Discovery

Physicist Paul Davies talks to Jim al-Khalili about the origin of life, the search for aliens and the evolution of cancer. Paul Davies is interested in some of the biggest questions that we can ask. What is life? How did the universe begin? How will it end? And are we alone? His research has been broad and far-reaching, covering quantum mechanics, cosmology and black holes. In the 1980s he described the so-called Bunch-Davies vacuum - the quantum vacuum that existed just fractions of a second after the big bang - when particles were popping in and out of existence and nothing was stable. As the chair of SETI (the Search for Extra-Terrestrial Intelligence) Post Detection Task Group, he’s the person responsible for announcing to the world when we make contact with aliens. He’s now Regents Professor of Physics at Arizona State University in the American south west where he runs research groups studying the evolution of cancer and the origins of life. Paul Davies talks to Jim al-Khalili about how he applies

In the 1950s a batch of polio vaccine in the US was made badly, resulting in 10 deaths and the permanent paralysis of 164 people. Paul Offit, a paediatrician in Philadelphia, says the disaster did not turn people away from vaccines. He believes that current vaccine hesitancy needs to be tackled online - where fake news spreads quickly. The German state of Brandenburg wants to make pre-school vaccinations compulsory - like neighbouring France and Italy - because immunisation rates there dropped to 73%. But some doctors believe busy parents can instead be gently persuaded to take up vaccines. Perhaps this is where psychological research can play a role. Sander van der Linden, Director of the Cambridge Social Decision Making Lab in the UK, is working on an online game which "inoculates" people against fake news - by showing them how they can be manipulated online. He says the effects last about 6 weeks - so a "booster" may be necessary. Head of the Vaccine Confidence Project Heidi Larson applauds 18 year old Ame

Global attitudes towards vaccinations are revealed in the Wellcome Trust’s Global Monitor survey. Our guide through the new data is Heidi Larson, Professor of Anthropology, Risk and Decision Science at the London School of Hygiene and Tropical Medicine who also leads the Vaccines Confidence Project. She says the most vaccine-sceptical country is France – because of past scares around different vaccines.The success of vaccines means people have forgotten how measles can be fatal – and parents are now influenced by scare stories about vaccines. More than half of the 1,000 recent cases of measles in the US have been in the Orthodox Jewish community in New York city. We hear from some of the parents who still don’t vaccinate and from a family doctor about trustworthy sources of information. Things couldn’t be more different in Madagascar where more than 1200 children have died from measles and parents walk for miles to have their children immunised. Half the country’s children are malnourished – which can increas

"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 emerges from our vocal cords. Acoustic engineer Trevor Cox, author of Now You're Talking, explains why German and French babies have a different accent. And neuroscientist Sophie Scott describes what happens when boys' voices break, and why a similar thing can happen to women during the menopause.Finally, our voices often change dramatically in later life, as demonstrated by comedy impressionist Duncan Wisbey. Expect cameos from David Attenborough, Dumbledore and Paul McCartney.Bird Song"Winter is finally over and the birds are all singing their hearts out at dawn. What is all the noise about? And why are some songs so

“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 that are bigger than others? We discuss the mind-bending nature of infinity with mathematician Eugenia Cheng, author of Beyond Infinity.Next we turn to physics to see if we can find something in the Universe that is truly infinite. Theoretical physicist Sean Carroll from Caltech University discusses the infinitely small inside subatomic particles. Plus cosmologist Andrew Pontzen from University College London travels into the heart of a black hole to see if we can find a something that is infinitely dense.But if we’re looking for something that is infinite, how about the Universe itself? We find out how physicists meas

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 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.Part 2: Randomness"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? "How do computers manage to pick random numbers?" asks J

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 squid on the icy moon Europa?When it comes to intelligent life we may have to scout even further into the Universe. But what are the chances of finding complex life in the cosmos? And where might it live?Featuring astronomer Seth Shostak from the SETI Institute in California, planetary scientist Monica Grady from the Open University, exoplanet hunter Sara Rugheimer from the University of St Andrews and zoologist Matthew Cobb from Manchester University.Send your Curious Cases for consideration in to curiouscases@bbc.co.ukPresenters: Hannah Fry, Adam Rutherford Producer: Michelle Martin.Main Image: This image obtai

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 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."Why do people experience pain diffe

