Curious Cases

Why do we find the young of other species cute?

Finding baby humans adorable makes evolutionary sense, ensuring that we care for them properly. But what about babies of other species? Hannah and Dara go down a fluffy rabbithole of cuteness: pondering the science behind things that make us go 'ahhhh'; exploring the phenomenon of 'cute aggression'; and discovering there can be such a thing as cuteness overload.

We also discover what Dara would look like as an elf, and what happens when you make Hannah scientifically less cute. Brace yourselves...

If you have a scientific mystery for the team to investigate, contact them on curiouscases@bbc.co.uk.

Contributors: Anthony Little – Reader in Psychology at the University of Bath Daniel Mills – Emeritus Professor of Veterinary Behavioural Medicine at the University of Lincoln Chris Holliday – Senior Lecturer in Liberal Arts and Visual Cultures Education at King's College London

Producer: Lucy Taylor Executive Producer: Sasha Feachem A BBC Studios Production

We may think of tessellation as being about how to tile a flat plane but this week we reveal how repeating patterns actually occur all over the place, and can even help us solve some of nature's most complex problems.

The presenters start with the simple principal that for shapes to fill a space without leaving any gaps or overlapping, the angles in the corners have to add up to exactly 360° - which means squares, triangles and hexagons are all strong contenders. Then they try their hand at creating their own tiles, based on a technique referred to as the 'Escher' method.

If you have an everyday mystery for the team to investigate, contact them on curiouscases@bbc.co.uk.

Contributors:

Dr Katie Steckles Prof Mark Miodownik Dr Vince Gallo

Producer: Lucy Taylor Executive Producer: Sasha Feachem A BBC Studios Production

We often associate yawning with being tired or bored - but this week's episode explores whether it could be a clever way to cool down our brains?

Hannah and Dara discover humans aren't the only species that yawn. From cats to chimpanzees and even fish, plenty of other vertebrates engage in this ancient behaviour which scientists believe evolved hundreds of millions of years ago. And it doesn't always happen as a spontaneous reflex to feeling tired but can also be triggered by watching other people do it.

If you have an everyday mystery for the team to investigate, contact them on curiouscases@bbc.co.uk

Contributors:

Stephen Jackson - Professor of Cognitive Neuroscience, University of Nottingham Laura Kelley - Associate Professor in Behavioural Ecology at University of Exeter

Dr Andrew Gallup - Professor of Behavioral Biology at Johns Hopkins University

Producer: Lucy Taylor Executive Producer: Sasha Feachem A BBC Studios Production

What happens when you give water a really good shake? You might expect splashing, spilling and general aquatic chaos - but under exactly the right conditions, something much stranger can happen...

In this episode, Hannah Fry and Dara Ó Briain dive into the world of 'Faraday waves': amazing geometric patterns that, in certain circumstances, will appear on the surface of a vibrating liquid. They discover how the renowned physicist Michael Faraday accidentally discovered this remarkable phenomenon in the 19th Century; debate whether they could ever occur in a swimming pool; and find out what on earth alligators have to do with it.

Along the way, the pair encounter eerie ‘square’ seas and learn about new ways satellites are helping us to understand the ocean’s wildest waves!

If you have an everyday mystery for the team to investigate, contact them on curiouscases@bbc.co.uk.

Contributors: Cédric Beaume - Associate Professor in Applied Mathematics at the University of Leeds Lucy Bricheno - Group Head of Coastal Ocean at Liverpool’s National Oceanography Centre Glynn Holt - Former Professor of Mechanical Engineering at Boston University

Producer: Lucy Taylor Executive Producer: Sasha Feachem A BBC Studios Production

Ever wondered how close nature can get to making a human clone? And what happens if identical twin brothers marry identical twin sisters and have babies - how similar are they? Our listener Chris has been pondering this very issue, and his question takes Hannah and Dara down another scientific rabbit hole.

Our intrepid duo consider how one fertilised egg can somehow become two babies, why those babies aren’t quite genetic photocopies, and why even identical twins gradually become more different as they grow up. They also find out how studying twins is helping scientists learn lessons about how all of us age - and explore the classic, movie-perpetuated mystery of “twin telepathy”… could there maybe, possibly, be something to it?!

There’s also just time to address the tricky issue of cloning. From Dolly the sheep to regenerative medicine, cloning science has paved the way for some serious breakthroughs; but could we ever clone a human? And more to the point, should we?

Expect sheep, sci-fi, identical cousins, and a dash of disproven twin mythology, as Curious Cases makes its return!

If you have an everyday mystery for the team to investigate, contact them on curiouscases@bbc.co.uk.

Contributors: Xand van Tulleken - Doctor, broadcaster and Honorary Associate Professor of Infection and Population Health at University College London Kevin Sinclair - Professor of Developmental Biology and Head of Animal Sciences at the University of Nottingham Claire Steves - Principal Investigator at TwinsUK and Professor of Ageing and Health at King’s College London Chris van Tulleken - Doctor, broadcaster and Professor of Infection and Global Health at University College London

Producer: Lucy Taylor Executive Producer: Sasha Feachem A BBC Studios Production

Hannah Fry and Dara Ó Briain return for a new series, and a whole lot of new problems to solve!

One winter morning, listener Jane opened her curtains to find her car roof covered in breathtaking, fern-like frost so intricate it looked like a William Morris print. But how does something as ordinary as ice create patterns so beautifully complex?

Hannah and Dara explore this crunchy, slippery, delicately patterned branch of chemistry to uncover the rules and mysteries that govern the extra-ordinary world of ice. Why does ice come in so many shapes and sizes? And does all ice form at 0 degrees Celsius? Is every snowflake truly unique? We have questions a plenty for our eager chemists, who, as all good chemists do, have a few demonstrations up their sleeves to help explain.

And we explore nature’s hidden geometry to find why these frost ferns follow the same rules as lightning bolts, river deltas and even human lungs.

You can send your everyday mysteries for the team to investigate to: curiouscases@bbc.co.uk

Contributors Sarah Hart – Professor Emerita of Mathematics, Birkbeck University of London Christoph Salzmann – Professor of Physical and Materials Chemistry, UCL Dr Thomas Whale – Lecturer, Institute for Climate and Atmospheric Science, University of Leeds

Producer: Emily Bird Executive Producer: Sasha Feachem A BBC Studios Production

From pharaohs' tombs in Ancient Egypt and medieval currency, to priceless royal jewellery and Spandau Ballet songs - gold has been prized for millennia. But it's only really in the last century or so that we've started uncovering its usefulness in less decorative applications.

Today, gold is used in masses of electricals; it's also revolutionised part of the manufacturing sector by stopping a dangerous reliance on mercury as a catalyst; and it's vital to space missions. Although there are also some more frivolous modern uses for gold, as Hannah and Dara discover. (Gold-leaf in your cocktail, anyone?)

Challenged to find out whether all the world's mined gold would really fit in an Olympic swimming pool, our science-savvy duo discover that this antisocial element might just be the best darn thing on the periodic table...

Contributors: - Graham Hutchings, Regius Professor of Chemistry at the University of Cardiff - Frances Wall, Professor of Applied Mineralogy in the Camborne School of Mines at the University of Exeter - Tim Peake, Astronaut

Producer: Lucy Taylor Executive Producer: Sasha Feachem A BBC Studios Production

What exactly is 'phantom pain' and how does it work? Hannah and Dara investigate a medical phenomenon that's been known about for centuries but is often misunderstood; and involves masses of unanswered questions.

The condition 'phantom pain' is when someone gets a sensation of pain that feels like it's coming from a part of their body that's no longer there - so that could be an amputated limb, or perhaps something that has been removed, such as a tooth or an organ. It's thought to be caused by how the brain and body process pain and physical awareness, but there's still debate around what exactly is going on neurologically.

Researchers around the world are looking into the condition; in the meantime, people who experience phantom pain - like today's studio guest Lynn - often have to try out a range of treatments, to find out what combination works best for them. But as the team discover, pain is deeply subjective - and in this case, there is really no 'right answer'...

Contributors: - Tamar Makin, Professor of Cognitive Neuroscience at the MRC Cognition and Brain Sciences Unit at the University of Cambridge, where she leads the Plasticity Lab; - Lynn Williams, a qualified therapist and upper limb amputee who volunteered as a subject for one of Tamar’s research programmes; - Carlos Roldan, Associate Professor in the Department of Pain Medicine at the University of Texas MD Anderson Cancer Center; - Keren Fisher, a Consultant Clinical Psychologist who’s worked in the NHS for more than four decades; largely in pain management at the Royal National Orthopaedic Hospital.

Producers: Emily Bird & Lucy Taylor Executive Producer: Alexandra Feachem

A BBC Studios Audio Production

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: curiouscases@bbc.co.uk

Contributors: - 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: curiouscases@bbc.co.uk 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 Office

Producer: 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, Boulder

Producer: 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: curiouscases@bbc.co.uk

SPACE 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: NASA

Producer: 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: curiouscases@bbc.co.uk

Contributors: - 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 Feachem

A 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: curiouscases@bbc.co.uk

Contributors 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: curiouscases@bbc.co.uk

Contributors: - 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 practitioner

Producers: Lucy Taylor & Emily Bird Executive Producer: Alexandra Feachem

A 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: curiouscases@bbc.co.uk

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, Margate

Producer: Emily Bird Executive Producer: Sasha Feachem A BBC Studios Production

Hannah Fry and Dara Ó Briain return to Curious Cases HQ for a brand-new series. And curios, there’s a lot to unpack! Coming soon to BBC Sounds.

The term 'bird brain' might suggest our feathered friends are stupid, but Hannah and Dara learn it's completely untrue. They play hide and seek with a raven called Bran, and hear how his behaviour changes depending on his mood. Corvid expert Nicola Clayton explains these creatures are actually cleverer than the average 8-year-old, and can learn how to choose specific tools for different scenarios. And neurobiologist Andreas Nieder tells them that while crows evolved totally different brains from humans - 300,000 years apart - they might just be capable of the same type of intelligence.

Contributors:

Bran the raven Lloyd Buck, bird handler Professor Nicky Clayton, University of Cambridge Professor Andreas Nieder, University of Tubingen

Producer: Marijke Peters Executive Producer: Alexandra Feachem

A BBC Studios Audio Production

Could you ever trade memories with someone else? Fancy downloading the experience of landing on the moon, winning an Oscar or performing at Glastonbury? Listener Adam wants to know, and Hannah Fry and Dara Ó Briain are on the case.

With expert insights from Professor Chris French and Professor Amy Milton, they dive into the mind’s tendency to blur the lines between reality and imagination - often embellishing, distorting, or downright making stuff up.

Discover how memory conformity makes us “see” things like spoons being bent by paranormal forces, how scientists can implant artificial memories in mice, and hear Al Hopwood’s hilariously vivid tales of things that definitely never happened. Chris even spills the secrets of how to deliberately plant false memories in others (don’t try this at home!).

From rewiring trauma to curing phobias, the potential of memory manipulation is both exciting and unnervingly sci-fi. Prepare to question everything you think you remember.

Contributors:

Amy Milton - Professor of Behavioural Neuroscience at the University of Cambridge Chris French - Professor of Anomalistic Psychology at Goldsmiths University Al Hopwood - Artist, writer and curator

Producer: Ilan Goodman Executive Producer: Alexandra Feachem A BBC Studios Audio Production

Can you slow down time by hurtling through space at breakneck speed? Could listener Saskia’s friend - currently one year older - end up the same age as her if he went fast enough? It sounds bananas, but it’s all part of Einstein’s mind-warping theory of relativity.

With expert copilots Professor Sean Carroll and Dr. Katie Clough, Hannah Fry and Dara Ó Briain embark on a cosmic roller coaster through space and time. They uncover why GPS satellites - whizzing around Earth at 14,000 km/h - need to account for time bending, why penthouse dwellers age faster than those on the ground floor, and, most importantly, why clowns on trains might just hold the key to understanding modern physics.

