CrowdScience

By
- BBC World Service

0 Ratings: 0
Episodes: 500
Avg. duration: 31min
Language: English
Format
Category: Non-fiction

We take your questions about life, Earth and the universe to researchers hunting for answers at the frontiers of knowledge.

Episodes

Will I get hit by a meteor?Stare up at the night sky, and if you’re lucky, you might see a shooting star. Some people might make a wish, but CrowdScience listener Scott in California in the USA, thinks differently. He’s wondering how dangerous they might be. Shooting stars are actually meteors, ending their incredible journey whizzing through the depths of space by burning through our atmosphere, and crashing down to earth. And Scott’s not wrong to worry about them! In May 2026, an enormous meteor exploded off the coast of Massachusetts, causing a loud sonic boom before crashing into the ocean, releasing the equivalent energy of 300 tons of TNT! So, should we be worried? Marnie Chesterton is on the case. In Australia, Hadrien Devillepoix is the chief scientist for the Desert Fireball Network, which tracks meteors through the sky, and tries to recover any meteorites which make it to earth. He explains just how many of these smaller space rocks arrive on our planet every day, how many of them survive long enough to make it to the surface, and tries to figure out how much should we be worried about it happening to us. Over in the USA, NASA are less worried about the meteors, and more concerned about their big brothers – asteroids. These are the ones which could take out your whole neighbourhood. Or your whole city. Or even the whole planet. Kelly Fast, with NASA's Planetary Defense Coordination Office explains what the chances are one might be headed our way, and what we could do about it if they are. Push them away, pull them off course, or blow them up, are the options on the table. But space rocks, small OR large, aren’t the only things which could be tumbling down on our heads from outside our atmosphere. In fact, you might be more likely to be hit but something of our own – a man-made piece of space junk, falling out of orbit and whizzing towards the surface. Stephen Wokes, chief engineer at Astroscale, explains their mission: to use their innovative satellite to clean up Low Earth Orbit, and reduce the risk to us here on the ground. PRESENTER: Marnie Chesterton PRODUCER: Emily Knight PRODUCTION COORDINATOR: Stuart Laws EDITOR: Ben Motley (photo: Meteor Impact On Earth - Fired Asteroid In Collision With Planet - Contain 3d Rendering - elements of this image furnished by NASA - stock photo- Credit: RomoloTavani via Getty Images)
504|41min
Is anything truly random?We’re delving into the CrowdScience archive to give you another chance to hear an award-winning show from 2025. CrowdScience listener Dorit has a problem. She wants the tiles in her new bathroom to be arranged randomly but, no matter what she does, it still looks like they form some kind of pattern. This has got Dorit thinking about randomness – what is it, how do you create it, why do we find it so hard to recognise, and is anything really random at all? And if nothing is truly random, does it mean that everything is theoretically predictable? Tiling your bathroom is a much more existential problem than you might have thought. Never afraid of a question, whether big (is everything pre-determined?) or small (how do I tile my bathroom?), CrowdScience is on the case. Anand Jagatia heads to Switzerland to meet Hugo Duminil-Copin, a mathematician at the University of Geneva who specialises in probability theory. On the top floor of an old bank, Hugo has Anand flipping an imaginary coin in a random order. Hugo explains that randomness is something that cannot be predicted by any means – so why is it so easy for Hugo to guess what Anand’s next move is? Meanwhile, at the National Institutes of Mental Health in Maryland USA, Susan Wardle is a cognitive neuroscientist who researches how the human brain processes visual information. Can neuroscience help Dorit with her tiling problem, and is there a reason why the human brain likes to put random objects into some kind of order? Geneva is also the birthplace of the first Quantum Random Number Generator for smartphones, and CrowdScience has persuaded some of the University of Geneva’s finest quantum physicists to hook a photon detector up to a synthesiser. Thanks to Tiff Brydges and Nicolas Brunner, we can actually hear quantum particles behaving randomly. But is quantum randomness truly random, or just a pattern that we can’t see? And could quantum physics help Dorit tile her bathroom? Presenter: Anand Jagatia Producer: Ben Motley Editor: Cathy Edwards (Photo: Many wooden dice - stock photo- Credit: akiyoko via Getty Images)
