CrowdScience

The space between stars is usually measured in light years, but this makes it less easy to acknowledge the true scale of the distance. Even the closest star system to Earth, Proxima Centauri, is 4.2 light years or 40.13 trillion kilometres from Earth. If we are ever going to bridge the gap between the stars, we will have to have some very fast spaceships, with extremely reliable, long-lasting technology on board. So does science allow for these spacecraft to exist? That’s what listener Allan wants to know, and to find out, Presenter Anand Jagatia speaks with Tracy Drain, a systems engineer at NASA JPL responsible for overseeing the development and missions of multiple unmanned interplanetary probes including some around Jupiter and Mars. She tells us the challenges involved with simply keeping our spacecraft working for the long-haul.Even if we can overcome issues of wear and tear over time, powering a ship to other star systems will not be easy. Today’s chemical rockets are too inefficient for the job, so we speak with Rachel Moloney, a researcher in electric propulsion to ask if this relatively new technology could power ships through interstellar space. Faster than light travel is the solution most often found in Science Fiction, but it goes against Einstein’s laws of relativity. Is there a way around it? Theoretical physicist Professor Miguel Alcubierre thinks there may be, and he describes the way a spaceship may be able to create a bubble of spacetime around itself to move faster than light without breaking these fixed laws. But there’s a catch... Contributors: Tracy Drain – Systems Engineer - NASA Jet Propulsion Lab, California, USA Rachel Moloney – Researcher in Electrical Propulsion - Surrey Space Centre, UK Professor Samuel Tisherman – Surgeon – University of Maryland school of Medicine, USA Dr John Bradford – President & CTO of SpaceWorks, USA Professor Miguel Alcubierre – Theoretical physicist known for the ‘Alcubierre Warp Drive’ – National University of Mexico Presented by Anand Jagatia Produced by Rory Galloway [Image: Speceship. Credit: Getty Images]

From dumping raw sewage into rivers to littering the streets with our trash, humans don’t have a great track record when it comes to dealing with our waste. It’s something that CrowdScience listener and civil engineer Marc has noticed: he wonders if humans are particularly prone to messing up our surroundings, while other species are instinctively more hygienic and well-organised.Are we, by nature, really less clean and tidy than other animals? Farming and technology have allowed us to live more densely and generate more rubbish - maybe our cleaning instincts just aren’t up to the vast quantities of waste we spew out? CrowdScience digs into the past to see if early human rubbish heaps can turn up any answers. We follow a sewer down to the River Thames to hear about The Great Stink of Victorian London; turn to ants for housekeeping inspiration; and find out how to raise hygiene standards by tapping into our feelings of disgust and our desire to follow rules.Presented by Marnie Chesterton and produced by Cathy Edwards for the BBC World Service.[Image: Man on beach with rubbish. Credit: Getty Images]

This year, dramatic wildfires wreaked havoc across the globe from Australia to Siberia. CrowdScience listener Melissa wants to know the extent to which climate change is a factor in blazes that appear to be increasing in both frequency and intensity.Presenter Anand Jagatia hears how scientists use alternative worlds in computer models, to understand the role that global warming plays. After Siberia’s hottest ever year on record, he discovers the impact of increasing temperatures on boreal forests – and how they could help release huge stocks of carbon that has been stored in the soil. But is there anything we can do to prevent this happening? He visits the UK’s Peak District region, where conservationists are re-wilding a massive area with a special species of moss, which may offer a solution to an increase in infernos.Presented by Anand Jagatia and Produced by Melanie Brown for the BBC World Service. [Image: Forest Fire. Credit: Getty Images]

Every year, Western Afghanistan is hit with a fierce 120-day wind, and listener Hamid wants to know what causes this phenomenon? He’s from the city of Herat, where what starts as a gentle breeze in the morning can pick up to become a dangerous gale just a few hours later, devastating buildings and causing power outages. The BBC’s Abdullah Elham in Kabul tells us the country has plenty of other ‘friendly’ wind but this one is considered ‘fierce’. CrowdScience talks to Professor Amir Aghakouchak to discover more about the phenomenon, and learns about the pollution problems Herat’s summer storm causes in neighbouring Iran. But it’s not all bad news. Professor Lorraine Remer explains how NASA used satellites to map how wind transport Saharan sand almost half way round the world, fertilising the Amazon rainforest. Presented by Marnie Chesterton and produced by Marijke Peters for the BBC World Service[Photo: Tree in wind in desert. Credit: Getty Images]

We all feel pain on a regular basis; when we stub a toe, break a bone or even experience heartbreak. Bebeto from Cameroon wants to know how to cope with a pain in his wrist that just won’t go away. Does a positive mindset help? Or perhaps meditation? Marnie Chesterton speaks to psychologists and neuroscientists to find the answers. We hear from two people with very different experiences of pain. Lucy has fibromyalgia and experiences pain all over her body every day. While Stephen has a rare genetic condition which means he doesn’t feel physical pain at all. But they both argue that pain shouldn’t always be unwanted. Perhaps we need to embrace and accept our pain in order to beat it. Presented by Marnie Chesterton. Produced by Caroline Steel for the BBC World Service[Image: Man in pain. Credit: Getty Images]

CrowdScience listeners come in all shapes, sizes and ages. This episode is dedicated to our younger listeners who, as we’ve learned before, are experts at asking those superficially obvious questions that for parents, are anything but easy to answer. To start off with, Sylvia, asks why elephants are so big? As we hear from our expert – mammals were at one time, much larger – so perhaps the question should be, why aren’t they bigger? We investigate what drives body size in the animal kingdom.Presenter Marnie Chesterton, together with our ‘cub’ reporter Arlo, goes in search of the most brilliant scientific minds to respond to a slew of other queries. Shambhavi, from Singapore wonders why humans have five digits on each hand? And Benni from California asks why dogs don’t get sick when they drink from muddy puddles? Do dogs have some amazing ability to fight off viruses and bugs?Beyond the confines of our planet, we’ve also got a question from Olivia, from Sydney, Australia, who regularly contemplates the universe: what is the biggest object in it she wonders? Marnie and her experts do their best to solve these mysteries.Presented by Marnie Chesterton, produced by Dom Byrne for the BBC World Service. Image: Getty Images