Contributors:

Katy Clough - Research Fellow at Queen Mary University of London Sean Carroll - Professor of Natural Philosophy at Johns Hopkins University Peter Buist - Manager of the Galileo Reference Centre Richard Dyer - PhD student at the University of Cambridge

Producer: Ilan Goodman Executive Producer: Alexandra Feachem A BBC Studios Audio Production

How big can animals really get before they collapse under their own weight or run out of snacks? Could a 12-foot comedian survive their first punchline without snapping in half? Listener Andrew sends Hannah and Dara on a deep dive into the science of supersized species.

With evolutionary biologists Ben Garrod and Tori Herridge as their guides, they explore the quirky rules of scaling: why giant bones need air pockets, how pressure stockings aren’t just stylish but essential, and why massive creatures have to choose between inefficient chewing or letting dinner ferment in their cavernous stomachs.

Discover why scaling up a mouse would turn it into a blood-boiling disaster and learn the curious logic behind whether the meat bear should eat the two meat dogs, or vice versa (it’s a maths thing…you’ll have to listen). Oh, and here’s the weird constant: whether you’re a mouse or an elephant, everyone takes roughly the same time to pee!

Join Hannah and Dara for a colossal romp through the wild world of ancient giants and the gross super blobs of the (possible) future.

Contributors:

Tori Herridge - Senior Lecturer in evolutionary biology at the University of Sheffield Ben Garrod - Professor of Evolutionary Biology and Science Engagement at the University of East Anglia Martin Sander - Professor of Palaeontology at the University of Bonn

Producer: Ilan Goodman Executive Producer: Alexandra Feachem A BBC Studios Audio Production

Think of a shark and you'll probably conjure up images of Jaws, but it turns out their skin is also covered in tiny teeth. Hannah and Dara investigate the incredible properties of these so-called dermal denticles, to find out whether they could be replicated at a nanoscale to increase vehicle speeds. They learn that while sharks might look like they have beautifully sleek surfaces, up close their skin is covered in something extremely rough and textured, a property that helps them swim up to 12 percent faster. And it's already inspiring airlines to design ultra-thin films that can reduce drag and increase efficiency.

Contributors

Dr Jess Wade Professor Manish Tiwari

Producer: Marijke Peters Executive Producer: Sasha Feachem

A BBC Studios Audio Production

Why do we giggle, snort, and bust a gut laughing? Is it just humans being weird, does it serve some higher function or do other animals crack up too? And, okay, Dara is a comedian, but has he ever really made anyone laugh, like properly?

With help from Professor Greg Bryant and Professor Sophie Scott, they dive into the science of LOLs, exploring how laughter bonds us, eases stress, and even spices up flirting. They uncover the difference between genuine belly laughs and those polite chuckles that pepper everyday interactions.

Contributors:

Sophie Scott - Professor of Cognitive Neuroscience at UCL Greg Bryant - Professor of Communication at UCLA Betty La France - Professor or Communication, Northern Illinois University

Producer: Ilan Goodman Executive Producer: Alexandra Feachem A BBC Studios Audio Production

Ever wondered why some people are mosquito magnets and other people barely get bitten? Hannah and Dara grapple with the question of whether these insects are evil or genius, discovering how they’re experts at finding blood when they’re hungry, even using a specially designed syringe to suck it out. But when Professor Leslie Vosshall tells them some people are more than 100 times likely to be attacked than others, the pair start wondering which one of them is more attractive? So they put the science to the test, and reluctantly agree to send their stinky socks to Professor Sarah Reece. She reveals that one of them smells extra special to these annoying little animals, possibly because of their cheesy feet. But can you guess who?

Contributors: Professor Sarah Reece Professor Leslie Vosshall Professor John Pickett

Producer: Marijke Peters Executive Producer: Alexandra Feachem A BBC Studios Audio Production

The team test the theory that you can use the weather to predict pain, separating science fact from fiction. It's an area with a huge amount of conflicting research, but one man who has investigated this is Professor Will Dixon, who explains that low pressure could be causing people's joints to ache more. Dara and Hannah are intrigued to hear our genes may also be responding to changes in temperature and hear how we might be pre-programmed to produce more inflammation during wintertime to fight off bugs - which has the unfortunate side effect of making other some conditions worse. But don't despair! The pair find out 21 degrees is the optimum temperature for health and wellbeing - a perfect English summer day.

Contributors:

Dr Chris Wallace Professor Will Dixon Professor Trevor Professor Trevor Harley

Producer: Marijke Peters Executive Producer: Alexandra Feachem

A BBC Studios Audio Production

From mouldy bread to athlete’s foot, fungi don’t exactly scream “home improvement.” But what if this misunderstood kingdom is the secret to the sustainable materials of the future?

Listener Alexis - definitely not a gnome - wants to know how much of our homes we could build with fungi. Professor Katie Field describes how the mushroom is the just tip of the iceberg - it’s the network of thread-like filaments called mycelium where fungi really do their best work. Architect Phil Ayers explains how fungi, like yeast in bread, can bind waste products into firm, MDF-like blocks. And while we’re not constructing skyscrapers with mushrooms just yet, it turns out fungi-based materials are already making waves in interior design. Think sound-absorbing wall panels or insulation that’s both eco-friendly and chic.

And here’s a cool one: mushroom leather! Using discarded stalks from mushroom farms, one company is crafting strong, flexible material for trainers, handbags, and even car dashboards. Move over, cows - mushrooms are pushing their way up.

Oh, and NASA? They’re dreaming big with fungi too - to grow habitats in space. From mould...to the moon!

Contributors:

Katie Field - Professor of Plant-Soil Processes at the University of Sheffield Phil Ayres - Professor of Biohybrid Architecture at the Royal Danish Academy Patrick Baptista Pinto - co-founder of Really Clever Maurizio Montalti - Co-founder and Chief Mycelium Officer of SQIM / MOGU Lynn Rothschild - Senior Research Scientist at NASA Ames research centre

Producer: Ilan Goodman Executive Producer: Alexandra Feachem A BBC Studios Audio Production

What happens in your brain when Cupid’s arrow strikes? As a teenager, Alison developed an intense crush on George Harrison from the Beatles. But, she wants to know, why do we develop these feelings for pop stars we’ve never actually met? And what potent swirl of neurochemistry drives those fierce emotions?

With neuroscientist Dr. Dean Burnett and evolutionary anthropologist Dr. Anna Machin as their guides, Hannah and Dara investigate everything from the brain’s chemical fireworks during a crush to the evolutionary perks of love and bonding. Along the way, they dissect teenage infatuations, lifelong love affairs with football teams, and why love can feel as addictive as heroin.

There’s even a guest appearance from two cute rodents: the monogamous prairie voles and their more, shall we say, commitment-phobic cousins, the montane voles, who gave us early clues about the role of the ‘cuddle’ hormone oxytocin.

Whether you're a hopeless romantic or a hard-nosed skeptic, prepare to fall head over heels for the science of love.

Contributors:

Dr Anna Machin - evolutionary anthropologist and author of Why We Love Dr Dean Burnett - honorary research fellow at Cardiff Psychology School, author of The Idiot Brain and The Happy Brain. Carmine Pariante - Professor of Biological Psychiatry at King’s College London

Producer: Ilan Goodman Executive Producer: Alexandra Feachem A BBC Studios Audio Production

Hannah and Dara tackle a disarmingly simple question: is anything in the universe truly invisible? After ruling out mysterious Nordic spirits and ‘Dara’s ire’, our curious duo start to track down the invisible waves all around them. Including, it turns out, some which are emanating from their VERY OWN FACES! An infrared camera reveals Hannah’s nose as a particular hotspot.

Turning their gaze to bigger things, they wonder: what does our own galaxy look like when viewed in this invisible spectrum? Infrared reveals vast loops and whorls of dust and gas - gigantic structures otherwise totally hidden. But there are even cooler surprises. Ever wondered what an X-ray of the universe looks like? Turns out it’s a sparkly map of white-hot black holes!

Back on earth, the discussion turns to ways of making objects disappear by bending light in tricksy ways. But why is the fancy science of ‘metamaterials’ still struggling to make a proper invisibility cloak? Sorry, Harry Potter fans.

In the end, our physicists reveal a universe bursting with even more elusive, even more mysterious stuff: dark matter and dark energy. Prepare to see the unseen in a whole new light!

Contributors:

Matthew Bothwell - the Public Astronomer at the University of Cambridge and author of The Invisible Universe Andrew Pontzen - Professor of Physics at Durham University Mitch Kenney - Assistant Professor in metamaterials at the University of Nottingham

Producer: Ilan Goodman Executive Producer: Sasha Feachem A BBC Studios Audio Production

For any of you who have ever told a porkie pie, don't worry, this week we hear why we all do it... and discover that deception is actually good for social bonding. From the red squirrels who cry wolf to scare off the competition, to kids who look you in the eye as they tell bare faced lies, this is a behaviour that occurs across all species. And one man who's particularly good at it is Traitors contestant Paul Gorton who reveals he felt absolutely no guilt about his tv trickery. But it seems that while we're masters at telling tall stories, we're terrible at detecting them, because we've all been focusing on completely the wrong cues.

Contributors:

Paul Gorton Professor Richard Wiseman Professor Sophie van der Zee

Producer: Marijke Peters Executive Producer: Alexandra Feachem

A BBC Studios Audio Production

“Diamonds are nonsense!” Hannah boldly proclaimed in a previous episode. But listener Guy is a diamond enthusiast, and he and his diamond-loving pals were NOT OKAY WITH THIS. He demanded we re-open the case, and here we are...

SO in this glittering showdown, Dara is on a quest to flip Hannah’s perspective from “meh” to “marvelous.” And for Hannah, some uncomfortable facts soon emerge. It turns out that diamonds are much more than just overpriced bling. They're the secret ingredient in all sorts of high-tech gadgets with a whole arsenal of little-known superpowers.

Enter electrochemist Julie Macpherson, who blows Hannah’s mind by showing how diamonds can slice through ice like butter, thanks to their unmatched ability to conduct heat. Not impressed yet? Physicist Mark Newton makes a diamond glow in the dark, using nothing but his phone flashlight.

And that’s just to start! These ultra-robust gems can scrub nasty chemicals from water, serve as supercharged electrodes, and even reveal deep-earth secrets locked away for billions of years.

By the end of this episode, will Hannah finally admit diamonds are forever cool?

Contributors:

Charlie Bexfield - Gemmologist and diamond specialist Julie MacPherson - Professor of Chemistry at the University of Warwick Mark Newton - Professor of Physics at the University of Warwick Grahame Pearson - Professor of Earth Sciences from the University of Alberta

Producer: Ilan Goodman Executive Producer: Sasha Feachem A BBC Studios Audio Production

Hannah Fry and Dara Ó Briain return to tackle listener's questions with the power of science!

The buzz of a fly hovering just above your head has got to be one of the most irritating sounds around, but this week we try to work out just how fast they could be flying. Could a claim horseflies reach speeds of up to 90 mph possibly be true, and Dara wants to know if this is what makes them so difficult to swat?

Entomologist Erica McAlister is better known as the ‘fly lady’ and speaks up in defence of these tiny creatures, explaining there are 7,000 known species in the UK alone. Which makes it all the more shocking there are several that don’t have wings.

For Professor Graham Taylor the question of speed comes down to a simple calculation, and the team try to work out whether a horsefly beats its wings fast enough relative to its size to travel so rapidly. He explains horseflies aren't clever, but scientists are interested in their simple brains and are studying them to use as models for drones and mini robots.

Contributors:

Dr Erica McAlister, Natural History Museum Professor Graham Taylor, Oxford University

Producer: Marijke Peters Executive Producer: Alexandra Feachem A BBC Studios Audio Production

Anyone who has ever done a long car journey with kids will be familiar with the idea of being bored to death – but can this feeling really be fatal?

