Tortoises have traditionally been the poster child for slowness. These ancient, armoured reptiles are solitary, territorial and all-too-often dismissed as dull.In fact, tortoises have distinct personalities. They have changeable moods, can learn simple tasks, remember certain useful information for years and even recognise familiar people. But can they play?Hot on the trail of tortoise tomfoolery, Hannah and Dara explore the stereotype-smashing studies that show there's far more to these creatures than previously thought; and find out that these complex behaviours might apply not only to the turtle clan, but potentially other reptiles as well...To submit your question to the Curious Cases team, please email: [email protected]: - Anna Wilkinson, Professor of Animal Cognition at the University of Lincoln - Unnar Karl Aevarsson, Herpetologist at ZSL London Zoo - Gordon Burghardt, Distinguished Service Professor in the Departments of Psychology, Ecology and Evolutionary Biology at the University of Tennessee Producer: Lucy Taylor Executive Producer: Alexandra Feachem A BBC Studios Production

Could you survive an eternal winter? Or is endless summer sun a more appealing prospect? Lots of us are grateful for the seasonal changes that shape the world around us, but this week Hannah and Dara are asking what life would look like without the axial tilt that brings each hemisphere closer and further away from the sun as the seasons change each year. Listener Andrew from Melbourne wants to know what would happen if the planet stood perfectly upright, no lean, no tilt, no seasons. But what else could happen? Is Earth’s 23-degree slant the cosmic fluke that made life possible? To find out, Hannah and explore how losing the tilt reshapes climate, ecosystems, evolution and maybe even the fate of the dinosaurs.You can send your everyday mysteries for the team to investigate to: [email protected] Contributors Dr Robin Smith - Climate modelling researcher at the University of Reading Professor Rebecca Kilner - Evolutionary Biologist and Head of the Department of Zoology at Cambridge Professor Amaury Triaud - Professor of Exoplanetology at the University of Birmingham Aidan McGivern - Meteorologist and Senior weather presenter at the MET OfficeProducer: Emily Bird Executive Producer: Sasha Feachem A BBC Studios Production

Could immortality ever be possible for humans? It sounds like something from a sci-fi movie, but floating in oceans around the world is a tiny, transparent jellyfish that could hold the answer...Turritopsis dohrnii, known as 'the immortal jellyfish', isn’t immortal in the true sense of word - it can die - but it has a nifty way of avoiding that fate. In times of stress, this miniscule jelly can biologically reverse its aging process, reverting from 'medusa' (adult jellyfish) to a juvenile form and starting its life-cycle again; potentially ad infinitum.Abilities like these could hold the key to - if not exactly 'immortality', then at least regenerative or long-life treatments for humans in future. But of course there's a catch: these extremely delicate jellyfish can still easily die from predation, disease, or environmental threats and are extremely difficult to keep healthy in a lab environment. Hannah and Dara hear about new technology that could change the way we study immortal jellyfish, and discover various other super-abilities in the animal kingdom that could help in our quest for healthier, longer lives.Contributors: - Miranda Lowe, Principal Curator of Crustacea and Cnidaria at London’s Natural History Museum - Alex Cagan, Assistant Professor in the Department of Genetics, Department of Pathology and Department of Vet Medicine at the University of Cambridge - Maria Pia Miglietta, Associate Professor of Marine Biology at Texas A&M University in Galveston - Nicole Xu, Assistant Professor of Mechanical Engineering, Robotics and Biomedical Engineering at the University of Colorado, BoulderProducer: Lucy Taylor Executive Producer: Sasha Feachem A BBC Studios Production

Space: the final frontier, a deep dark realm full of questions and mysteries - many of which science can't yet satisfactorily answer. But that won't stop the Curious Cases team!In a special edition recorded in front of an audience at the BBC Radio Theatre in London, Hannah Fry and Dara Ó Briain team up with a panel of guests who know their way around the universe: presenters from the world's longest running science TV show, The Sky At Night.With the intergalactic expertise of George Dransfield, Chris Lintott and Maggie Aderin-Pocock, Hannah and Dara tackle a slew of space-related questions put forward by the listeners - exploring topics ranging from the sound of stars and the shape of the universe, to the search for alien life. To submit your question to the Curious Cases team, please email: [email protected] AUDIO CLIPS:- Maggie's Choice: In 2005, the European Space Agency's Huygens probe descended to the surface of Saturn's moon Titan. Microphones aboard Huygens recorded the sounds of descent and landing, then The Planetary Society and scientists at the University of California helped ESA process the audio. CREDIT: European Space Agency (Huygens probe) / HASI-PWA Team (instrument and data) / The Planetary Society (processing)- George's Choice: The black hole at the centre of the Perseus galaxy cluster has been associated with sound for years, since astronomers discovered that pressure waves sent out by the black hole caused ripples in the cluster's hot gas that could be translated into a note. This new sonification was released for NASA's Black Hole Week in 2022. CREDIT: NASA- Chris's Choice: In 2023, the Planck space telescope picked up echoes left by soundwaves that travelled through the early Universe. This primordial hum was then translated into frequencies we can hear. CREDIT: NASAProducer: Lucy Taylor Executive Producer: Alexandra Feachem A BBC Studios Production

