CrowdScience

Smartwatches are increasingly popular and many of us use these wearable devices to monitor our performance and improve our fitness. But how reliable is the data they collect, and can they actually make us healthier? CrowdScience listener Caitlin from Malawi is a big fan of her smartwatch. Her husband Fayaz, however, is much more sceptical of its accuracy, and has asked us to investigate. We meet up with them both at the gym, where Caitlin and presenter Caroline Steel put their fitness trackers – and themselves – to the test. We visit public health researchers Dr Cailbhe Doherty and Rory Lambe, who investigate the accuracy of wearable consumer devices, at University College Dublin. Caroline again pushes herself to the limit to see how her smartwatch results measure up to those from gold standard laboratory equipment. But is it crucial for smartwatches to be accurate? If they get us off the couch, is that what makes the difference to our health? Health behaviour expert Dr Ty Ferguson from the University of South Australia has studied this very question. And finally, how does quantifying our every move affect the way we think about ourselves and how we live? Professor Deborah Lupton from UNSW Sydney, shares some insights. Presenter: Caroline Steel Producers: Jo Glanville and Sophie Ormiston Editor: Cathy Edwards Technical producer: Sarah Hockley Production co-ordinator: Ishmael Soriano

While watching a feisty cockatoo chase after a hawk, CrowdScience listener Alison saw the hawk catch a thermal and rise effortlessly into the sky. The cockatoo gave chase, but the hawk climbed higher and higher until it became just a tiny speck, barely visible to the naked eye. And that got Alison thinking: just how high can birds go? Are there altitude limits for our feathered friends? Could a cockatoo, a sparrow, or even a duck reach such dizzying heights if they really put their wings to it? Presenter Alex Lathbridge sets out to investigate. Biologist Catherine Ivy reveals that life above the clouds isn’t easy. At high altitudes, the air is thinner, oxygen is scarce, and wings don’t generate as much lift. But some bird species have evolved incredible adaptations to overcome these challenges. Among them: bar-headed geese, renowned for their daring flights over the world’s tallest mountains. Physiologist Lucy Hawkes delves into how these geese defy the odds with their remarkable physiology, revealing the surprising discoveries she made while putting some of them on a treadmill. From super-powered hearts to clever lungs, we uncover the secrets behind nature’s impressive aviators. Presenter: Alex Lathbridge Producers: Ilan Goodman and Jeremy Grange Editor: Cathy Edwards Production co-ordinator: Ishmael Soriano Technical producer: Sarah Hockley

Carbon footprints are a measure of how much we each contribute to the greenhouse gases that warm the Earth’s atmosphere. The global average of carbon dioxide emissions is nearly 5 tonnes per person per year, although it can be triple that in certain countries. But one CrowdScience listener in Ghana is wondering about the bigger picture. After all, humans aren’t the only species on this planet. So which other animal has the biggest carbon footprint? CrowdScience presenters Caroline Steel and Marnie Chesterton are on the case, examining and arguing over the animal that deserves the top spot for this title. Caroline, a vegan, points to the cow as the top contender, since the livestock sector produces 14.5% of total greenhouse gas emissions, and cows, whether as meat or dairy animals, are responsible for the majority of that. The team look at initiatives around the world to be more efficient with each animal out there. But maybe it’s time to put another sector in the spotlight? Pets. We love our dogs and cats but do their meat-based diets win them a place on the podium? From most loved to most detested, we look at the role that key pests play in upsetting the carbon budget. Could a small beetle with a large appetite for greenery be an unusual winner, thanks to the trees these pests destroy over their lifetimes? Is the biggest offender a carbon footprint, hoofprint, pawprint, or clawprint? Presenters: Caroline Steel and Marnie Chesterton Producer: Marnie Chesterton Editor: Cathy Edwards Production co-ordinator: Ishmael Soriano Technical producers: Sarah Hockley and Donald MacDonald