Hannah and Dara hear about a club where members count roundabouts and collect milk bottle tops, but boredom expert Wijnand van Tilburg explains these dull-sounding hobbies might actually have mental health benefits. He explains that science and comedy are stereotypically both seen as exciting subjects but warns them their chat about Venn diagrams might tip the balance the other way.

Mind-wandering specialist Mike Esterman reveals why we're rubbish at staying on task when there are more rewarding things to do, and sets the pair a challenge to play a computer game that distracts them with pictures of cute babies and fluffy animals.

Contributors:

Dr Wijnand van Tilburg: University of Essex Dr Mike Esterman: Boston Attention and Learning Lab

Producer: Marijke Peters Executive Producer: Alexandra Feachem A BBC Studios Audio Production

When you die, would you want to be frozen so that one day you might be brought back to life? Listener Elspeth wants to know if that’s even possible. So Hannah and Dara embark on a quest to explore the chiling science of ‘cryobiology’: preserving living things at really low temperatures.

It turns out there are already thousands of people alive who were once suspended in antifreeze and stored in liquid nitrogen - when they were just a small clump of cells! There’s even a frog which can turn into a ‘frogsicle’ for months on end. But re-animating full size humans is a challenge no one has solved…yet. Will some miraculous nanotechnology of a distant future solve the problem?

Contributors:

Professor João Pedro de Magalhães: University of Birmingham Hayley Campbell: Author and broadcaster Professor Joyce Harper: UCL Dr Hanane Hadj-Moussa: The Babraham Institute, Cambridge Garrett Smyth: Cryonics UK

Producer: Ilan Goodman Executive Producer: Alexandra Feachem A BBC Studios Audio Production

Wake up! It’s time for a dreamy new episode of Curious Cases all about the science of sleepwalking.

Listener Abigail has done some strange things in her sleep, from taking all the pictures off the wall, to searching for Turkish language courses. And she wants to know: WHY IS THIS HAPPENING?

It turns out Abigail is not alone. Hannah and Dara hear weird and wonderful stories of extreme sleepwalkers - from the lady who went on midnight motorbike excursions, to the artist who does all his best work while asleep. They delve into the neuroscience to find out how you can remain in deep sleep while walking, talking or even peeing in your mum's shopping basket. They learn about some cutting edge research where the participants were sleep deprived and then half-woken with scary sounds, and they zero in on the key triggers, from a boozy night out to a squeaky bed.

Contributors Professor Russell Foster: University of Oxford. Professor Guy Leschziner: King’s College London and Guys’ and St Thomas’ hospital Lee Hadwin: the sleep artist Professor Francesca Siclari: The Netherlands Institute for Neuroscience

Producer: Ilan Goodman Executive Producer: Alexandra Feachem A BBC Studios Audio Production

Fruit-powered batteries are the ultimate school science experiment, but they’re normally used to power a pocket calculator. This week’s listener wants to know if they could do more, and sends the team on a quest to discover whether they could used to send a rocket into space?

Professor Saiful Islam is the Guinness World Record holder for the highest voltage from a fruit-based battery, but disappoints the team when he reveals they produce very little power. He used 3,000 of them and only managed a measly 2 Watts. Given that spaceships are famously difficult to get off the ground, it seems a lemon battery might just fail the acid test.

Author Randall Munroe is undeterred and suggests alternative ways to get energy from citrus, including burying them to make oil. Then the team discuss the pros and cons of switching to a lemon-based diet.

For battery expert Paul Shearing, all this raises a serious question, about how we will power the planes of the future. He suggests solar power could play a part in short-haul flights and discusses some of the exciting battery materials being tested today.

Contributors:

Randall Munroe, author Professor Paul Shearing, Oxford University Professor Saiful Islam, Oxford University

Producer: Marijke Peters Executive Producer: Alexandra Feachem A BBC Studios Audio Production

Are you more of a rhino or a kitten? More like a tortoise or a hare? Listener Ivy wants to know what makes a good athlete and so Hannah and Dara tackle the science of sport.

Our curious duo get to grips with the rigours of training tailored for endurance events vs those based on more explosive bursts of activity. They consider the contribution of genetics, fast vs slow twitch muscle fibres, the unique advantage of Michael Phelps's body proportions and whether butterfly really is the most ridiculous stroke in swimming.

And after a rigorous scientific analysis, Dara turns out to be ideally suited for…netball. Much to his surprise.

Contributors Dr Polly McGuigan: University of Bath Dr Mitch Lomax: University of Portsmouth Professor Alun Williams: Manchester Metropolitan University Dr Josephine Perry: Sports psychologist

Producer: Ilan Goodman Executive Producer: Alexandra Feachem A BBC Studios Audio Production

Listener Vivienne has heard that tardigrades - aka moss piglets - have special powers of survival. Radiation? Drought? Extreme cold? NO PROBLEM. Does that mean they could survive an apocalypse? And could they even help us master space travel!?

Hannah and Dara learn how to find these little moss piggies in roof gutters and garden corners. And they're amazed by their capacity to dry out and hunker down for decades before springing back to life. But calamity strikes when it turns out that fine glass tubing - in the form of pipettes - is their natural predator. And worse is to come: our curious duo learn that there may be some tardigrades stuck on the moon, and one researcher has even fired them out of a gun. All in the name of science.

But they have survived at least 5 mass extinctions so far. So their chances of surviving the next one are pretty good. As long as pipettes aren't involved. Contributors Dr James Frederick Fleming: Natural History Museum of Norway and the University of Oslo Dr Nadja Møbjerg: University of Copenhagen Dr Thomas Boothby: University of Wyoming

Producer: Ilan Goodman Executive Producer: Alexandra Feachem A BBC Studios Audio Production

If there’s one type of discharge you really want to avoid, it’s lightning, but what happens when it hits you?

We hear from lightning survivor Kerry Evans, and discover that the best place to shelter – if you ever find yourself in a similarly charged storm – is in a car, or low to the ground. And why this is never a good time to take a selfie.

Dr Dan Mitchard from Cardiff University’s excitingly-named Lightning Lab explains why there's no lightning at the poles, and the presenters lament that polar bears and penguins are missing out.

We all know about the gods of lightning, but the mysticism doesn't stop there. Above cloud level there are many other types of unusually-named phenomena, reaching to the edge of space, including sprites, trolls and even pixies.

And Professor Karen Aplin reveals that lightning has even been discovered on other planets, in a science story that could affect our plans to colonise Mars.

Contributors:

Dr Daniel Mitchard, Lightning Laboratory, Cardiff University Professor Karen Aplin, University of Bristol

Producer: Marijke Peters Executive Producer: Alexandra Feachem A BBC Studios Audio Production

11 year old Esther visualises days of the week in a kind of 3D structure. It’s something called ‘synaesthesia’ and she wants to know why it happens - and why other people don’t experience things the way she does.

Hannah Fry and Dara Ó Briain explore the vibrant and varied ways different people experience the world, from the man who tastes individual words - including all the stops of the tube - to the composer who sees music in shapes and colours.

And along the way, they figure out why Mozart is white wine while Beethoven is red.

Contributors:

Professor Julia Simner: Professor of Psychology,University of Sussex Professor Jamie Ward: Professor of Cognitive Neuroscience, University of Sussex James Wannerton, President of UK Synaesthesia Association CoriAnder: electronic music producer

Producer: Ilan Goodman Executive Producer: Alexandra Feachem A BBC Studios Audio Production

It’s sometimes said that timing is everything and this week the pair investigate the mystery of rhythm, discovering why some of us might be better at staying in tempo.

From the daily cycle of dawn and dusk to sea tides and circadian clocks, rhythm governs many aspects of our lives, and cognitive psychologist Dr Maria Witek says it makes sense we also place great importance on its presence in music. She specialises in ‘groove’, or the feeling of pleasure associated with moving to a beat – and it’s not just something the dancers among us enjoy; groove has even been used to treat patients with Parkinson’s Disease.

Neuroscientist Professor Nina Kraus has studied drummers’ brains and found their neurons fire with more precision. She explains that teaching kids rhythm can improve their language and social skills. But no need to take her word for it, because Skunk Anansie’s drummer Mark Richardson is in the studio to put Hannah to the test. Can she handle a high hat at the same time as a snare?

Contributors: Dr Maria Witek, University of Birmingham Professor Nina Kraus, Northwestern University Mark Richardson, drummer with Skunk Anansie

Producer: Marijke Peters Executive Producer: Alexandra Feachem A BBC Studios Audio Production

9 year old listener Koby sends Hannah and Dara on a mission to find the shiniest thing in the world. And so they enter a world of mirrors…

The journey takes them into the subatomic goings on of shiny metal surfaces, where electrons waggle and dance and send light waves back at *just* the right angle. Our curious duo play with an astonishingly reflective plastic film that can be found hidden in devices we all use. And they probe the mysterious power of refraction, harnessed to make the $2 million mirrors which reflect the lasers at the huge LIGO experiment.

And everyone ponders the surprisingly reflective properties of a pint in space.

Contributors:

Dr Felix Flicker: University of Bristol, author of The Magick of Matter Professor Stuart Reid: University of Strathclyde Quinn Sanford: optical engineer from 3M GariLynn Billingsley: Optical Sciences Group Leader at LIGO

Producer: Ilan Goodman Executive Producer: Alexandra Feachem A BBC Studios Audio Production

Would you eat food that fell on the floor? That’s the question Hannah and Dara are getting their teeth into this week as they put the so-called ‘5 second rule’ through its paces.

For some people it’s 3 seconds, and for others its 10 – especially if it involves a dropped ice cream and a screaming child. But microbiologist Don Schaffner says there’s no safe amount of time to leave food on the floor if you’re planning to eat it. And while you might think buttered toast would pick up the biggest number of bugs, it may surprise you to hear that wet foods like watermelon are actually the worst when it comes to attracting harmful bacteria. If all this is putting you off your dinner, the bad news is that the rest of your kitchen is also a microbiological minefield. Research shows nearly 70% of us keep our fridges are the wrong temperature, which sparks a lively discussion about whether it’s ever safe to reheat rice.

For home hygiene guru Sally Bloomfield it’s all a question of being a bit more clever about the kind of germs we expose ourselves to and weighing up risks.

Contributors:

Dr Don Schaffner: Rutgers University Dr Ellen Evans: Cardiff Metropolitan University Professor Sally Bloomfield: International Scientific Forum on Home Hygiene

Producer: Marijke Peters Executive Producer: Alexandra Feachem A BBC Studios Audio Production

While chatting at the back of class, best mates Abi and Sofia got curious about bubbles. How do you make really giant ones? Could you even get one around the entire planet?

Hannah and Dara set out to investigate. They hear from a renowned 'bubbleologist', and learn how NASA helped him blow his way to a world record. They coax a physicist to reveal the secrets of his peer-reviewed bubble-juice formula, and investigate how bubbles work in space and in the ocean.

Our curious duo also discover an audacious project aiming to build a Brazil-sized raft of bubbles... in space!

Contributors:

Dr Helen Czerski, UCL Dr Justin Burton, Emory University Dr Awesome, Bubbleologist Professor Carlo Ratti, MIT

Producer: Ilan Goodman Executive Producer: Alexandra Feachem A BBC Studios Audio Production

Curious Cases is returning! Superstar mathematician and broadcaster Hannah Fry teams up with legendary comedian and fellow science nerd Dara Ó Briain for an all-new series of the show which takes your quirkiest questions and solves them with the power of science.

In this short preview ep, our dynamic duo tease some of the upcoming episodes in which they enlist the world’s top experts to tackle the most profound and puzzling questions to have ever trickled through your curious minds: Could you power a spaceship with a lemon? Can you actually die of boredom? Why do some people *taste* words? Why does Hannah have absolutely no sense of rhythm? And could we stop climate change with massive space bubbles!?

Producers: Marijke Peters and Ilan Goodman Executive Producer: Alexandra Feachem A BBC Studios Audio Production

There is a bizarre number in maths referred to simply as ‘i’. It appears to break the rules of arithmetic - but turns out to be utterly essential for applications across engineering and physics. We’re talking about the square root of -1. WHICH MAKES NO SENSE.

