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 RutherfordFirst 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 RutherfordProducer: Ilan GoodmanFirst 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 RutherfordProducer: Ilan GoodmanFirst 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 GoodmanFirst broadcast on BBC Radio 4 in February 2022.

Our sci-curious detectives will be investigating a menagerie of mysteries sent in by listeners - from teenage brains to the magic of Wi-Fi and our strangely symmetrical bodies.

As huge tech companies race to develop ever more powerful AI systems, the creation of super-intelligent machines seems almost inevitable. But what happens when, one day, we set these advanced AIs loose? How can we be sure they’ll have humanity’s best interests in their cold silicon hearts?Inspired by Stuart Russell’s fourth and final Reith lecture, AI-expert Hannah Fry and AI-curious Adam Rutherford imagine how we might build an artificial mind that knows what’s good for us and always does the right thing.Can we ‘programme’ machine intelligence to always be aligned with the values of its human creators? Will it be suitably governed by a really, really long list of rules - or will it need a set of broad moral principles to guide its behaviour? If so, whose morals should we pick?On hand to help Fry and Rutherford unpick the ethical quandaries of our fast-approaching future are Adrian Weller, Programme Director for AI at The Alan Turing Institute, and Brian Christian, author of The Alignment Problem.Producer - Melanie Brown Assistant Producer - Ilan Goodman

The refrain ‘robots will take your job’ is one heard with increased frequency, but how quickly is automation of the labour force really happening and would it really be such a bad thing if many jobs were powered by artificial intelligence?In this third episode, inspired by this year’s BBC Reith lectures from AI expert Stuart Russell, Adam Rutherford and Hannah Fry - together with expert guests - imagine what the future of work might look like. Will the move towards increased use of artificial intelligence in areas like healthcare, customer service and manufacturing see jobs disappear or will it simply create new ones we cannot yet imagine?Economists are divided on what the effects of machines doing our jobs will be. Some argue it could lead to wide scale unemployment, or skilled workers being forced in into lower skilled jobs. Others believe this might be an opportunity to reshape our socio-economic systems to one where workers are freed from tedious repetitive jobs and instead have more leisure time to pursue their own interests and find meaning outside of work. Will we all one day receive a universal basic income and stop asking each other what we do for work when we meet someone new?Producer - Melanie Brown Assistant Producer - Ilan Goodman

What if a despotic leader could programme a swarm of drones to kill a set of identified targets with just the push of a button? Due to ever expanding AI capabilities this extreme dystopian vision may not be technically unfeasible. In this second of a four part series responding to this year's BBC Reith lectures from Stuart Russell, Adam Rutherford and Hannah Fry unpick the role of AI in warfare.Joining them to help them navigate the battlefield of information is Ulrike Franke, a senior policy fellow at the European Council on Foreign Relations who specialises in the future of warfare.Together they will be investigating 'lethal autonomous weapons' - these are weapons that can find, chose and kill human targets without human supervision. We will be discussing how advanced this technology actually is - some think the world may have already experienced the first ever autonomous strike in Libya. What are the repercussions of this technology for safety on the battlefield , and what are the wider geo-political ramifications?Stuart Russell has deep concerns over the development of these types of weapons and Rutherford and Fry pick apart some of the ethical debates this technology raises. Who would be responsible if a system malfunctioned and killed a civilian? What's to stop it getting into the wrong hands? Should we even be creating these weapons in the first place - do we instead need a convention banning them? And is that even possible?

Artificial Intelligence (AI) is already ubiquitous in our lives. It curates our nightly TV entertainment, connects us to our friends online and navigates us, mostly successfully, to our destinations. However these uses are just the beginning, and it will likely bring societal changes we can’t yet imagine.In this year’s BBC Reith lectures, AI expert Professor Stuart Russell will be exploring how AI has been represented in popular fiction, envisaging how this technology might shape our futures and how we best prepare for it. So who better to unwrap his ideas than science sleuths Adam Rutherford and Hannah Fry, with their customary curiosity and irreverent insights?In this, the first of four episodes, Rutherford and Fry – together with guests author and podcaster Azeem Azhar and AI scholar Kate Crawford - will be unravelling what we actually mean by AI, exploring how far machine learning already underpins our lives, imagining the functions it might provide in the future and asking what challenges and risks might lie ahead. Can AI transform society as profoundly as electricity once did leading to a golden age for humanity, or have we all watched too many sci-fi movies?

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 RobertsFirst broadcast on BBC Radio 4 in November 2021.