We’ve probably all got a friend who sings along wildly out of tune - or maybe you are that person. But why are some of us apparently tone deaf, while others can hold a melody? Can you train yourself to sing in tune, or is it mostly down to raw talent?These musical questions, from CrowdScience listeners Jenny and Anastasia, certainly struck a chord with us. Anastasia loves to sing but her friends tell her she’s off-key - or that “a bear trod on her ear,” as they say in her native Russia. Is it possible for her to improve her singing voice, and what are the best ways of going about it?Both musicians and scientists help us tackle these questions, and explain what’s going on in our ears, brains and throats when we try to sing the right notes. We learn about congenital amusia, a condition which makes it almost impossible to tell if you’re in tune or not, and attempt to tease out the relative influence of our genes and our environment when it comes to musical ability.Presented by Marijke Peters and produced by Cathy Edwards for the BBC World Service.Image: Child Singing. Credit: Getty Images

All living things are related to each other, from elephants to algae, e-coli to humans like us. Within our cells we hold genetic information in the form of DNA or RNA. But despite viruses sharing these molecules, many scientists don't consider them to be 'life'. Viruses cannot reproduce on their own, but some can insert their DNA into a host to pass genes sideways through the branching tree of life. As a result, viruses’ relationship with life is.... complex. Two of our listeners had viruses on the mind, so they sent in the same question to CrowdScience. Senan from Singapore and Melvin from South Africa want to know how viruses began to see if this can tell us whether they shared a common ancestor with humans. To dig into this complexity Marnie Chesterton speaks with an expert on Koala genetics – Dr Rachael Tarlinton. Koalas are in the middle of tackling a retroviruses, a type of virus that plants DNA into our cells as a reproduction strategy. Her research could reveal why humans life has so much viral DNA within our genomes. Marnie speaks with a computational biologist Professor Gustavo Caetano-Anolles, who has found a new way to trace the family tree for billions of years using proteins common to all life on earth, and speaks with Professor Chantal Abergel who paints a picture of how viruses went from being the losers of evolution, to being highly successful parasites of cells. If you have a question for CrowdScience, please email: [email protected] by Rory Galloway Presented by Marnie Chesterton Contributors: Dr Chelsey Spriggs - Postdoctoral fellow at the University of Michigan in the USA Dr Rachael Tarlinton - Associate Professor at the University of Nottingham in the UK Professor Gustavo Caetano-Anolles - The University of Illinois in Urbana Champagne, USA Professor Chantal Abergel - Aix Marseille Université in France Graeme Dick - Head Keeper, Longleat Zoo and Safari Park, UK

Curious CrowdScience listeners have suddenly been struck by the oddity of their behaviours. Elise ponders why she blushes. Thankfully, listener David is a vascular surgeon and knows a thing or two about blushing, as he performs operations on people debilitated by constant red-dening. He has some answers for us, but asks why did blushing evolve?In the past, red cheeks have been linked to necrophilia, repressed cannibalism, and even a de-sire for men to experience menstruation! Thankfully, research has come a long way since then, as blushing experts Peter de Jong and Corine Dijk explain. Scientists believe that it evolved as a nonverbal signal to show someone you’re sorry or that you care about what they think. This would have important for our survival in the group, en-suring we didn’t get into a fight or get kicked out the group. Anand Jagatia gets to grips with blushing and other bodily behaviours – including a question from Thai listener Nitcha who wonders why we yawn as well as a question from Mohamed in Ghana and Biana in Trinidad and Tobago who both asked why people scratch their heads when they think. To answer these questions, Anand’s joined by yawning researcher Andrew Gallup and Sophie Scott as well as body language expert Blanca Cobb. Produced by Graihagh Jackson for the BBC World Service.

Crowdscience solves a range of listeners’ cosmic mysteries, from the reason we only ever see one side of the moon, to why planets spin, and discover the answer can be found in the formation of the solar system. We talk to astronomer Dr Carolin Crawford to understand how stars are made, and investigate the art of astronomy with journalist Jo Marchant, hearing how the ancient Greeks came up with a zodiac long before the invention of a telescope, revealing an intimate relationship between humans and the night sky.Presenter: Marnie Chesterton Producer: Marijke Peters [Image: The Solar System. Credit: Getty Images]

Why am I embarrassed to be naked? Chumbuzzo in Zambia wonders. And what would happen if we ditched our clothes and embraced nudity? Presenter Anand Jagatia and Producer Caroline Steel spend the day naked with other naturists to see if they can shift their embarrassment. Maybe there are good evolutionary reasons to cover up or perhaps we are contributing to inequality and negative body image by hiding our real selves? Marnie Chesterton explores different cultural attitudes to nudity and finds out about the science behind embarrassment. Clothes optional. Presented by Marnie Chesterton. Produced by Caroline Steel for the BBC World Service

Many of us willingly subject ourselves to pain and irritation by eating chilli. CrowdScience listener Tina wonders what’s driving this apparent masochism: why does ‘feeling the burn’ make so many of us feel so good?It’s just one of several tasty questions we tuck into in this episode. Also on the menu is stew: why does it taste better the next day? Listener Helen’s local delicacy is Welsh cawl, a meat and vegetable concoction. Tradition dictates it should be eaten the day after it’s made, but is there any science behind this?And we finish the meal with cheese. Listener Leander asks what makes some cheeses blue, some hard and crumbly, and some run all over your fridge. How is milk transformed into such radically different end products?Presented by Marnie Chesterton and Alex Lathbridge Produced by Cathy Edwards, Marnie Chesterton and Alex Lathbridge for the BBC World Service.[Photo:Woman eating red Chilli Pepper. Credit: Getty Images]

