BBC World Service
CrowdScience
We take your questions about life, Earth and the universe to researchers hunting for answers at the frontiers of knowledge.
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Episodes
What are these strange rocks? 10.07.2026 26:28
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 Gian...
How did plants evolve to attract insects? 06.07.2026 26:28
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...
Do animals care about the past? 26.06.2026 26:28
“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...
How does Bluetooth work? 19.06.2026 26:30
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 t...
Why does paper fold so well? 12.06.2026 26:29
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...
Do plants have personalities? 05.06.2026 29:16
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 condit...
What's the deal with tongues? 29.05.2026 26:28
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...
Why am I an introvert? 22.05.2026 26:28
CrowdScience listener Daniel in Accra, Ghana is an introvert. Or at least, he thinks he is. And he’s worried that his preference for quiet spaces and lower social interaction might be holding him back in life. But what is introversion really? How do introverts and extroverts see the world differently? And is it better to be one or the other? Presenter Alex Lathbridge spends his working days talkin...
Why do we itch? 15.05.2026 26:28
Why do we feel itchy? So many listeners have emailed in with questions about itchiness, and presenter Anand Jagatia on the case. We explore why we itch, the different types of itch, the different causes, and why scratching can help with the itchy sensation. Anand puts your questions to an expert panel: Dr Sonja Ständer, professor of Dermatology and Neurodermatology at the University of Münster an...
How come sea levels are rising faster in some places than others? 08.05.2026 31:24
As our oceans warm due to climate change, sea levels are rising. It ought to be straightforward – as water gets warmer, it increases in volume. All the world’s oceans are connected, so how come sea levels are rising at different rates around the world, and even falling in some places? CrowdScience listener Alison in Australia wants to know the science behind the mystery. Presenter Anand Jagatia t...
Why can't I recognise faces? 01.05.2026 26:28
CrowdScience listener Jeroen finds it hard to remember people's faces - and he wants to know why. He wonders if it's to do with getting older and if there’s any way of improving. Presenter Caroline Steel has the same problem and is keen to find an answer too. She meets Professor Zaira Cattaneo, a neuroscientist based in Italy who researches face perception. Zaira has discovered which parts of the...
Do animals hold funerals? 24.04.2026 26:28
CrowdScience listeners Dougie and Molly have been wondering what happens to animals when they die, and whether there are animals that hold rituals to mark the passing of one of their kin. Presenter Caroline Steel is on the case, trying to work out what happens to the bodies of animals when they die. Dougie and Molly say they rarely see animal carcasses where they live - so where do they all go? Dr...
Why does salt taste so good? 17.04.2026 26:28
Salt can be found in almost every kitchen in the world. But how did this seemingly simple ingredient become the world's favourite flavour enhancer? This week, Crowdscience sets out to uncover why these tiny crystals have such a powerful effect on us. We explore the magic behind this tiny mineral that has shaped our tongues, our culture, and our cravings. Our investigation begins with CrowdScience...
When will the next super-volcano erupt? 10.04.2026 29:05
Is the world sitting on a ticking time bomb? CrowdScience listener Christel recently watched a documentary about a volcanic eruption in 536 AD that left her native Sweden under a cloud of ash for three years. It got her thinking, do we know when this could happen again? With more than 300 volcanoes – and 24 of them listed as currently active – the Philippines is a country where trying to predict e...
Will rabbits become super predators? 03.04.2026 26:28
Listener Bart in Australia sees invasive species in his area almost every day – rabbits, foxes, and cats. They were transplanted to Australia from Europe more than 100 years ago, but seem to be thriving in their new home. This got him wondering: how are they going to evolve, now that they are in a new habitat? Can we predict what future evolution will look like based on what we already know? To fi...
Could AI present CrowdScience? 27.03.2026 26:29
CrowdScience listener Po wants to know whether AI could one day replace all human jobs. And while he requests that CrowdScience continues to be hosted by people, it made presenters Caroline Steel and Anand Jagatia wonder – could an AI really present this show? To find out more about how AI models work and what they’re capable of, Caroline Steel speaks to AI journalist Alex Hern from The Economist....
Can I unlock my car using my head? 20.03.2026 26:28
CrowdScience listener Doug has been experimenting with holding his wireless garage key to his chin. Why? Because he's testing a strange trick of physics. The range of a key can apparently double when held against your head rather just being held in your hand. Could this really be true, and if so why? Presenter Caroline Steel goes on a wavy journey of self-experimentation with antennas. She follows...
Can I really manifest the future? 13.03.2026 26:28
CrowdScience listener Kassy in India wants to know if there’s any science to support the practice of ‘manifesting’ – the idea that you can make your wishes come true just by writing down your goals and sending your dreams out to the universe. Is it just a wacky belief or can it be backed up by research? Caroline Steel looks at the evidence to see if manifesting works. She talks to researcher Lucas...
What keeps the universe in balance? 06.03.2026 31:05
CrowdScience listener Ndanusa in Ghana, is gazing up at the stars, and wondering. Big philosophical questions, like… what keeps our universe in balance? From our perspective here on earth, the universe seems like a vast, harmonious system, perpetuating eternally without change. But Ndanusa knows a thing or two about the stars, and he knows that they use up hydrogen as they burn, and release helium...
How can we save the Great Barrier Reef? 27.02.2026 26:28
Australia’s Great Barrier Reef is one of the richest and most complex natural ecosystems on earth, and it’s home to over 600 species of coral – marine animals that are most closely related to jellyfish. But the coral is under threat, with climate change, ocean acidification and marine heatwaves endangering the reef and the many iconic animals that depend on it. CrowdScience listener Felix, aged 9,...
Why don't more animals have opposable thumbs? 20.02.2026 26:28
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?...
Can we cancel light waves? 13.02.2026 26:28
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 cancelli...
Do multiple choice questions make us biased? 06.02.2026 29:01
CrowdScience listener Griffith in Ghana, isn’t JUST a CrowdScience listener. He’s also a listener to our sister show on the World Service, Unexpected Elements. But he’s noticed something funny. In the weekly Unexpected Elements multiple-choice quiz, the answer is almost NEVER ‘a’. It’s nearly always ‘b’, or ‘c’. Why is this? When we set the quiz, why are we so reluctant to choose option ‘a’? His q...
Why do I tan more in the US? 30.01.2026 26:28
CrowdScience listener Namrata and presenter Chhavi Sachdev have something in common. They both get more tanned in the summer in the United States than back home in India. Namrata wants to know why she came back from her run in Boston with such a deep tan and doesn’t have the same experience in India. She’s got quite a few theories herself and wonders if it’s to do with the angle of the sun, pollut...
Do fish know what they look like? 23.01.2026 26:28
There’s something fishy going on in the Czech Republic, where CrowdScience listener Ian lives. He keeps tropical fish, and he’s noticed that when he adds new ones to his tank, they swim with others of the same breed. He wants to know how they recognise each other. Do they know what they look like, and recognise others that look the same, or is there something else going on? Presenter Anand Jagatia...
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