Hannah and Adam return to crack open the Curious Cases they’ll be examining during the coming series, from the sound of musical instruments to the science of hypnosis.

Please send your questions for future episodes and entries for Curio of the Week to: [email protected].

Presenters: Hannah Fry, Adam Rutherford

"My name is Ava and I've never had a hangover," writes Ava Karuso. "I'm a 25 year-old Australian and I enjoy going out for drinks. However, the next day when everyone else sleeps in and licks their wounds, I get up early and get right back to my normal routine.”

Drs Rutherford and Fry investigate the ancient origins of alcohol, from Sumerians drinking beer through straws, to Aristotle's teachings ‘On Intoxication’.

But what can modern science tell us about how alcohol affects our brains? What causes the morning-after hangover and do some drinks make you feel worse than others? Are there any hangover cures that have been scientifically validated?

Featuring health psychologist and hangover researcher Sally Adams, chemist Andrea Sella and science writer Adam Rogers, author of 'Proof: The Science of Booze'.

Presenters: Hannah Fry, Adam Rutherford

First broadcast on BBC Radio 4 in 2018.

“Why does bad food taste so good?” asks Alan Fouracre from Tauranga, New Zealand. "And by ‘bad’ food, I mean the things we are told to hold back on like sausage, chips and chocolate."

From sugar to salt and fat, we investigate why our body derives pleasure from the very foods we're often told to avoid.

Adam discovers why retronasal smelling makes bacon taste delicious on a trip to the BBC canteen with materials scientist, Mark Miodownik.

Hannah consults food scientist Linda Bartoshuk on her fizzy pop habit. Plus The Angry Chef, Anthony Warner, discusses the dangers of labeling certain foods as 'bad'.

Presenters: Hannah Fry, Adam Rutherford

First broadcast on BBC Radio 4 in 2018.

In the second part of our eternal quest to investigate infinity, inspired by this question from father and son duo Sorley and Tom Watson from Edinburgh: “Is anything in the Universe truly infinite, or is infinity something that only exists in mathematics?”

Hannah and Adam try and find something that is truly infinite, from the infinitely small particles that live in the subatomic world to the infinitely dense heart of a black hole. But how about the Universe itself? We find out how physicists go about measuring the shape of the Universe, with the help of an orange and a game of Asteroids. Plus, we consider the possibility that the Universe might be finite and have an edge. If so, what's on the other side?

Theoretical physicist Sean Carroll from Caltech and cosmologist Andrew Pontzen from University College London help us navigate our biggest question yet.

Presenters: Hannah Fry, Adam Rutherford

Producer: Michelle Martin

First broadcast on BBC Radio 4 in 2018.

“Is anything in the Universe truly infinite, or is infinity something that only exists in mathematics?”

This momentous question came from father and son duo from Edinburgh Sorley aged 10 and Tom, aged adult. It's a subject so big, that we've devoted two episodes to our never-ending quest to investigate infinity.

The first installment is a story of mathematics, music and murder. We'll find out why the ancient Pythagoreans decided that infinity was evil, and why some infinities are bigger than others.

Featuring the marvellous mathematical minds of Steven Strogatz from the Cornell University and Eugenia Cheng, author of 'Beyond Infinity'.

Presenters: Adam Rutherford, Hannah Fry

Producer: Michelle Martin

First broadcast on BBC Radio 4 in December 2018.

"How do accents start and where did they come from?” asks Sachin Bahal from Toronto in Canada.

Hannah is schooled in speaking Geordie by top accent coach Marina Tyndall. And Adam talks to author and acoustics expert Trevor Cox about how accents evolved and why they persist.

We meet Debie who has Foreign Accent Syndrome - an extremely rare condition in which your accent can change overnight. After a severe bout of flu, which got progressively worse, Debie's Brummie accent suddenly transformed into something distinctively more European.

If you have any more Curious Cases for the team to solve, please send them in for consideration: [email protected]

Presenters: Adam Rutherford, Hannah Fry

Producer: Michelle Martin

First broadcast on BBC Radio 4 in November 2018.

"Is it true all British people can trace their ancestry to Vikings and how do ancestry DNA tests work?" asks Chloe Mann from Worthing.

Genetic ancestry tests promise to reveal your ancestral origins and map your global heritage, but do they? Rutherford and Fry are here to bust some myths.

Adam takes a trip through Norse history with Viking historian Janina Ramirez, whilst flying over the Medieval town of Ludwig.

Meanwhile Hannah discovers how DNA ancestry tests work with evolutionary geneticist Mark Thomas, including why most of us can rightly reclaim our royal lineage.

If you have any more Curious Cases for the team to solve, please send them in for consideration: [email protected]

Presenters: Adam Rutherford, Hannah Fry

First broadcast on BBC Radio 4 in November 2018.

"Why do people experience pain differently when they go through the same event?" asks Claire Jenkins from Cwmbran in Wales.

Professor of Pain Research, Irene Tracey, welcomes Adam in to the room she calls her 'Torture Chamber'. Burning, electrocuting, lasering and piercing are all on the menu, but which will hurt the most?

Hannah speaks to Steve Pete from Washington who has a rare genetic condition which means he doesn't feel pain. For chronic sufferers, this sounds like heaven, but a life without pain has brought untold suffering to him and his family, including the tragic story of his brother, Chris.

We look at how the body creates pain, why some people feel it more than others, and how this knowledge could help scientists treat pain more effectively in the future.

Presenters: Adam Rutherford, Hannah Fry

Two random questions in this episode. "Is anything truly random, or is everything predetermined?" asks Darren Spalding from Market Harborough.

Hannah and Adam go in search of random events, from dice throws to lava lamps. Can we predict the outcome of any event? And "how do computers manage to pick random numbers?", asks Jim Rennie from Mackinaw in Illinois.

Joining them are a random selection of experts: mathematician Colva Roney-Dougal, technology journalist Bill Thompson, Science Museum Curator Tilly Blyth and quantum physicist Jim AlKhalili.

Presenters: Adam Rutherford, Hannah Fry

"How fast can a human run and would we be faster as quadrapeds?" This question flew in via Twitter from historian Greg Jenner.

Is there a limit to human sprinting performance? In this episode we investigate the biomechanics of running, statistical trends in human performance and which kind of monkey runs the fastest.

But first, an experiment. Due to some spurious and possibly fictional injuries, neither Hannah nor Adam are fit enough to take part in a sprint trial at the University of Bath. So long-suffering Producer Michelle steps up to the challenge and into the starting blocks. Not known for her love of athletics, or exercise of any sort, how will she fair in the ultimate speed test?

Biomechanist Peter Weyand from Texas discusses the role of different muscle types in speed versus endurance. Sports scientist Polly McGuigan reveals why Usain Lightning Bolt is still the fastest man in the world. And Prof of Sports Engineering Steve Haake reveals how fast a man can run like a monkey.

Presenters: Hannah Fry, Adam Rutherford