CrowdScience

In humans if you have two X chromosomes you are female and if you have an X and a Y then you are male. It is textbook science. But CrowdScience listener Du in Singapore has done some extra homework and found a piece of intriguing fish research which suggests a different outcome, at least for one species – tilapia, a popular fish on restaurant menus worldwide and as it happens, the first fish to visit space. Whilst humans couldn’t exist without an X-chromosome, tilapia apparently, can. In fact, they are happy with just two Y chromosomes. The existence of this odd breed comes down to the tilapia fish’s ability to change from male to female. Nature has come up with an array of bizarre solutions when it comes to sex determination and what sets you on one genetic path or another. And like with the tilapia fish, the decision isn't always for life. Some species of fish, lizards and even birds sidestep the chromosome system and morph between the sexes to survive a changing environment. How can they have both genetic sex pathways latent within them? And why can’t humans do the same trick?Presenter: Marnie ChestertonProducer: Louisa Field(Photo: A male Asian sheepshead wrasse courting a female featured in BBC’s Blue Planet II. Credit: Getty Images)

It’s the central question for the current generation of Mars missions. Since the first close-up pictures of the red planet back in 1965, decades of space missions have revealed our neighbouring planet to be cold, rocky and sterile. But there are hints of a more dramatic past; of raging volcanoes and flash floods. Could this be a planet where life existed? Could life still exist under the surface? And could humans live there, or even travel the distance to get there safely, at some point in the coming decades? CrowdScience listeners from Australia, Ghana and Canada have been musing on all sorts of Martian matters. Presenter Marnie Chesterton visits a corner of Stevenage, UK, with a distinctly unearthly appearance and takes a virtual tour of the Martian atmosphere. She also puts listeners’ questions to the scientists designing the spacecraft and instruments they hope will unlock the secrets of Mars. (Image: illustration of Mars shot from space. Credit: Getty Images)

The idea of creating underwater habitats has captured the imagination of writers, thinkers and scientists for decades. However, despite numerous grand visions, these dreams of aquatic metropolises have not yet come to fruition. Crowdscience listener and scuba enthusiast Jack wonders whether - given improved technology and the growing environmental pressures facing humans on land - it is time to reconsider the ocean as an alternative permanent living space for humans.Marnie Chesterton dons her flippers for Crowdscience in search of the oceanographers and architects who have dedicated their lives to designing vessels, labs and underwater habitats. She explores whether oceanic cities remain a sci-fi dream or a realistic solution to some of our modern challenges. Can the oceans’ largely unexplored resources be harnessed to support living underwater? (Photo: Illustration of a modern city under the sea. Credit: Getty Images)

What is light and can we trap it in a box? On this edition of CrowdScience, Marnie Chesterton brings you a kaleidoscope of colourful questions from listeners around the world, from Kampala to Chicago. Shireen asks why people have a favourite colour and whether other animals show colour preferences too. Marnie heads to the zoo to see what the birds, bees and butterflies think. There, she meets a colour-changing chameleon to find out how and why it does because of a question from Dramadri in Uganda. Meanwhile, Paul in Melbourne is interested to know more about colour blindness. And finally, Feroze asks why we only see a portion of the electromagnetic spectrum and wants to know if we might, one day, hack our vision to see beyond the seven colours of the rainbow.Presenter: Marnie Chesterton Producer: Graihagh Jackson(Photo: Stardust and magic in a woman hands on a dark background. Credit: Getty Images)

Hedgehogs are the UK’s favourite British mammal. They have cute furry faces, a snuffly nose and the ability to gobble up garden slugs. What’s not to like? Answer: quite a lot if you live in the Outer Hebrides. Hedgehogs were introduced to South Uist in the 1970s as garden pest controllers, but are now serious pests in their own right – munching their way through the eggs and chicks of globally important wading bird populations. This emblem of cuteness is really a killer. So what’s to be done? That’s the quandary facing this week’s CrowdScience thanks to a question from Juan Carlos in Cuba. He wants to know how different parts of the world are dealing with invasive species – one of the biggest threats to global biodiversity. Presenter Anand Jagatia heads to the Uists to hear how having an invader that’s loved by millions can cause a whole host of problems. He also discovers how various warring parties eventually came together to solve this very prickly problem. Also in the programme, Anand travels to South Africa to find out how researchers are coping with invasive trees by introducing another non-native species. While in the Caribbean, we hear how people are dealing with invasive fish by eating them. Presenter: Anand Jagatia Producer: Anna Lacey(Photo: A European hedgehog. Credit: Getty Images)