Professor Fry waxes lyrical about the beauty and power of this so-called ‘imaginary’ number to a sceptical Dr Rutherford. Dr Michael Brooks tells the surprising story of the duelling Italian mathematicians who gave birth to this strange idea, and shares how Silicon Valley turned it into cold hard cash. It's all about oscillations, Professor Jeff O’Connell demonstrates. And finally, Dr Eleanor Knox reveals that imaginary numbers are indispensable for the most fundamental physics of all: quantum mechanics.

Imaginary, impossible…but essential!

Contributors: Professor Jeff O’Connell, Ohlone College California, Dr Michael Brooks, Author of 'The Maths That Made Us', and Dr Eleanor Knox, Philosopher of Physics at KCL and a Senior Visiting Fellow at the University of Pittsburgh.

Producer: Ilan Goodman

This episode will render you oblivious, conked out and blissfully unaware. It’s about anaesthetics: those potent potions that send you into a deep, deathly sleep. Listener Alicia wants to know how they work, so our sleuths call on the expertise of consultant anaesthetist Dr Fiona Donald. Fiona shares her experience from the clinical frontline, and explains what we do and don’t know about how these chemicals work their mind-numbing magic. We hear about ground-breaking research led by Professor Irene Tracey, which reveals how a pattern of slow brain waves can be used to determine the optimum dosage of these dangerous drugs.

And finally, Drs Rutherford and Fry wonder: what does all this tell us about normal consciousness? Professor Anil Seth shares how we can use brain tech to measure different levels of conscious awareness – from sleepy to psychedelic.

Presenters: Hannah Fry and Adam Rutherford Producer: Ilan Goodman

‘Can we bring back extinct species?’ wonders listener Mikko Campbell. Well, Professor Fry is pretty excited by the prospect of woolly mammoths roaming the Siberian tundra once more. And everyone is impressed with the science that might make it happen. But Dr Rutherford comes out STRONGLY against the whole thing. Can our expert guests win him over?

Dr Helen Pilcher shares the tale of Celia the lonely mountain goat, and makes the case for cloning to help protect species at risk of extinction. Professor Beth Shapiro sets out how biotech company ‘Colossal’ plans to engineer Asian elephants’ DNA to make a new group of mammoth-like creatures. And we hear how genetic technologies are being used in conservation efforts around the world.

BUT WHAT ABOUT T-REXES? Not gonna happen. Sorry.

Contributors: Dr Helen Pilcher, author of ‘Bring Back the King: The New Science of De-Extinction’, Professor Beth Shapiro from the University of California Santa Cruz, Dr Ben Novak of Revive and Restore and Tullis Matson from Nature’s SAFE.

Presenters: Hannah Fry and Adam Rutherford

Producer: Ilan Goodman

The Great Pyramids of Giza are awesome feats of engineering and precision. So who built them - and how? Was it a mysteriously super-advanced civilization now oddly extinct? Was it even aliens?

Nah, course not! Rutherford and Fry investigate how these inspiring monuments were really constructed, and learn about the complex civilisation and efficient bureaucracy that made them possible.

Professor Sarah Parcak busts the myth that they were built by slaves. In fact, she reveals, it was gangs of well-paid blokes fuelled by the ancient Egyptian equivalent of burgers and beer. And Dr Chris Naunton explains how it was not some mysterious tech, but incredible organisation and teamwork which made it possible to transport massive stone blocks over long distances several thousand years before trucks arrived.

Dr Heba Abd El Gawad points out how racism led to bizarre assumptions in the history of archaeology, and how those assumptions linger in contemporary conspiracy theories which refuse to accept that Egyptians could have built the pyramids themselves!

Presenters: Hannah Fry and Adam Rutherford Contributors: Professor Sarah Parcak, University of Alabama, Dr Chris Naunton, Egyptologist and broadcaster, Dr Heba Abd El Gawad, University College London Producers: Ilan Goodman & Emily Bird

Magnets are inside loads of everyday electronic kit - speakers, motors, phones and more - but listener Lucas is mystified: what, he wonders, is a magnetic field?

Our sleuths set out to investigate the mysterious power of magnets, with the help of wizard / physicist Dr Felix Flicker - author of the The Magick of Matter - and materials scientist Dr Anna Ploszajski.

They cover the secrets of lodestones - naturally occurring magnetic rocks - and how to levitate crystals, frogs and maybe even people.

Matthew Swallow, the Chair of the UK Magnetics Society, explains why magnets make the best brakes for rollercoasters, and Dr Ploszajski explains how magnetically-induced eddy currents are used to sort through our recycling.

Finally, Dr Flicker persuades Adam and Hannah that to really understand magnetic fields you have to leave classical physics behind, and go quantum... So our sleuths take a leap into the strange subatomic realm.

Contributors: Dr Felix Flicker, Lecturer in Physics at Cardiff University and author of ‘The Magick of Matter’, Dr Anna Ploszajski, materials scientist and author of ‘Handmade’, Matthew Swallow, Chair of the UK Magnetics Society

Presented by Hannah Fry and Adam Rutherford Producer: Ilan Goodman

Close your eyes and think of a giraffe. Can you see it? I mean, *really* see it - in rich, vivid detail? If not - you aren’t alone! We’ve had scores of messages from listeners who report having a ‘blind mind’s eye’. They don’t see mental images at all and they want to know why. Jude from Perth wants to know what makes her brain different, and Diane from Scotland wonders whether it affectes her ability to remember family holidays.

Our sleuths learn that this is a condition recently termed ‘aphantasia’. They meet the chap who came up with the name, Professor Adam Zeman, a neurologist from the University of Exeter, and quiz him on the brain mechanisms behind this mystery. Professor Julia Simner - a psychologist who, herself, doesn’t see mental images - shares the surprising research into how aphants differ slightly from others in a range of cognitive skills. We also hear about the world class artists and animators who can’t visualise - but can create beautiful, imaginary worlds. Philosophy professor Fiona Macpherson from the University of Glasgow, deepens the mystery: perhaps this largely hidden phenomenon is behind some of the most profound disagreements in the history of psychology. Our mental experiences are all very different - maybe that’s why thinkers have come up with such different theories about how our minds work. Search for the “VVIQ” or Vividness of Visual Imagery questionnaire to take the test yourself. Look for “The Perception Census” to take part in this massive online study of perceptual variation. And look up the 'Aphtantasia Network' if you're curious to find out more.

Presenters: Hannah Fry and Adam Rutherford Contributors: Professor Adam Zeman, Professor Julia Simner, Professor Fiona Macpherson Producer: Ilan Goodman

What do you get if you smash two hydrogen nuclei together? Helium and lots of energy. That’s no joke – it's nuclear fusion!

Nuclear fusion is the power source of the sun and the stars. Physicists and engineers here on earth are trying to build reactors than can harness fusion power to provide limitless clean energy. But it’s tricky...

Rutherford and Fry are joined by Dr Melanie Windridge, plasma physicist and CEO of Fusion Energy Insights, who explains why the fourth state of matter – plasma – helps get fusion going, and why a Russian doughnut was a key breakthrough on the path to fusion power.

Dr Sharon Ann Holgate, author of Nuclear Fusion: The Race to Build a Mini Sun on Earth, helps our sleuths distinguish the more familiar nuclear fission (famous for powerful bombs) from the cleaner and much less radioactive nuclear fusion.

And plasma physicist (another one!) Dr Arthur Turrell describes the astonishing amount of investment and innovation going on to try and get fusion power working at a commercial scale.

Contributors: Dr Melanie Windridge, Dr Sharon Ann Holgate, Dr Arthur Turrell

Producer: Ilan Goodman

Sneezes, wheezes, runny noses and red eyes - this episode is all about allergies. An allergic reaction is when your immune system reacts to something harmless – like peanuts or pollen – as if it was a parasitic invader. It’s a case of biological mistaken identity. Professor Judith Holloway from the University of Southampton guides our sleuths through the complex immune pathways that make allergies happen and tells the scary story of when she went into anaphylactic shock from a rogue chocolate bar. Professor Adam Fox, a paediatric allergist at Evelina Children’s Hospital, helps the Drs distinguish intolerances or sensitivities – substantial swelling from a bee sting, for example - from genuine allergies. Hannah’s orange juice ‘allergy’ is exposed as a probable fraud! Hannah and Adam explore why allergies are on the increase, and Professor Rick Maizels from the University of Glasgow shares his surprising research using parasitic worms to develop anti-allergy drugs! Producer: Ilan Goodman Contributors: Professor Judith Holloway, Professor Adam Fox, Professor Rick Maizels

Hungry for pi? Chow down on this!

Pi is the ratio between a circle’s diameter and its circumference. Sounds dull – but pi turns out to have astonishing properties and crop up in places you would never expect. For a start, it goes on forever and never repeats, meaning it probably contains your name, date of birth, and the complete works of Shakespeare written in its digits.

Maths comedian Matt Parker stuns Adam with his ‘pie-endulum’ experiment, in which a chicken and mushroom pie is dangled 2.45m to form a pendulum which takes *exactly* 3.14 seconds per swing.

Mathematician Dr Vicky Neale explains how we can be sure that the number pi continues forever and never repeats - despite the fact we can never write down all its digits to check! She also makes the case that aliens would probably measure angles using pi because it’s a fundamental constant of the universe.

NASA mission director Dr Marc Rayman drops in to explain how pi is used to navigate spacecraft around the solar system. And philosopher of physics Dr Eleanor Knox serves up some philoso-pi, revealing why some thinkers have found pi’s ubiquity so deeply mysterious.

Hannah grins with delight for most of show. It’s all maths!

Producer: Ilan Goodman

Contributors: Matt Parker, Dr Vicky Neale, Dr Marc Rayman, Dr Eleanor Knox

Why are some smells so nasty and others so pleasant? Rutherford and Fry inhale the science of scent in this stinker of an episode.

Our sleuths kick off with a guided tour of the airborne molecules and chemical receptors that power the sense of smell. Armed with a stack of pungent mini-flasks, Professor Matthew Cobb from the University of Manchester shows Hannah and Adam just how sensitive olfaction can be, and how our experience of some odours depends on our individual genetic make-up.

Dr Ann-Sophie Barwich from Indiana University reveals how most everyday smells are complex combinations of hundreds of odorants, and how the poo-scented molecule of indole turns up in some extremely surprising places.

With the help of a flavoured jellybean and some nose clips, Hannah experiences how smell is crucial to flavour, adding complexity and detail to the crude dimensions of taste.

Speaking of food, listener Brychan Davies is curious about garlic and asparagus: why do they make us whiff? Professor Barry Smith from the Centre for the Study of the Senses reveals it's down to sulphur-containing compounds, and tells the story of how a cunning scientist managed to figure out the puzzle of asparagus-scented urine.

Finally, another listener Lorena Busto Hurtado wants to know whether a person’s natural odour influences how much we like them. Barry Smith says yes - we may sniff each other out a bit like dogs - and cognitive neuroscientist Dr Rachel Herz points to evidence that bodily bouquet can even influence sexual attraction!

Producer: Ilan Goodman

Contributors: Professor Matthew Cobb, Professor Barry Smith, Dr Ann-Sophie Barwich, Dr Rachel Herz

How do winds start and why do they stop? asks Georgina from the Isle of Wight. What's more, listener Chris Elshaw is suprised we get strong winds at all: why doesn't air just move smoothly between areas of high and low pressure? Why do we get sudden gusts and violent storms?

To tackle this breezy mystery, our curious duo don their anoraks and get windy with some weather experts.

Dr Simon Clark, a science Youtuber and author of Firmament, convinces Adam that air flow is really about the physics of fluids, which can all be captured by some nifty maths. The idea of pressure turns out to be key, so Hannah makes her own barometer out of a jar, a balloon and some chopsticks, and explains why a bag of crisps will expand as you walk up a mountain.

