Crowdscience

Milk: drink a lot of it and we’ll grow big and tall with strong bones. That’s what many people are told as children, but just how true is this accepted wisdom? CrowdScience listener JJ in Singapore is sceptical. He wants to live a healthy life for as long as possible, and he’s wondering whether drinking cow’s milk will help or hinder him on this mission. All mammals produce milk, and our mother’s milk is our very first drink as babies. So what actually is the white stuff? Mary Fewtrell, professor of paediatric nutrition at UCL, gives presenter Chhavi Sachdev the lowdown on just how fundamental breastmilk is to us all. But are we meant to continue drinking milk from other animals once we grow up? This behaviour of ours is rare among mammals… so Christina Warinner, professor of evolutionary biology at Harvard University, tells us when in our history cow’s milk entered our diet, and how we even came to be able to digest it. And is there any truth in the accepted wisdom that cow’s milk will give us stronger bones

What will remain of us hundreds of millions of years from now? And how can we be so certain that we are the first technologically advanced species on Earth?These unsettling questions have been haunting listener Steve. If fossils can be lost to deep time through erosion and subduction into the Earth’s mantle, how would anyone — or anything — ever know that we had been here? And if an earlier species had built a civilization that rose and fell, would we even be able to find traces of it?To investigate, CrowdScience presenter Caroline Steel speaks to the scientists trying to answer these questions, while producer Sam Baker goes fossil hunting on the Jurassic Coast in the UK. Caroline speaks with astrophysicist Adam Frank at the University of Rochester in the US, who along with NASA scientist Gavin Schmidt developed the Silurian hypothesis – the idea that if an advanced species had existed deep in Earth’s past, they might have vanished without leaving a trace. But palaeontologists Jan Zalasiewicz and Sarah Gabbot

Camouflage isn't just for chameleons! Military forces around the world deck their soldiers out in those distinctive green and brown uniforms, to give them the best chance of staying safe, and remaining undetected. But how do they work? Why do they look so different from country to country? And why do you still see soldiers wearing it in the city, when it can't possibly work as camouflage? These are the questions in the mind of Crowdscience listener Paul, in Uganda. In his home of Kampala he often sees soldiers on patrol. As a botanist, he's fascinated by the nature-inspired designs, and he wants to know how they came to be. So Alex Lathbridge sets off to find out. At Camolab at the University of Bristol, Laszlo Talas talks Alex through the history of battle-dress. There have been some extraordinary designs over the years, some of them quite beautiful in their way, and many with hidden easter eggs printed into the design! In a patch of forest on the outskirts of Prague, Alex gets to try some of the lates

When listener Rob from Devon, UK, heard of a newly detected planet light years away, he was struck by the sheer scale the light must travel to reach us here on Earth. It got him wondering: How long does light last? What’s the oldest light we’ve ever observed? And does light ever die? To find out, presenter Anand Jagatia calls on some of the brightest minds in astronomy and physics. Astronomer Matthew Middleton from the University of Southampton describes himself as “a kid in a sweet shop” when it comes to physics, and that enthusiasm comes in handy, because scientists still struggle to define exactly what light is. What we do know is that light comes in many forms, and choosing the right kind can peel back the cosmic curtain, revealing the universe’s deepest and darkest secrets. That knowledge will prove vital in Anand’s search for the oldest light ever observed. At the European Southern Observatory in Chile, staff astronomer Pascale Hibon gives Anand a behind-the-scenes look at the Very Large Telescope, one

CrowdScience listener Rit, from Pune in India, is staring out of his window at the falling rain. It’s been pouring for four days now, and shows no sign of stopping. The laundry is piling up, all his shoes are wet, and he’s worried about the effect it’s having on the environment, and on agriculture. When it rains like this, the animals suffer, and the crops are destroyed. Cloud seeding and Weather Engineering are hot topics right now, and can bring the rain to places that need it. But Rit wants to know whether we can artificially stop the pouring rain, especially in an emergency. Following the devastating floods in Texas, it’s clearly not just a problem for countries with a monsoon season. Presenter Chhavi Sachdev is also sitting in a downpour at home in Mumbai. She dons her rain jacket and rubber boots to try and find out whether science can help Rit with his question. From controlling the clouds in India, to bringing rain to the deserts of the UAE, to firing high-powered lasers into the skies above Geneva, w