Teenagers are known for ignoring their parents’ advice, but is this reputation for rebellion well-founded? If so, is rejecting the advice of previous generations and treading our own path an important part of what it means to be human? Are we successful as a species precisely because of our questioning natures? Listener Hans started pondering these questions after his own adolescent children repeatedly ignored his nagging. Many animals simply follow in their parents’ footsteps – so what makes human children different? Marnie Chesterton and a panel of experts look at the science of taking advice and making decisions, finding out how human curiosity and exploration compare to other animals, learning the best ways to give and take advice, and seeing whether we’re more likely to trust artificial intelligence than the wisdom of our elders. Finally, we give listener Hans some expert advice on whether or not to keep nagging his kids.Presenter: Marnie Chesterton Producer: Cathy Edwards(Image: A father and son having communication issues. Credit: Getty Images)

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)

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)

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

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)

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)

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)

Hypnosis has a long and controversial history, with its roots in animal magnetism or mesmerism, the theory developed by 18th Century German doctor Franz Mesmer. He believed he had discovered an invisible natural force possessed by all living things, and that he could channel this force for healing purposes. Popularity of hypnosis has since waxed and waned, but was largely denounced as quackery until the 20th Century, when it began to be studied scientifically. However it is only in the last twenty years or so that is has become incorporated into mainstream science and medicine. But is it a real phenomenon, asks listener Gratian from Poland; and Anton from Ireland wants to know how it works and what happens to people’s brains and bodies under hypnosis?CrowdScience speaks to Dr Quinton Deeley, consultant psychiatrist and senior lecturer at the Institute of Psychiatry, who has used it in practice for many years, and Dr Amir Raz, a magician-turned-neuroscientist who is shedding light on how hypnosis works. To see how hypnosis is being used clinically, CrowdScience visits the Berkeley Clinic in Glasgow, Scotland, to witness a hypnotised patient having a tooth extracted with very little anaesthesia.Meanwhile, presenter and self-confessed arachnophobe Nastaran Tavakoli-Far takes part in the Friendly Spider programme at London Zoo, an afternoon event that uses hypnotherapy and group therapy to ease or eliminate the fear of spiders. Presenter: Nastaran Tavakoli-Far Producer: Helena Selby(Image: A silver pocket watch swinging on a chain on a black background to hypnotize. Credit: Getty Images)

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)

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 Chesterton Producer: Marijke Peters(Image: Clock on an empty plate. Credit: Getty Images)

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)

Kenyan listener Docktor can’t help himself. When music is playing he must move to the beat and he wants to know why. What role does dance play in human evolution? And what does dance mean to us? To help answer the many twists and turns in Docktor’s questions, the CrowdScience team heads to one of the most vibrant and diverse dance scenes in the World, Havana in Cuba. For Cubans dancing is at the heart of their cultural identity. They tell stories, bond with others, practice religion and celebrate their African ancestry through dance ¬– which came to Cuba with the slave trade. For all humans, dancing is intimately connected to our love of music and is likely to be one of our oldest cultural practices. But why would our ancestors have wasted energy on what superficially seems to serve no survival benefits? Evolutionary anthropologist Bronwyn Tarr tells us that one clue lies in the brain. When we dance with others our brains reward us with a cocktail of feel-good hormones and this likely leads to profound social effects. Presenter Anand Jagatia gets challenged on the dance floor, discovers how deeply rooted dance is in Cuban society and why we should dance more.Presenter: Anand Jagatia Producer: Louisa Field(Image: Dancers in Cuba)