Professor Liz Bentley, Chief Executive of the Royal Meteorological Scoiety, reveals how the dynamics of a simple sea breeze – where air over land is heated more than air over water – illustrates the basic forces driving wind of all kinds.

Then everyone gets involved to help Adam understand the tricky Coriolis effect and why the rotation of the Earth makes winds bend and storms spin. And Professor John Turner from the British Antarctic Survey explains why the distinctive features of the coldest continent make its coastline the windiest place on earth.

Producer: Ilan Goodman Contributors: Dr Simon Clark, Professor Liz Bentley, Professor John Turner

DO WE HAVE YOUR ATTENTION?

Good! But how does that work!?

Our intrepid science sleuths explore why some things immediately catch your eye - or ear - while others slip by totally unnoticed. Even, on occasion, basketball bouncing gorillas.

Professor Polly Dalton, a psychologist who leads The Attention Lab at Royal Holloway University, shares her surprising research into ‘inattentional blindness’ - when you get so absorbed in a task you can miss striking and unusual things going on right in front of you.

Dr Gemma Briggs from the Open University reveals how this can have dangerous everyday consequences: you are four times more likely to have a crash if you talk on the phone while driving - even handsfree.

Drs Rutherford and Fry also hear from stroke survivor Thomas Canning, who developed the tendency to ignore everything on the left side of space, despite his vision being totally intact. And Dr Tom Manly, from the University of Cambridge’s Cognition and Brain Sciences Unit, helps our sleuths unpack the neuroscience of this fascinating condition.

Producer: Ilan Goodman Contributors: Professor Polly Dalton, Dr Gemma Briggs, Dr Tom Manly

The world is full of colour! But, wonders listener Maya Crocombe, ‘how do we see colour and why are some people colour blind?’

Dr Rutherford and Professor Fry set out to understand how special light-sensitive cells in our eyes start the process of colour perception, why people sometimes have very different experiences of colour and whether, in the end, colour is really just ‘in our heads’.

Dr Gabriele Jordan from Newcastle University explains why lots of men struggle to discriminate between certain colours and why there were lots of complaints from colour-blind viewers when Wales played Ireland at rugby.

Professor Anya Hurlbert, also from Newcastle University, tackles the most divisive of internet images: The Dress! Did you see it as blue-black or yellow-gold? Anya explains why people see it so differently, and why our ability to compensate for available light is so useful.

Finally, Dr Mazviita Chirimuuta, a philosopher at the University of Edinburgh, gives us her take on what all this means: are colours real, or just in our minds?

If you want to see some of the images and activities referenced in the episode read on... To take the colour perception test which Hannah and Adam do in the epsiode, search for the 'Farnsworth Munsell Hue test' - you can do it online for free. To see the Dunstanborough Castle illusion as described in the episode, check out the Gallery section on the Curious Cases BBC website. To learn more about colour blindness, and for support and resources go to colourblindawareness.org

Producer: Ilan Goodman

First broadcast on BBC Radio 4 in March 2022.

Mathematician Hannah Fry and geneticist Adam Rutherford investigate your everyday science queries.

They get stuck into two questions about tides.

Lynn Godson wants to know why isn’t high tide at the same time at all points around the coast? Whilst Tim Mosedale asks, could we ever harness tidal power commercially?

Did you think tides are caused by the pull of the Moon? And that they come in and out twice a day?

Well, yes, that’s true but it turns out there’s so much more to it than that, especially here in the UK, which has the second largest tidal range in the world at the Seven Estuary near Bristol, coming in at an average of 15 metres (50ft in old money). But why should high and low tide times be so different even in places that are relatively close to each other?

The answer partly lies in something called bathymetry (which has more to do with baths than you might think – well basins at any rate).

As for harnessing sea power, there are some ambitious projects currently in development and predictions that wave and tidal could make up as much as 15 percent of the UK’s energy needs in future. But how realistic is this and how do you ensure that your power generators can survive the rigours of the ocean – storms, saltwater and all those pesky barnacles?

To help answer these queries, Hannah and Adam are joined by Physicist and Oceanographer, Helen Czerski and Professor Deborah Greaves OBE, who heads up the COAST lab at the University of Plymouth which studies marine renewable energy technologies.

Producers: Rami Tzabar and Jen Whyntie

First broadcast on BBC Radio 4 in March 2022.

Why does human hair go grey and is it ever possible for it to go white overnight from shock?

Hannah and Adam explore why hair goes grey, how much stressful life events and a lack of sleep can speed up the process.

They hear from the pilot whose hair turned white after a flight where all 4 of his engines failed after flying through a volcanic ash cloud - was the shock responsible?

They also uncover new research which has shown it's possible for greying hair to return to its natural colour and ask if this finding could be exploited to uncover a cosmetic way to reverse hair greying?

Presenters: Hannah Fry and Adam Rutherford Producer: Pamela Rutherford

First broadcast on BBC Radio 4 in March 2022.

Two eyes, two arms, two legs - we’re roughly symmetrical on the outside, but inside we’re all over the place!

We just have one heart, which is usually on the left, one liver on the right, one spleen and one appendix.

Why is that?’ wonders listener Joanne.

Our science sleuths discover that being symmetrical down the middle - at least on the outside - is by far the most common body plan across the animal kingdom.

Professor Sebastian Shimeld from the University of Oxford takes us on a journey into the deep evolutionary past, to uncover how two-sided body structures first emerged in ancient worm-like creatures, and why this layout eventually proved so useful for swimming, walking and flying.

Garden snails turn out to be a surprising exception – their shells coil in one direction and on just one side of their body. Professor Angus Davison from the University of Nottingham tells the tale of his international quest to find a romantic partner for Jeremy – a rare left-coiling snail who could only mate with another left-coiling snail!

Dr Daniel Grimes from the University of Oregon unfolds the delicate mechanisms by which an initally symmetrical embryo starts to develop differently down one side, and everyone puzzles over the mystery of the left-handed 'mirror molecules' - so called L-amino acids - which turn out to be the building blocks of every living organism. A curious case indeed!

Presenters: Hannah Fry and Adam Rutherford

Producer: Ilan Goodman

First broadcast on BBC Radio 4 in March 2022.

We use Wi-Fi every day, but do you know how it works? “Is it waves and science or just some mystical magical force?” wonders listener Abby.

Well, our science sleuths are on the case. To help them navigate the strange realm of electromagnetic waves they are joined by Andrew Nix, Professor of Wireless Communication Systems from the University of Bristol. He explains why your wi-fi router won’t heat up your baked beans, but your microwave will.

Andrea Goldsmith, Professor of Electrical and Computer Engineering at Princeton University, also joins to reveal how these waves are crammed full of 0s and 1s- whether that's a pic of your pets or a video chat with pals.

And finally, how do you get the best Wi-Fi at home?

Dr Rutherford, it turns out, has made some rookie errors...

Listen out for our top tips so you don't make them too!

Presenters: Hannah Fry and Adam Rutherford

Producer: Ilan Goodman

First broadcast on BBC Radio 4 in 2022.

‘Why are teens prone to risky behaviour?’ asks Dr Mark Gallaway, ‘especially when with their friends?’

13 year old Emma wonders why she’s chatty at school but antisocial when she gets home.

And exasperated mum Michelle wants to know why her teens struggle to get out of bed in the morning.

Swirling hormones and growing bodies have a lot to answer for but, as Professor of Psychology from the University of Cambridge Sarah-Jayne Blakemore explains, there’s also a profound transformation going on in the brain.

Dr Adam Rutherford and Dr Hannah Fry discover how the adolescent brain is maturing and rewiring at the cellular level and why evolution might have primed teens to prefer their peers over their parents.

Frances Jensen, Professor of Neurology at the University of Pennsylvania, tells us how all these brain changes can impact social relationships.

And Dr Rachel Sharman, a sleep researcher from the University of Oxford, reports the surprising findings from her sleep study tracking 100 teenagers around the UK.

Producer: Ilan Goodman

First broadcast on BBC Radio 4 in February 2022.

Whilst watching a documentary about some poisonous frogs, Curio Janni in Amsterdam, started to wonder what would happen if a frog licked itself or another frog of the same species.

She asks Dr Adam Rutherford and Professor Hannah Fry to investigate whether an animal would react badly to a toxin it itself produces?

In essence 'can a venomous snake kill itself by biting itself?'

Of course the answer is complicated, but the sleuths know exactly who to ask.

Steve Backshall, award-winning wildlife explorer, best known for his BBC series 'Deadly 60'. Author of 'Venom – Poisonous Creatures in the Natural World'. Steve has been bitten, stung and spat at by a plethora of venomous creatures during his career. He also studied the first known venomous newt - the sharp-ribbed newt - a creature that has sharpened ribs that when it's under attack, it will squeeze its body force those ribs out through its skin, coating them in venom, which is then delivered into the mouth of an attacker.

Professor Nick Casewell, studies venomous snakes and their impact on humans. He works on treatments for snakebites at the Liverpool School of Hygiene and Tropical Medicine. Snakebites have a huge impact on communities in South Asia, Sub-Saharan Africa and South America. It's now been reinstated as one of the most serious neglected tropical diseases by the World Health Organisation. Traditional treatments - antivenins - can be expensive, difficult to access and don't always work - Nick is looking into alternative medicines to treat snakebite victims.

Dr. Ronald Jenner is Principal Researcher in the Comparative Venomics group at the Natural History Museum's Life Sciences, Invertebrates Division and co-wrote the book ‘Venom -the secrets of nature's deadliest weapon.’ He explains the evolutionary arms race between venomous predators and their prey and poisonous prey and their predators. He explains how resistance to venom has evolved and how venom has evolved to be more or less powerful over time, answering another Curio - Scott Probert's question on the evolution of venom.

Christie Wilcox wrote 'Venomous – How Earth’s Deadliest Creatures Mastered Biochemistry'. She studied the molecular basis of lionfish venom. Christie describes how venom and immunity to venom works at the molecular level.

Presenters: Adam Rutherford and Hannah Fry

Producer: Fiona Roberts

First broadcast on BBC Radio 4 in November 2021.

'What is the slipperiest thing in the world?' asks 8 year old Evelyn.

Why do my feet slip on a wet floor but when my feet are even slightly moist it's nearly impossible to put on a pair of socks without falling over and cursing the universe. What is going on here?' asks Evelyn's Dad, Sam.

Hannah and Adam investigate the science of friction and lubrication - so called 'tribology' with the help of tribologists and mechanical engineers Professor Ashlie Martini from California University Merced and Professor Roger Lewis from the University of Sheffield.

With their help Hannah and Adam find out why leaves on the line are so slippery, what happens to graphite in space and what is the slipperiest food. Professor of Materials, Mark Miodownik from University College London explains what's going on when friction stops two materials sliding past each other and wonders whether the slipperiest substance was actually discovered accidentally in a lab by scientists looking for something completely different.

Also in the programme why the ability to reduce friction, even by minuscule amounts could have a huge impact for sustainability and reducing energy use.

Producers: Jen Whyntie and Pamela Rutherford

First broadcast on BBC Radio 4 in November 2021.

Why does my heart not ache after exercise? asks listener Keith. Rutherford and Fry explore how and why heart muscle cells are special.

Dr Mitch Lomax is a sports scientist at the University of Portsmouth. She helps actual Olympic swimmers get faster. She explains how most of the muscles attached to our skeletons work: Tiny fibres use small-scale cellular energy, which, when all these fibres work in concert, turns into visible muscular movement. Mitch also explains how the dreaded Delayed Onset Muscle Soreness, or DOMS, can hit, taking a stair-wincing 48-72 hours to peak after exercise.

But skeletal muscles turn out to be quite different to heart muscles, as consultant cardiologist Dr Rohin Francis explains. Heart cells are more efficient and don't get fatigued like skeletal muscle cells. They are extremely energetic and 'just want to beat'. He also explains that the sensory feedback from the heart muscles is different too. They have a different sort of nerve supply, with fewer sensory nerves, so that there is less chance of pain signals being sent to the brain.

