Cover image of CrowdScience


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

Weekly hand curated podcast episodes for learning

Popular episodes

All episodes

The best episodes ranked using user listens.

Podcast cover

Is maths real?

Faced with one cake and eight hungry people, it’s pretty obvious how maths underpins reality. But as mathematics gets further from common sense and into seemingly abstract territory, nature still seems to obey its rules - whether in the orbit of a planet, the number of petals on a flower, or the structure of an atom. But what exactly is the relationship between mathematics and reality? That’s the impossibly difficult question CrowdScience has been set this week by our listener Sergio in Peru. It’s one that’s been pondered by humans for millennia: the Greek philosopher Pythagoras believed “All is number”. Is maths a human construct to help us make sense of reality - a tool, a model, a language? Does maths create its own reality? Or is it reality itself?CrowdScience explores these questions with the help of experts from the fields of philosophy, mathematics and science: Dr Eleanor Knox, Dr Eugenia Cheng, Professor Lucie Green, Alex Bellos and Stefano Centineo. Presenter: Marnie ChestertonProduced by Cathy Edwards for the BBC World Service(Photo: A young woman with her eyes closed standing in front of chalkboard, working out maths formulas. Credit: Getty Images)


18 Oct 2019

Rank #1

Podcast cover

The Fourth Dimension

How would a fourth dimensional being appear to humans?"It would look just weird" is one way to answer the question 'How would a fourth dimensional being appear to humans?' But it's more complicated than that - theoretical cosmologist Andrew Pontzen describes how objects are viewed from one dimension to another, and how it might affect parking spaces. Also on the programme: our panel of experts discuss bubble experiments, a theory that the Black Death was a virus, space elevators, algae as a biomass fuel, what affects the speed of digestion in our gut, a short definition of dark energy and the question is it true our DNA has alien properties?With Helen Czerski, department of mechanical engineering, University College London; virologist Jonathan Ball, University of Nottingham; and cosmologist Andrew Pontzen, University College London.Do you have a question we can turn into a programme? Email us at crowdscience@bbc.co.uk.(Image: Stripes and points of light, one guess what a 4th dimension might look like, Credit: Thinkstock)


10 Dec 2016

Rank #2

Similar Podcasts

Podcast cover

How can I live a longer life?

Human life expectancy has been increasing for decades. In many developed countries, we can now expect to live into our 80s, and it isn’t uncommon to live to 90 or even 100 years old. But eventually our bodies fail, old age is undoubtedly a clear indicator of approaching death. This fact annoyed 79 year old CrowdScience listener Bill, who emailed in to set presenter Geoff Marsh the task of seeking out the secrets to a longer, healthier life. Bill has a personal target to live to 200 years old, so can he do it? Well some people appear to age more slowly. In one part of Costa Rica, people commonly hit their hundredth birthday. CrowdScience’s Rafael Rojas visits these Central American centenarians to ask them their secrets to a longer life. Then, in interviews with the best age researchers around the world, including Professor Linda Partridge and Professor Janet Lord, Geoff reveals the science behind longer lifespans, and what people can do to live for longer, healthily. Presented by Geoff MarshProduced by Rory Galloway(Image: A group of older men sitting together at an event, Costa Rica. Credit: Rafael Rojas)


11 Oct 2019

Rank #3

Podcast cover

How Bad is Flying for the Planet?

What effect does air travel have on the climate? That is the question listener Neil sent CrowdScience from New Zealand. If you have ever looked up at the sky and seen the wispy white streaks that airplanes leave behind, then you are looking at one of the major environmental impacts of air transport – contrails. To find out more, Anand Jagatia goes on a journey through the rugged, lava-ridden Icelandic landscape with earth scientist Thor and discovers how both natural events like volcanic eruptions as well as man-made acts of terror can shed light on the environmental impact of aircraft. Plus, we meet a man who tailgates 737 airliners to measure their emissions. Do you have a question we can turn into a programme? Email us at crowdscience@bbc.co.uk.


5 Dec 2016

Rank #4

Most Popular Podcasts

Podcast cover

Can we be too clean?

To be healthy you need to be clean – or so we’ve thought throughout human history.The dazzling array of antibacterial products that exploded onto the scene in the 20th century took things to the next level, with their promises of eliminating 99.9% of germs.But could an obsession with cleanliness actually be bad for us? There’s a whole world of microbes out there: some make us sick, but others are essential for our health.How do we tell the difference? Listener Younes’s question gives CrowdScience the chance to sift the good dirt from the bad, with the help of hygiene expert Professor Sally Bloomfield. Along the way we soap up our hands with schoolchildren in Mumbai, get knee deep in mud on an English farm, and find out why snuggling up to a cow might be a good idea.Do you have a question we can turn into a programme? Email us at crowdscience@bbc.co.ukPresenter: Marnie ChestertonProducer: Cathy Edwards and Marijke Peters


7 Jan 2017

Rank #5

Podcast cover

Could All Cars Be Electric?