Humans have the potential to eat pretty much anything – but the reality is we don’t. Wherever we live in the world, we eat just a small fraction of the foodstuffs available and show strong preferences for certain foods over others. Those preferences can change dramatically from person to person, or as the saying goes – one man’s meat is another man’s poison. Then at the extreme end of the spectrum you get so-called ‘fussy eaters’ who reject so many foods that they are confined to beige diets of crisps, crackers and cereal. So why do we show such different preferences for food? And why are some people fussier than others? That’s what CrowdScience listeners Orante Andrijauskaite in Germany and Anna Nicolaou in Belgium would like to know, and what Datshiane Navanayagam is off to find out. She discovers how both biology and culture shape whether a food is disgusting or delicious and learns why we should stop giving children a hard time about finishing their dinner. She also learns how global cuisines evolved and what that can teach us about helping fussy eaters to overcome their food fears.Presenter: Datshiane Navanayagam Producer: Anna Lacey(Photo: Fried Bugs in Bangkok night market. Credit: Getty Images)

Carbon dioxide levels are far higher than at any other point in human history, thanks to our reliance on burning fossil fuels. But having pumped huge amounts of CO2 into the air, are there ways to get it back out again? If so, where would we put it all? And the big question: can that help solve our climate change problem, or is it a distraction from the urgent task of reducing our emissions?When CrowdScience delved into ancient carbon dioxide levels last year, it sparked a flurry of emails from our listeners asking these questions and more, so this week we investigate our options for restoring equilibrium to our atmosphere. Since the CO2 came from deep underground - in the form of coal, oil and gas - can we put it back there? We travel to Iceland where they’re capturing carbon dioxide directly from the air - and turning it into rock. Presenter: Marnie Chesterton Producer: Cathy Edwards(Photo: Nesjavellir geothermal power plant in Iceland. Credit: Getty Images)

Short-sightedness is reaching epidemic proportions around the world. The way things are progressing, one-third of the world’s population – 2.5 billion people - could need glasses by the end of the decade. And scientists are beginning to understand why: children spend too much time indoors, bent over screens and books. Marnie Chesterton travels to Singapore, where rates of myopia are one of the highest in the world and to see how the government is curbing the condition with an array of tools, from eye-drops to sunshine remedies. She does so in the hope of better understanding whether screens are bad for children’s eyes, a question raised by a concerned Mexican father, Fernando, about his two-year old daughter.Presenter: Marnie Chesterton Producer: Graihagh Jackson(Photo: A little girl wearing headphones while using a digital tablet at home. Credit: Getty Images)

Will gravity on earth ever change? Why do insects fly towards the light? Is the plasma in a TV the same as plasma in a fusion reactor? Why are mosquito bites so itchy? What does the Higgs boson do for the Universe? In a Q+A special, Marnie Chesterton is joined by scientists Malcolm Fairbairn, Kate Lancaster and Erica McAlister to tackle a selection of questions from the CrowdScience inbox. Presenter: Marnie Chesterton Producer: Alex Mansfield(Photo: Alates insects light bulb and night. Credit: Getty Images)

Dementia affects nearly 50 million people worldwide – but doctors are still struggling to find a cure. CrowdScience investigates why this particular group of brain diseases are so hard to treat, from the difficulties around diagnosis to why the drugs just don’t currently work.In the absence of a medical solution is it time to take a new approach? As geneticists develop tests to predict who might develop brain disease, there are others focusing on better care for those who already have it. Presenter Bobbie Lakhera visits a village in the Netherlands helping sufferers live longer independently, and hears how music projects improve non-verbal communication.Presenter: Bobbie Lakhera Producer: Marijke Peters(Photo: Neurology research examining the neurons of a human head to heal memory loss or cells due to dementia. Credit: Getty Images)