CrowdScience listener Jon started wondering how our teeth are created while he was in the dentist’s chair. It took his mind off the drilling. He wants to know how our teeth are made, what goes into them and how come we only get two sets of teeth when other animals, like sharks, grow thousands of new ones throughout their lives.Anand Jagatia goes back to prehistoric times to discover how the story of teeth began millions of years ago. Palaeontologist Yara Haridy explains that teeth weren’t designed originally for eating at all, but as a kind of armour on the exoskeletons of fish that was also sensitive to the environment. It turns out that our teeth in fact are part of our evolutionary success story. Biological anthropologist Peter Ungar reveals that we flourished as a species because our teeth are designed to get the maximum energy from our food. Anand discovers how teeth can even be grown in a lab when he meets researchers Ana Angelova Volponi and Xuechen Zhang whose team has managed to replicate the environ

The epic space story of a sci-fi dream that changed spaceflight forever. Told by the Nasa astronauts and team who made it happen. Our multi-award-winning podcast is back, hosted by space scientist Maggie Aderin-Pocock. She tells the story of triumph and tragedy - of a dream that revolutionised modern space travel forever.You can listen to the trailer here. To hear episodes, search for 13 Minutes Presents: The Space Shuttle, wherever you get your BBC podcasts. 13 Minutes Presents: The Space Shuttle is a BBC Audio Science Unit production for the BBC World Service. Theme music by Hans Zimmer and Christian Lundberg, and produced by Russell Emanuel, for Bleeding Fingers Music. Archive: Mission audio and oral histories, Nasa History Office.

What comes to mind when you imagine the future of humanity? Could a computer make your mind more efficient? Enhance your cognition? Or cure a disorder you've been grappling with all your life? CrowdScience listener Mariana from Mexico hopes that one day technology will be able to help improve our brains.  Presenter Alex Lathbridge seeks out some of these brain boosters, exploring emerging technologies in deep brain stimulation at City St George’s University of London in the UK. Professor Francesca Morgante and Dr Lucia Ricciard explain how they’re using technology to treat Parkinson’s. And could brain technology help with even the most enigmatic elements of our minds? Dr Robert Hampson at Wake Forest University in the USA takes us through his research in restoring memory impairment.   Along the way we interrogate the ethical implications of the breakneck speed of progress in brain augmentation research with researcher Anders Sandberg from the Institute of Future Studies in Sweden.    Presenter: Alex Lathbridg

Your whole life is governed by spin. The rotation of our planet tells you when to wake up, and Earth’s orbit around the Sun is the reason why some of us dig out a jumper for half the year and a t-shirt for the rest. But what if that all changed? That’s exactly what 8-year-old Geronimo in Ecuador wants to know. He and his dad, Fabian, have got themselves dizzy trying to figure out what would happen if the Earth stopped spinning, or better yet, started spinning in the opposite direction. Would everyone fly off into space? Would school be at night? Eager for answers, they decided to ask CrowdScience. Presenter Anand Jagatia embarks on an interstellar journey, blasting off with the celestial origins of spin itself. Astronomer Amy Bonsor from the University of Cambridge in the UK explains how Earth’s rotation began, with collapsing clouds of gas, planetary pile-ups and crushing gravitational force. At Keele Observatory, things get apocalyptic. Anand meets astronomer Jacco van Loon, who explains what would happe

Here's a conundrum that has captivated scientists: when Earth formed 4.5 billion years ago, our planet was essentially a ball of molten rock. Any water that might have been present during the planet's formation would surely have boiled away immediately. Yet today, water covers about 70% of Earth's surface. So where did all this water come from? And more intriguingly, when did it arrive? Listener Bill in the USA wants to know, and Presenter Caroline Steel is after answers. Assistant Professor Muhammad Abdul Latif is an early earth physicist at United Arab Emirates University. He explains how his modelling has helped us to understand when water first appeared in our universe. The early earth was not a water-friendly place - a hellscape of molten rock, volcanic eruptions and constant bombardments from comets and asteroids, with high levels of solar radiation. These conditions would have evaporated the water. And according to Professor Richard Greenwood at Open University, our earth’s molten iron core would have