In the past stout beer has been touted for its supposed health benefits. Is there any truth to those claims - and what happens if you take the alcohol out?CrowdScience listener Aengus pondered these questions down at the pub, after noticing most of his friends were drinking non-alcoholic beers. He wondered how the non-alcoholic stuff is made – what’s taken out and what’s added in – and whether the final product is better for you than the alcoholic version.It’s a question that takes us to Belgium, home to the experimental brewery of a global drinks company which takes the growing market for alcohol-free beer very seriously. David De Schutter, head of research and development, shows host Marnie Chesterton how to take alcohol out of beer without spoiling the flavour.We also find our way to a yeast lab in Leuven, Belgium where Kevin Verstrepen and his team have found another way to make alcohol-free beer with the help of industrious microbes: yeast varieties that brew beer without producing any alcohol in the first place. And how do they compare to the alcoholic versions? We discuss the importance of aromas in our perception of beer’s taste.So should listener Aengus stick to non-alcoholic stout? We speak to scientist Tim Stockwell about the health drawbacks of alcohol, even in moderation. And gut microbiome researcher Cláudia Marques fills us in on her delicious pilot study, which looked at the effects of both non-alcoholic and alcoholic beers on our digestive tract. Along the way, Marnie taste-tests what's on the market, and asks the experts why this particular grocery shelf has become so much bigger and more flavourful in recent years.Presenter: Marnie Chesterton Producer: Sam Baker Editor: Cathy Edwards Production co-ordinator: Ishmael Soriano Technical producers: Giles Aspen, Andrew Garratt and Donald MacDonald(Image: Close-up of waitress holding craft beer at bar, Brazil Credit: FG Trade via Getty Images)

When listener Diana fell on a run on her birthday, her first instinct was not to check her bruised hand, but instead to get up as quickly as possible and act as if nothing had happened. She felt embarrassed. Meanwhile, her son Marley loves to watch fail videos that, mostly, show people falling over. So why does falling – something that can cause serious injury – elicit both embarrassment and laughter? In the name of CrowdScience, presenter Caroline Steel trips, stumbles and falls. She spends a morning with clown Sean Kempton who teaches her slapstick skills, including how to do it safely. Psychologist Rowland Miller explains why falling can be embarrassing and shares his theory of why humans have developed this emotion in the first place. Then it’s time for Caroline to try out Diana’s predicament herself. If a BBC presenter falls in a park, will she feel embarrassed? From embarrassment to laughter, psychologist Janet Gibson lists the ingredients of a funny fall, and humour expert Caleb Warren explains how they can get funnier with distance. Then Caroline tries, semi-successfully, to make members of the public laugh. Will clown Sean do a better job? Presenter: Caroline Steel Producer: Florian Bohr Editor: Cathy Edwards Production coordinators: Ishmael Soriano Sound engineers: Bob Nettles, Tim Heffer and Giles Aspen

Did you know that flies fly in rectangles, fish hide by lighting themselves up and the moon is lifting the ground underneath your feet? Anand Jagatia quizzes members of the CrowdScience team on the moments from the past year that had them scratching their heads in amazement. We hear Dr Erica McAlister’s attempts to calculate how many flies have ever existed, and about flies’ mating choreography, courtesy of Prof Jochen Zeil. We learn how to tell a mosquito’s sex thanks to Eggrey Aisha Kambewa and Dr Steve Gowelo. Astronomer Dr Darren Baskill describes tides not of water but of land; Dr Edie Widder paints a vivid picture of a camouflaged creature of the deep; and we explore starfishes’ five-fold symmetry with Dr Imran Rahman. Khimlal Gautam, Mountaineer and Chief Survey Officer for the Government of Nepal, tells us of the near-death experience he had when checking the height of Mount Everest. And finally, axolotl expert Dr Elly Tanaka is astonished at the dedication of CrowdScience presenter Alex Lathbridge to the subject of her research. Presenter: Anand Jagatia Producer: Ben Motley Editor: Cathy Edwards Production Co-ordinator: Ishmael Soriano Studio Managers: Donald MacDonald and Giles Aspen(Photo: Lost in formulas Credit: Cimmerian via Getty Images)

