Podcast · Tech & Science

CrowdScience

by BBC World Service · English · Tech & Science

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

New episodes: Weekly
Typical length: 26 min
Latest: 2 Oct 2026
Language: English

Latest episode

2 Oct 2026 · 26 min

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 creatures have the architectural prowess to make shells in delicate ornamental shapes with beautiful colours and patterns. The job of sea-creature-investigator-in-chief falls to presenter Marnie Chesterton. She heads to the Natural History Museum in London, UK, where they have more shells than they can…

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Earlier episodes 29 most recent

25 Sep 2026 · 26 min

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 that hugging a tree is good for us? Anand Jagatia talks to scientists about what happens to a plant when it's touched. Molecular biologist Olivier van Aken, from Lund University in Sweden, explains what happens inside a plant's cells – from mimosa whose leaves close up when touched to a Venus…
18 Sep 2026 · 34 min

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 email accounts, social media profiles, gaming avatars and even our conversations with AI, we’re all leaving behind a trail of digital footprints that can outlive us. So what happens to them when we die? Are they deleted, recycled or preserved? And who gets to decide? Presenter Anand Jagatia travels…
11 Sep 2026 · 26 min

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 like meat but made from vegetables. This has her wondering though, are these alternative meats better for the planet than actual meat would be? And what about her health? Given that many of these foods are highly processed, would eating meat be better for her? Presenter Chhavi Sachdev speaks to food…
4 Sep 2026 · 29 min

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 this ride, at this theme park, hurtling towards the ground at a frightening speed. But why? An adrenaline rush is the body’s fight-or-flight response to intense fear, stress or excitement. It sends signals from the brain to the body, releasing hormones and redirecting the flow of blood around our…
2 Sep 2026 · 26 min

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 eels who have this amazing ability. Dr Stefan Schuster and Susanne Proschke introduce us to their collection of electric fish, and help us conduct some experiments to work out how the fish are wired. We’ll be diving into electric fishes' anatomy, learning how a specialised organ allows them to…
21 Aug 2026 · 26 min

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 lizards? Caroline Steel meets evolutionary biologist Dr Manuel Leal from the University of Missouri in the US, who explains the differences between ectotherms (cold-blooded animals) and endotherms (warm-blooded animals). She discovers that the terms cold blooded and warm blooded are actually misleading,…
14 Aug 2026 · 26 min

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 concentrating, whether mental effort can tire you out more than physical effort, why we zone out when faced with a difficult task and how the ability to multitask is governed by our overall cognitive load. To find the answers, presenter Alex Lathbridge is paying attention to a team of experts. Psychology…
7 Aug 2026 · 26 min

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 what CrowdScience listener John in Tanzania wants to know, and presenter Marnie Chesterton is on the case. Over in Paris, she’s joined by Dr Claas Kirchhelle, historian of science, medicine and technology at French National Institute of Health and Medical Research (INSERM) to look into the history…
31 Jul 2026 · 37 min

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…
24 Jul 2026 · 27 min

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…
17 Jul 2026 · 26 min

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…
10 Jul 2026 · 26 min

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…
6 Jul 2026 · 26 min

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…
26 Jun 2026 · 26 min

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…
19 Jun 2026 · 27 min

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…
12 Jun 2026 · 26 min

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…
5 Jun 2026 · 29 min

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…
29 May 2026 · 26 min

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…
22 May 2026 · 26 min

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 differently? And is it better to be one or the other? Presenter Alex Lathbridge spends his working days talking to interesting people like Daniel. He loves meeting people, and talking to them too, yet he also thinks that deep down, he might be an introvert. To understand how and why people come to be…
15 May 2026 · 26 min

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 panel: Dr Sonja Ständer, professor of Dermatology and Neurodermatology at the University of Münster and and Gil Yosipovitch, Professor of Dermatology at the Miller School of Medicine at University of Miami. Also joining them from the University of Hull in the UK is Dr Henning Holle who studies the…
8 May 2026 · 31 min

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? CrowdScience listener Alison in Australia wants to know the science behind the mystery. Presenter Anand Jagatia travels to the Philippines to investigate. The country is being particularly affected by the issue, with its more than 7,500 islands experiencing sea level rises that are double the global average. On…
1 May 2026 · 26 min

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 neuroscientist based in Italy who researches face perception. Zaira has discovered which parts of the brain are engaged in facial recognition. She explains how we recognise faces and why ageing could be a factor in Jeroen’s difficulty. Caroline travels to Bournemouth in the UK to meet researcher…
24 Apr 2026 · 26 min

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 die. Dougie and Molly say they rarely see animal carcasses where they live - so where do they all go? Dr Sarah Perkins of Cardiff University in the UK runs a research project called Roadlab, which logs how quickly the bodies of animals killed by traffic disappear, and she thinks she might have a clue.…
17 Apr 2026 · 26 min

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 that has shaped our tongues, our culture, and our cravings. Our investigation begins with CrowdScience listener George, who heard from a friend that if he added a few grains of salt to his morning coffee, he could make it taste less bitter. Following some light investigation at his local coffee…
10 Apr 2026 · 29 min

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 volcanoes – and 24 of them listed as currently active – the Philippines is a country where trying to predict eruptions has huge real world consequences. Presenter Anand Jagatia travels to Manila to meet the scientists at PHIVOLCS, the Philippine Institute of Volcanology and Seismology, including the head of…
3 Apr 2026 · 26 min

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 a new habitat? Can we predict what future evolution will look like based on what we already know? To find out, Marnie Chesterton visits Sandy Ingelby at the Australian Museum, who manages the mammal collection. She shows Marnie how indigenous Australian animals have evolved to suit where they live.…
27 Mar 2026 · 26 min

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 work and what they’re capable of, Caroline Steel speaks to AI journalist Alex Hern from The Economist. She creates an AI version of herself with Nicky Birch, Innovation Lead for the BBC’s generative AI program, and hears how the BBC is attempting to navigate the ethical use of this new technology.…
20 Mar 2026 · 26 min

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 why? Presenter Caroline Steel goes on a wavy journey of self-experimentation with antennas. She follows the story of Doug as he wanders the streets of Calgary in Alberta, Canada testing the key on his head from different distances and even testing it on his dog Maura’s head. To understand the physics…
13 Mar 2026 · 26 min

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 research? Caroline Steel looks at the evidence to see if manifesting works. She talks to researcher Lucas Dixon in Australia, who has found that people who believe in manifesting are more likely to take risky financial decisions or end up bankrupt. She meets neuroscientist Sabina Brennan in Ireland who…

About CrowdScience

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

CrowdScience is a English tech & science podcast from BBC World Service. Melo plays each episode straight from the publisher's own feed — no ads added, no account needed — and remembers where you stopped, in this browser only.

Publisher: BBC World Service
Language: English
Category: Tech & Science
New episodes: Weekly
Typical length: 26 min
Latest episode: 2 Oct 2026
Feed: RSS — paste into any podcast app
Apple Podcasts: podcasts.apple.com/podcast/id1172855980
Website: bbc.co.uk/programmes/p04d42rc
Rights: (C) BBC 2026

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