Discovery

"What happens to the human voice as we age? If I hear a voice on the radio, I can guess roughly how old they are. But singer's voices seem to stay relatively unchanged as they age. Why is this?" All these questions were sent in by Jonathan Crain from Long Island in New York. Doctors Adam Rutherford and Hannah Fry discover how the human voice is produced and listen to how our voice sounds when it e...

“Is anything in the Universe truly infinite, or is infinity something that only exists in mathematics?” This question came from father and son duo from Edinburgh in Scotland, Tom and Sorely Watson. First, we investigate the concept of infinity in mathematics with a story of mathematics, music and murder from Steven Strogatz from the Cornell University. Did you know that there are some infinities t...

4/6 Part 1: Déjà vu "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 paran...

3/6 In this instalment of The Curious Cases of Rutherford & Fry, Hannah and Adam boldly go in search of scientists who are hunting for ET, spurred on by questions sent in by listeners across the globe, from Australia to Columbia. They start by asking how we define life and why we are obsessed with finding it on Mars. Should we be looking further out in the Solar System, and could we find space...

2/6 "How fast can a human run and would we be faster as quadrapeds?" This question flew in via Twitter from 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...

1/6 "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. In this new series of The Curious Cases of Rutherford and Fry, Hannah and Adam are joined by the Curious Cases band - Matt Chandler and Wayne Urquhart - to play with to...

Our senses create the world we experience. But do animals have a ‘sense’ of time, and does that differ between species, or between us and other animals? We know that animal senses reveal a wealth of information that humans can't access. Birds can see in ultra violet, and some fish can 'feel' electricity. So perhaps their sense of time is similar. If you've ever tried to swat flies, you'll know tha...

Dr Catherine Hobaiter studies how apes communicate with each other. Although she is based at the University of St Andrews in Scotland, she spends a lot of her time in the forests of Uganda, at the Budongo Research Centre. There, she is endlessly fascinated by the behaviour of great apes. Cat Hobaiter tells Jim al-Khalili about the difficulties of carrying out research on chimps in the wild. It can...

Carlo Rovelli is a theoretical physicist who became a household name when his book Seven Brief Lessons on Physics became an unexpected international bestseller. His concise, and poetic, introduction to the laws and beauty of physics has sold more than a million copies. He’s also a pioneer of one of the most exciting and profound ideas in modern physics, called loop quantum gravity. Carlo Rovelli t...

Professor Corinne Le Quéré of University of East Anglia talks to Jim Al-Khalili about tracing global carbon. Throughout the history of planet Earth, the element carbon has cycled between the atmosphere, the oceans and the biosphere. This natural cycle has maintained the amount of carbon dioxide in the atmosphere and has allowed life to exist for billions of years. Corinne Le Quéré is a climate sci...

Jim Al-Khalili talks to Ken Gabriel, the engineer responsible for popularising many of the micro devices found in smartphones and computers. Ken explains how he was inspired by what he could do with a stick and a piece of string. This led to an engineering adventure taking in spacecraft, military guidance systems and the micro-mechanical devices we use every day in our computers and smartphones. K...

Donna Strickland tells Jim Al-Khalili why she wanted to work with lasers and what it feels like to be the first woman to win a Nobel Prize for Physics in 55 years. When the first laser was built in 1960, it was an invention looking for an application. Science fiction found uses for these phenomenally powerful beams of light long before real world applications were developed. Think Star Wars light...

Imagine finding a notebook containing the secret recipes of some of the world’s most iconic perfumes? Formulas normally kept under lock and key. That’s what happened to medical research scientist and trained chemist Andrew Holding. His grandfather Charles “Rex” Holding had been Chief Perfumer at the Bourjois Chanel factory in Croydon, near London, during the 1960s. After his death, he left behind...

