CrowdScience BBC World Service

Listener Julie lives close to the coast in New Zealand and wants to know why the water that washes up on the beach isn't fresh. How exactly does all that salt get into the world's oceans?
In India, a country where salt became symbolic of much more than well-seasoned food, host Chhavi Sachdev visits coastal salt farms and a research institute dedicated to studying all things saline, to better understand our relationship with salty seas.
The team also ventures to a very briny lake on the other side of the globe in Salt Lake City, Utah, to learn how salt makes its way into water bodies.
Speaking to an expert in deep sea exploration, we learn how hydrothermal vents may play a role in regulating ocean saltiness, and how much the field still has to explore.
Meanwhile, listener Will wants to know how much melting ice sheets are affecting ocean salinity. But ice melt isn’t the only thing affecting salt levels when it comes to the impacts of climate change.
And... how many teaspoons of salt are in a kilogram of sea water anyway? We do the rigorous science to answer all these salient saline questions.
Featuring:
Deepika - small scale salt farmer
Mark Radwin - PhD candidate in geology and geophysics at the University of Utah
Brenda Bowen - Geology & Geophysics, Atmospheric Sciences, University of Utah
Chris German - Geology & Geophysics, Woods Hole Oceanographic Institution
Prasan Khemka - Chandan Salt Works
Paul Durack - Lawrence Livermore National Laboratory
Bhoomi Andharia - Central Salt & Marine Chemicals Research Institute
Presenter: Chhavi Sachdev
Producer: Sam Baker
Editor: Cathy Edwards
Production Coordinator: Liz Tuohy
Studio Manager: Sarah Hockley
(Photo: Shiv Salt Works, Bhavnagar, Gujarat in India. Credit: Chhavi Sachdev, BBC)

CrowdScience listener Eleanor was lying in bed one rainy evening, listening to the radio. She lives in New Zealand, but happened to hear a weather forecast that told her it was raining in the UK too.
She started wondering: could it be the same rain falling there and outside her window in New Zealand? Can a raindrop really travel all the way around the world?
There are a number of routes the droplet could take, including traveling as moisture in the air. Presenter Caroline Steel meets meteorologist Kei Yoshimura, who puts his powerful weather simulation to work plotting the raindrop’s journey through the sky.
What if the raindrop falls along the way and gets trapped? Where might it end up? Hydrologist Marc Bierkens talks Caroline through the detours it could take, ranging from short stop-offs in plant stems to extremely long delays in deep groundwater.
Finally, could the drop of water make it to New Zealand by circulating through the world’s ocean currents? Oceanographer Kathy Gunn maps the droplet’s path through the ocean – and explains how climate change might affect its journey.
Featuring:
Prof. Kei Yoshimura, Professor of Isotope Meteorology, University of Tokyo
Prof. Marc Bierkens, Professor of Earth Surface Hydrology at Utrecht University
Dr. Kathy Gunn, Lecturer in Climate Sciences at the University of Southampton
Presenter: Caroline Steel
Producer: Phil Sansom
Editor: Cathy Edwards
Production Co-ordinator: Liz Tuohy
Studio Manager: Tim Heffer
Additional recording: Knut Heinatz
(Photo: Textures of rain on the surface of the ocean. Credit: Philip Thurston/Getty Images)

It’s often said that fine wine gets better with time, and this week’s oenophile listener Jeremy has a cellar full of dust-covered bottles. He is curious whether chemistry can account for the range of flavours that develop as wine matures, but also wonders why some of it tastes like vinegar if you leave it too long?

We head off to the Bordeaux region of France, where vines were planted almost 2,000 years ago. Here, winemakers are joining forces with scientists to better understand wine ageing, a process so subtle and intricate that even the scientists refer to it as magic.

In the world-famous vineyards of Chateau Margaux, presenter Marnie Chesterton learns that the key ingredient for good grapes is a sandy soil type; and that in this part of France, the warming climate is actually having a positive effect on the vines, which need very little water to thrive. Over in the lab, we meet the chemist mapping the molecules responsible for aromas associated with a well-aged Bordeaux.