What does science say about controlling urination, and other bodily functions? We tackle three queries about peeing triggers, pooing positions and missing sweat. This episode CrowdScience presenter Marnie Chesterton poses some of the best listener follow-up questions that have landed in our inbox to a panel of experts.Listener Samuel in Ghana is wondering why watery sounds seem to induce urination. Producer Melanie Brown heads out to survey whether this is the case for individuals in an actual crowd at a public fountain in London. And urologist and trustee of the International Continence Society Marcus Drake talks Marnie through how he uses the sound of running water during his work as a hospital doctor helping patients with common but distressing peeing issues, and the limitations of research into this question.And he’s not the only listener who wants us to dig deeper into topics we’ve explored on the show before. Anna in Tokyo also got in touch after hearing our show about toilets, to ask if there is a toilet design that is most ‘natural’ for our health. Gastroenterologist Anton Emmanuel explains why small changes in people’s posture whilst pooing can have a significant impact on their quality of life.Finally, listeners Stelle, James and Joel emailed [email protected] after hearing Marnie investigate hyperhidrosis: Sweating too much. They and their relatives experience the opposite:

If you’re one of the millions of people who used lockdown to try something new like baking sourdough bread, you may well be wondering what’s happening chemically inside your loaf, especially if the end result keeps changing. Well, you’re not alone. Listeners Soheil and Sean are both keen bakers but want to know more about the thing that makes bread rise: yeast. What is yeast? Where does it come from and can you catch it? And how hard is it to ‘make’ yourself? Soon after lockdown took effect, commercial supplies of the stuff disappeared from supermarket shelves across the globe. The shortage also affected brewers the world over. A big fan of yeast in most of its forms, Marnie Chesterton took on the challenge of creating her own. She talks to the brewers who hunt rare strains to create the perfect beer, and hears from the biologist who says these amazing microbes, used for thousands of years, could be used to make food production more sustainable. And she discovers how this simple ingredient could be instrumental in the fight against climate change. Presented by Marnie Chesterton and Produced by Marijke Peters for the BBC World Service.

Squelching into the science of slime, Chhavi Sachdev seeks to find out why it took so long for listener Helen Tyson to remove slime from her fingers, after she picked up a tiny slug while gardening. This unfortunate and hugely repulsive experience set Helen to wonder what it is about the structure of slug slime that makes it gloopy, so she sent Chhavi to meet with slug slime expert Professor Andrew Smith who reveals how the complex molecular structure of this pervasive fluid makes it so difficult to scrub off.Slime is used by all sorts of creatures including the Giant African Land snail, which invaded India by hitching a ride on imported timber. But invasive species biologist Dr TV Sajeev reveals that these snails are themselves giving a lift to another meningitis-causing parasite that can infect people. Chhavi looks for these massive molluscs in her own garden in Mumbai. Marine biologist Helen Scales describes how animals can use slime for catching food, mating, defence, or even transportation, and Chhavi speaks with Dr Adam Celiz who has been inspired by this slimy adaptability to create a tool that can provide new cells to replace damaged heart cells after a cardiac arrest. Slugs, snails and even fish keep a variety of useful chemicals in their slime. Some make them taste bitter, and others numb the mouth of predators, but they may also prevent the animals from contracting infections. Dr Sarah Pitt has investigated these compounds in the slimy mucus of a garden snail and discovered an antibiotic that is brand new to science. Slime is pretty disgusting, but it’s also completely fascinating. Presented by Chhavi Sachdev Produced by Rory Galloway (Photo: Slugs Mating. Credit: Getty Images)

Anyone else had their flight cancelled? The COVID 19 pandemic has had a huge impact on air travel – air traffic in 2020 is expected to be down 50 per cent on last year. But beyond the obvious disruption to business and people’s lives, how might the quieter skies affect our weather and climate? One curious listener, Jeroen Wijnands, who lives next to Schiphol airport in the Netherlands, noticed how there were fewer clouds and barely any rainfall since the flights dropped off. Could airplanes affect our local weather? Also, did we learn anything from another occasion when airplanes were grounded, during the post-9/11 shutdown? How will the current period impact our future climate? Marnie Chesterton investigates this question and discovers some of the surprising effects that grounded aircraft are having: on cloud formation, forecasting and climate change. Presenter: Marnie Chesterton, Producer: Dom Byrne[Photo:Commercial airplane parking at the airport. Credit: Getty Images]

Listener Avalon from Australia wants to know why people use conspiracy theories to explain shocking events. Are we more likely to believe conspiracy theories in times of adversity? What purpose do conspiracy theories serve in society? Marnie Chesterton speaks to the scientists to explain their popularity, even in the face of seemingly irrefutable evidence. Presented by Marnie Chesterton. Produced by Caroline Steel for the BBC World Service.Image: All-seeing eye of God inside triangle pyramid. Credit: paseven, Getty Images

These days we’re more acquainted with soap than ever before, as we lather up to help stop the spread of coronavirus. And for CrowdScience listener Sharon, this set off a steady stream of soapy questions: how does soap actually work? How was it discovered in the first place, long before anyone knew anything about germs? Are different things used for washing around the world, and are some soaps better than others? We set up a CrowdScience home laboratory to explore the soap making process with advice from science-based beauty blogger Dr Michelle Wong, and find out what it is about soap’s chemistry that gives it its germ-fighting superpowers. Soap has been around for at least 4000 years; we compare ancient soap making to modern methods, and hear about some of the soap alternatives used around the world, like the soap berries of India.And as for the question of whether some soaps are better than others? We discover why antibacterial soaps aren’t necessarily a good idea, and why putting a toy inside a bar of soap might be more important than tweaking its ingredients.Presented by Marnie Chesterton. Produced by Cathy Edwards for the BBC World Service.Image: Child with thoroughly washed hands. Credit: Getty Images.