Just one per cent of vehicles are powered by electricity, but CrowdScience listener Randall from Lac du Bonnet in Canada wants to know how quickly that might change, and whether one day all cars could be electric. Marnie Chesterton begins her journey in an electric car, stuck in traffic on a Los Angeles freeway. It was in California where the modern electric car revival began in the late 1990s with the EV1 – popular with Hollywood celebrities like Mel Gibson and Danny DeVito. More than two decades on, several countries have pledged to go all-electric in future. The latest is China, who currently lead the world in the number of electric vehicles on the road. But is the planet’s power infrastructure even capable of supporting this global electric dream? Marnie talks to experts about the practicalities of power supply and charging, takes a ride in an electric prototype with enough acceleration to impress even the most cynical petrol head and discovers an extraordinary vision for the future of personalised urban transport.Do you have a question we can turn into a programme? Email us at crowdscience@bbc.co.ukPresenter: Marnie ChestertonProducer: Jennifer Whyntie(Image: Electric power cord plugged in and recharging the electric vehicle Credit: Getty Images)


15 Sep 2017

Rank #6

Podcast cover

Why Does Dark Matter, Matter?

Scientists have been searching for dark matter for 80 years, so CrowdScience wondered whether they could find it faster. Armed with a boiler suit, hard hat and ear defenders, Marnie Chesterton travels over a kilometre underground into a hot and sweaty mine to see how we could catch dark matter in action. She investigates various theories as to what it might be with popping candy and gazes at galaxies to determine how we know it exists in the first place. But most importantly, she questions whether it really matters. And, as our Singaporean listener Koon-Hou askes, what impact would finding it have on our everyday lives? Presenter: Marnie ChestertonProducer: Graihagh Jackson(Photo: Finding dark matter could have galactic implications. Credit: Getty Images)


9 Feb 2018

Rank #7

Podcast cover

Is Being Fat a Choice?

The human race is getting fatter. But is it our fault? There are a whole host of factors influencing our weight - how many of them can we control?CrowdScience discovers how factors like our environment and our genes can tip the scales in the wrong direction.We visit an apartment complex originally designed for Olympic athletes, to see if people can get fitter just by living there. And from a brand new menu plan for overweight Mumbai police, to hormone injections that stop you getting hungry, CrowdScience asks the experts what we can do if we’ve been dealt a bad hand when it comes to our weight.Do you have a question we can turn into a programme? Email us at crowdscience@bbc.co.ukPresenter: Marnie Chesterton Producer: Cathy Edwards(Image: Women and a Man standing next to each other holding hands. Credit: ThinkStock.)


14 Mar 2017

Rank #8

Podcast cover

Why are There Morning People and Night People?

Some of us want to be up with the larks, while others are more like night owls. But is our preference down to our genes, or more to do with habits and surroundings? We set out to find the answers, inspired by a question from Kira, a night owl CrowdScience listener in Philadelphia, USA.Our daily, or circadian, body clocks are a hot topic of discussion at the moment - this year’s Nobel Prize for Medicine went to three scientists who discovered the gene that makes these clocks tick. To answer our listener’s question, we need to know why different clocks tick at different rates, so we visit a specialist sleep centre to see how having a slow-ticking clock makes it hard for you to leap out of bed in the morning.And the morning sun helps all of us regulate our daily rhythm, so what happens when it doesn’t rise at all? We travel to Tromsø, in the far north of Norway, to see how morning and evening types fare during the long polar nights - and meet the reindeer who seem to be able to switch off their daily clocks altogether. Meanwhile down near the equator, we hear about the hunter-gatherer community in Tanzania where there’s nearly always someone awake.Sami song, the joik of Ráikku-Ánte, is performed by Ken Even BergDo you have a question we can turn into a programme? Email us at crowdscience@bbc.co.ukPresenter: Anand JagatiaProducer: Cathy Edwards(Image: L - Women smiling on a run R - Women DJ. Credit: Getty Images)


17 Nov 2017

Rank #9

Podcast cover

Why are Dogs so Different?

