

CrowdScience
BBC World Service
We take your questions about life, Earth and the universe to researchers hunting for answers at the frontiers of knowledge.
Episodes
Mentioned books

Apr 8, 2022 • 28min
How many fossils are there?
The odds of becoming a fossil are vanishingly small. And yet there seem to be an awful lot of them out there. In some parts of the world you can barely look at a rock without finding a fossil, and museum archives worldwide are stuffed with everything from ammonites to Archaeopteryx. But how many does that leave to be discovered by future fossil hunters? What’s the total number of fossils left to find? That’s what listener Anders Hegvik from Norway wants to know and what CrowdScience is off to investigate. Despite not having the technology or time to scan the entire planet, presenter Marnie Chesterton prepares to find a decent answer. During her quest, she meets the scientists who dig up fossils all over the world; does some very large sums; and asks, have we already found all the T-rexes out there?Presented by Marnie Chesterton and produced by Anna Lacey(Photo: Fossilized dinosaur bones and skull in the send. Credit: Getty Images)

Apr 1, 2022 • 44min
Why do animals migrate? Part 2
Many animals undertake remarkable migratory journeys; travelling thousands of miles only to return to same burrow or beach they departed from. Yet, unlike humans, they don’t have digital or paper maps to guide their way, so how are they able to orientate themselves with such accuracy?In the second part of this migration story, CrowdScience’s Anand Jagatia explores how animals are able to navigate using the sun, stars, smells, landmarks and magnetism to help guide them. Anand journeys to the coast of Florida where he helps to place a satellite tracker on a sea turtle in order to follow the long-distance journeys of these animals. He then visits a lab in North Carolina to meet a team that is recreating the earth’s magnetic fields to examine how sea turtles might be using these forces to find their feeding and nesting grounds.Anand wades into the hotly contested topic of just how birds may be sensing magnetic fields – and hears about one of the latest theories that suggests birds eyes may be exploiting quantum physics. The range of navigational tools we encounter throughout the animal kingdom from whales to ants is beguiling, Anand asks what does our increased understanding of these feats might mean for animal conservation as well as human development of mapping systems.Contributors:
David Godfrey – Sea Turtle Conservancy
Rick Herren – University of Florida
Tim Guilford – University of Oxford
Ken Lohmann – University of North Carolina
Kayla Goforth – University of North Carolina
Henrik Mouritsen – University of Oldenburg(Photo: Sea Turtles. Credit: Getty Images)

Mar 25, 2022 • 37min
Why do animals migrate? Part 1
Wherever you are in the world you are probably near an animal that has undertaken a remarkable migratory journey, be that a butterfly, bird or sea turtle. But what CrowdScience listener Moses in Kenya wants to know is why they bother making such long and precarious voyages - and how they're able to reliably navigate over hundreds and sometimes even thousands of miles. In this first of two episodes, presenter Anand Jagatia travels to the Americas to meet the scientists finding and tracking these animals in order to solve the puzzle of where they go and why.Deep in the lush and noisy Belizean jungle, Anand joins avian biologist Abidas who is collecting data on the beautiful birds that visit tropical forests to escape harsh winters. Here, using misting nets, Abidas and her team carefully catch birds to measure their health and status before tagging and releasing them so they can continue stocking up on jungle food. Anand finds out why having long term data on migrant birds can help in understanding why some birds, like the wood thrush, have been declining in their native homes further north.Anand then jumps aboard a turtle boat in Florida where scientists from the Sea Turtle Conservancy have been collecting data on these dinosaur-like creatures. But finding them is harder it might seem. They move fast, so Anand accompanies the research team who are experienced in safely catching them, will he be lucky and find one of these magnificent creatures?Presented by Anand Jagatia and produced by Melanie BrownContributors:
David Barrie – Navigator & author
Tim Guilford – University of Oxford
Abidas Ash – University of Belize
Kristen Ruegg - Colorado State University
David Godfrey – Sea Turtle Conservancy[Image credit: BBC Staff, Melanie Brown]

Mar 18, 2022 • 32min
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 Chesterton
Produced 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)

4 snips
Mar 11, 2022 • 35min
Does massage work?
Massage has been used for thousands of years to soothe our aches and pains and help us relax. Today there are a wide array of styles to choose from – Swedish massage, deep tissue, hot stone, sport, Thai, the list goes on. But which techniques are backed up by evidence?CrowdScience listeners Catherine and Stacy are keen for us to untangle this knotty issue, so presenter Caroline Steel selflessly ventures from her desk to the massage table all in the name of science.Is there such thing as a muscle 'knot' and can massage help to get rid of them? Does lactate build up in our muscles and need to be released? And why does rubbing sore muscles feel so good? We dig into the physiological and psychological aspects of what's happening in our bodies when we get a massage.With scientists only beginning to study massage in recent decades, we put the research to the test with our many questions and even a bit of myth-busting. Can massage help us avoid injury or recover faster when we exercise? Does drinking water after a massage flush out toxins? Is self-massage or massage from a friend or family member just as good as that from a professional massage therapist? Can children benefit from massage?Caroline talks to medical professionals and experts to find out what works when it comes to treating a stiff neck and tight muscles and unpacks the importance of touch in relieving the tensions of modern life.Presented by Caroline Steel and produced by Sam Baker for BBC World Service. Featuring:
● Cecillia Ljunggren, London School of Massage
● Mark Tarnopolsky, McMaster University
● Tiffany Field, Touch Research Institute, University of Miami Health System
● Wichai Eungpinichpong, Department of Physical Therapy, Khon Kaen University[Image credit: Getty Images]