Think of the oceans and an empty and peaceful expanse relatively untouched by humankind might come to mind. But is this peace an illusion? CrowdScience listener Dani wants to know if the noise of shipping and other human activity on the oceans is impacting on sea life.To find out, Marnie Chesterton takes a deep dive to learn how marine animals have evolved to use sound; from navigating their environments to finding a mate or hiding from prey. She then speaks to a scientist who is using acoustic observatories to track the many ways human activity - like sonar and shipping - can interfere.Marnie virtually visits a German lab which tests the ears of beached whales, dolphins and seals from around the world to try and ascertain whether they suffered hearing damage, and what might have caused it. What other smaller creatures are negatively impacted by underwater noise? Marnie learns that acoustic trauma is more widespread than first thought.As human life continues to expand along ocean waters, what is being done to reduce the impact of sound? Marnie meets some of the designers at the forefront of naval architecture to see how ship design, from propellers to air bubbles and even wind powered vessels can contribute to reducing the racket in the oceans.Presented by Marnie Chesterton. Produced by Melanie Brown for the BBC World Service.Main Image: The front of a humpback whale underneath the sea in Shetland Islands, Scotland, December 2016. Credit: Richard Shucksmith / Barcroft Im / Barcroft Media via Getty Images

Worms are not the cutest of creatures. They’re slimy, often associated with death and tend to bring on feelings of disgust in many of us. But listener Dinesh thinks they’re underrated and wants to know whether earthworms could be the key to our planet’s future agricultural success? He’s an organic farmer in India’s Tamil Nadu province who grows these annelids to add to the soil, and he wants Crowdscience to find out exactly what they’re doing. Anand Jagatia dons his gardening gloves and digs the dirt on these remarkable creatures, discovering how they can help improve soil quality, prevent fields from becoming waterlogged, and improve microbial numbers, all of which has the potential to increase crop yield.But he also investigates the so-called ‘earthworm dilemma’ and the idea that in some parts of the world, boreal forest worms are releasing carbon back into the atmosphere, which could have dangerous consequences for climate change.(Photo:

Shoes are a surprisingly recent human invention. But running isn’t. That means for most of our time on the planet, we’ve run barefoot. Today, in most countries it’s rare to see people out in public without shoes, let alone running. But might our aversion to the free foot be causing us pain?CrowdScience mega-fan Hnin is an experienced runner, she enjoys ultra-marathons back home in Australia. But about six months ago she developed extreme foot pain, the condition ‘Plantar Fasciitis’, and this has meant she had to stop doing what she loves. She reached out to CrowdScience presenter Chhavi Sachdev, to find out if barefoot running could reduce her pain and improve her performance. Simply put, is barefoot running better? In an attempt to find Hnin some answers, Chhavi hits the ground… running. Literally throwing off her own shoes on the streets of her home city of Mumbai, India, to see how feeling the ground can change her whole gait. And with Prof. Dan Lieberman, Chhavi learns what sets the human runner apart from other species while uncovering the strange form our feet have. She speaks with the Dr Peter Francis, a researcher whose life’s work has focused on curing the pain in his own feet and learning how to help others. But performance is also important for runners. Biomechanics and shoe expert Dr Sharon Dixon explains how modifications to the sports-shoe are helping marathon runners set records, and blade-running athlete Kiran Kanojia shows Chhavi how the technology behind her two prosthetic legs let her emulate either natural walking or natural running. Presented by Chhavi Sachdev Produced by Rory Galloway (Photo: barefoot running on beach. Credit: Getty Images)

If you put one person’s blood into another person , sometimes it’s fine and sometimes it’s a death sentence. French physician Jean-Baptiste Denis discovered this when he performed the first blood transfusion back in 1667. He put the blood of a lamb into a 15-year boy. The teenager survived but Denis’s third attempt killed the patient and led to a murder charge.In 1900, Austrian doctor Karl Landsteiner discovered the reason for this lottery – blood types. The red blood cells in our bodies are decorated with different marker molecules called antigens. These define us as A, B, AB or O blood type. And this is just one of 38 different systems for classifying our blood. CrowdScience listeners have discovered that we aren’t the only animal with blood types and want to know more. Dogs have 12 different blood groups, so how do they cope when they need a transfusion? CrowdScience meets some very good dogs who donate a pint to the pet blood bank in return for a toy and a treat. Each pint saving up to 4 other dogs’ lives. We also hear how examining our blood types can tell us more about our links to our ape-like cousins and how the human species spread around the world. And what about the future of blood types – can we use science, and animal blood to get around the problems of transfusions?Producer and Presenter: Marnie Chesterton Photo: Red Blood Cells. Credit: Getty Images

What exactly it means to be conscious has long been a question of profound debate amongst philosophers, and more recently, scientists. There are no easy answers, and it gets even trickier when you start asking whether animals are conscious: how can you find out about their subjective experience when they can’t tell you about it?Never afraid to tackle the impossible, CrowdScience is looking for answers after listener Natalie got in touch. She has lived with her cat for years and has a strong sense that he has thoughts and feelings: he has his own personality, acts in complex ways, and even has ‘grumpy days’. But is this consciousness? Is there any way of scientifically testing for it? How different from our own inner world is that of a cat, an octopus, or a bumblebee? And if we can find any answers to these puzzling questions, how does that affect the way we treat animals - not just our pets, but all the animals we share our planet with?We meet Natalie and her cat, and discover how scientists have explored the minds of pigs, cows and cuttlefish. Helping us ponder the elusive question of animal consciousness are philosopher Peter Godfrey-Smith, neuroscientist Anil Seth, animal welfare expert Donald Broom, ethicist Jessica Pierce, and comparative psychologist Alex Schnell.Featuring David Seddon as the voice of Chicco the Cat.Presented by Anand Jagatia and Produced by Cathy Edwards for BBC World Service.(Photo: Black Cat. Credit: Getty Images)

We were bowled over by a question from one CrowdScience listener in Australia wants to know how likely it is that the atoms in his body have been used in someone else’s body? We all like to think we are unique; no one is quite like us. But is that really true?Presenter Marnie Chesterton tackles Moshe’s question with help from every area of science. From geologists helping us work out how many atoms are on the Earth’s surface to biologists helping us work out how many atoms each body uses. Perhaps we are much less special than we think.Presented by Marnie Chesterton. Produced by Caroline Steel for the BBC World Service. (Photo:

Have you ever broken up a fight? Or pushed someone out the way of an oncoming vehicle, only to be hit by it yourself? Most of us probably haven’t taken as many risks as listener Alix, who has put herself in peril to save strangers on several occasions, and she wants Crowdscience to investigate why. At a time when medical professionals have to weigh up the personal dangers of working on the frontline of the Coronavirus crisis, it’s a particularly timely question. Marnie Chesterton finds out why it’s a good thing that children push the boundaries of what’s safe during playtime, because it makes them less anxious adults. And she questions the existence of the so-called bystander effect, discovering how evolution has ensured we’re a much braver species than we sometimes give ourselves credit for. But she hears from some social scientists who say there’s no such thing as a ‘hero’, however likely they are to intervene to help others.The virtual reality experience in this programme was created by the Human-Computer Interaction Lab of the University of Udine, ItalyThis programme has been updated since its original publication to correct an editorial error.Presented by Marnie Chesterton Produced by Marijke Peters

This week the kids take over. Our younger listeners are as curious as their parents, it seems, so presenter Marnie Chesterton seeks out the finest minds and attempts to answer a raft of their science questions, including why can’t you tickle yourself? Why don’t our eyebrows grow as long as the hair on our heads? Not content with humankind, these whizz kids have been pondering deeply about other animals. Ava, 9, from the UK wants to know if any other animals kill for fun, like some humans do. Not limited by planet Earth, these little thinkers have been contemplating even weightier questions. Joshua, 13, from Kenya wonders if our Solar System rotates around anything. And Seattle-based Michael, 10, puzzles over what would happen if a black hole collided with a wormhole. These and other mysteries are uncovered by Marnie and her experts. Presenters: Marnie Chesterton & Arlo Byrne Producer: Dom Byrne[Photo: Children Tickling each other, Adorable laughter. Credit: Getty Images]

There are over 7000 living languages on earth today. These mutually unintelligible means of communication are closely associated with different groups' identities. But how does a new language start out? That’s what listener BK wants to know. BK lives on one of the islands of the Philippines, where he speaks three languages fluently and has noticed there is a different language on almost every island. Presenter Anand Jagatia finds language experts from around the world who tell him about the many different ways that languages can form. Professor Dan Everett explains that languages naturally change over centuries to the point they are mutually unintelligible, and Quentin Everett describes how his research has identified striking similarities between biological, and linguistic evolution. Sally Thomason, Professor of linguistics in the USA tells us about the more unusual ways that languages can form through contact, or purposeful distancing measures, and Anand speaks with a producer of the BBC’s Pidgin service, about how the contact language nigerian pidgin may be developing into an official language West Africa. Finally, the inventor of a constructed language from the movie Avatar, tells CrowdScience what he has learned about language by creating the fully functional Na’vi language from scratch, and what Na’vi’s adoption by speakers around the world can tell us about the importance of language for creating community. Hearing from different languages from around the world through the programme, CrowdScience get to grips with the many ways new languages can form. Presented by Anand Jagatia, Produced by Rory Galloway (Photo: Chalk board of languages, Credit: Getty Images)

Despite being a universal need, talking about our toilet use and the infrastructure that aids us remains somewhat taboo. Whilst sectors like telecommunications and computing have undergone rapid transformations over the past century, the flush toilet and wastewater system have mostly remained unchanged. CrowdScience listeners Linda and Allison wonder if flush toilets – and the clean water used to wash waste away - make economic or environmental sense. So CrowdScience presenter Marnie Chesterton looks under the toilet lid, to probe (in a sanitary fashion) whether our sewerage systems and plumbed toilets are fit for purpose. In a future where population growth and climate change are likely to affect water demands, can we continue to use clean water to dispose of our waste and should the developing world be emulating this model?Around 2 billion people don’t have access to proper toilets or latrines, risking serious health consequences. Marnie investigates how countries without comprehensive sewerage infrastructure deal with human waste and how science is providing novel ways to dispose of - and use – human waste. Marnie speaks to a Kenyan scientist using poo-eating fly larvae to process faeces and a North American scientist who is developing a smart-toilet she hopes will monitor our health through sampling our daily movements. Are we ready to break taboos to innovate our toilet habits?Presenter: Marnie Chesterton Producer: Melanie Brown(Image: Man looking at toilet. Credit: Getty Images)

What is the smallest particle of matter? How does radiation affect our bodies? And, how is particle physics useful in our everyday lives?CrowdScience takes on particle physics questions from listeners all over the world. Marnie Chesterton and Anand Jagatia get help from particle physicists from the Large Hadron Collider at CERN and medical physicist Heather Williams. Presented by Marnie Chesterton and Anand Jagatia Produced by Cathy Edwards, Jen Whyntie and Louisa Field (Photo: Particle collider, Credit: Getty IMages)

What’s the importance of zero, and how was it discovered? How do scientists calculate Pi’s infinite digits? Why do so many people find maths difficult – and what’s the most difficult thing in maths?CrowdScience takes on a whole bunch of questions sent in by high school students in Spain. Like many children all over the world, their school is currently closed due to the coronavirus lockdown, but lessons continue at home. So how are their studies going, and can CrowdScience help out?We attempt to answer some of their trickiest maths questions, with the help of mathematicians Katie Steckles and Matt Parker, and mathematical biologist Kit Yates.Presenter: Marnie Chesterton. Producer: Cathy Edwards (Photo: A boy studying. Credit: Getty Images)

If you're an exercise fan, you'll know that sweating is how our bodies keep us cool, but how much water we lose and which bits of us get wettest depend on a whole host of factors. Jamaican listener Andre wants to know why he sweats in a heart-shape when he hits the gym, and we find out how everything from the clothes he wears to the moves he's doing explain his unusual perspiration patterns. In Kenya we meet a woman whose permanently clammy hands cause her to drop her mobile phone, and sweaty feet start to stink when she spends too long in shoes. Hyperhidrosis is a condition affecting millions of people worldwide but an expert explains some of the treatments for this mysterious condition. Presenter: Marnie Chesterton Producer: Marijke PetersImage Credit: Getty Images