503|27min
Are there diseases in space?Space missions are searching for evidence of extra-terrestrial life. CrowdScience listener George in Kenya wants to know what could be up there, and if there’s a risk it could harm humanity. With rovers currently analysing samples on Mars, missions searching for the building blocks of life on Jupiter’s icy moons, George’s concern that there could be diseases in space is timely. Presenter Anand Jagatia sets out to try and find an answer while keeping his feet on the Earth. He meets astrobiologist Dr Michaela Musilova, who runs experiments to try and understand what kinds of microbes could survive on other planets. In her work at NASA’s Jet Propulsion Laboratory, she recreates Mars-like environments that test lifeforms’ resilience to the rigours of the Red Planet. And if there are harmful pathogens in space, how do we make sure these missions don't bring them back to Earth? Anand talks to ‘planetary protection officer’ Silvio Sinibaldi from the European Space Agency, who explains what experts are doing to protect us. He helps Anand get suited and booted in specialist clothing so they can enter a highly sterile environment called a ‘clean room’, where things being sent to space are built. He also meets Paul Meacham, former chief engineer on the Rosalind Franklin Rover. The rover is being sent to Mars to try to determine whether life ever existed there, and even whether it still does. Paul shows us around the Airbus Defence and Space site where his team built the rover and explains high-tech measures to avoid contamination. And what would a programme on space be without an astronaut? Anand meets Kate Rubins, who spent 300 days on the International Space Station. While she was there, she ran experiments investigating what happens to microbes in space. It turns out that microbes affect humans differently in orbit to how they affect us on Earth. Presenter: Anand Jagatia Producer: Tom Bonnett Editor: Ben Motley (Photo : 3D render of the Coronavirus Covid-19 floating in the air with astronaut wearing space suit. - stock photo- Credit: Artur Debat via Getty Images)
502|29min
What are these strange rocks?CrowdScience listener Liana from Canada got in touch to ask about some very specific rocks she’d seen on an island in Indonesia – jagged, rugged and a very strange shape: hexagonal. They were in long columns, and clicked together like a jigsaw. But what are they, and how did they get there? Across the world in the UK, CrowdScience listener Sarah emailed us to ask about the famous rocks of the Giant’s Causeway in Northern Ireland. What makes them so uniformly hexagonal? Presenter Alex Lathbridge investigates, visiting the Giant’s Causeway to speak to geologist Dr Kirstin Lemon from the Geological Survey of Northern Ireland. She explains how this amazing landscape formed, and why the mythical rocks look the way they do today. We also hear from Dr Alfend Rudyawan from Institut Teknologi Bandung in Indonesia about Liana’s intriguing rocks. Are these distant locations more closely related than you might think? And we look to nature – because angular, uniform hexagons crop up surprisingly often. Professor Jean-Marc Schlenker from the University of Luxembourg explains why hexagons are much better than other shapes. Presenter: Alex Lathbridge Producer: Hannah Fisher Editor: Ben Motley (photo: Giant`s Causeway in Northern Ireland Stock photo- Credit: MANUEL FIL ORDIERES GARCIA via Getty Images)
501|29min
How did plants evolve to attract insects?Many plants need pollen from another plant of the same species in order to reproduce, but they don’t have legs so they can’t simply walk around looking for a mate. As a result, many of them rely on animals to transfer pollen from one plant to another. They’ve developed a hugely diverse range of techniques to attract them, including their appearance, taste and smell. CrowdScience listener Alice in the UK wants to know how they have evolved to do this. To try and answer the question, presenter Anand Jagatia goes trekking up a mountain in the Philippines, battling mud and leeches in the hunt for an incredibly rare flower. Rafflesia has evolved to look and smell like rotting meat in order to attract flies, so it’s the perfect example of a plant that goes to fascinating extremes to make sure it gets pollinated. It only blooms for a few days each year, so to find it Anand is going to need the help of scientists at