The Moon has always sparked human curiosity. It governs the tides and biological rhythms. It’s inspired myths and stories. It’s inspired us to reach out and explore it. And it's certainly inspired CrowdScience listeners, who have sent us a host of questions about it. And in a special lunar-themed episode we’ve brought together a panel of astronomers and planetary scientists to help answer them. What would life be like if there was no Moon? Would there even be life? Or what if we had two moons? Are the Moon and Earth equally battered by meteors? What would happen if an asteroid collided with the Moon? And could the Moon ever escape Earth’s gravity? Anand Jagatia is joined by Prof Sara Russell, Head of the Planetary Materials Group at the Natural History Museum in London; Prof Neil Comins from the University of Maine, author of the book What if the Moon didn’t Exist?; and Prof Katarina Miljkovic from Curtin University in Perth, Australia. Presenter: Anand Jagatia Producer: Jeremy Grange Editor: Cathy Edwards Production Co-ordinator: Ishmael Soriano Studio Manager: Andrew Garratt(Photo: Landscape with the rising of the full moon during the golden hour Credit: Jose A. Bernat Bacete via Getty Images)

It seems bizarre to seek out experiences that are uncomfortable or downright painful. Yet examples abound: it’s common to eat painfully hot chillies, drink bitter coffee, or ‘feel the burn' when exercising - and enjoy it. CrowdScience listener Sandy is baffled by this seemingly counterintuitive phenomenon, and has asked us to investigate. Presenter Anand Jagatia turns guinea pig as he tests a variety of unpleasant sensations, and unpicks the reasons we’re sometimes attracted to them. He meets chilli-eating champion Shahina Waseem, who puts Anand’s own attraction to spicy food to the test. Food scientist John Hayes explains how our taste receptors work and why our genes affect the appeal of bitter food. Neuroscientist Soo Ahn Lee describes her research looking at what happens in participants’ brains when they eat chocolate and capsaicin, the chemical that makes chillies hot. As for the ‘pleasurable pain’ we sometimes experience when exercising, sports doctor Robin Chatterjee reveals the secrets of the ‘runner’s high’, while neuroscientist Siri Leknes explains why the feeling that something’s good for us can make discomfort pleasurable. Presenter: Anand Jagatia Producer: Jo Glanville Editor: Cathy Edwards Production co-ordinator: Ishmael Soriano Sound engineer: Sue Maillot(Image: Young man have bath in ice covered lake in nature and looking up, Czech Republic Credit: CharlieChesvick via Getty Images)

For their fans, jigsaw puzzles are a satisfying challenge, a focus, a chance to put everything else aside for a moment and be creative. But for other people they’re a frustrating jumble of random shapes and colours, a pointless task which is best left in the box. CrowdScience listener Heather is definitely a fan. She loves doing jigsaw puzzles and she wants to know why some people are so good at them. What skills do you need to find a pattern amongst all those shapes and colours? How do our brains, eyes and hands assemble the fragments into the finished article? And why do we enjoy doing them anyway? Presenter Alex Lathbridge puts together the pieces to answer Heather’s question. He sits down to work on a jigsaw with Sarah Mills, the ten-times UK jigsaw puzzling champion (yes... competitive jigsaw puzzling really is a thing!) As he watches Sarah complete the puzzle at lightning speed he gets a few of her top tips. So what’s going on in our brains when we’re doing a jigsaw puzzle? How do we recognise and process colour and shape? Prof Mark Mattson from Johns Hopkins University in the USA has the answer. And it’s all to do with a little seahorse-shaped part of the brain called the hippocampus. Alex also explores the effect of jigsaws on our brains with neuropsychologist Dr Patrick Fissler. He’s carried out research to investigate the benefits of jigsaw puzzles on our brains as we grow older. Both listener Heather and ten-times-champion Sarah seem to be better at jigsaws than Alex is. So, based on that sample size of three, women are superior puzzlers compared to men! But has anybody actually cast the net wider to see if that’s really the case? Alex talks to Daniela Aguilar from the University of Lethbridge in Canada about her study to investigate exactly that – and she reveals the results. Heather’s also wondering if any other species enjoy puzzles. And it seems they do! Alex meets Dr Cody McCoy from the University of Chicago to find out about the optimistic, tool-using crows of New Caledonia. From crows to competitive puzzlers, it seems we all relish a challenge!Presenter: Alex Lathbridge Producer: Jeremy Grange Editor: Cathy Edwards Studio Manager: Bob Nettles Production Co-ordinator: Ishmael Soriano