From Chihuahuas to Great Danes, Mexican Hairless to Afghan Hounds, dogs are the most diverse mammal on the planet. There are currently over 500 recognised breeds worldwide with almost every conceivable combination of size, shape, coat, colour and behaviour. But why are there so many different kinds of dog?That's what listener Simon St-Onge in Quebec, Canada wants to know – and CrowdScience has taken up the challenge. Presenter Marnie Chesterton heads to Sweden, a world-class centre of canine research, to sniff around for answers. She finds out how the grey wolf morphed into the vast variety of dogs we have today, and heads out on a moose hunt with one of Scandinavia's most ancient breeds.But are dogs really as different as they seem on the surface? The dog genome is revealing more about man's best friend than ever before – and could now be the answer to understanding both dog and human health.Do you have a question we can turn into a programme? Email us at crowdscience@bbc.co.uk(Image: Tika, the Russian-European Laika)


21 Jan 2017

Rank #10

Podcast cover

Why Does My Dog Love Me?

Dogs have been living and working with humans for thousands of years. But they’re much more than just pets. As any dog owner will tell you, the bond we have with our canine friends is often so strong that they feel more like family. So how is it that dogs have come to fit so seamlessly into human life? That’s what CrowdScience listener Peter Jagger in the UK wants to know, and Marnie Chesterton is off to sniff out some answers. She starts by revisiting a previous episode of CrowdScience based in Sweden, where she saw the dog-human bond come alive during a moose hunt. She then heads to the Dog Cognition Centre in Portsmouth to discover how a unique and often unconscious communication system helps our dogs to understand us. Finally, Marnie finds out about the fate of dogs that are no longer wanted by their humans. After thousands of years of domestication, can they ever live without us?Presenter: Marnie Chesterton Producer: Anna Lacey(Photo: Image of young girl with her dog, alaskan malamute. Credit: Getty Images)


5 Jan 2018

Rank #11

Podcast cover

Must Life be Carbon-Based?

Carbon is special, but is it necessarily the unique building block of life in the universe? Science fiction has long speculated on non-carbon biochemistries existing in the universe – notably in the work of authors such as Isaac Asimov as well as in the popular American TV series Star Trek, which once featured a rock-munching, silicon-based life form called ‘Horta’. Marnie Chesterton explores the real science behind this intriguing idea and wonders whether in the current search for Earth-like planets elsewhere in the galaxy, we should be looking at completely different possible sets of rules when it comes to the hunt for life? Producer Alex MansfieldPresenter Marnie Chesterton(Photo: Saturn viewed from Titan moon. Credit: Getty Images)


2 Feb 2018

Rank #12

Podcast cover

How Could Humanity Become Extinct?

Nuclear weapons and mega asteroids: what would the aftermath look like? CrowdScience explores past extinction events and future dystopias. In a past episode, CrowdScience headed to Denmark to find out whether humans could go the way of the dinosaurs – mass extinction triggered by a large asteroid impact 66 million years ago. Although no killer rocks are on route to Earth any time soon, we do not have to look far for other dystopias. “Do we have enough nuclear weapons to destroy the world?”, listener Ronald from Uganda asks CrowdScience. It turns out there is a web app which can help answer this question. Together with its maker nuclear historian Alex Wellerstein, presenter Anand Jagatia tests hypothetical nuclear disaster scenarios and uncovers the nature of nuclear destruction in interviewees with climate scientist Alan Robock.Do you have a question we can turn into a programme? Email us at crowdscience@bbc.co.ukPresenter: Anand JagatiaProducer: Louisa Field(Image: Explosion of a nuclear bomb Credit: Getty Images)


8 Sep 2017

Rank #13

Podcast cover

Is Fasting Healthy?

For some it's a way to get closer to God, for others a tried and tested way to lose weight - but listener Amine wants to know if fasting has any other, unexpected health benefits? So presenter Marnie Chesterton cuts down on cookies and investigates the science behind low-calorie or time-restricted eating. She hears how some cells regenerate when we're deprived of food, which one researcher says could reduce breast cancer rates. And she finds out what happens in our brains when our bodies rely on our own fat reserves for fuel. Presenter: Marnie ChestertonProducer: Marijke Peters(Image: Clock on an empty plate. Credit: Getty Images)


25 May 2018

Rank #14

Podcast cover

Why Do We Have So Many Accents?