If you have ever watched a spider as it works to build a web, spiralling inwards with a thread of silk, that intersects each glistening spoke with a precise touch of the foot, you will know that it is a remarkably complex behaviour. In this episode, presenter Geoff Marsh dives into the minds of spider-constructors as they build their webs. CrowdScience listener Daan asked us to find out how spiders can build webs without ever being taught how to do it. Are they just little robots controlled entirely by their genetic instructions? Spider silk expert Dr Beth Mortimer, describes the process of building a web in detail, while Professor Iain Couzin explains the simple modular behaviours that build up, in sequence, to create apparently complex instincts, like the huge locust swarms that are sweeping across vast areas of Africa and Arabia. Taking us deep under the exoskeletons of invertebrates, Professor Gene Robinson reveals an animal's behaviours can be altered by their genes, and the root similarity between learning and instincts. Spiders, despite their tiny size, have fascinating behaviours. Some jumping spiders can work out the best way out of a maze, and one arachnologist reveals how some social spiders can cooperate to build communal webs and capture moths that are many times their size. Geoff searches for the science that can reveal how instinct can create complex behaviour by setting up interviews at the homes of spider experts from around the world. Presented by Geoff Marsh. Produced by Rory Galloway for BBC World Service.Image: European garden spider, Araneus diadematus hanging in the web. Photo by: Michael Siluk / Universal Images Group via Getty Images

Listener Keith from Lincolnshire wants to know how to reduce stress as he is under extreme pressure as a firefighter. Not only does he have to cope with the stress of responding to emergency situations but he has to do it while wearing challenging breathing equipment.We all experience times of stress, especially given the current situation, our chest starts to feel tight and our breathing becomes shallow. Claudia Hammond – presenter of BBC World Service programme Health Check – explains steps we can take to protect our mental health during this pandemic.How should we alter our breathing to manage stress? Presenter Anand Jagatia speaks to breathing experts to find techniques to help listener Keith, and everyone else.Presented by Anand Jagatia. Produced by Caroline Steel for BBC World Service.

In medicine, it’s long been recognised that a placebo, a sham medicine or treatment, can have a powerful positive effect on a patient’s health. Part of that effect relies on a person’s belief that an inactive substance or treatment (for example, a sugar pill) is in fact an active drug. Placebos come in many forms, and the scientific study of placebo is an active area of research. With this in mind, CrowdScience listener Nigel got in touch to ask if can placebos be used to improve sports performance. As an amateur sports enthusiast, he’s been reading up on his sports psychology to try and improve his game, but he wonders if any coaches or psychologists use placebos to improve performance? Always ready to take up a challenge, presenter Anand Jagatia explores the world of endurance sport to find out how a placebo might used to improve athletes’ performances, as well as his own, and look at how advances in brain science are helping us understand the unusual neurobiology of placebo. And what of the amateur golfer, or rugby or table tennis player - can a placebo help? On an individual level, so called ‘verbal placebo’ is a technique that can help players with anxiety, confidence and concentration, and ultimately make them win more. And what about team sports? When, say, a new manager takes over at an ailing football club, and sparks a massive reversal in poor results, is that a placebo effect in action? The CrowdScience team investigates.Produced by Dom Byrne, presented by Anand Jagatia.

If you've ever felt the urge to shop till you drop, then you may already know about some of the clever ways retailers convince us to consume. From flash sales to so-called unbelievable offers, there are a whole range of techniques aimed at encouraging us to flash the cash. Listener Mo works in marketing, so knows more than most about the tricks of the trade - but he wants CrowdScience to investigate how neuroscience is being used to measure our behaviour and predict what we’ll buy. Marnie Chesterton finds out how brain scans are being used to discover which specific aspect of an advertisement a person is responding to, and then she hears how this information is being used by companies who want to sell us more stuff. But there's also evidence to suggest we have less control over these decisions than we think, and that computers are getting closer to detecting our intention before we're even aware of it ourselves. And this could have huge implications for the way we shop.Presented by: Marnie Chesterton Produced by: Marijke Peters(Photo:

Many of us are fascinated by our ancestry: knowing where our families came from can give us a sense of identity and roots. Tracing your family tree is a time-honoured tradition, but several companies now sell DNA tests that offer you insights into your heritage: so you might find out you’re 70% Nigerian, 39% Italian, or 11% South Asian, for example.There’s no doubt that genes contain clues about your family history, but how reliable are these commercial tests? That’s what CrowdScience listener Karen wondered after an update of her test results showed her going from 39% Scandinavian to 2% Norwegian. How confident can she be in her results now? And what does it actually mean to be 2% Norwegian, in terms of your family tree?Presenter Alex Lathbridge delves into his own African and European ancestry, talks to some of the companies offering these tests, and unpicks the complex relationship between genetic science and family trees. We meet a woman who found her long-lost uncle with a combination of a DNA test and old-fashioned archive research; and look to the Americas to ask whether genetic testing can restore ancestral ties erased by the inhumanity of the transatlantic slave trade. Presented by Alex Lathbridge Produced by Cathy Edwards for the BBC World Service(Photo: Elderly hands looking at old photos of self and family. Credit: Getty Images)

Since the outbreak of a new strain of coronavirus late last year, health workers and governments have been rushing to limit transmission by deploying containment tactics and anti-contamination campaigns. But, as the virus spreads around the world, what are scientists doing to help our bodies fight off or resist this new infectious disease? Viruses that cause human disease can be notoriously tricky to tackle. They don’t respond to antibiotics, can spread rapidly between human hosts, and even evolve improved ways of working as they multiply. Presenter Marnie Chesterton heads to the University of Oxford’s Nuffield Department of Medicine to meet the researchers who are urgently searching for solutions. Professor Tao Dong is Director of Chinese Academy of Medical Sciences Oxford Institute, collaborating with colleagues on the ground in China to see how Chinese patients’ immune systems are responding to the virus, which could inform vaccine design. Professor Sarah Gilbert leads the Jenner Institute’s influenza vaccine and emerging pathogens programme. She’s been developing a vaccine against another strain of coronavirus that caused the Middle East Respiratory Syndrome (MERS) outbreak, and is using the same technology to generate a new vaccine against the 2019 coronavirus. And, whilst that’s being developed, there is a possibility that some existing antiviral drugs may even help infected patients – Professor Peter Horby is working with colleagues in China on clinical trials to see what might work. CrowdScience goes into the laboratories using cutting edge science to combat coronavirus. Presented by Marnie Chesterton Produced by Jen Whyntie for the BBC World Service(Photo: Coronavirus Credit: Getty Images)