Since the end of the 19th century, scientists have been predicting we would be eating a meal in a pill, but is it a serious answer to the world’s food problems? That’s what Australian listener Bridget is wondering and whether it’s possible to produce an artificial food source that can provide all the nutrients for healthy human life.With increasing urbanisation, diets are changing and estimates suggest food production will have to increase some 60 percent by 2050 to keep up with demand. But can we provide all that extra food with limited natural resources and traditional farming methods?First, Marnie Chesterton finds out what artificial food is currently available and whether the existing products are healthy. And while a meal in a pill might sustain our bodies, will it sustain our minds? The experience of eating involves so much more than simply taking in the right nutrients, as Marnie discovers at the Gastrophysics Chef’s Table, a restaurant and multi-sensory dining experience. On the menu is jellyfish, a possible alternative source of food for the future. It’s in plentiful supply in our oceans, but like eating insects, the thought of it may be disgusting to some, so Marnie explores how sensory-driven strategies can be used to make these food sources more appealing.CrowdScience also visits the future of farming: A hydroponic vertical farm called Growing Underground, which is built in World War Two air-raid shelters under London. Using LED lighting instead of sunlight, leafy vegetables grow very quickly and need very little space. With higher crop yields per square metre than traditional farming, vertical farms allow fresh produce to be grown in urban centres with less impact on the environment. Hydroponic farming is something the European Space Agency is also experimenting with as part of Project Melissa, which is developing a closed loop ecological system - using rats instead of astronauts - aimed at one day helping us grow fruit and vegetables on Mars. Listen to the podcast version of the programme to hear this interview.Producer: Helena Selby(Photo: Pills on a plate. Credit: Getty Images)

Listener Nikolai sends CrowdScience hunting through space and time with his deceptively simple question. Can we find perfect stillness? You are probably reading this sentence whilst standing or sitting still. So is it a daft question? We discover that there are no simple answers as we unravel the science of motion, which tells us that we cannot always trust our senses to tell us ‘the truth’ about the natural world. The ancient Greeks believed it was the sun that rises and sets each day and this idea remained until the 16th century astronomer Nicolaus Copernicus showed us that this an illusion – that we are the ones in motion, orbiting the Sun. Later, through the work of Isaac Newton and then Albert Einstein, scientists came to the conclusion that nothing in the universe can ever be truly still. Except perhaps, the fastest thing in the universe – light. Confused? Don’t worry, so is Marnie Chesterton who sets out to explore not just the science of stillness but also the physics of stopping. To satisfy listener Nikolai’s curiosity about motion in space, CrowdScience also travels to ESA’s European Space Research and Technology Centre in the Netherlands. Here we find out how you stop a space craft and hear the story of when things got prickly for astronaut Tim Peake and his crew when docking at the International Space Station. Presenter: Marnie Chesterton Producer: Louisa Field(Photo: Astronaut wearing pressure suit against a space background. Credit: Getty Images)

Are you the master of your own decisions? Independent-minded? A free spirit? Like it or not, the answer is probably no - as we are profoundly influenced by the people around us. But why do humans follow the crowd? CrowdScience listener Cath Danes wants to know and this week we are going to be giving her answers at the BBC’s Free Thinking Festival in Gateshead. Marnie Chesterton is joined by a crack team of neuroscientists and psychologists, who reveal the secrets behind our inner sheep. We also run an experiment to find out whether you should trust the wisdom of the crowds with life’s big decisions.Presenter: Marnie Chesterton Producer: Anna Lacey(Photo: A flock of sheep being herded in a pasture. Credit: Getty Images)

Unlike nuclear fission power stations, which leave harmful radioactive waste to be stored or disposed of for thousands of years, a nuclear fusion power plant would create precious little burden on future generations. The fuel source would be seawater, and the energy created limitless. Back in the 1950s, the technology to “tame the hydrogen bomb” seemed just a few decades away from practical deployment, and governments across the divide of the cold war shared the challenges, costs and laboratories.But to the outsider, it might look like progress has been slow. In 1997 the Joint European Torus at Culham in the UK set the world record for energy released from a controlled fusion reaction, but even that was less than the energy was put in. Keeping the plasma – the super-hot atoms of exotic types of hydrogen – at temperatures many times the temperature of the sun safely in place inside a magnetic field is not a trivial task. Last year construction of the International Experimental Thermonuclear Reactor, ITER, reached its halfway point at its huge home in France, and if all goes to plan it should produce its first plasma by 2025. The hope is that operational fusion reactions will take place within a decade after that, paving the way for its successor DEMO - which would actually generate electricity - to be built sometime before 2050.But in parallel with the big intergovernmental roadmap, in recent years a number of small commercial startups have joined the race to achieve commercial fusion energy. With their various different approaches and more ambitious timelines, will the private sector beat the publicly funded science to the goal?Presenter: Bobbie Lakhera Producer: Alex Mansfield(Photo of ITER Organization, with permission)

