Episodes
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Ten years of CrowdScience
In November 2016 the BBC World Service launched a brand new show in which listeners would send in their science questions, and a team of fearless presenters would find answers. Ten years on, CrowdScience is still going strong. We’ve answered over five hundred questions from our listeners, spoken...
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Are right-handed people more creative?
CrowdScience listener Nyok, in South Sudan, is right-handed and has always felt very creative. He's also noticed that left-handed people seem to be more logical. He's wondering if this has anything to do with the idea that different sides of your brain can be dominant for different tasks. We...
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How do insects hear?
CrowdScience listener Lauren from Belgium has near-complete hearing loss in one ear, because all the sensory hair cells in her inner ear have died. This got her thinking about how complicated the human ear is and whether there are other animals with simpler ears, in particular insects. Do they…
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Why don't we lay eggs?
Some animals lay eggs, and their young hatch out of them. Other animals give birth to live young. But which strategy is best? That’s the question that’s been bothering CrowdScience listener Sameer in Canada. Is giving birth to live young a good reproductive strategy? It takes a lot of time and...
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Are we really in charge?
Have you ever found yourself doing something – perhaps getting a glass of water, eating a snack, or even sitting on the toilet – without remembering making the decision to do it? CrowdScience listener Mohammed certainly has. It’s left him wondering: does he really have free will, or is he a…
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How are shells made?
Where do shells come from? CrowdScience listener Tamsyn got in touch, a little embarrassed, confessing that she had managed to reach her twenties without realising that shells are made by living creatures. Suddenly, her curiosity ran wild and she asked CrowdScience to investigate how these sea...
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Do plants know we're here?
CrowdScience listener Gurmeet in India wants to know if plants can sense that we're around. She started wondering about this at a wellness centre where she was encouraged to hug a tree. She enjoyed the experience, but what about the tree? Did it enjoy being touched? And is there actually evidence...
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How many dead people are on the internet?
CrowdScience listener Devin in Canada has just had a baby. Worried that all the good email addresses might be taken by the time his child needs one, he has already set up an account. But it got him wondering: how many email addresses belong to people who have died? From websites and blogs to…
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Can my veggie sausages save the world?
CrowdScience listener Lisa, who is from South Africa but now lives in the UK, has been a vegetarian for many years. Sometimes though, she still finds herself craving meats – like spaghetti bolognese or a burger. To satisfy these cravings, she eats ‘alt-meats’, products meant to look and taste…
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Why do I love rollercoasters?
Your heart pounds, your chest tightens, your stomach drops and your legs feel weak and shaky. Your palms are sweating and a tingling rush spreads through your arms and fingertips as your brain is overwhelmed with feelings of tension and fear. And yet, you’ve asked for this. You wanted to be on…
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How do electric fish make electricity?
Some fish can deliver electric shocks with four times the voltage of the electricity in your plug sockets at home . Crowdscience listener Mouhammed in Cameroon was stunned by this, so he charged us with finding out how they do it. Presenter Caroline Steel heads to Bayreuth in Germany to meet some...
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Why am I warm blooded?
CrowdScience listener Matt wants to know why he's warm blooded. He started thinking about this when he was watching some ants during the recent heatwave in Europe and wondered why their blood didn't boil. What are the pros and cons of being warm-blooded like us or cold-blooded reptiles like...
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Why can't I concentrate?
Why is it hard to concentrate, and why does it feel like such hard work? The CrowdScience inbox is full of questions like that, so for this show we’re concentrating on concentration and focusing on how we focus. We’ll be answering questions about the extra energy the brain uses when we’re...
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Why is TB still killing people?
Tuberculosis kills more than a million people every year. It’s the world’s leading cause of death from a single infectious agent. This is despite the fact that we've had a cure for TB since the 1940s and a vaccine that’s over 100 years old. So why is TB still causing so many people to die? That’s...
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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...
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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...
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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...
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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?…
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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...
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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...
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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...
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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...
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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...
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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 -...
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Why am I an introvert?
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...
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Why do we itch?
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...
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How come sea levels are rising faster in some places than others?
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?…
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Why can't I recognise faces?
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...
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Do animals hold funerals?
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...
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Why does salt taste so good?
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...
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When will the next super-volcano erupt?
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…
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Will rabbits become super predators?
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…
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Could AI present CrowdScience?
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...
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Can I unlock my car using my head?
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...
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Can I really manifest the future?
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...
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What keeps the universe in balance?
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…
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How can we save the Great Barrier Reef?
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...
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Why don't more animals have opposable thumbs?
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...
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Can we cancel light waves?
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...
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Do multiple choice questions make us biased?
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...
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Why do I tan more in the US?
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...
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Do fish know what they look like?
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…
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Why do I find silence unbearable?
Is silence blood-curdling or blissful? CrowdScience listener Ziqi finds it intolerable and thinks that there’s a good reason for it – silence is so rare in nature that it could be a signal for danger. Presenter Marnie Chesterton is on a mission to test Ziqi’s theory, starting with her own…
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How do cicadas know what season it is?
Crowdscience listener Ryosuke grew up in Japan, and spent his childhood summers catching cicadas in the park. For people in Japan, the sound of their chirping signals the first true summer day. But until they emerge, these enigmatic insects live underground - often for many years. Ryosuke wants…
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Did I inherit my laugh?
CrowdScience listener Limbikani in Zambia is always being told he has his Dad’s laugh, so he set us the challenge of trying to find out whether a laugh can be passed down in our genes or if it’s something we learn from our environment. Presenter Caroline Steel steps into the world of one of the...
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The CrowdScience quiz of the year
In 2025, the crack team of intrepid presenters here on CrowdScience have been on some incredible adventures. They’ve wondered whether water is wet, and gone a hunt for a missing tangerine. They’ve wondered why animals swallow rocks, imagined what would happen if the earth spun backwards and...
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How do we adapt to the cold?
When some people are wandering around in shorts and a t-shirt, others are wrapped up in warm coats and jumpers. How come our responses to cold weather are so different? People have been living in cold environments for thousands of years. So why do some of us struggle with the cold more than…
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Can you play the guitar underwater?
Smashing up guitars is a classic rock star activity, but how about drowning them? Seven-year-old listener Cornelius asked CrowdScience to find out what happens if you play a guitar underwater. Could this be the next avant-garde music sensation? Host and amateur musician Caroline Steel tackles...
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Can we turn deserts green?
Can we turn the world’s deserts green? CrowdScience listener Youcef is captivated by the idea of bringing water back to Earth’s driest landscapes. With sea levels rising and huge stretches of land drying out each year, he wonders whether redirecting seawater inland could offer a solution to both...
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How big is a rainbow?
When listener Sakura’s husband came home from his morning walk in Cambridgeshire, UK, he told her about a massive rainbow he’d seen. But when he showed her a picture, she didn’t think it was particularly large. So how big is a rainbow really? Are they always the same size? And if some are bigger...
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About this show
We take your questions about life, Earth and the universe to researchers hunting for answers at the frontiers of knowledge.
Hosted by
BBC World Service
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