Jump on-board a doomed mission to the Moon. Apollo 13: the extraordinary story, told by the people who flew it and saved it. Search for 13 Minutes to the Moon wherever you get your podcasts. #13MinutestotheMoon

Why are we obsessed with crime? Kay from Hamburg, Germany asks as every Sunday evening Germans pile into their local pubs to watch Tatort, a hugely successful crime drama which has been running for 50 years. Presenter Marnie Chesterton starts with the science and speaks with psychologists to get to the bottom of where this obsession might come from. Have we evolved to have an innate obsession with danger or are we addicted to feeling fear?Or perhaps the dramatisation of crime fuels our obsession. Producer Caroline Steel visits the film set of BBC crime drama, Line of Duty. Producer Jed Mercurio explains what draws us to crime narratives and the techniques he uses to keep his audience captivated. But does the way we chose to represent crime in media match up with reality? And what is the impact of this on society and policy?(Photo: body outline. Credit: Getty Images)

Weather: wet, dry, cold, hot, sunny, windy or downright weird - there’s nothing quite like it as a conversation starter, from Austin to Jakarta. And judging from the large volume of emails about all things meteorological in the CrowdScience inbox, there’s plenty to talk about. What’s the weirdest weather on Earth, and how big a chance is there of it happening? Why does it always seem to rain on the days when we’re not working? And – conversely – is there any way we could make it rain when and where we need it to? Presenter Anand Jagatia finds out the answers to these questions and more by bringing together a panel of experts under the CrowdScience umbrella: Prof Liz Bentley, Royal Meteorological Society; Dr Anthony Rea, World Meteorological Organization, and Dr Rebecca Buccholz, National Centre for Atmospheric Research. Presented by Anand Jagatia. Produced by Jen Whyntie for the BBC World Service (Photo: Lenticular Cloud. Credit: Getty Images)

A lovely day out in the countryside can be blighted when swarms of midges or mosquitos invite themselves to the party. A CrowdScience listener in New Zealand has noticed that, when sand-flies come a-biting, she and her daughter are targeted, while her husband and other daughter escape unharmed. She wants to know why some, but not all of her family become bait for insect bites. CrowdScience delves into a world of smells, called semiochemistry, which explores the aromas one animal uses to attract or repel another. Does our attractiveness as a blood meal to insects come down to what we wear, what we’ve eaten or is it all in our genes? Host Marnie Chesterton discards the DEET and bravely offers herself up as a meal for mozzies, in a quest for answers.(Photo:Mosquito on skin. Credit: Getty Images)

Cancer is the second leading cause of death in the world. Many of us will at some point in our lives be confronted with the disease – either by falling ill ourselves or through a family member or friend. For CrowdScience presenter Marnie Chesterton, the diagnosis would change her life. The range of cancer symptoms and mortality rates vary considerably. Not all cancers are fatal and in some cases, cancer ends up more like a chronic debilitating disease, resulting in patients eventually dying from some other condition. This has got listener Gill in Scotland wondering – why do we call all cancers, cancer? And when did doctors first realise that all cancers are part of the same problem? First described by the Egyptians thousands of years ago and later coined by the Greek physician Hippocrates as “karninos”, the Greek word for “crab”, cancer is ominously absent from medical literature until the late 19th century. Throughout history it has puzzled, infuriated and enticed doctors and scientists to push medical science to its breaking point. Archaeologists have recently discovered that the ancient Egyptians had a term for cancer and that remedies they used then contain compounds that are found in modern chemotherapy. As we uncover the science and history of cancer, presenter Marnie Chesterton takes us on a journey through her own experience of living with and beyond the diagnosis and we examine the promise of future treatments. Presented by Marnie Chesterton. Produced by Louisa Field. [Photo: Cancer Cell. Credit: Getty Images]

Today, once-fatal diseases like the plague, sepsis, or cholera can be treated simply and quickly with a pill. These tiny tablets hold compounds that can fix illnesses, and most people don’t think twice about taking an asparin for a headache. Modern medicine looks nothing like the plants that many of them are derived from. But there must have been a moment, when the first humans decided that a particular plant, fungus, or mineral might cure them of an upset stomach, or infected wound. Right? That’s what listener Andrew Chen wondered, so he emailed CrowdScience to find answers.Presenter Anand Jagatia speaks with an archaeologist, a botanist, an ethno-pharmacologist, a zoologist and a historian to uncover the story of early human experimentation with ‘drugs’ from plants, fungi, animals and minerals. The history of humans is full of illness and poor health, and it seems we’ve always tried to fix this. Anand discovers the connection between food and medicine while making tonic water from scratch with Kim Walker at the Royal Botanic Gardens of Kew, and tastes the daisy-like Chinese herb that was first used thousands of years ago, and then – once tested - became one of the best modern drugs for treating the world’s most deadly infectious disease. Listener Andrew’s inspiration came from a previous episode of CrowdScience ‘Who were the first farmers?’ and so we return to expert anthropologist Cheryl Makerewicz who tells us about the ecological knowledge of hunter-gatherers and pastoralist communities. With Jaap de Roode, Anand discovers that conscious thought isn’t a pre-requisite of medical discovery, and historian Vivienne Lo explains how written word helped to standardise generations of medical knowledge in East Asia. Previously medical knowledge had been irrevocably linked with shamanism, magic and spirituality, but with modern medicine this changed – but today there is still much we can learn from ancient forms of knowledge, Christophe Wiart explains how his science focuses of discovering what plants tribal people in east Asia have used for centuries to cure their ailments. These early methods may help us combat new diseases today. Presented by Anand Jagatia Produced by Rory Galloway [Photo: Women using plant medicines. Credit: Getty Images]