Humans have used dogs' excellent sniffing talents ever since our ancestors figured out that canine companions could help them track down their next meal.But what about other animals? Can they take us beyond the limits of our own senses? That's what CrowdScience listener Beth wants to know, so we obligingly try to sniff out some answers.After immersing ourselves in the world of insect senses at our local zoo, we visit an insect lab in Germany to find out whether sniffer bees could take over from sniffer dogs. And could ants help us fly the drones of the future? We meet the scientists trying to turn ant vision into computer code, to send robots into places GPS can't reach.Presenter: Nastaran Tavakoli-Far Producer: Cathy Edwards(Photo: A bee on a human finger. Credit: Getty Images)

A cacophony of singing and screaming creatures’ accents are explored to answer: Can animals of the same species from different places communicate with each other? Presenter Geoff Marsh tries to identify how different these calls really sound for CrowdScience. From wolves to birds to whales and chimpanzees, most animals use sound to communicate, but if groups in different places vocalise in different ways, they may not be able to communicate with others.CrowdScience questioner, Kitty, sets us on an exploration of the vast and varied world of animal communication with inspiration from her dog Monty. Presenter: Geoff Marsh Producer: Rory Galloway(Photo: Three wolves howling on a cold day. Credit: Getty Images)

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 Chesterton Producer: 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

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 Chesterton Producer: Graihagh Jackson(Photo: Finding dark matter could have galactic implications. Credit: Getty Images)

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 Mansfield Presenter Marnie Chesterton(Photo: Saturn viewed from Titan moon. Credit: Getty Images)

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

Meet the entrepreneurs turning bugs into food and get top tips on how to cook them. In this week’s episode we return to the topic of edible insects and the story of Kahitouo Hein’s caterpillar factory in Burkina Faso, West Africa. Kahitouo is trying to turn a traditional food like the shea caterpillar, available for just a few weeks a year, into a year-long sustainable staple for the whole population. We also put your questions about edible insects directly to the researchers in Burkino Faso. Discover the best way to cook a bug, explore the curious effects of hornet venom and find out whether eating insects is better for the environment then eating red meat.Do you have a question we can turn into a programme? Email us at [email protected]: Anand Jagatia Producer: Louisa Field(Photo: Worker at Kahit’s factory cooking caterpillars)

Most of us instinctively know when someone’s singing and when they’re talking. But since music and speech are both just sounds, how do our brains tell them apart? This week’s question comes from Eugene, a music teacher in Northern Ireland, who often hears music in people’s speech, and wonders why.Step forward, the ‘speech-to-song illusion’. This curious phenomenon means that when certain spoken phrases are repeated, they turn into music as if by magic. We talk to the Diana Deutsch, the scientist who discovered this illusion, and find out what it reveals about how the brain is adapted to understand both music and speech.But are some languages more musical than others? Many people around the world speak tone languages, where the pitch of a word affects its meaning. One such language is Dinka, spoken in South Sudan; we meet a Dinka speaker and hear how respecting the melody of the language is essential when writing songs.Presenter: Datshiane Navanayagam Producer: Cathy EdwardsDinka recordings courtesy of Elizabeth Achol and Anyang Malual(Photo:Young woman listening to music on yellow headphones. Credit Getty Images)

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)

Crowdscience revisits the evidence on the best forms of biometric identification. Earlier in the year we explored digital fingerprints, gait (walking style) recognition and iris scanners. Today presenter Anand Jagatia looks at systems which use your face and your voice to identify you. One airline is currently testing facial recognition in airports as a means of replacing your passport. Meanwhile, Anand tries to fool a speech recognition system that measures over a thousand characteristics of your voice in order to protect your identity. But will it be able to cope if you have a cold?Presented by Anand Jagatia Produced by Marijke Peters.Picture: Facial Recognition Credit: Getty Images

Reindeer castration, plants get chatty and more quirky science revealed in this Christmas special of CrowdScience where we will also be hearing from the people that make this series possible. That’s you – our listeners. CrowdScience has been on air for just over a year which means we’ve had over 60 adventures. Every time we put a show together there’s a heart-breaking process where amazing facts we wanted to share end up on the cutting-room floor. To celebrate the holidays we’ve gone scavenging for the best untold stories, edgy science facts and incidents from behind the scene. Presenter: Marnie Chesterton Producer: Louisa FieldPicture: Reindeer in Snow Credit: Getty Images

