“We play many musical instruments in our family. Lots of them produce the same pitch of notes, but the instruments all sound different. Why is this?” asks Natasha Cook aged 11, and her Dad Jeremy from Guelph in Ontario, Canada.

For this instrumental case Hannah and Adam are joined by the Curious Cases band - Matt Chandler and Wayne Urquhart - to play with today's question.

Bringing the science we have acoustic engineer and saxophone player Trevor Cox. Plus materials expert Zoe Laughlin demonstrates a selection of her unusual musical creations, including a lead bugle.

Presenters: Adam Rutherford, Hannah Fry

First broadcast on BBC Radio 4 in 2019.

"Will the periodic table ever be complete?" asks Philip Craven on Twitter.

In 2016 four new chemical elements were given the official stamp of approval - nihonium, moscovium, tennessine, and oganesson. And 2019 was named by the UN as the International Year of the Periodic Table.

In this episode, Hannah and Adam dive into the test tubes of history to hear why the first element was discovered in boiled urine, why chips don't explode and how a cancelled trip to a cheese factory resulted in the creation of the periodic table.

We'll hear from Dawn Shaughnessy from Lawrence Livermore National Lab, part of the team that discovered the latest 'superheavy' elements. Science writer Philip Ball shows Adam around Humphry Davy's lab equipment at the Royal Institution of Great Britain and Jim Al-Khalili explains why scientists are eager to reach the Island of Stability.

Presenters: Adam Rutherford, Hannah Fry

First broadcast on BBC Radio 4 in April 2019.

“Is hypnosis real, and if so how does it work? Does it have any practical uses and which of Hannah and Adam is most susceptible?”

This question came from two Curios, Peter Jordan aged 24 from Manchester and Arran Kinnear aged 13 from Bristol.

Arch sceptics Hannah and Adam visit stage hypnotist Ben Dali to find out if they are susceptible to the power of suggestion. One of them will be successfully hypnotised, but who will it be?

Along the way we hear about the history of hypnosis from Wendy Moore author of 'The Mesmerist'. Plus psychologist Devin Terhune explains what we know about the science of hypnosis today.

Presenters: Hannah Fry, Adam Rutherford

Producer: Michelle Martin

First broadcast on BBC Radio 4 in April 2019.

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.