CrowdScience heads to Freetown, Sierra Leone for a panel debate in front of a live audience to answer listener questions about how artificial intelligence is helping tackle some of the world’s most pressing issues. Anand Jagatia is joined by regional science experts to explore how robots, drones and big data are transforming sectors such as agriculture, health and governance. Could clever machines help eradicate invasive species? Will block chain IDs eventually replace physical documents? And while this technology is heralded as a force for change we’ll ask whether fears of an AI takeover are unfounded?Presented by Anand Jagatia and Produced by Marijke Peters and Mel Brown(Photo: The panel and Audience at Crowd Science live event in Sierra Leone. Credit: BBC)

Super-sized volcanic eruptions and giant asteroids crashing in from outer space are the stuff of disaster movies. They have listener Santosh from South Africa slightly concerned. He’d like to know what’s being done in real life to prepare for this kind of event. Although the chance of these events occurring is low, Santosh isn’t entirely wrong to be worried: Earth has a much longer history than humans do, and there’s evidence that several past extinction events millions of years ago wiped out the dominant species on the planet at the time, as we’ve heard before on CrowdScience. The kind of extraordinary geological and extra-terrestrial hazards thought to be responsible for the death of millions of lives do still exist. So is there really any way that humans could survive where the dinosaurs – and plenty of other species – have failed? Presenter Marnie Chesterton finds out by meeting experts who are already preparing for the remote but real possibility of the biggest disaster we could face. It turns out that in real life most things we can think of which could cause an extinction event are being watched closely by scientists and governmental agencies. How worried we should really be by the possibility of a sudden super-volcanic eruption at Yellowstone in the USA, or one of the other enormous volcanoes dotting our planet’s surface? Marnie heads into an underground bunker near the remote Scottish coast to find out if hiding out is a viable survival option. Now a museum, Scotland’s Secret Bunker, formerly RAF Troywood, is one of a network of nuclear shelters built by nation states during the Cold War. And she hears about one of the combined space agencies most ambitious projects yet: NASA and ESA’s Asteroid Impact and Deflection Assessment mission to crash an impactor into an asteroid’s moon to find out whether we could knock any potentially problematic collisions off-course well before Earth impact.Produced by Jennifer Whyntie for BBC World Service(Photo: Post apocalypse sole survivor. Credit: Getty Images)

Is there something bigger than infinity? Does quantum mechanics affect how I think? And why can I suddenly do algebra? As ever, we’re not afraid to tackle the big questions on CrowdScience. After a previous episode about the relationship between mathematics and reality, we received a flood of profound and difficult questions, so we dive back into the world of maths, physics and philosophy to try and answer them. A panel of experts help us puzzle out whether some infinities are bigger than others - and why that matters, as well as what quantum mechanics can teach us about the workings of the brain. And we seek answers for one of our listeners who surprised himself by being able to figure out mathematics equations he previously found unfathomable. With philosopher of physics Dr Eleanor Knox, mathematician Dr Katie Steckles, and Dr Aldo Faisal, an expert in neurotechnology.Presented by Marnie Chesterton Produced by Cathy Edwards for the BBC World ServicePhoto:

Reducing climate change and global warming is one of the biggest and most urgent challenges for everyone as we enter a new decade. The CrowdScience team have been trying to figure out how to play our part in reducing our carbon footprint. So what’s the best way forward? Presenter Marnie Chesterton starts to find out by pitting three of her colleagues against each other for the first phase of our challenge. Anand Jagatia, Geoff Marsh and Melanie Brown have all been tasked with answering a listener’s question in the lowest-carbon way possible. Along the way, they must monitor and account for every emission – from their travel methods to their choice of sustenance whilst working. It turns out that the challenge is not only in acknowledging all the types of activity that produce emissions, but in working out the volume of greenhouse gases produced. Marnie judges her colleagues’ efforts, determines a winner, and dispatches the losing challenger to look further into carbon calculation, and to find out about the possibilities of legitimately offsetting the overall footprint. And we start our on-going experiment using a broadcast industry carbon calculator to find out the most carbon-efficient and sustainable ways to keep answering everyone’s questions and sharing more cutting-edge global science. Presented by Marnie Chesterton Produced by Jen Whyntie for the BBC World Service(Photo:

Two years ago reporter Anand Jagatia travelled up beyond the Arctic Circle to meet Norwegian researchers in order to answer a question from US listener Kira on why some people function best in the mornings whilst others only come alive at night. In this episode we revisit the topic with the help of science writer and Parentland podcast presenter Linda Geddes, author of Chasing the Sun, a book which explores the science behind the sun’s effects on our bodies and our minds.The morning sun helps to kick-start our day and our body’s biological cycle – so what happens when it barely rises above the horizon or we live for prolonged periods in artificial environments where the sun never shines? Research has suggested that some communities in northern latitudes are better protected against the mental and physical effects of reduced exposure to sunlight in the winter which might have implications for those suffering the winter blues. Presenter Anand Jagatia, Producer: Rami Tzabar(Photo: Woman basking in the sun. Credit: Getty Images)

What is empathy? This week’s question comes from Maria in Amsterdam who has noticed that when one of her friends is in pain, she feels their pain too, literally. Maria wants to know - is she experiencing a type of ‘super’ empathy? To help find the answer, Marnie Chesterton visits the Netherlands Institute for Neuroscience and gets into an MRI scanner to discover what is happening in her brain when she empathises. She talks with a pro-social psychopath to find out how psychopaths experience empathy differently and how they navigate social situations.And Marnie meets with a mediator specialising in The Israeli–Palestinian conflict, to learn the value of empathy when the stakes are at their highest. (Photo: Back view of loving Mum hug teen daughter. Credit: Getty Images)

As CrowdScience celebrates its third birthday, the team takes time to revisit some of our early episodes, and catch up with listeners to discover if the answers we uncovered changed the course of their lives? We hear from Zach, who has learned to let go of a possibly lost memory and Erin, who discovered technology could hold the key to finding the man of her dreams. And two years after he emailed to ask why he couldn’t kick his habit, we ash Sharif whether he has finally managed to stop smoking? (Photo: Man listening to podcast. Credit: Getty Images)