Do you find your bearings quickly or are you easily disorientated? Do your friends trust you with the directions in a new city? Finding our way in the physical world, whether that is around a building or a city, is an important everyday capability, one that has been integral to human survival. This week CrowdScience listener David wants to know whether some people are ‘naturally’ better at navigating, so presenter Marnie Chesterton sets her compass and journeys into the human brain. Accompanied by psychologists and neuroscientists Marnie learns how humans perceive their environment, recall routes and orientate themselves in unfamiliar spaces. We ask are some navigational strategies better than others? Professor Hugo Spiers from UCL shares his latest lab for researching navigation and tells us that the country you live in might be a good predictor of your navigation skills. But is our navigational ability down to biology or experience, and can we improve it? With much of our modern map use being delegated to smartphones, Marnie explores, with Prof Veronique Bohbot what an over-reliance on GPS technology might do to our brain health. Presenter: Marnie Chesterton Producer: Melanie Brown(Photo: Man standing on rural road holding up a road map, head obscured by map. Credit: Noel Hendrickson/Getty Images)

As we enter our teenage years, many of us feel like life is just getting started. But for dogs, celebrating a ‘teen’ birthday is a sign of old age, entering a phase when things start slowing down. Listener Susan was besotted with her beloved corgi Copper John and wants to know why our furry companions rarely live as long as us. We investigate what accounts for the huge differences in lifespans across animal species. From fish that live a few weeks, to sharks who can survive for 500 years, what are the factors that affect the ticking on our biological clocks? Central to this field is the idea of ‘live fast, die young’, with some animals burning more quickly through their ‘life fuel’. But is this rate set in stone?Presenter Anand Jagatia find out how animals’ growth, reproduction and anti-ageing methods contribute to the length of their survival. Dr Kevin Healy, a macroecologist at the University of Galway, discusses some of these theories, explaining how the dangers and luxuries faced by animals during their evolution shape their speed of life. One example of extreme slow living is the Greenland Shark. John Fleng Steffensen, Professor of Marine Biology at the University of Copenhagen, describes how he helped figure out how old they really are, and how their cold living quarters increase their lifespan. Alessandro Cellerino, physiologist at the Scuola Normale Superiore in Pisa, finds the key to the sharks’ longevity in their DNA.Anand also goes on a hunt on the west coast of Ireland for a creature that lives fast but surprisingly, dies old. Noel Fahy, research student at the University of Galway, is his guide, while Dr Nicole Foley, Associate Research Scientist at Texas A&M University, reveals the life-extending secrets of this creature.And geneticist Trey Ideker, Professor at the University of California San Diego, busts the myth that one dog year is seven human years. But how much is this misconception off by?Presenter: Anand Jagatia Producer: Julia Ravey Content Editor: Cathy Edwards Studio Manager: Sarah Hockley Production Coordinator: Ishmael Soriano(Photo: Copper John the Welsh Pembrokeshire Corgi, by listener Susan)

