

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

Jul 20, 2018 • 35min
How Do Magnets Work?
This deceptively simple question from listeners Andy, Mike and James is actually one of the hardest questions CrowdScience has ever tackled. Why? Because even scientists struggle to explain the true nature of the magnetic force and to do so in a way that even presenter Marnie Chesterton can understand is a serious challenge. What is a magnet? And just what is going on when magnets exert a force?With the help of Melanie Windridge, Sean Giblin, Steve Bramwell, Charlotte New and Peter Morris we attempt to navigate the oddities of one of the most fundamental phenomena in the universe. (Image: A horseshoe magnet attracting some hammer nails. Credit: Getty Images)

Jul 13, 2018 • 29min
Why do Humans have Different Coloured Skin?
Anand Jagatia heads to the rainbow nation of South Africa, to answer listener Lucy’s deceptively simple question. He follows the path of early human migration to understand the relationship between light skin and latitude, and find out how the world become more multi-coloured as people ventured further away from the equator. And he learns how our genes have helped us adapt to less sunny environments, hearing from the remote KhoeSan tribe in the Kalahari desert, who took part in a massive study aimed at giving scientists a better understanding of pigmentation. Producer: Marijke Peters
Presenter: Anand Jagatia(Image: Four diverse women’s arms holding each others wrists in a circle. Credit: Getty Images)

Jul 6, 2018 • 31min
Where Do All Our Vegetables Come From?
Listener Pogo wants to know why there aren’t any cabbages – or any of the other vegetables – in his local forest. Where did they all come from? And could they someday disappear? Presenter Gareth Barlow goes hunting for wild snacks in a city park and unearths the evolution of our most beloved greens. The vegetables on our supermarket shelves today were not always nicely wrapped and tasty. Humans have been selecting for specific genes in plants for thousands of years by choosing to grow those we liked the most. Tomatoes have been transformed from a small prickly desert plant in Peru into a water guzzler with round, juicy, sweet fruits. But with breeding – and sometimes cloning – of plants we have also created genetic bottlenecks in many of the crops we rely heavily on. This has left many of our vegetables across the world vulnerable to shifts in climate, natural disasters, wars and diseases. To find solutions to this massive breach in food security, CrowdScience heads to the Millennium Seed-bank in England. By collecting and storing our most precious seeds in vaults beneath the ground, scientists are protecting the genetic diversity that we will need to overcome the challenges ahead.Presenter: Gareth Barlow
Producer: Louisa FieldPicture: Man holding basket of vegetables
Credit: Getty Images/valentinrussanov

Jun 28, 2018 • 26min
Do Plants Talk about Sex?
Sex – for most organisms - is about meeting the right partner. But what if you and your mate are stuck far apart with no ability to travel? This dilemma could put a bit of a downer on your sex life, but is faced by plants everywhere. Presenter Anand Jagatia uncovers the happy fact that not only have plants overcome this problem, they positively excel at it. From hay fever to honey, the sexual strategies of plants affect us daily, and we couldn’t live without their success. In this episode, CrowdScience is answering the questions you sent after a previous episode entitled ‘Can plants talk?’ which explored the way plants and trees use a fungal network to communicate. This time, we explore how plants ‘feel’ bees as they fly past, and more complex communication involving the ‘wood wide web’.Presenter Anand Jagatia
Producer: Rory Galloway(Image: A yellow dandelion flower attracts a pollinator in the evening sunlight. Credit: Getty Images)

Jun 22, 2018 • 30min
Will We Run Out of Groundwater?
Some of the biggest reserves of freshwater are right under our feet and they're really important for farming as well as providing us with water to drink. However, in some areas of the world, groundwater is being slurped up quicker than it can be replenished. In fact, about 1.7 billion people live in regions where groundwater is under stress, 60% of them in India and China. This figure is set to rise as the climate changes and as the population grows.CrowdScience listener Waheed from Afghanistan wants to know if we will run out of groundwater and what the repercussions might be. Marnie Chesterton trots around the globe to find out, starting with a row on the River Thames before hearing from Afghanistan to understand what’s happening where Waheed lives. She learns of what has happened to London, Mexico and Malta when they over pumped their aquifers. Finally, Marnie looks to Bangalore where the population is booming to understand how they’re coping with increasing demands on water. Presenter: Marnie Chesterton
Producer: Graihagh Jackson(Image: Children holding their hands up - asking for drinking water. Credit: Getty Images)

Jun 15, 2018 • 32min
What Shapes Our Musical Taste?
What sounds heavenly to one person might sound like boring noise to another - but why are our musical preferences so different? Is it all down to what we hear growing up, or are other factors at play? CrowdScience listener and music lover Jocelyne from Canada wants to know why she has a different song for every mood, and why she likes different music from her friends and family.
Meanwhile in Italy, composer Elisabetta Brusa asks us whether the rules of harmony align with the laws of science, and should therefore not be broken. We talk to both musicians and neuroscientists to explore the truth about harmony and discord. We find out how age, personality and experience all affect whether we find certain songs pleasing or offensive, and learn why the search for the true universals of music pleasure is a race against time.Presenter: Marnie Chesterton
Producer: Cathy Edwards(Image: A couple laying in the grass listening to music on headphones. Credit: Getty Images)

Jun 8, 2018 • 30min
Is Hypnosis a Real Thing?
The podcast explores the history and effectiveness of hypnosis, from Mesmerism to modern clinical practice. It discusses using hypnosis to treat fears and manage pain, showcasing a demonstration of pain-free dental work. The episode also follows a fear-conquering exercise involving encountering spiders and delves into the brain mechanisms and neuroscience behind hypnosis.

Jun 1, 2018 • 29min
How Green Are Electric Vehicles?
Electric cars are labelled as ‘zero emissions’ vehicles – but what does that really mean? Jack Stewart puts your questions about EVs to the experts. According to a new report by the Union of Concerned Scientists, just how green your EV is compared to a petrol or diesel vehicle, depends on how the electricity powering the battery was produced, as well as how cleanly the battery itself was manufactured. Jack also explores what could be a compelling alternative to plugging in – filing up with Hydrogen, and creating nothing but water as exhaust.Presenter: Jack Stewart
Producer: Rami Tzabar(Image: Electric cars on charge. Credit: Getty Images)

May 25, 2018 • 31min
Is Fasting Healthy?
This podcast explores the potential health benefits of fasting, including weight loss and reduced breast cancer rates. It discusses the impact of fasting on energy sources, appetite suppression, diabetes, and brain function. The speaker also explores how fasting enhances memory and improves gut flora. The podcast highlights the varying definitions of fasting and the potential health benefits of skipping breakfast.

May 18, 2018 • 32min
How is Your Brain Better Than a Computer?
Why is it that computers are so much faster than brains at some tasks? Or could human brains one day be used to better effect? Listener Praveen from India was wondering how it can be that supercomputers are so very powerful compared to the human minds that created them. So CrowdScience, with the help of a small voice-activated guest presenter, is off to discover how the first computers remembered what they were told, how a million processors are being connected together to mimic a small percentage of a human brain, and how the mind-boggling speeds of modern computing is enabling the current leaps in artificial intelligence. Producer: Alex Mansfield
Presenter: Marnie ChestertonSpeakers:
Sarah Baines, David Lewis - Museum of Science and Industry, Manchester
James Sumner, Steve Furber - University of Manchester
Aldo Faisal - Imperial College, London.(Photo: 3D transparent human head and brain image. Credit: Getty images)