It lurks behind sofas and collects in corners, apparently appearing from nowhere. But what is household dust? And should we bother sweeping it away? That’s what Australian listener Moshe wants to know and what Marnie Chesterton is off to find out for this week’s CrowdScience. She embarks on a mission to discover not only what dust is made of, but whether it poses any health risks. Although most people sweep it away without a thought, dust contains all sorts of secrets about our habits and everyday lives. Marnie finds out how dust can reveal the pets you keep, the chemicals in your surroundings, the location of your house and how fecal bacteria can uncover whether more men or women live in your home.Presenter: Marnie Chesterton Producer: Anna Lacey(Image: Woman Vacuuming Up Dust. Credit: Getty Images)

Trees are old – they transcend human generations – but are they the oldest living things on Earth? This story began in June 2017 when we explored a question sent in from CrowdScience listener William. Many of you got in touch after the programme with questions of your own. So we’re revisiting our trees programme but also exploring another question from listener James, who wants to know what, pound for pound or gram for gram, is the strongest animal alive on Earth today? Marnie Chesterton wrestles with one of them and – spoiler alert – it’s not a gorilla. Presenter: Marnie Chesterton Producers: Jen Whyntie(Photo: Kumbuka, a 15-year-old western lowland gorilla. Credit: Oli Scarff/Getty Images)

Dodos are dead, but are they gone forever? Reviving extinct species is a trope of science fiction, but real-life scientists are working on every stage of the problem today. Meeting scientists focused on uncovering ancient animal genomes, or reviving individual cells to conserve species still around, Marnie Chesterton seeks out whether new technologies might, just possibly, bring back the iconic dodo. But what would it take to bring back that most iconic of extinct species? Following listener Rachel’s question, CrowdScience gets to grips with the dodo’s past, and finds out what’s left of this iconic bird, meeting the scientists inadvertently piecing it back together.Presenter: Marnie Chesterton Producer: Rory Galloway Picture: An accurate reconstruction of nesting Dodos Photo Credit: Dr Julian Hume

How does technology affect how we fall in love? Crowdscience travels to India to answer listener Erin’s questions about the impact of the internet on our search for soulmates. We meet the traditional matchmaker who says her service provides security in an era of digital fraud. And ask whether computer algorithms are the best way to help people make permanent romantic connections?Presenter: Chhavi Sachdev Producer: Marijke Peters(Photo: A couple kiss while taking a selfie. Credit: Getty Images)

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 [email protected]: Anand Jagatia Producer: Cathy Edwards(Image: L - Women smiling on a run R - Women DJ. Credit: Getty Images)

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 [email protected]: Marnie Chesterton Producer: Louisa Field(Image: Woman scratching head, thinking brain melting into lines. Credit: Getty Images)

People often talk about being descended from apes. But go back a bit further and we have a more unlikely ancestor – fish. Improbable as it may sound, the creature that gave rise to every bird, reptile and mammal on Earth today lived a fully aquatic life. So how did it switch to life on land? And how hard was it to swap swimming for walking and breathing fresh air? That’s what CrowdScience listener Pierre in France wants to know, and what Marnie Chesterton is in Scotland to find out. She goes fossil hunting with members of the TW:eed Project team, as they try to uncover remains of creatures that are crucial in helping solve the puzzle of terrestrial life. She also discovers the landscape these early ancestors walked into – an alien and relatively empty world completely different to what we see today - where grass and flowers were yet to evolve. But not everything in this story is preserved in rock. Marnie goes to see a living relic of this period of evolution, and finds out what it can tell us about possibly the most important event in the history of our species.Do you have a question we can turn into a programme? Email us at [email protected]: Marnie Chesterton Producer: Anna Lacey(Image: Artists impression of underwater environment of Carboniferous swamp depicting a rhizodont; a large predatory fish. Credit: Mark Witton)