However, heart cells' incredible abilities are counterbalanced by one Achilles-like flaw: They cannot easily heal. Professor Sanjay Sinha is a British Heart Foundation (BHF) Senior Research Fellow and a Professor in Cardiovascular Regenerative Medicine at the University of Cambridge. His job is to fix broken hearts and he explains to Adam how new research into stem cells could be used to fix normally irreparable heart cells.

Presenters: Hannah Fry and Adam Rutherford

Producers: Jennifer Whyntie and Fiona Roberts

First broadcast on BBC Radio 4 in October 2021.

“I don’t really understand why water has so many properties on different scales ranging from very large and cosmic to very small quantum and quarky - Could you help by zooming in and out on water to explain what is known about it? "Asks Neil Morton in Stirling.

“Why does boiling water sound different to cold water?’ asks Barbara Dyson in Brittany in France

Ollie Gordon, in Christchurch in New Zealand, wants to know ‘why water is essential for all life as we know it?’

And many more questions on the weirdness of water are tackled by super science sleuths Hannah Fry and Adam Rutherford.

With assistance from:

* Quantum physicist Professor Patricia Hunt, at the Victoria University in Wellington in New Zealand

* Science writer and author of ‘H2O – a biography of water’ Philip Ball

* Physicist and bubble expert in the Department of Mechanical Engineering at UCL, Dr Helen Czerski.

Producer: Fiona Roberts

First broadcast on BBC Radio 4 in October 2021.

“I don’t really understand why water has so many properties on different scales ranging from very large and cosmic to very small quantum and quarky - Could you help by zooming in and out on water to explain what is known about it?" asks Neil Morton in Stirling.

Rutherford and Fry learn about the special hydrogen bonds that makes water such an unusual liquid.

Quantum physicist Professor Patricia Hunt, at the Victoria University in Wellington in New Zealand explains to Hannah the quantum properties of individual water molecules and how they link up with other water molecules in liquid water and solid ice. She describes the hydrogen bonds that give water some of it’s weird and wonderful properties such as why ice floats, why water is able to store huge amounts of heat and why water has such a strong surface tension.

Science writer and author of ‘H2O – a biography of water’ Philip Ball describes how in the 18th century it was discovered that water was not one of the classical elements, but a compound liquid of water and hydrogen and explains to Adam why there are at least 15 different types of ice.

Physicist Dr. Helen Czerski sets the record straight on how ice forms in oceans and lakes and why water is at its densest at 4 degrees Centigrade and not zero.

Presenters: Hannah Fry & Adam Rutherford

Producer: Fiona Roberts

First broadcast on BBC Radio 4 in October 2021.

How do guide dogs know where they're going? It's not like their handler whispers in their ear and asks to go to the pharmacy, maybe the toothpaste aisle. So how does it work? asks Charlotte, aged 42.

Dogs and humans have gone paw in hand for thousands of years. Historic and genetic evidence shows we’ve shaped each other's existence over millennia. But dogs were only first trained as guides for blind people in the UK 90 years ago. What’s the biology behind this extraordinary partnership? Hannah heads to Guide Dogs UK’s training school in Royal Leamington Spa. She meets up with expert Graham Kensett to find out what it takes to make a guide dog from nose to tail, starting from before birth and following the life course through to retirement.

Hannah also meets the delightful Wendy and Wilmott, a German shepherd and a retriever cross. Despite both still growing into their ears, they show her their already extraordinary skill set, from tackling obstacle courses to safely crossing roads. Cool, calm, patient, unflappable: Guide dogs are the astronauts of the canine world. But, as trainer Jenna explains, it’s all in the partnership with the owner, who needs to do plenty of work in terms of training and learning routes to journey in harmony with their furry guide.

Richard Lane has owned guide dogs for over 25 years, and confirms this first hand. He reveals just how he gets to the toothpaste aisle, and tells Adam how at its peak a partnership can navigate London Waterloo station better than some sighted people, even at rush hour. Richard also explains how deeply felt the bond that forms between owner and dog is, and describes the hardest part of guide dog ownership: Letting go at the end.

Presenters: Hannah Fry & Adam Rutherford Producer: Jen Whyntie

A BBC Audio Science Unit production for BBC Radio 4

It was a dark and stormy night. A secret message arrived addressed to Rutherford & Fry from a mysterious woman called Heidi Daugh, who demanded to know: "Why do people like to be scared? For example, going on scary amusement park rides and watching horror movies that make you jump.”

What followed was an investigation, which would test our intrepid duo to their very limits. They explore the history of horror, starting with its literary origins in the Gothic fiction classic 'The Castle of Otranto'.

Adam challenges Hannah to watch a horror film without hiding behind a cushion. She quizzes horror scholar Mathias Clasen to find out why some people love the feeling of terror, whilst it leaves other cold.

Sociologist Margee Kerr and psychologist Claudia Hammond are also on hand to explore why scary movies are so powerful and popular. Then Rutherford and Fry investigate the more physical side of fear, when they delve into the history of roller coasters to investigate why we enjoy being scared.

Never ones to shy away from a challenge, the pair attempt to channel their inner adrenaline junkies with a trip on one the UK's scariest roller coasters at Thorpe Park.

David Poeppel from New York University studies the science of screaming, and we discover what makes screams uniquely terrifying. Plus, psychologist and broadcaster Claudia Hammond describes some early experiments which tested how fear affects our body.

This episode is a remake of two earlier broadcast episodes.

Producers: Fiona Roberts & Michelle Martin

Presenter: Adam Rutherford & Hannah Fry

First broadcast on BBC Radio 4 in February 2021.

Why are some people left-handed, whereas the majority are right handed? Rutherford and Fry revisit The Sinister Hand episodes to further investigate handedness in humans and animals. They considered cockatoos, chimpanzees and Hannah's dog, Molly, to discover that humans are unique, with just one in ten of us being left-handed.

They ask if there is an evolutionary reason for just 10% of the human population being southpaws

Hannah talks to primatologist Prof Linda Marchant from Miami University about Neanderthal teeth and termite fishing.

Adam consults handedness expert Prof Chris McManus from University College London. He's been trying to track down the genes responsible for whether we're right or left handed.

And what about left-handed brains or eyes or molecules?

Prof Andrea Sella explains handedness, or chirality, at the molecular scale and why when we consider Thalidomide, something seemingly so trivial can be extremely important.

They also explore the left-handed brain. Some researchers point to a link between left-handedness and impairments like autism or dyslexia. Others claim that lefties are more creative and artistic.

So what's the truth? The team consults Professors Sophie Scott, Chris McManus and Dorothy Bishop to find out.

This episode is an updated version of two earlier broadcast episodes.

If you have any Curious Cases for the team to investigate please email curiouscases@bbc.co.uk

Producers: Fiona Roberts & Michelle Martin

Presenter: Adam Rutherford & Hannah Fry

A BBC Audio Science Unit production for BBC Radio 4, first broadcast in 2021.

The doctors continue their investigation into gravity, and answer Peter Fraser’s question:

Is dark matter a proper theory or just a fudge to fit existing 'proper' theories to otherwise inexplicable observations?

Whilst scientists are pretty convinced our understanding of gravity is largely correct, there are still some significant gaps. Namely, given the way galaxies are observed to behave, around 85% of the matter that they think should be in our universe is missing. So where – and, as importantly, what – is it? Cosmologist Andrew Pontzen introduces the evidence from our observations of the cosmic microwave background, light leftover from the Big Bang, which indicate that dark matter exists.

However, this evidence alone is not enough for science. Physicist Chamkaur Ghag is trying to find particles of dark matter here on Earth. Unsurprisingly, no-one is quite sure where these critters are hiding in the particle zoo of protons, neutrons, electrons, quarks, bosons, muons and the rest – or even what they look like. One theory suggests a weakly interacting massive particle, or WIMP, may be the dark matter minibeast. Hundreds of thousands of these could be flying through our fingertips every second. To tell whether they’re there, Cham and hundreds of scientists are building detectors, huge vats of liquid xenon in underground caverns.

Bond villain-esque lairs don’t come cheap, and listener Peter’s query is valid – what if dark matter goes the same way as the aether, an all-permeating (and ultimately non-existent) material that was hypothesised to carry light through the vacuum of space?

Astrophysicist Katy Clough reiterates that experiments are the way to test predictions. Building a picture of how gravity works continues to take many people enormous effort, but this is the scientific process.

Presenters: Hannah Fry & Adam Rutherford

Producer: Jen Whyntie

A BBC Audio Science Unit production for BBC Radio 4, first broadcast in 2021.

The doctors investigate a millennia-old query, as listener Emma in New Zealand asks:

‘How does gravity pull us?’

People have been thinking about how gravity works for a very long time. Way longer than when that particular apple almost certainly didn’t fall on the head of Isaac Newton. Cosmologist Andrew Pontzen begins guiding us through our journey by taking us back to the almost entirely incorrect writings of ancient Greeks.

We then fast forward past Galileo and Newton, and throw in an extra dimension. Using an all-too-believable analogy where some merry cyclists suddenly ride into a meteor crater, astrophysicist Katy Clough tells us how Einstein’s spacetime works.

Limitations of analogies accepted, this explains some of the observations that didn’t fit with Newton’s workings alone. But there are other snags with our understanding of gravity, both at the very small quantum scale and the very large galactic scale. Physicist Chamkaur Ghag introduces what scientists think may account for some of these issues: the mysterious dark matter.

Presenters: Hannah Fry & Adam Rutherford

Producer: Jen Whyntie

A BBC Audio Science Unit production for BBC Radio 4, first broadcast in February 2019.

Do individuals perceive time differently?

Psychologist and presenter of All in the Mind, Claudia Hammond wrote the book ‘Time Warped – Unlocking the Mysteries of Time Perception’. She explains how emotion and memory are big factors in how time is perceived. She stresses how time can stretch and squeeze depending on whether you are looking backwards or forwards. And she explains how lockdown has warped time in different ways for different people.

Professor David Eagleman, from Baylor College of Medicine in Houston, conducted a very famous experiment on time dilation, to see whether time slows down when you are very frightened. He wanted to see whether people actually have increased time resolution during a terrifying moment, and tested whether his students actually see in slow motion when they leapt off a tall building (in a safe manner).

Professor Marc Whitman is a neurologist who has spent his career looking for the clock in our brains. He says that time is dealt with in many parts of the brain, with some parts dealing with different durations, from milliseconds to decades.

Katya Rubia is Professor of Cognitive Neuroscience at Kings College London and is an expert on time perception in children with ADHD. She links the impulsiveness of children with Attention Deficit Hyperactivity Disorder to problems with time perception and has found that the pre frontal lobe, which is key for perceiving time is both functionally and structurally different in children with the disorder, which means that time goes much slower for them. This goes some way to explain their impatience and inability to sit still.

Producer: Fiona Roberts

Presenters: Dr Hannah Fry and Dr Adam Rutherford

A BBC Audio Science Unit Production for BBC Radio 4, first broadcast 2021.

The doctors put mosquitoes on trial, as listener Cathy in the UK asks, ‘What is the point of mosquitoes?’ in response to our show about wasps.

Mosquitoes have undeniably played a role in killing millions of people. Malaria is the single biggest cause of death in human history. But Erica McAlister, senior curator of flies and fleas at the UK’s Natural History Museum, reveals that not all mosquitoes are interested in biting us for a blood meal, or are involved in transmitting disease. Only the females of about 10 species are the most problematic for humanity, from around 3600 true species of mosquito. Limited research indicates that many play important roles in ecosystems, for example as pollinators on land and as food sources during their larval stage in aquatic environments.

Nonetheless, those roughly 10 species cause devastating disease. Kate Jones’ research at University College London examines the interface of ecology and human health. Malaria and dengue fever alone cause over 300 million infections annually.

