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...

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...

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...

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...

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...

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...

From exposing fraud to finding true love, mathematician Hannah Fry follows the numbers on thrilling adventures of data and discovery. Join her for Series 2 of Uncharted.

Behind every line on a graph, there lies an extraordinary human story. Mathematician Hannah Fry is here to tell us ten of them.

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...

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...

‘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...

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...

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...

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...

The new series kicks off very soon! As a little aperitif, Hannah and Adam review some surprising studies published in scientific journals. Warning: contains fruity language and grisly medical scenarios…

Ella Al-Shamahi introduces her new series, Why Do We Do That? An anthropologist's guide to the modern world. Listen and subscribe on BBC Sounds.

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 –...

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...

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...

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. ...

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...

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...

We asked you to send us the boldest, barmiest bits of published research you could find and, dear Curios, you didn't disappoint! It’s time for some silly science.

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...