the University of the Philippines Los Baños and Lewis Barrett, Senior Botanical Propagator at the University of Oxford Botanic Garden and Arboretum. Anand also visits the University of the Philippines Laguna Quezon Land Grant, a huge site containing more than 5,500 hectares of protected forest land. Professor Pastor Malabrigo Jr shows him a fig tree that has a fascinatingly gruesome relationship with its pollinator wasps. So how did these amazingly diverse plants end up needing insect pollinators in the first place? Dr Kyra Krakos is a professor of biology at Maryville University and a research associate at the Missouri Botanical Garden in the United States. She explains to Anand that plants are surprisingly sexy – but how did they end up needing insects to survive? Back in the Philippines, Anand’s guides have never actually seen the Rafflesia flower themselves, despite many attempts. So could this be the time they finally get lucky? Presenter: Anand Jagatia Producer: Dan Welsh Editor: Ben Motley With special thanks to Dr Chris Thorogood, Associate Professor of Biology at the University of Oxford and founder of the Community for the Conservation & Research of Rafflesia (photo: Edited high angle view of Rafflesia on green gradient - Stock photo- Credit: Mohamed Tazi Cherti / 500px via Getty Images)
500|29min
Do animals care about the past?“What separates humans from animals, is an interest in the past”. That’s a 900-year-old quote from a textbook that Nigerian listener Taiwo came across, and he wrote to CrowdScience to ask if modern science would agree. Most of us spend time thinking about the past, whether it is nostalgia for a bygone age or just wondering where we put the house keys yesterday. But is that just a human activity or do other animals also ruminate on their history and use it to make decisions? Taiwo wants to know if there is any evidence to show that animals have an interest in the past and if it matters to them. Presenter Caroline Steel has a history of answering questions like this, so she sets out to find an answer. She meets researchers who have found evidence that animals not only remember past events, but use their memory for planning. She talks to neuroscientist Dr Freyja Olafsdottir and discovers that some animals, including rats and mice, have the same brain structure for memory as humans. She meets baby magpies in Professor Nicola Clayton’s laboratory in the UK and finds out about some of the very smart tactics jays use to hide their food from rivals, evidence that they’re using their memory to protect their interests. She talks to psychologist Dr Gema Martin-Ordas whose research has shown that chimpanzees not only remember past events, but use what they’ve learnt in the future. And she tests the memory of her own cat Oli, wondering if his ability to remember dinner time suggests that he is interested in the past too. Ultimately it comes down to questions of consciousness, so as Caroline grapples with the idea that we can’t even be certain that other humans are genuinely conscious, what hope do we have of finding an answer for Taiwo? Presenter: Caroline Steel Producer: Jo Glanville Editor: Ben Motley (Photo: Cute clever cat with glasses reading a book. The cat lies on a stack of old books on a blue background. Credit:vvvita/Getty Images)
499|30min
How does Bluetooth work?CrowdScience listener Rachel uses Bluetooth headphones on her cycle to work, seamlessly playing music from her phone without using wires. But how does this technology send information through the air? To find out, Rachel and presenter Caroline Steel travel to Cambridge in the UK to meet telecommunications expert William Webb. He explains what Bluetooth signals actually are – and demonstrates why their properties are linked to the invention of leaky microwave ovens. Caroline speaks to Jaap Haartsen, the inventor of Bluetooth, who reveals the hidden meaning of its logo, and what the name has to do with an ancient Viking king. And she learns how a new flavour of “low energy” Bluetooth is having an unexpected application: helping ecologists like Damien Farine understand animal behaviour. Which leads her to an old tobacco barn in Switzerland, to meet researcher Bettina Almasi and her team – along with some very cute baby barn owls. Presenter: Caroline Steel Producer: Anand Jagatia Editors: Ben Motley & Ilan Goodman (Photo:Composite photo collage of hands hold phone device internet antenna connection technology bluetooth - stock photo- Credit: Deagreez via Getty Images)
498|30min
