Curious Cases

"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: curiouscases@bbc.co.ukPresenters: Adam Rutherford, Hannah FryProducer: Michelle MartinFirst 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: curiouscases@bbc.co.ukPresenters: Adam Rutherford, Hannah Fry Producer: Michelle MartinFirst 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 Producer: Michelle Martin.

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 Producer: Michelle Martin.

"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 Producer: Michelle Martin.

Do alien civilisations exist? When will ET phone home?In the second part of our alien double bill, Hannah and Adam boldly go in search of intelligence. They may be some time.What will aliens look like? Where should we look for them? And what are the chances of finding complex life in the cosmos? Featuring astronomer Seth Shostak from the SETI Institute in California, exoplanet hunter Sara Rugheimer from the University of St Andrews and zoologist Matthew Cobb from Manchester University,Presenters: Hannah Fry, Adam Rutherford Producer: Michelle Martin.

Mike Holcombe from Largs in Scotland asks, "How do we look for alien life and what are we expecting to find?"In the first of two episodes on the search for ET, Hannah and Adam look for life inside the Solar System. How do we define life and why we obsessed with finding it on Mars? Or should we be looking for space squid on Europa instead?Features interviews with planetary scientist Monica Grady from the Open University, senior astronomer Seth Shostak from SETI and zoologist Matthew Cobb from the University of Manchester.Send your Curious Cases for consideration in to curiouscases@bbc.co.ukPresenters: Hannah Fry, Adam Rutherford Producer: Michelle Martin.

"Winter is finally over and the birds are all singing their hearts out at dawn. What's all the noise about? And why are some songs so elaborate?" asks Tony Fulford from Ely in Cambridgeshire. We find out how birds produce multiple notes at once, which one has the widest repertoire of songs, and why males like to show off quite so much. Plus, we talk to researcher Lauryn Benedict about the project which aims to solve the mystery of why female birds sing - www.femalebirdsong.org.Featuring interviews with RSPB President and nature presenter Miranda Krestovnikoff, and world-renowned birdsong expert and sound recordist, Don Kroodsma.Archive of 'singing like a wren' courtesy of The One Show, BBC TV.Send your cases for consideration to curiouscases@bbc.co.uk.Presenters: Adam Rutherford, Hannah Fry Producer: Michelle Martin.

"My boss insists that if you choose the same numbers in the lottery each time your probability of winning will increase. Is this true?" asks Vince Scott from Edinburgh. National lotteries are played in more than 80 countries worldwide, but can you increase your chances of winning? Hannah consults statistician Jen Rogers to discover the best way to select your lucky numbers. Adam talks chance and luck with David Spiegelhalter and hears how the field of probability began with a philandering gambling polymath in 16th century Italy. Plus, we meet the Oxford professor who tried to beat the house in a Las Vegas casino, using a computer concealed inside his shoe.Presenters: Adam Rutherford, Hannah Fry Producer: Michelle Martin.

"Do we know what causes déjà vu?" asks Floyd Kitchen from Queenstown in New Zealand. Drs Rutherford and Fry investigate this familiar feeling by speaking to world-leading reseacher Chris Moulin from the University of Grenoble in France and memory expert Catherine Loveday from Westminster University. Plus, they find out why early investigations classed déjà vu as a type of paranormal phenomenon.For most of us, it's a fleetingly strange experience, but for some people it can become a serious problem. Lisa from Hulme in Manchester started experiencing déjà vu when she was 22 with episodes that could last all day. The origin of her déjà vu has been the key to helping psychologists investigate its cause.Presenters: Hannah Fry, Adam Rutherford Producer: Michelle Martin.