Maybe you have a deep, booming voice. Or perhaps it’s light and mellifluous. Some people’s voices are honey-smooth while others are as rough as gravel. But why does your voice sound the way it does? CrowdScience listener Hannah in Berlin is training as a teacher and will be using her voice a lot in the classroom in future. She wants to understand more about it: how can she improve the quality of her voice and protect it? And what factors - physical, genetic and environmental - determine the sound of your voice in the first place? Together with presenter Marnie Chesterton, Hannah pays a visit to speech tutor Prof Viola Schmidt at the Ernst Busch University for the Performing Arts in Berlin. Viola and actor Aurelius give us a masterclass in just what your voice can do, as they throw words and sounds to each other across the rehearsal room at a dizzying pace. And Viola gives Hannah a few top tips on using her voice clearly and authentically in the classroom. Hannah’s isn’t the only voice-related question in this episode. Peter from the Kingdom of Eswatini thinks people there speak more loudly than in other countries, and wonders why. To answer Peter’s question we turn to Prof Caleb Everett from the University of Miami. The jury’s out on whether people in some countries really do turn up the volume, but Caleb shares evidence of a link between the climate of a particular region and the sound of its native language. And finally, listener Jonathan has an unusual question for Marnie. When listening to CrowdScience, he can’t tell whether he’s hearing Marnie or fellow presenter Caroline Steel. This got him wondering whether it’s common for two people to sound very similar. Marnie gives Caroline a call, and together they set out to discover if your voice really is unique to you. Caroline tracks down a forensic speech scientist - Dr Jess Wormald from the University of York in the UK – while Marnie speaks to Dr Melanie Weirich from the Friedrich Schiller University of Jena in Germany. And both experts agree that Jonathan may be onto something!Presenter: Marnie Chesterton with Caroline Steel Producer: Jeremy Grange Editor: Cathy Edwards Production co-ordinator: Ishmael Soriano Studio Manager: Donald MacDonald

CrowdScience listeners David and Tatiana have long been captivated by an unusual dinner table discussion: the peculiar change they’ve noticed over the past 16 years in the sunlight streaming through their bedroom window in Ostend, Belgium. They’re convinced that the room has not only become sunnier but that the actual angle of sunlight has shifted.Intrigued by their observations, we head to Ostend. Our mission: to investigate three of their theories, enlisting expert help along the way.Theory 1 – A celestial anomaly? René Oudmaijer at the Royal Observatory of Belgium considers whether our shifting position in the solar system might explain the change.Theory 2 – Movement in the Earth’s crust? Alejandra Tovar from the Geological Survey of Belgium examines tectonic data to see if the Earth’s crust is moving enough to alter the angle of sunlight.Theory 3 – Subsidence? Structural engineer Kath Hannigan helps us inspect the building for signs that it may be sinking or twisting.And we explore one final theory of our own, enlisting memory expert Julia Shaw to examine whether it could all be a trick of the mind. Will the team crack the case?Presenter: Caroline Steel Producer: Harrison Lewis Editor: Cathy Edwards Production co-ordinator: Ishmael Soriano Studio Manager: Sarah Hockley(Photo: CrowdScience listeners David and Tatiana standing in front of a window in their house)

Fungi are a mysterious and understudied life form. And to add to the intrigue, some of them actually glow in the dark. This phenomenon has sparked CrowdScience listener Derek's curiosity, and he's asked us to investigate.Presenter Caroline Steel gets on the case. This is just one example of the natural wonder that is bioluminescence – living organisms that glow. How do they produce their light, and is there any reason for it? Caroline visits a bioluminescent bay in Puerto Rico, and Dr Brenda Soler-Figueroa explains what makes it sparkle.But it turns out there are many different explanations for why living things glow. Fungi, which listener Derek is particularly interested in, are neither plants nor animals, but an entirely different kingdom of life that we know much less about. Professor Katie Field takes on the task of trying to grow us some bioluminescent mushrooms, while Prof Cassius Stevani explains how – and importantly, why – they glow.And finally – could we ever harness the power of bioluminescence to our advantage in the future?Presenter: Caroline Steel Producer: Hannah Fisher Editor: Cathy Edwards Production co-ordinator: Ishmael Soriano Studio Manager: Neva Missirian(Photo: Omphalotus nidiformis, or ghost fungus, Penrose, NSW, Australia Credit: Louise Docker Sydney Australia via Getty Images)