When Paradise burned down last year, it made the Camp Fire the most destructive and deadly in Californian history. A few months earlier the nearby Ranch Fire was the largest. In southern California, a series of chaparral fires have brought danger to towns along the state’s coast. And the statistics show that large, dangerous fires have been increasing for decades. But the reasons are not simple. R...

Los Angeles is a city of Angels, and of earthquakes. Deadly earthquakes in 1933, 1971 and 1994 have also made it a pioneer in earthquake protection – for example with tough engineering standards to save buildings. Since 2013, with the help of scientists at the US Geological Survey, the city has been developing a resilience plan which culminated in the release of an app that should give residents p...

For more than 100 years chemical weapons have terrorised, maimed and killed soldiers and civilians alike. As a chemist, the part his profession has played in the development of these weapons has long concerned Andrea Sella, professor of chemistry at University College London. In this programme he examines the motivation of chemists like Dr Fritz Haber, who first encouraged the German military to d...

In the first of two programmes he looks back to the first attempts to ban the use of chemical weapons at the end of the 19th century. Heavily defeated in the Crimea, Russia succeeded in getting unanimous agreement at the 1899 Hague Convention that poison and poison weapons should be banned from warfare. But chemicals such as chlorine, phosgene and mustard gas were heavily used in the First World W...

In a dry creek bed in the middle of the Australian outback is a palaeontological prize like no other: 95-million-year-old footprints stamped in a sandstone slab by three species of dinosaur. One of the beasts was a massive, lumbering sauropod that measured 18 metres from nose to tail. But the precious trackway is in danger of being damaged by the next floods, so must be moved. In the final episode...

The atoll of Tetiaro is a string of tiny islands in French Polynesia, about 60km away from Tahiti. The islands – known as ‘motus’ to local Polynesians – are unique ecosystems that are crucial nesting sites for native seabirds. But invasive species threaten to disrupt these fragile environments – a fate seen across many islands in the Pacific. Rats arrived with early human settlers and have driven...

The Night Parrot was supposed to be extinct and became a legend among birdwatchers in Australia: a fat, dumpy, green parrot that lived in the desert and came out at night. The last bird seen alive was promptly shot dead in 1912. Over 90 years later, a decapitated Night Parrot was found beside a fence in outback Australia, and the hunt for a living bird was on. Ornithologists descended onto the ari...

On this mission, SOFIA is setting out to study Titan, Saturn’s biggest moon, by flying into the faint shadow that it casts as it blocks the light from a faraway star. It’s a phenomenon called an occultation, and if the mission succeeds, it will reveal new details about Titan’s atmosphere. SOFIA is a very unusual observatory. It is a 747 aircraft with a hatch in the side, which opens in flight to r...

The Six Cornered Snowflake, a booklet written by Johannes Kepler as a New Year's gift, sought to explain the intricate and symmetrical shape of winter's tiny stars of snow. His insightful speculations about minerals and geometry were the beginning of the modern understanding of crystals. Philip Ball tells the story of how Kepler became a key figure in the scientific revolution of the 17th Century....

2000 years ago Lucretius composed a long poem that theorised about atoms and the natural world. Written in the first century BCE, during a chaotic and frightening time when the Roman Republic was collapsing, Lucretius encouraged people to feel free through contemplating the physics of the Universe. He said that despite living through a time of bloody civil wars and dictatorship people should not b...

Philip Ball's tale is of a solar eclipse 100 years ago observed by Arthur Eddington, a British astronomer who travelled to the remote island of Principe off the coast of West Africa and saw the stars shift in the heavens. His observations supplied the crucial proof of a theory that transformed our notions of the cosmos and turned a German physicist named Albert Einstein into an international celeb...

On Christmas Eve in 1968 Bill Anders was in orbit around the moon in Apollo 8 when he took one of the most iconic photos of the last fifty years: Earthrise. The image got to be seen everywhere, from a stamp issued in 1969 to commemorate the success of Apollo 8, to posters that are still available today. Gaia Vince explores the impact of this image on the environmental movement and our understandin...