Mar 4, 2022 • 27min
How high can insects fly?
If you took a fly into a really tall elevator and let it out at the top, would it still be able to fly? And what’s the absolute highest an insect could possibly go? It’s a question that’s been bugging CrowdScience listener Chee for a while, but presenter Alex Lathbridge is on the case.
He discovers that when they’re not buzzing around your lunch, insects can be routinely found flying high up in the atmosphere travelling from A to B. There are also ground-dwelling bumblebees living in the mountains of Sichuan, China that have demonstrated an ability to fly at altitudes higher than the highest point on the planet.
But leaving aside how high insects DO fly, how high COULD they fly if given the chance? Alex explores the theoretical limits of insect flight with the help of a bit of biomechanics – before contemplating the ultimate heights of the International Space Station where the mystery of whether a fruit fly will fly in zero gravity is finally answered.
Contributors:
Jason Chapman, University of Exeter
Inés Dawson, science youtuber and expert in insect flight biomechanics
Michael Dillon, University of Wyoming
Wes Shaw, Head Gardener, Sky Garden
Sharmila Bhattacharya, NASAPresented by Alex Lathbridge
Produced by Ben Motley for the BBC World Service[Photop credit: Getty Images]

Feb 25, 2022 • 31min
How did we discover fire?
Controlling fire was a turning point in the development of human civilisation. But how did fire become part of the human toolkit? It's a question that has got Crowdscience listener Joseph wondering. He wants to know how humans first made fire and how that knowledge spread around the world, eventually developing into our industrial civilisations today. Archaeologists have many different ideas and theories about this. Did humans learn the skill millions of years ago, and carry it with them as they migrated out of what is now Africa? Or was it a skill developed much later, after different groups had settled in different locations? Did people share the skill with each other or did different groups of people discover it individually?Marnie Chesterton speaks to experts to try to piece together the archaeological clues to discover what kindled humankind's relationship with fire and flame. She hears about the early evidence of fire from Anand Jagatia, who visits Wonderwerk Cave in South Africa, and she speaks to an archaeologist who has found remains of burned flint suggesting campfire locations dating back hundreds of thousands of years in Israel. Marnie also tries her hand at making fire, Neanderthal style. Contributors:
Dr Andrew Sorensen, Leiden University
Prof Nira Alperson-Afil, Bar-Ilan University
Prof Richard Wrangham, Harvard University
Dr David Morris, McGregor Museum
Candice Koopowitz, Simon Fraser University
Dr Katharine MacDonald, Leiden University Presented by Marnie Chesterton and Produced by Hannah Fisher for BBC World ServiceImage Credit: Getty Images

Feb 18, 2022 • 32min
How do you navigate in space?
How good are you at finding your way from A to B? Humans throughout history have used all sorts of tools to get us to our destination – from a trusty map and compass to the instant directions on a smartphone. But CrowdScience listener Pam from Florida wants to know what happens when we leave the surface of the Earth and try to navigate our way around space. Is there a North and South we can use to orientate ourselves? Which way is left if your nearest landmark is a million light years away? And if you can’t tell which way is up, how do spacecraft know where they’re going? Presenter Anand Jagatia speaks to experts in an attempt to find his way through the tricky problem of intergalactic space navigation.Contributors:
Ethan Siegal, journalist and astrophysicist
Michelle Baker, ESA
Coryn Bailer-Jones, Max Planck Institute for Astronomy
Presented by Anand Jagatia
Produced by Caroline Steel for the BBC World Service

Feb 11, 2022 • 35min
Are we too selfish to save the planet?
Climate change and biodiversity loss are two of the biggest threats humanity has ever faced - and tackling them is going to take a whole lot of collaboration and putting others before ourselves. But are humans cut out for this level of cooperation? Or are we fundamentally too self-interested to work together for the common good?Listener Divyesh is not very hopeful about all this, so he’s asked CrowdScience if humans have a “selfish gene” that dooms us to failure when trying to meet these challenges. He's worried that humans are destined by our evolution to consume ever more natural resources and destroy the environment in the process.But while it's true that humans often act in our own interest, we also show high levels of cooperation and care. Could tapping into these beneficial behaviours help us solve our global problems? Marnie Chesterton goes on the hunt for the best ways to harness human nature for the good of planet Earth - from making sure the green choice is always the cheaper and easier option, to encouraging and nurturing our better, altruistic and collaborative sides.We visit a rural mountain community in Spain to see the centuries-old system they have for sharing common resources; while in the city, we meet activists figuring out how to live a more community-spirited and sustainable urban life. And we speak to experts in evolution, ecology and psychology to find out what helps nudge us into greener habits.Presenter: Marnie Chesterton. Produced by Cathy Edwards for BBC World Service.Image Credit: Getty Images

Jan 28, 2022 • 29min
How does my radio work?
How is a small budget pocket radio able to recreate all the atmosphere and sounds of a football match? CrowdScience listener Andy wants to know about the science enabling his radio listening, so presenter CrowdScience Geoff Marsh sets off - microphone in hand - to follow the journey of sound on the radio. Starting with the microphone, Geoff learns how acoustic energy is converted into electrical signals. Then BBC World Service presenter Gareth takes Geoff to a little-known room in the BBC called the Radio Shack. Gareth demonstrates how these electrical signals are attached to radio waves before being sent over the airwaves and they take a radio kit apart to understand how these waves are received and converted back into sound waves.
Geoff talks to a speech and hearing specialist who, through the use of auditory illusions, shows Geoff that our brains are often filling in the gaps of lower quality audio.Finally, Geoff visits an acoustic lab at Salford University where he hears a demonstration of ‘object based audio’. This technology could enable us to create our own bespoke mix of dramas and sports, such as heightening the commentary sound or choosing to hear just the crowd, just by using the everyday speakers many have lying around them, such as mobile phones.Tune in and join us!
Presented by Geoff Marsh
Produced by Melanie Brown[Image Credit: Getty Images]