Can learning new languages make us forget our mother tongue? CrowdScience listener Nakombe in Cameroon is concerned that his first language, Balue, is slipping from his grasp. He has learned multiple languages through his life, but Balue is the language of his family and home. It’s central to his identity and sense of belonging. So why does it seem to be fading from him, and what can he do to get it back?We search for answers, investigating what happens in our brains when we struggle to recall languages, as well as the social and economic factors that lead to language loss. Presenter Anand Jagatia asks Michael Anderson from the University of Cambridge, an expert on memory and forgetting, whether forgotten languages disappear from our brain, or just become difficult to access. Linguist Monika Schmid from the University of York takes us through the phenomenon of first language attrition, and has words of reassurance and advice for Nakombe and others in his situation.And we meet Larry Kimura from the University of Hawai’i at Hilo, a pioneer of Hawaiian language revitalization, and Gabriela Pérez Báez, an expert in indigenous languages and language revitalization at the University of Oregon. They explain why languages around the world become threatened, and how to keep them alive.Presenter: Anand Jagatia Producer: Margaret Sessa Hawkins Editor: Cathy Edwards Production Co-ordinator: Ishmael Soriano Studio Managers: Sarah Hockley and Omera Ahamed(Photo: Diccionario, Argentina Credit: PonyWang via Getty Images)

While there is a myriad of deodorants, shower gels and perfumes helping us stay fresh and fragrant today, that hasn’t always been the case. How did humans stay clean in the past, or did they not care so much? And is there an evolutionary reason for human body odour in the first place? These are questions that CrowdScience listener Sarah has pondered on trips in her camper van, when she wants to keep clean, but washing isn’t always convenient. In search of answers, presenter Anand Jagatia delves into the sweaty details: where body odour comes from, why some people's armpits don't smell, and whether this heady stink serves any purpose. Could our natural odour really help to attract a partner, or is it just a smelly bacterial by-product? Anand explores the intriguing mystery of human pheromones, and hears how for hundreds of years, Europeans were terrified of washing. Contributors: Dr Madalyn Nguyen, Dermatologist Dr Kara Hoover, Biological Anthropologist, University of Alaska Fairbanks Katherine Ashenburg, author, The Dirt on Clean: An Unsanitized History Dr Tristram Wyatt, Department of Biology, University of Oxford Presenter: Anand Jagatia Producer: Sophie Eastaugh Production co-ordinator: Ishmael Soriano Editor: Cathy Edwards Sound engineer: Emma Harth(Photo: Girl sweating smelly armpit, Taiwan Credit: PonyWang via Getty Images)

2024 is the biggest election year in history. From Taiwan to India, the USA to Ghana, by the end of the year almost half of the world’s population will have had the chance to choose who governs them. But there are a huge number of possible voting systems – and listener James wants CrowdScience to find out which is the fairest. To do so, we create a fictional country called CrowdLand to try out different electoral systems. Presenter Caroline Steel consults mathematician David McCune and political scientists Eric Linhart and Simon Hix, and we hear from listeners around the world about how they vote in their respective countries. Can we find the perfect voting system for CrowdLand? Contributors: Prof David McCune, William Jewell College, USA Prof Eric Linhart, University of Technology Chemnitz, Germany Prof Simon Hix, European University Institute, Italy Actors: Charlotte Bloomsbury Ross Virgo Presenter: Caroline Steel Producer: Florian Bohr Editor: Cathy Edwards Production Co-ordinator: Ishmael Soriano Studio Manager: Donald MacDonald(Image: Hand of a person casting a vote into the ballot box during elections, Thailand Credit: boonchai wedmakawandvia Getty Images)

With huge heads on top of spindly stalks, how do sunflowers defy gravity to stay standing? That was a question sent to CrowdScience by listener Frank, whose curiosity was piqued by the towering sunflowers on his neighbour’s deck. They stay up not only when the weather is fine, but, even more impressively, during strong winds. Could this feat of strength, flexibility and balance inspire the construction of tall buildings? It's a question that takes presenter Anand Jagatia to a sunflower festival in England, to see how the sunflower’s long evolutionary lineage has honed its structure. And from tall flowers to tall buildings, we turn to structural engineers, asking how these concepts factor into the design of the world’s tallest skyscrapers. Can ideas drawn from sunflowers or other natural structures help buildings withstand wind, or even storm surges?Contributors: Stuart Beare, partner and grower at Tulley’s Farm Roland Ennos, Visiting Professor in Biological Studies, University of Hull Sigrid Adriaenssen, Professor of Civil and Environmental Engineering, Princeton University Koichi Takada, founder of Koichi Takada Architects Presenter: Anand Jagatia Producer: Tom Bonnett Editor: Cathy Edwards Production Co-ordinator: Ishmael Soriano Studio Manager: Bob Nettles(Image: Tall Sunflower blooming in a field, Melbourne, Victoria, Australia Credit: Naomi Rahim via Getty Images)