Featuring:
Philippe Bascaules, Chateau Margaux
Prof Cornelis van Leeuwen, Bordeaux Sciences Agro
Dr Stephanie Marchand-Marion, ISVV
Alexandre Pons, ISVV

Presented by Marnie Chesterton
Producer – Marijke Peters
Editor – Cathy Edwards
Production Co-ordinator – Liz Tuohy
Studio Manager – Sarah Hockley
(Photo: Aged bottles on wine racks in a cellar. Credit: Morsa Images/Getty Images)

The Blue Ridge Parkway is 469 miles of beautiful vistas, a mountainous road that winds from Virginia to North Carolina in the USA. The route is peppered with elevation signs, telling you how many metres above sea level you are. Which has CrowdScience listener Beth wondering: as we are told that sea level is rising, will all the elevation signs need repainting?
It’s a task she’s passed over to the CrowdScience team, who like a difficult challenge. The height of an enormous pile of rock like Ben Nevis, or Mount Everest feels unchangeable. But we measure them relative to the nearest patch of sea, which is where our story becomes complicated. Unlike water in a bath, sea level is not equal around the world. The east coast of America has a different sea level to its west coast. And as host Marnie Chesterton discovers in Finland, in some parts of the world the land is being pushed up, so sea level is actually falling.
In fact, when nothing on earth - not the sea, the shore or the mountains - seems to be stable or constant, the question of what you measure from and to becomes incredibly tricky. But that hasn’t stopped oceanography and geography scientists risking life and fingers to use an ever-evolving array of technologies to find answers. In this show we find out why they care so much, and why we should too.
Featuring:
Dr Paul Bell – National Oceanography Centre, Liverpool, UK
Dr Severine Fournier – NASA Jet Propulsion Laboratory / California Institute of Technology
Dr Jani Särkkä – Finnish Meteorological Institute
Khimlal Gautam – Mountaineer and Chief Survey Officer, Government of Nepal
Dr Derek van Westrum – National Oceanic and Atmospheric Administration, USA
Presented and produced by Marnie Chesterton
Editor – Cathy Edwards
Production Co-ordinator – Liz Tuohy
Studio Manager – Steve Greenwood
(Photo: Sea Level Elevation Sign in Death Valley, California. Credit: Mitch Diamond/Getty Images)

Prayer and meditation are key features of religious and spiritual practices around the world, suggesting they’re intimately linked to the human condition. But what is going on in the brain during prayer? And is praying beneficial for our mental health?
CrowdScience listener Hilary is keen to find answers to such questions. She’s a counsellor with a strong Christian faith, and is curious to know whether science can illuminate religious and spiritual practices.
Presenter Caroline Steel talks to neuroscientists researching how our brains respond to prayer and meditation; and practices mindfulness herself to explore its similarities to prayer. She discovers that having a relationship with God may depend on more than religious practice. And is there a ‘spiritual part’ to our brains? Or is prayer just one activity among many - like going for a walk or playing music - that can have similar effects on our state of mind?
Featuring:
Professor Andrew Newberg, Director of Research Marcus Institute of Integrative Health, Thomas Jefferson University and Hospital, USA
Tessa Watt, mindfulness teacher
Ven. Hin Hung Sik, Centre of Buddhist Studies, University of Hong Kong
Dr Junling Gao, Centre of Buddhist Studies, University of Hong Kong
Dr Blake Victor Kent, Westmont College, USA
Presenter: Caroline Steel
Producer: Jo Glanville
Editor: Cathy Edwards
Studio Manager: Tim Heffer
Production Co-ordinator: Liz Tuohy
(Photo: A crowd of people praying. Credit: Digital Vision/Getty Images)

Mosquitoes are responsible for more human deaths than any other animal. These tiny creatures transmit many diseases, but the most devastating is malaria. It kills over half a million people every year, most of them children.
So why are people still dying of malaria in such large numbers, when so much time and money has been invested in trying to eradicate it? What do we know about mosquitoes and malaria, and what do we still need to learn? CrowdScience visits Malawi, one of the African countries leading the way against malaria, with the rollout of the world’s first malaria vaccine programme.
Presenter Caroline Steel is joined by a live audience and a panel of experts: Wongani Nygulu, Eggrey Aisha Kambewa and Steve Gowelo. Together they explore questions from our listeners in Malawi and around the world, like why female mosquitoes feed on blood while males drink nectar; why some people are more likely to be bitten by mosquitoes than others; and how we might modify the insects’ DNA to stop them spreading diseases.
About half a million children across Malawi have been vaccinated since 2019. We visit a clinic in nearby Chikwawa to meet the staff involved in the vaccination programme there, and the mothers embracing the opportunity to protect their babies against this deadly disease.
Recorded at Malawi Liverpool Wellcome Trust (MLW), Blantyre, Malawi.
Contributors:
Dr. Wongani Nygulu, Epidemiologist, Malaria Alert Centre
Eggrey Aisha Kambewa, MLW entomologist, MLW
Dr. Steve Gowelo, University of California San Francisco Malaria Elimination Initiative
Presenter: Caroline Steel
Producer: Jeremy Grange
Researcher: Imaan Moin
Additional Recording: Margaret Sessa Hawkins & Sophie Ormiston
Editor: Cathy Edwards
Production Co-ordinator: Liz Tuohy
(Photo: A mosquito, that is silhouetted against the moon, bites a human arm. Credit: LWA/Getty Images)