Why do we have so many accents - even when we’re speaking the same language? What's happening in our brains and mouths to make us sound so different from each other? This week’s question from listener Amanda takes CrowdScience to Glasgow in Scotland: home to one of the most studied - and distinctive - accents of English. Along the way we visit a voice coach to try and learn a Texan accent, use ultrasound to see what different sounds look like inside our mouths and find out how a brand new dialect was formed when many accents collided in New Zealand.Do you have a question we can turn into a programme? Email us at crowdscience@bbc.co.ukPresenter: Nastaran Tavakoli-Far Producer: Cathy EdwardsNew Zealand Mobile Unit recordings courtesy of Ngā Taonga Sound & Vision(Image: A mouth screaming white letters. Credit: Thinkstock)


31 Mar 2017

Rank #15

Podcast cover

How Can I Remember More?

Sometimes our memory fails us and we wish facts would just stick better. Listener Mothibi is a student and has spent three years trying to remember as much as possible for his exams. He wants to know how he can train his brain to better to remember things – and does the brain have a limit on how much stuff we can cram into it? To find the answers presenter Marnie Chesterton seeks help from memory magician, Simon, at the European Memory Championship. Using the loci technique she accomplishes a memory feat she didn’t think possible. Thought to have been developed by the Greeks, the loci method is a technique that enables the brain to remember extraordinary amounts of information. It turns out, we all have the right wiring to remember more and better, but we need to train our brains.Also, CrowdScience heads to Cambridge University where Marnie Chesterton lands herself in a study. The scientists scan her brain while she exercises her memory muscles and we discover why sometimes memories get muddled up. Do you have a question we can turn into a programme? Email us at crowdscience@bbc.co.ukPresenter: Marnie ChestertonProducer: Louisa Field(Image: Woman scratching head, thinking brain melting into lines. Credit: Getty Images)


10 Nov 2017

Rank #16

Podcast cover

What is the Real Time?

It sounds like a simple question – what is the time? But look closer and you realise time is a slippery concept that scientists still do not fully understand. Even though we now have atomic clocks that can keep time to one second in 15 billion years, this astonishing level of accuracy may not be enough. The complexity of computer-controlled systems, such as high-frequency financial trading or self-driving cars which rely on the pinpoint accuracy of GPS, could in future require clocks that are even more accurate to ensure everything runs ‘on time’. But what does that even mean? As Anand Jagatia discovers, time is a very strange thing. He visits the origins of modern time-keeping at the Royal Observatory in Greenwich and meets scientists at the National Physical Laboratory who have been counting and labelling every second since the 1950s. He meets Demetrios Matsakis, the man who defined time and visits the real-life ‘Time Lords’, at the International Bureau of Weights and Measures (BIPM) in Paris to find out how they co-ordinate the world’s time and why the leap second is ‘dangerous’.Do you have a question we can turn into a programme? Email us at crowdscience@bbc.co.uk


29 Jan 2017

Rank #17

Podcast cover

How does the Moon affect life on Earth?

From worms who time their mating ritual with an inner lunar calendar, to how full moons could cause cows to give birth early. Listener Andreas sends CrowdScience on a mission to separate fact from fiction.Presenter: Marnie ChestertonProducer: Marijke PetersPicture: The moon rises over Kadam mountain in Uganda, on January 31, 2018, during the lunar phenomenon referred to as the 'super blue blood moon'. Credit: Yasuyoshi Chiba / AFP / Getty Images


16 Feb 2018

Rank #18

Podcast cover

Spider Silk and Super Fly Senses

CrowdScience is uncovering the super-powers of spiders, flies and the most irritating mosquitos. Anand Jagatia meets spider specialist Jamie Mitchells at London Zoo to find out how spiders create such vast webs and speaks to researchers in Sweden about how they are trying and succeeding in recreating spider’s silk. Rory Galloway heads to Cambridge University’s Fly Lab to find out how their tiny brains process the world up to four times faster than humans. And Bobbie Lakhera is at the London School of Hygiene and Tropical Medicine to find out how attractive she is to mosquitos and how they use their super-senses to home-in on our blood. Do you have a question we can turn into a programme? Email us at crowdscience@bbc.co.ukPresenter: Anand JagatiaProducer: Laura Hyde(Image: Close-up of a Jumping Spider. Credit: Getty Images


1 Sep 2017

Rank #19

Podcast cover

How Far Can I See?

How far can you see? A few kilometres down the road? Or do you struggle to see past the end of your own nose? Well one listener thinks he might be able to see 15 quintillion miles away... but can he really? Marnie Chesterton and Bobbie Lakhera are on the case for this week’s multi-question human body special. As well as delving into the power of vision, they also discover why male mammals have nipples despite not needing to breastfeed, and Marnie puts herself in a giant refrigerator in the name of finding out why some people feel the cold more than others.Presenter: Marnie Chesterton Producer: Anna Lacey


26 Jan 2018

Rank #20