And there are many more diseases transmitted by mosquitoes: Zika, West Nile fever, Yellow fever, Japanese encephalitis – the list goes on, and with urbanisation and climate change, the picture is constantly changing.

So what can be done? Should we try to annihilate the disease-carrying species?

Insecticide use has historic and ongoing controversy, as the difficulties of needing to stop deaths in the short term risks longer term environmental damage, with unforeseen and possibly greater consequences for humanity. So Adam turns to new, genetic technology with zoologist Matthew Cobb. Can and should we modify mosquitoes to wipe themselves out, by wrecking local populations with sterile males, or use a technique called a gene drive to perpetuate debilitation through generations? Or could life find a way to evolve past our attempts at control, and cause greater problems?

The doctors deliberate and try to decide a verdict on mosquitoes’ fate.

Presenters: Hannah Fry & Adam Rutherford

Producer: Jen Whyntie

A BBC Audio Science Unit production for BBC Radio 4, first broadcast in 2021.

Astrology – could there be something to it? asks Dan from Australia. Rutherford and Fry investigate the science that has investigated astrology.

Professor Richard Wiseman, (sceptical of all things paranormal and a Virgo) and Professor in the Public Understanding of Psychology at the University of Hertfordshire, explains the long history of the scientific investigation of astrology. He has also run his own experiments to test whether astrology can help you play the stock market and to investigate if people born in the summer are luckier than those born in the winter – the results may surprise you.

Journalist and author, Jo Marchant (Leo and fascinated non-believer) has written all about the history of astrology in her new book – 'The Human Cosmos – A Secret History to the Stars'. In the beginning astrology and astronomy were one and the same. She explains how astrology flourished with the elite and ruling classes of ancient Babylon, Egypt and Greece.

Data scientist, Alex Boxer (Taurus and cautious astrology tourist) explains that astrology may have been humanity's first attempt to predict the future with algorithms, something we’re doing more and more of now. In his book, ‘A scheme of heaven, astrology and the birth of science’, he describes how astrological and scientific algorithms are all just big data science looking for patterns. The issue lies in what that data is.

Presenters: Hannah Fry (Pisces) & Adam Rutherford (Capricorn) Producer: Fiona Roberts (Libra)

First broadcast on BBC Radio 4 in 2021.

Why do some people find noises like a fork scraping a plate so terrible? asks Findlay in Aberdeenshire. Rutherford and Fry endure some horrible noises to find out the answer.

Warning - This episode contains some horrible sounds

Trevor Cox, Professor of Acoustic Engineering at the University of Salford, has run experiments to find out the worst, most cringe-making sound. He divided horrible sounds into three categories: scraping sounds, like nails down a blackboard; disgusting sounds like a snotty sniffy nose; and sounds that make us cringe because of what we associate them with, like the dentist’s drill. All horrible sounds have some sort of association whether it’s a primal scream or fear of catching a disease, and they’re dealt with in the ancient part of the brain – the amygdala.

Professor Tim Griffiths is a Cognitive Neurologist at Newcastle University’s Auditory Cognition Group. He has been studying people with misophonia, a condition where ordinary, everyday sounds, such as someone eating or breathing causes a severe anxiety and anger response. Misophonia may affect around 15% of the population and Tim thinks that different parts of the brain – the insula and the motor cortex - are involved in this fight or flight response to seemingly innocuous sounds.

Cat Thomas’s job is to make horrible sounds. She is a foley artist at Boompost. If you watch Call the Midwife or Peaky Blinders, all the incidental sounds are created by Cat and her team. She also created some of the sounds for the horror film Camilla, which involved evisceration and disembowelling with the aid of some squishy oranges and bananas. Adam Rutherford and Hannah Fry try their own horror sounds when they chop off a finger with the aid of some large pasta shells, an orange and a knife.

If you want more information on misophonia – http://www.misophonia-uk.orghttps://www.allergictosound.com

Presenters: Hannah Fry & Adam Rutherford

Producer: Fiona Roberts

A BBC Audio Science Unit production for BBC Radio 4 first broadcast in January 2021.

Can I make a pizza that contains my recommended daily intake of everything? asks listener Paul in Manchester. We investigate whether a pizza can meet our full dietary requirements.

The optimum diet for humans has been long contested. From William the Conqueror's alcohol diet to the infamous apple cider vinegar diet, discovering the healthiest nutrition is a centuries-long work in progress. So could The Pizza Diet be the next food fad?

We investigate a theory that a basic margherita pizza – with its components of a flour-filled base, along with a cheese topping – should meet our needs for carbohydrate, protein and fat. Adam meets up with body-weight geneticist Giles Yeo from their respective kitchens for a remote cook-off to find out if it's possible to make this mythical one-meal wonder in practice.

On closer inspection of the evidence-based government dietary requirements, this task appears somewhat challenging. Dietitian Clare Thornton-Wood analyses the components of a margherita and unsurprisingly finds they do not entirely meet the guidance.

She then scrutinises our attempt to retrofit a recipe that might do the job. Giles attempts to put our proposed pizza into practice. He has to ad-lib, as the resultant mountain of eclectic toppings – chickpea and sweetcorn pizza, anyone? – and giant base won’t fit in his oven.

Disappointingly for hardcore pizza fans like Paul who may be attempting healthier eating habits in 2021, it seems that this particular approach is not the way forward. Food choice psychologist Suzanna Forwood explains why there is so much more to our dietary decisions than digestive physiology, and offers tips for listeners hoping to make seasonal steps in a healthy direction.

Presenters: Hannah Fry & Adam Rutherford

Producer: Jen Whyntie

A BBC Audio Science Unit production for BBC Radio 4 first broadcast in 2020.

"Why are some fungi helpful and others harmful?" asks Paul Glaister in Reading. Rutherford and Fry try to outdo each other with fungal top trumps to get to grips with the answer.

Decomposition ecologist Lynne Boddy, Professor of Microbial Ecology at Cardiff University, helps Hannah calculate the amount of dead plant material we’d be buried in across the globe, if we didn’t have fungi to recycle it. And she describes her first fungal encounter in her student flat which was riddled with dry rot, and explains how without fungi, we wouldn’t have plants.

On Adam’s team is Curator of Mycology, Dr. Bryn Dentiger, at the Natural History Museum of Utah. Bryn tells Adam that he can’t think of a single food that doesn’t have some association with fungus. And the links are mostly positive rather than just mould on the top of your jam or rotten fruit in your fridge. He introduces Adam to the Humungous Fungus – the biggest living organism on Earth - and they get excited at the prospect of 20,000 different fungal sexes.

The pros and cons of fungi don’t stop there. Microbiologist Dr. Ada Hagan, in Michigan lists some of the fungal diseases we’re prone to, and the numerous drugs derived from fungi that help treat a whole host of common diseases.

Presenters: Hannah Fry & Adam Rutherford Producer: Fiona Roberts

A BBC Audio Science Unit production, first broadcast on BBC Radio 4 in 2020.

What would it take for humans to live permanently on Mars? asks Martin in Weston-super-Mare, UK. The doctors dig into requirements and possibilities of a long-term Martian outpost.

We know that many missions to Mars have failed, for a range of reasons – malfunctions, crashes and even a mix-up between imperial and metric units. Getting to Mars – let alone decelerating from 30,000 miles per hour to a safe landing speed in about seven minutes – is not straightforward. Aerospace engineer Anita Sengupta helped land NASA’s Curiosity rover on Mars. She knows first-hand the challenges of putting a robot on the red planet.

But getting robots to Mars is an easier proposition than doing the same for humans. Even if we work out how to survive the radiation exposure on the eight-month journey and the pulverising descent, Mars’ surface isn’t easily habitable. Principal investigator for NASA’s Mars Atmosphere and Volatile Evolution Mission (MAVEN) Bruce Jakosky describes the conditions on Mars: Freezing, with an atmosphere containing mostly carbon dioxide and very little water, and subject to annual global dust storms.

However, this isn’t deterring space agencies and private companies from researching the challenge. The European Space Agency and Russian Institute for Biomedical Problems focussed on finding out the physiological and psychological tolls by selecting six candidates to spend 520 days in a simulated spacecraft and landing module. Diego Urbina explains the personal challenge of taking part in the Mars500 experiment.

Some private company owners have gone even further. As well as making technology based on the current physical conditions, could those constraints themselves be altered? Could Mars be terraformed, or warmed, for easier human survival? Bruce Jakosky shares just what that would take – and compares these requirements with what’s actually available.

Presenters: Hannah Fry & Adam Rutherford Producer: Jen Whyntie A BBC Audio Science Unit production, first broadcast on BBC Radio 4 in 2020.

"How many hamsters on wheels would it take to power London?" asks Judah from Virginia in the USA. Rutherford & Fry return with engineering, ethics and economics to answer this electric query.

Smart grid engineer Lynne McDonald helps keep the lights on for 8.3 million homes and businesses across London at UK Power Networks. She explains how the kilowatt hours we see on our electricity bills relate to the thousands of gigawatt hours required when thinking about powering the whole of London. In theory, a hamster in a wheel might be able to produce about half a watt of power – enough to run a small LED light bulb.

Whilst the doctors argue the case on the resultant practicalities and ethics of even considering such a scenario – as, for example, the required cubic kilometre stack of hamster habitats would cover Canary Wharf – Royal Veterinary College researcher Zoe Davies points out some biological and anatomical home truths. As an expert in biomechanics currently investigating athletic performance in racehorses, she walks Adam through the impossibilities of using pretty much any animal, bird or insect as a source of power.

There may be one exception though: humans. Veteran lecturer of undergraduate chemistry for biologists and cycling enthusiast, Andrea Sella discusses whether human power might realistically work. We consider what this or other more realistic sources of renewable energy could mean for the future of our national grid.

Presenters: Hannah Fry & Adam Rutherford

Producer: Jen Whyntie

A BBC Audio Science Unit production for BBC Radio 4, first broadcast in December 2020.

Is there a point in space where the Sun could heat a burrito perfectly? asks Will.

The doctors tackle this and a plethora of other conundrums from the Curious Cases inbox.

Featuring expert answers from:

Astrophysicist Samaya Nissanke Cosmologist Andrew Pontzen Cognitive neuroscientist Sophie Scott

Presenters: Hannah Fry & Adam Rutherford

Producer: Jen Whyntie

First broadcast on BBC Radio 4 in July 2020.

‘Today I learnt that tigons and ligers are what you get when lions and tigers interbreed?!’ surprised listener Jamz G tells the doctors. ‘What determines whether species can interbreed?’

Geneticist Aoife McLysaght studies molecular evolution. She explains the modern definition of a species, built on ideas from Aristotle, Linnaeus and Darwin: a species is a group of organisms capable of interbreeding to produce fertile offspring. Hybrids – such as ligons and tigers – are usually infertile, because their common ancestors long ago diverged into the lions and tigers we know today. However, this definition isn’t absolute, and there are many ways a new species can be formed.

Hybrids also offer rich study subjects for scientists. Mathematical biologist Kit Yates discusses why he’s been reading research papers about hebras and zorses (horse x zebra) as their patterns offer insights into how cells spread and develop into organisms, building on a prediction made by codebreaking mathematician Alan Turing.

And it turns out that these hybrids are even more intriguing. As speciation and evolution expert Joana Meier explains, hybrids are not always infertile. Hybridisation can lead to successful new species arising, such as in Lake Victoria’s cichlid fish, who it seems have been having a wild evolutionary party for the last 15,000 years. And the picture gets even murkier when we discover that modern genetics reveals our human ancestors successfully mated with Neanderthals.

Presenters: Hannah Fry & Adam Rutherford

Producer: Jen Whyntie

First broadcast on BBC Radio 4 in July 2020.

Everyone knows about the Big Bang being the beginning of the universe and time - but when and how is it going to end? ask brothers Raffie and Xe from Rome.

For this series, with lockdown learning in mind, Drs Rutherford and Fry are investigating scientific mysteries for students of all ages. The doctors sift science from philosophy to find out.