The Moon and Earth are drifting gradually further apart. Every year the gap between them increases by a few centimetres. We know that the Moon’s gravity has an important effect on Earth - from controlling the tides to affecting the planet’s rotation - but slowly, imperceptibly, over billions of years, that influence will diminish as the Moon moves away. For CrowdScience listener Tony in the UK that idea poses another question. What if we were to look back in time? What effects did the Moon have when it was closer to Earth? Would it counteract the planet’s gravity more so that, at the time of the dinosaurs, a Brontosaurus would weigh a little less that it would if it existed now? It’s an intriguing question. And, given that it involves both the Moon AND dinosaurs, it’s one that’s got presenter Anand Jagatia really excited! Anand begins his journey on Brighton beach on the South coast of the UK. He’s there to watch the full Moon rise - and get a few insights on Tony’s question - from astronomer Darren Baskill and astrophotographer (and cellist) Ivana Perenic. Anand talks to Darren about the influence of the Moon’s gravity on Earth today. As they stand on the beach, with the sea lapping at their feet, they can certainly see its effect on the ocean tides. But did you know that the Moon also causes tides on the land as well? Every time it’s overhead the ground you’re standing on is higher by a few centimetres. Professor Neil Comins, author of the book What If the Moon Didn’t Exist, explains why the tides are the reason the Moon is moving away from Earth – and it has been ever since it was first formed. And how was it formed anyhow? We turn back time with Prof. Sara Russell from the Natural History Museum in London to discover one of the most dramatic events in the early history of our solar system... when two worlds collided. And, of course, it helps to know what a dinosaur weighed in the first place. Anand turns to paleontologist Nicolas Campione, who’s been puzzling over the most accurate way to calculate the bulk of a Brontosaurus. Contributors: Dr. Darren Baskill, Astronomer, University of Sussex, UK Ivana Perenic, Astrophotographer Dr. Nicolas Campione, Paleontologist, University of New England, Australia Prof. Sara Russell, Cosmic Mineralogist, Natural History Museum, UK Prof. Neil Comins, Astronomer, University of Maine, USAPresenter: Anand Jagatia Producer: Jeremy Grange Editor: Cathy Edwards Production Co-ordinator: Ishmael Soriano Studio Manager: Jackie Margerum(Image: Tyrannosaurus Rex and Spinosaurus in front of the moon - stock photo Credit: MR1805via Getty Images)

18 is the age of majority, or maturity, in most countries around the world. Depending where you live, it might be when you can vote, buy alcohol, or get married. But what's so special about 18 that makes it the beginning of adulthood? CrowdScience listener Lynda didn't feel very mature back then. She recalls a difficult decision that made her wonder what science has to say about when we’re truly grown up. How developed are we, physically, mentally and emotionally, by the age of 18? And how much does this differ between people, or from culture to culture? Presenter Caroline Steel digs around for answers with the aid of neuroscientist Sarah-Jayne Blakemore, biological anthropologist Barry Bogin, and cultural anthropologist Bonnie Hewlett. And even some teenagers. Contributors: Barry Bogin, Emeritus Professor of Biological Anthropology, Loughborough University Sarah-Jayne Blakemore - Professor of Psychology and Cognitive Neuroscience at the University of Cambridge Professor Bonnie Hewlett - Associate Professor, Cultural Anthropology, WSU VancouverPresenter: Caroline Steel Producer: Richard Walker Editor: Cathy Edwards Production Co-Ordinator: Ishmael Soriano Studio Manager: Neva Missirian