Unpleasant man-made noise is something that disturbs many of us and even damages our health. But as millions more people move into crowded cities around the world, it's a cacophony that we almost unavoidably create ourselves. CrowdScience listener Diana from New York City in the USA got in touch to ask how we can temper the din and live a more peaceful life. Presenter Anand Jagatia heads to an acoustics lab at the University of Salford in Manchester, UK, to meet the researchers and engineers investigating the best ways to make cities more pleasant for our ears whilst still maintaining the ‘buzz’ of city life. And reporter Chhavi Sachdev takes us to Mumbai in India, where we discover how sound mapping is being deployed on the city’s streets as the first step to improve the life and health of its citizens.Do you have a question we can turn into a programme? Email us at [email protected]: Anand Jagatia Producer: Jen Whyntie(Image: Children cover their ears as the truck convoy front passes. Credit: Getty Images)

Is there any scientific proof of an afterlife? Six months ago, CrowdScience tackled a question from a listener who wanted to know whether there was life after death. But following more listener emails, presenter Marnie Chesterton returns to the subject to investigate the world of ghosts, souls and parapsychology. She meets Professor Susan Blackmore, who studies out-of-body experiences and has spent decades hunting for scientific proof of life after death. And she visits the woman who, despite dying in the 1950s, is alive and thriving on a cellular level and helping scientists find cures for cancer, Parkinson’s and other diseases, in laboratories across the world…Do you have a question we can turn into a programme? Email us at [email protected] and Presented by Marnie Chesterton

We test the science behind parasitic therapy to answer listener Michael’s question about whether intestinal worms can help us stay healthy, and visit a deworming programme in a rural Ugandan village.Do you have a question we can turn into a programme? Email us at [email protected]: Marnie Chesterton Producer: Marijke Peters(Picture: Tapeworm in human intestine, Credit: selvanegra/Getty Images)

Carbon dioxide levels in our atmosphere today are higher than at any point in human existence. But going back further into Earth’s history, when do we find concentrations as high as they are now - and what was the planet like back then?CrowdScience sets out to answer our listener Thomas’s question, travelling back through time with the help of Antarctic ice cores, ancient plant fossils, and microscopic popcorn-shaped organisms called foraminifera, all of which hold clues to past climates.Enlisting the help of chemists, botanists and palaeontologists, we find out about the huge swings in atmospheric carbon dioxide from prehistoric times to the present day, and ask the all-important question: can this help us understand what's happening to our climate now?Do you have a question we can turn into a programme? Email us at [email protected]: Marnie Chesterton Producer: Cathy Edwards(Image: Polar bear on an ice floe. Credit: Getty Images)

Human Organs are in short supply. But what if you could grow new ones in the lab? And if you donate your body parts to help others, where might they end up? That's what Sarah Gray wanted to know after making the difficult decision to donate the body of her son, Thomas, to medical science after he died from an incurable disease shortly after being born. Sarah then contacted the scientists whose research has been made possible by Thomas’ donation and discovered just how he is contributing to research which, may one day mean that organ donation is no longer necessary. Presenter Bobbie Lakhera talks to Sarah about her decision and meets some of the scientists working to create biological artificial lab-grown organs, tissues and even bones. Do you have a question we can turn into a programme? Email us at [email protected]: Bobbie Lakhera Producer: Louisa Field(Image: A doctor taking or delivering a bag containing a human organ for transplant. Credit: Getty Images)

Is it fair to kill invasive species which humans have introduced? When people move around the world, many of their favourite – and not so favourite - animals tag along for the ride. From cane toads through to rats, cats and crayfish, so-called ‘invasive species’ can destroy ecosystems and kill off native wildlife. CrowdScience listener Jude Kirkham wants to know if eradicating these invaders is justified.One country determined to do something about invasive species is New Zealand, where rats, stoats and possums are causing irreparable damage to the country’s unique bird life. If nothing is done, the iconic Kiwi could be extinct within 50 years. The government and volunteer groups across the country have responded with a plan to eradicate predatory mammals from New Zealand by 2050. But is all the time, energy and money needed to do this really justified? And is it morally right to kill off an animal species that humans introduced in the first place?Do you have a question we can turn into a programme? Email us at [email protected]: Marnie Chesterton Producer: Anna Lacey(Image: Headshot of a Possum Credit: Getty Images)