Listener Dickson Mukisa from Uganda has been gazing up at the stars. But he’s not making wishes. He wants to know whether we can harness their energy, in the same way we do with our OWN star – the sun. After all, they may seem small and twinkly to us, but each one is a gigantic flaming ball of energy, with a power outputs averaging around 40 quadrillion kilowatt-hours per year – EACH! With somewhere between 100 and 400 BILLION stars in our own galaxy alone, that’s a lot of power! Can we get ‘solar power’ from stars that are such a long way away from earth? And what might we use it for? Alex Lathbridge heads to the University College London Observatory, to peer through the eyepiece of an enormous telescope and see some stars for himself. Professor Steve Fossey explains just how much of the light energy of the stars reaches us on earth. In other words, how BRIGHT they are. Once the starlight reaches earth of course, we have to capture it. Could traditional solar panels do the job? Alex meets Professor Henry Sna

No one really cares that CrowdScience listener Sam has a younger brother, but they do care about his sister. In fact, they’re fascinated by her. That’s because Sam and his sister are fraternal twins. He’s been wondering all his life why he’s treated differently. Could it be cultural? Twins have long appeared in classical mythology, revered literature, and playful comedies—captivating artists and audiences alike across time and continents. Or is there something more scientific behind our fascination? Why are twins special? Anand Jagatia investigates with Karen Dillon from Blackburn College in the USA, who says it’s more complicated. Over the years we have created stereotypes of who and what twins are. Our perception has been warped by history and pop culture. As an identical twin herself, she knows firsthand how stereotypes can shape a twin’s identity. Philosopher Helena De Bres from Wellesley College in the USA believes these stereotypes play on human anxieties. Their similarities and differences are derived

Cycling is good for our health, good for the planet, and it can be an efficient way of moving around busy cities. But despite all the rational arguments for it, in most cities the number of people who get on their bikes is low.CrowdScience listener Hans wants to know whether it’s time to change our tactics. Could we persuade more people to cycle if we moved away from focusing on well-intentioned rational arguments and use messages that appeal to our desires and vanity instead? What does the science say? Presenter Caroline Steel is on the case. She meets Winnie Sambu from World Bicycle Relief to learn about why people in countries like Kenya to choose the bike to get around. She heads out on a ride with psychologist Professor Ian Walker from the University of Swansea to find out what barriers there might be to persuading people to cycle. She also takes a lesson from one of the world’s top cycling nations as she talks to Marie Kåstrup, a cycling campaigns expert who has advised the Danish government on inspiri

Was there ever a time when life on earth was peaceful? Free of violence? No predators, no prey, just... vibes? Or has nature always been 'Red in Tooth and Claw'? Have we always been eating each other? Our listener Scott sent us on a quest to discover the origins of predators and prey, and to find out what all this ‘eat or be eaten’ stuff is really about. Taking us back to the very dawn of life on earth, Professor Susannah Porter from the University of Santa Barbara lets Alex peer into an extraordinary world of microscopic warfare. It’s a dog-eat-dog (or, microbe-dissolve-microbe) world, with single celled organisms doing battle with each other. For billions of years, this was life on earth! Tiny, violent, and completely fascinating. But what about bigger creatures? More complex ones - animals? Speeding forward several billion years, Alex arrives in the Ediacaran Period – a time of unusual tranquility, where strange, plant-like animals lived in relative peace. At the Natural History Museum in Oxford, UK, pala

In the dead of night at his home in Machinjiri, Malawi, CrowdScience listener John can hear a small, but persistent, hum. Whenever it’s quiet enough, the hum is there – but what’s causing it? And is John the only one who can hear it?Reports of consistent, low-pitched noise have been popping up around the world for decades. No one knows this better than Dr Glen MacPherson, who runs the World Hum Map. He tells presenter Caroline Steel his theory for what’s behind these hums.And Caroline does some investigating of her own. We visit the Isle of Lewis off the coast of Scotland, where residents are reporting a hum. We hear about the impact that persistent noise has on people’s lives, and find out… can Caroline hear the hum too?We also ask why some people can hear a hum but others can’t. We head to an anechoic chamber – one of the quietest places in the world – to speak to Professor Jordan Cheer, who puts Caroline’s low-frequency hearing to the test.From industrial activity to internally generated sounds, we sift th