Whether you’re stuck in traffic, waiting at the airport whilst delay after delay is announced or just really missing someone far away, a lot of us have probably wished we could teleport. But is this superpower the stuff of science fiction? Or could it, one day, become a reality?Listener Faith wants to know whether Star Trek’s Transporter could ever deconstruct and reconstruct humans in the real world, and it turns out quantum physics holds some tantalising potential for this seemingly impossible task. To search for answers Hannah and Dara dive down the quantum rabbit hole, exploring entanglement, superposition, and trying on some very special socks. Contributors Ivette Fuentes - Professor of Quantum Physics at University of Southampton Winfried Hensinger - Professor of Quantum Technologies at the University of Sussex Helen Beebee - Professor of the Philosophy of Science at the University of Leeds Producer: Emily Bird Executive Producer: Sasha Feachem A BBC Studios Production

Cold and flu season is well and truly upon us, and whilst most of us are busy bemoaning the pesky viruses behind our sniffles and chesty coughs – one of our listeners has other ideas. Elizabeth wants to know whether we’re too hard on these oft-maligned microbes? We’ve all heard that some bacteria can be good for us, but what about viruses? Could they have a softer side too? Hannah and Dara explore the virome, from prehistoric placental proteins to ultra-precise disease fighting phages to find out if Viruses truly are the villains of the microscopic world or whether they just need a better PR team. Contributors Jonathan Ball - Professor of Molecular Virology at the Liverpool School of Tropical Medicine. Martha Clokie - Professor of Microbiology at the University of Leicester. Marylin Roosinck - Professor Emeritus of Microbiology at Penn State University US. Producer: Emily Bird Executive Producer: Sasha Feachem A BBC Studios Production

It has been said that you can't start a fire without a spark, but as Hannah and Dara are about to discover, that's not true!Welcome to the fiery phenomenon of spontaneous combustion, when something can ignite all on its own: no matches, no sparks, no external flame. It happens when certain materials heat themselves up internally through chemical or biological reactions, and if that carried on unchecked and the material gets hot enough, it can eventually ignite itself.This process can occur in various everyday items such as piles of hay or grass clippings, oily rags and in certain instances lithium batteries; but there are also several useful chemical substances that autoignite when they come into contact with air - as Hannah, Dara and a wary BBC fire officer witness in the studio...So how can we stop things regularly bursting into flames? How scared should we be about oiling floorboards and our increasingly battery-powered life? And is spontaneous human combustion really a thing? Our investigators are on the case. To submit your question to the Curious Cases team, please email: [email protected]: - Andrea Sella, Professor of inorganic chemistry at University College London - Emanuel ‘Big Manny’ Wallace, former science teacher now a science content creator - Matt Oakley, fire investigations officer at Surrey Fire and Rescue Service - Roger Byard, Emeritus Professor of pathology at the University of Adelaide and a senior specialist forensic pathologist at Forensic Science SA (FSSA)Producer: Lucy Taylor Executive Producer: Alexandra FeachemA BBC Studios Production

Are you a lucky person? Do the cards just fall well for you? Whether it's always finding a parking spot when you need one or chance encounters that change your life's trajectory for the better, some people seem to have more luck than others. Hannah and Dara explore the world of probability and psychology to figure out if some people are luckier than others, and if there's anything we can do to turn things around. You can send your everyday mysteries for the team to investigate to: [email protected] David Spiegelhalter - Emeritus Professor of Statistics in the Centre for Mathematical Sciences at the University of Cambridge Richard Wiseman - Professor of the Public Understanding of Psychology University of Hertfordshire Maia Young - Professor of Organization and Management at UC Irvine, California US Edward Oldfield Producer: Emily Bird Executive Producer: Sasha Feachem A BBC Studios Production

It turns out that the whole world wobbles. Everything has a natural frequency - the rate at which it moves when disturbed - be it a cup of tea, a building or a human organ.Even more incredibly, if an external force matches an object's natural frequency, it causes it to absorb that energy and vibrate with increasingly large waves; and that can have consequences, from helping a spider find its lunch to making a bridge collapse. On the trail of good and bad vibes and everything in between, Hannah and Dara investigate whether the famous 1940 collapse of the Tacoma Narrows Bridge in the USA was really down to resonance, explore examples of resonance in nature, and find out what this mysterious vibration can do to the human body: from the pressures of repetitive tractor-driving, to absorbing the reverberations of certain instruments...To submit your question to the Curious Cases team, please email: [email protected]: - Helen Czerski, Professor of Physics at University College London - Wanda Lewis, Emeritus Professor of Civil Engineering at Warwick University - Phillip Moxley, Senior Research Associate at the University of Southampton - Sana Bokhari, sound therapy practitionerProducers: Lucy Taylor & Emily Bird Executive Producer: Alexandra FeachemA BBC Studios Audio Production

We can all picture a crab, but did you know that nature has reinvented those claw clicking, sideways scuttling crustaceans at least five separate times? In recent years the internet has run wild with the idea that crabs are the ultimate life-form, and that even humans might one day end up with pincers too. But is there any truth behind the memes? Hannah and Dara scale the tangled tree of life and tackle taxonomy to figure out if ‘crab’ really is evolution’s favourite shape. Exploring coconut to spanner, ghost to hermit, soldier to spider they learn how to tell the ‘true’ crabs from the impostors.You can send your everyday mysteries for the team to investigate to: [email protected] Contributors Dr Joanna Wolfe – Evolutionary Biologist, Harvard University and UC Santa Barbara Professor Matthew Wills - Professor of Evolutionary Paleobiology, University of Bath Ned Suesat-Williams – Director of the Crab Museum, MargateProducer: Emily Bird Executive Producer: Sasha Feachem A BBC Studios Production