Cosmologist Jo Dunkley studies the origins and evolution of the universe. She explains how astrophysical ideas and techniques have evolved to tell us what we now know about our galaxy and far beyond, from the elegant parallax technique to standard candles. This particular distance measure, which uses stars of a known brightness to work out how far away other objects in the universe are, was discovered by American astronomer Henrietta Swan Leavitt in 1912, who worked at the Harvard University as one of several “computers” – women who processed and calculated data and made significant contributions to astronomy.

Curious Cases’ universal guru Andrew Pontzen puts this into context. Because the universe is so enormous, it turns out that these measurements are just the first steps on the cosmic distance ladder – a suite of tools that astrophysicists use to determine distances to celestial objects. Scientists know that objects are moving away from us because the wavelengths of light from them get stretched and appear redder in our telescopes – the so-called red shift effect. But having a handle on the distances to and between those objects allows cosmologists to monitor what’s happening to them over time. And it turns out that not only are they getting further apart, indicating that the universe is expanding, but that this process is accelerating.

So what might happen in the end? Expansion and then collapse – a big crunch? Expansion into the void – a big freeze, or a big rip? Or what if there is more than one universe – might a new one bubble up with totally different laws of physics that would cause our own to cease existing?

It turns out that when dealing with predictions for something involving infinite space and time, the possibilities are largely limited by human imagination alone. Ideas are where science starts, but experiments are required to build evidence confirming or rejecting them as fact. The doctors discuss how gravitational wave detectors and quantum computers might one day provide this.

Presenters: Hannah Fry & Adam Rutherford Producer: Jen Whyntie

First broadcast on BBC Radio 4 in June 2020.

"What’s the point of wasps?" asks listener Andrew, who is fed up with being pestered. For this series, with lockdown learning in mind, Drs Rutherford and Fry are investigating scientific mysteries for students of all ages. Do wasps do anything to justify their presence as a picnic menace?

Ecologist Seirian Sumner researches social wasp behaviour and champions their existence. Not only do yellow jacket wasps perform important ecological services as generalist pest controllers of aphids, caterpillars and flies in the UK, they have complex societies and may even perform pollination services, making them more like their better-loved bee cousins than many might think.

However, much remains unknown about wasps’ contribution to our ecosystem. Seirian works with entomologist Adam Hart, and together they run The Big Wasp Survey each summer, a citizen science project dedicated to find out more about UK wasp species and their populations. Prof. Hart sets up an experimental picnic with Dr Rutherford to try and attract some native wasps, and discusses why they are so maligned.

But in some parts of the world UK wasp species have become a major problem. Just after World War II, having unwittingly chosen some aircraft parts destined for New Zealand as their overwintering home, some wasp queens woke up in the city of Hamilton. With no natural predators or competitors, they quickly established a growing population. Fast forward to today, and by late summer the biomass of wasps becomes greater than all the birds, rodents and stoats in the southern island’s honeydew beech forests. Multiyear nests have been discovered that are over three metres tall and contain millions of wasps. Researcher Bob Brown is digging into wasp nests back in the UK to discover which species keep wasps in check here, and whether they might work as biological control.

This causes the doctors to ponder the problems of humans moving species around the planet. Accidental or even well-meaning introductions all too often become invasive. As climate change and urbanisation accelerate, wasps may become more helpful in some ways and more harmful in others.

Presenters: Hannah Fry, Adam Rutherford Producer: Jen Whyntie

First broadcast on BBC Radio 4 in 2020.

"Could you make a machine to make it rain in minutes?" asks listener Alexander from Hampshire, aged 12. For this series, with lockdown learning in mind, Drs Rutherford and Fry are investigating scientific mysteries for students of all ages. Rutherford and Fry dive into the clouded story of weather modification. First, we need to decide where and when we might deploy any rain machine. Liz Bentley, Chief Executive of the Royal Meteorological society, takes us through the science, maths and art of predicting the weather. Hannah heads down to the BBC Weather Centre to meet meteorologist Helen Willetts, who takes us through the highs and lows of forecasting.

And then for the technology itself. Mark Miodownik, scientist and author of Liquid: The Delightful and Dangerous Substances The Flow Through Our Lives, reveals that a technique called cloud seeding has almost certainly been tried in different places around the world for decades. But, whilst it’s supposed to induce showers and even clear the way for sunny spells, the results aren’t always reliable. And even if we can make it rain, Liz explains why messing with the weather may be at our peril. Presenters: Hannah Fry, Adam Rutherford Producer: Jen Whyntie

First broadcast on BBC Radio 4 in 2020.

"Why do our tummies rumble - and when they do, does it always mean we are hungry?" asks listener James, aged 12. For this series, with lockdown learning in mind, Drs Rutherford and Fry are investigating scientific mysteries for students of all ages. To get to the bottom of this noisy problem, the doctors tune in to our guts.

Geneticist Giles Yeo studies food intake and obesity. He explains the wavy workings of our digestive system, and how those audible rumbles are a sign that digestion is taking place – a phenomenon thought to be onomatopoeically named 'borborygmi' by the ancient Greeks, and explored further in the gruesome 19th century experiments of surgeon William Beaumont.

However, tuning in to the gut’s sounds can tell us more than whether we need a snack. Family doctor Margaret McCartney takes us through the process of how and why she and her medical colleagues may use a stethoscope to listen to your abdomen for both particular noises and silence.

Microbiologist Barry Marshall has taken medical listening one step further in his Noisy Guts Project. Inspired by microphones used to listen for termites hiding in walls, the Nobel Prize-winning scientist is trialling an acoustic belt, which could be worn to help diagnose and treat Irritable Bowel Syndrome.

Presenters: Hannah Fry, Adam Rutherford Producer: Jen Whyntie

First broadcast on BBC Radio 4 in 2020.

"What are wormholes and do they really exist?" asks Manlee-Fidel Spence, aged 12. In this exotic episode, the doctors investigate how wormholes would work.

Cosmologist Andrew Pontzen explains why wormholes could allow you to travel through time as well as space. And physicist Jim AlKhalili outlines the infinite problems this could generate.

When it comes to wormholes and time travel, many science fiction stories have married solid science and successful storytelling, as Jennifer Oullette describes, but others really have defied the laws of physics. Jim also reveals why some quantum physicists now think that wormholes could be everywhere. But don't expect to jump back to 1955 any time soon.

Presenters: Hannah Fry, Adam Rutherford Producer: Michelle Martin

First broadcast on BBC Radio 4 in 2020.

Two cold callers feature in this episode. Jennifer Langston from Ontario in Canada sent this message to curiouscases@bbc.co.uk:

"My husband has just taken up cold water swimming and he'll swim in temperatures as low as 6 degrees Celsius. I worry that it's too cold for him, but he claims that 'swimming in cold water is good for you', which drives me bonkers. Can you tell us if there is any scientific proof behind this?”

Adam takes a trip to his local lido and asks the locals why they get a kick out of a chilly winter dip. Meanwhile, Hannah calls the Antarctic to talk to meteorologist Richard Warren about the perils of a frozen beard.

Our second cold caller, Sarah Dudley, asks why women get cold feet in bed. Thermal physiologist Heather Massey is on hand with the answer.

But when it comes to the natural world, other animals are masters of sub-zero living. Frozen Planet producer Kathryn Jeffs, from the BBC's Natural History Unit, explains why polar bears are perfectly designed for the Arctic. And we discover why Paddington Bear is better suited to Peru.

Presenters: Hannah Fry, Adam Rutherford Producer: Michelle Martin

First broadcast on BBC Radio 4 in 2020.

“I suppose a cold is called a cold because we catch it in the winter," writes Alison Evans from St Albans. "But why is it that we get more colds in winter than in the summer?”

This week's Cold Case is all about the common cold, a set of symptoms caused by hundreds of different strains of cold and flu viruses.

Adam uncovers the stinky history of infectious disease with medical historian Claire Jones.

Virologists Jonathan Ball and Wendy Barclay describe how spiky viruses lock on to our cells, but why many of the symptoms of a common cold are due to our own body's overreaction.

Plus, we delve into the science of sneezing with nose doctor Carl Philpott.

Presenters: Adam Rutherford, Hannah Fry Producer: Michelle Martin

"My question is about something I became aware of at a young age," explains Samantha Richter from Cambridgeshire.

"I was sitting on the carpet at school, being read a story by the teacher. My hair felt as though it was standing on end as waves of a tingly sensation washed over my head. I subsequently found certain scenes in films had this effect, when actors were talking softly, or someone was having their hair brushed."

"Then, a few years ago, I discovered that there is a name for the tingles, it's called ASMR. My question is, what is ASMR, and why do we experience it?"

In this episode, we explore the world of Autonomous Sensory Meridian Response. It's a trend which has risen quickly on YouTube, with devoted subscribers following their favourite 'ASMRtists' whose videos receive millions of plays.

Hannah speaks to Dr Nick Davis, who published the very first research paper on the phenomenon in 2015. And Adam is put to the test by Dr Giulia Poerio, to see if he is susceptible to the sensation of ASMR. Are there any proven benefits for devoted fans, or is it just a YouTube fad?

We've concocted our very own Curious recordings so you can find out if your brain begins to tingle. You'll find them in our normal podstream, where you can enjoy Adam and Hannah crafting a very ASMRy cocktail for your listening pleasure.

Presenters: Hannah Fry, Adam Rutherford Producer: Michelle Martin

First broadcast on BBC Radio 4 in 2020.

Hannah Fry mixes a mojito. This ASMR recording accompanies the episode of The Curious Cases of Rutherford and Fry on the science of ASMR. Listen to that first, then grab some headphones and let us know if it gives you the brain tingles by emailing curiouscases@bbc.co.uk.

Adam Rutherford concocts an Old Fashioned. First listen to our episode on ASMR, then grab some headphones and let Adam mix you a cocktail. Let us know if it gives you the brain tingles, or any other kind of reaction, by emailing curiouscases@bbc.co.uk.

Two questions about love and heartbreak in this episode for our Valentine's special edition.

Jessica Glasco, aged 29, wrote in to ask about the power of love and how it affects our brain.

Hannah tracks down Dr Helen Fisher, who conducted some of the first MRI studies on love by putting besotted couples into the brain scanner.

Adam talks to broadcaster Claudia Hammond, author of Emotional Rollercoaster, to find out how psychologists have grappled with the messy business of love. And we hear why a small furry vole was thought to hold the answer to the mystery of monogamy.

Our second question concerns the pain of heartbreak - why does our heart ache? Can emotional hurt cause physical pain? On call is our very own agony aunt, Irene Tracey, Prof of Pain Research.

Presenters: Hannah Fry, Adam Rutherford Producer: Michelle Martin

First broadcast on BBC Radio 4 in 2020.

"How do you make gold?" asks curious listener, Paul Ruddick.

Inspired by the promise of riches, Hannah and Adam embark on a mission to discover the origin of gold. It's a tale that takes them from the clandestine codes of Aristotle to the alchemy of Isaac Newton, alongside materials scientist Mark Miodownik.

They boldly go into the cosmos with astronomers Lucie Green and Andrew Pontzen, to learn what happens in the most exotic areas of space. By the end one thing is for sure - you'll never look at your gold jewellery in quite the same way again.

Presenters: Hannah Fry, Adam Rutherford Producer: Michelle Martin

First broadcast on BBC Radio 4 in 2020.

"What would become the dominant species if, or when, humans go extinct?"

This cheery question leads Drs Rutherford and Fry to embark on an evolutionary thought experiment.

Zoologist Matthew Cobb questions whether humans really are the dominant species. Ecologist Kate Jones explains why some species are more extinction-prone than others. Plus Phil Plait, AKA The Bad Astronomer, busts some myths about why the dinosaurs went extinct.

Send your questions for future series, along with any Curio correspondence for the podcast, to: curiouscases@bbc.co.uk

Presenters: Hannah Fry, Adam Rutherford Producer: Michelle Martin

First broadcast on BBC Radio 4 in 2019.