapes across the sky to reveal what they can tell us about our atmosphere. Dr Claire Vincent at the University of Melbourne introduces us to one of the superstars of the cloud world, Hector the Convector to explain where thunderstorms come from. And we learn how people like you can help NASA to understand the clouds better with Marilé Colón Robles project scientist at the GLOBE programme.

Presented by Marnie Chesterton and Produced by Emily Bird

[Image: Dramatic looking clouds. Credit: Getty Images]