Listener Christine wants to understand one of the strangest phenomena in the universe. But to get to grips with it, she’ll need a crash course in the bizarre behaviour of the very small. Here, things don’t act the way you might expect — and it’s famously hard to wrap your head around. Anand Jagatia has assembled some of the sharpest minds in the field and locked them in a studio. No one’s getting out until Christine and Anand know exactly what’s going on. Or at least, that’s the plan. On hand to help are Kanta Dihal, lecturer in science communication at Imperial College London; James Millen, King’s Quantum Director at King’s College London; and particle physicist Harry Cliff from the University of Cambridge. Prepare to enter the world of the very small—and the very weird—where particles can be in two places at once, influence each other across vast distances, and seem to decide what they are only when observed. Hear how these once-theoretical oddities are now driving a technological revolution, transforming e

CrowdScience listener Saoirse is vegan and doesn’t eat honey. But she’s been wondering - might honey actually have environmental benefits, by giving bee populations a boost? To find out, presenter Anand Jagatia dons a bee suit and opens up some hives with biologist Dave Goulson, who reveals that there are over 20,000 bee species on earth – and not all of them need saving. Honeybee researcher Alison Mcafee talks about the importance of beekeeping for crop pollination, and why honeybee colonies around the world are collapsing. Although, as she explains, in some places beekeeping might actually be bad for endangered wild bees. We travel to Kenya to meet Loise Njeru and Lucy King, who show how the humble honeybee can be a powerful tool for conservation – helping to protect the mighty elephant. And, on a rooftop in London, former beekeeper Alison Benjamin explains how we can support the wild bee species that need our help. Producer and presenter: Anand Jagatia Location recording: Sophie Ormiston Series Producer:

Bulgaria is famous for its yoghurt, a fermented milk food full of ‘good’ bacteria that has kept hungry Bulgarians healthy for over 4000 years. Inspired by that, and a question from a CrowdScience listener in California USA, Marnie Chesterton and Caroline Steel are immersing themselves in Bulgarian culture with a programme about Bulgarian cultures, recorded at the 2025 Sofia Science Festival. So, are the ‘live’ cultures in fermented foods actually alive by the time you eat them, and how can you tell? If you can eat the mould in blue cheese, can you eat the mould on cheese that isn’t supposed to be mouldy? Is traditional food really better for you? And if you put a drop of vanilla into a litre of milk, how come it all tastes of vanilla? Marnie and Caroline are joined by a chemist who was a member of Sofia University’s ‘Rapid Explosion Force’, a food technologist with a PhD in sponge cakes and a Professor of molecular biology who says that we contain so much bacteria that we’re only 10% human. With questions on

You may have grown up hearing the saying “red sky at night, sailor’s delight, red sky in morning, sailor’s warning” - or maybe a variation of it. CrowdScience listener Alison, who sees many dazzling red skies from her home in the Yukon, Canada, certainly did. And now she wonders if the saying is a sensible prediction of coming weather or just another old wives’ tale. Alison and presenter Anand Jagatia run a little experiment, getting up at the crack of dawn and staying up until dusk for 5 days to record if the sunset and sunrise can predict their local weather. While we wait for the results, we track this weather proverb back to its ancient roots to find out how important it may have been to the people without satellites or even thermometers to guide them. We also tap into the expertise of modern-day weather predictors, meteorologists. What are the atmospheric pressure systems that cause red skies, and how do they influence the weather globally? And what exceptions to the rules might turn a trusty old proverb

Some people fall asleep almost as soon as their head touches the pillow, while for others it can take hours of tossing and turning. CrowdScience listener Assia needs at least 45 minutes to get to sleep: it's always taken her a long time to drift off no matter how tired she is, and nothing seems to make a difference. She asked us to investigate.  Presenter Caroline Steel turns to experts to find out what happens in our bodies when we fall asleep, and why it’s more difficult for some than others. Eus van Someren explains how our bodies know when it’s time to get some rest and what can influence the difficulty of getting to sleep from our earliest years. Morten Kringelbach reveals that there may be more stages of sleep than we thought, and Ada Eban-Rothschild tells us why we have something to learn from the birds and the bees about getting a good night’s rest. Caroline has trouble getting to sleep herself, and volunteers to have her sleep monitored in Cardiff University’s sleep lab. And we share some expert ti