Why does paper fold so well?CrowdScience listener Haruka has been making origami cranes out of paper since she was a child. Creating one out of a cloth napkin, however, was a next-level challenge. It gave her a new appreciation of paper’s excellent foldability, and made her wonder: what is it about paper’s structure that means it remembers its creases? We set out to unfold her question as we peer into paper’s secrets. First stop: Frogmore, the world’s first mechanised paper mill. Here, Dr Steven Mann is on hand to explain the papermaking process, the chemistry of paper, and why that makes for a foldable sheet. Host Caroline Steel tries to make a paper crane, assisted by both listener Haruka and origami teacher Toshiko Kurata, who also introduces us to an array of paper types. Each type folds differently, and, with the help of a trusty microscope, Professor Bill Sampson from the University of Manchester reveals why. Finally, we see just how complex paper folding can get, meeting Professor Tomohiro Tachi from the University of Tokyo, and his invention, The Origamizer. Presenter: Caroline Steel Producer: Cathy Edwards Editor: Ben Motley (Photo: Toshiko Kurata and Caroline Steel with origami creations - Credit:BBC)
497|30min
Do plants have personalities?CrowdScience listener George is showing Alex Lathbridge around a small, dark, and extremely hot shed, just outside the city of Accra in Ghana. Inside are row after row of shelves, stacked high with bulging grow-bags. And out of some of them, gorgeous cascades of oyster mushrooms are bursting into bloom. We’re on George’s mushroom farm, and he’s noticed something interesting. Even though the conditions in his grow-shed are tightly controlled – they have exactly the same food, water, and light as each other – nevertheless, they respond differently. Some are more vigorous than others, some bloom quicker, others last longer, and some are more tolerant when the conditions change. And this got George wondering. Could ‘brainless’ lifeforms like mushrooms, and plants, have different ‘personalities’? Do they experience the world differently, and live their lives differently from each other? Alex Lathbridge is on the case. He visits the PGRRI, the Plant Genetic Resources Research Centre, for a quick lesson on genetic variation in the plant world. Plants are all different at the genetic level, and it’s those differences which can result in a tastier fruit, or a hardier crop. But would we call traits like these personality? In the Minimal Intelligence Lab in the University of Murcia in Spain, Paco Calvo thinks that we absolutely should. He studies plant intelligence, and points Alex to a whole host of examples of plants being smart in ways which might surprise you. Each one is an individual, and if we can only slow down enough to appreciate them properly, we’d be able to understand them better too. Back in Ghana, Alex meets plant physiologist Dr Acheampong Atta-Boateng, in the beautiful grounds of Aburi Botanical Gardens, to meet some of these plants for himself. And he discovers that there’s a whole world of smart, resilient, and resourceful little organisms in the plant world, full of personality, if you know where to look. Who needs a brain!? Presenter: Alex Lathbridge Producer: Emily Knight Editor: Ben Motley (Photo: Drawing of a face and smiling eyes on a sunflower flower - stock photo- Credit: Jose A. Bernat Bacete via Getty Images)
496|33min
What's the deal with tongues?Why is there such a variety of tongues in the animal kingdom? CrowdScience listener Dale has observed that his dog’s tongue is different from his and so is his cat’s. He’d like to know the reason. Caroline Steel visits London Zoo in the UK to find out more about the different types of tongues - from giraffes and birds to lizards. She talks to evolutionary biologist Kurt Schwenk, who explains that the development of tongues made it possible for animals to make the leap from the sea to life on land. Fish could rely on water to help them swallow food, but air and gravity required a whole different mechanism for having dinner. But why is there such a variety of tongues between species - from the forked tongue of a snake to the rough tongue of a cat? And does it all come down to our diets? Researcher Callum Ross reveals how he’s pioneered a new technique for investigating how animals use their tongues when they eat and drink, and why tongues are so important for swallowing. Presenter: Caroline Steel Producer: Jo Glanville Editor: Ben Motley (Photo: Giraffe licking its lips - stock photo - Credit: laurenepbath via Getty Images)
495|30min

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