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 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, a glass bell and a spruce tuning fork.Presenters: Adam Rutherford, Hannah Fry Producer: Michelle MartinMain image: 1-25 Wind instruments, 26-34 percussion instruments, Egypt, engraving by Duhamel from Description of Egypt, or the collection of observations and researches which were made in Egypt during the expedition of the French Army), Etat moderne, Planches, Volume II, Plate PlCC, Imprimerie Imperiale, 1

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 that they seem to have super-powered reactions that let them escape before you can blink. Presenter Geoff Marsh asks whether flies have some sort of super-power to see the world in slow motion. Are they watching your hand come down at what might appear a leisurely pace?Science reveals a window into the minds of different species and their temporal perceptions. Some birds have such fast vision that they can see and react to movement at twice the speed you can, and our vision works at more than six times the speed of one species of deep sea fish. This programme delves into each moment of experience to ask 'what is time, bi

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 take years to win the trust of the apes. She says that her approach is to adopt the attitude of a moody teenager. Look bored and the chimps will ignore her, but at the same time she is watching them closely. Her particular research area is in understanding not the sounds that apes make, but their gestures. From her observations she has found that they use around 80 different gestures - many of which are common, in the sense that they have the same meaning, across different species like chimps and bonobos. One thing she and her team hope to learn from these studies is how we humans have evolved spoken language.(Photo

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 tells Jim al-Khalili how he first became interested in the nature of time when he took LSD as a young man. Later he became curious about the world of the almost absurdly small, where time has no meaning and space is grainy. He took seven years to complete his undergraduate degree, having spent a lot of time protesting against the political establishment, falling in love and travelling. All this rebelling taught him the value of seeing the world in a different way and the benefits of challenging the status quo. In the end he concluded it was easier, and more meaningful, to challenge Einstein’s understanding of time,

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 scientist who keeps track of where the carbon comes from and where it goes – all on a truly global scale. Corinne Le Quéré is the founder of the Global Carbon Budget, which each year reports on where carbon dioxide is being emitted and where it is being absorbed around the world. More specifically, she studies the relationship between the carbon cycle and the earth’s climate, and how it is changing.

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.Ken Gabriel now heads up a large non-profit engineering company, Draper, which cut its teeth building the guidance systems for the Apollo space missions, and is now involved in developing both driverless cars and drug production systems for personalised medicine.Ken himself has a career in what he terms ‘disruptive engineering’. His research married digital electronics with acoustics - and produced the microphones in our phones and computers. He has also worked for Google, taking some of the military research methods into a civilian start up. This led to the development of a new type of modular mobile phone which has y

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 sabres and people being sliced in half. Today lasers are used for everything from hair removal to state of the art weapons. Working with her supervisor Gerard Mourou in the 1980s, the Canadian physicist, Donna Strickland found a way to make laser pulses that were thousands of times more powerful than anything that had been made before. These rapid bursts of intense light energy have revolutionised laser eye surgery and, it's hoped, could open the doors to an exciting range of new applications from pushing old satellites out of earth's orbit to treatments for deep brain tumours. Producer: Anna Buckley

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 a lifetime of perfume memorabilia; bottles of Chanel perfume, rare ingredients, fragrant soaps, and in amongst his things, the most fascinating of finds – a notebook with handwritten formulas, including one for Soir de Paris, written by one of the greatest of all perfumery biochemists – Constantin Weriguine.Can Andrew recreate this almost one hundred year old fragrance? He travels to Versaille’s Osmotheque, the world’s only perfume archive, to smell the original 1928 scent. It’s where top perfumers – all chemists themselves - grant him access to the world’s rarest and sometimes now-forbidden perfume ingredients,

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. Roland Pease meets some of the experts trying to work out what is to be done. Producer: Roland PeaseImage: A man watches the Thomas Fire above Carpinteria, California, Credit: Getty Images

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 precious seconds of warning when an earthquake starts. Roland Pease meets the scientists, the Mayor and the officials making the system work.Picture: An apartment after the Northridge earthquake in 1994 Credit: Getty Images

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 deploy chlorine gas in World War One for the sake of “The Fatherland” and of Dr Gerhard Schrader, who, in his hunt for an effective pesticide, accidentally discovered a new class of lethal nerve agents for Nazi Germany.From chlorine, phosgene and the mustard gases, to tabun, sarin, soman, VX and the novichok agents used to target former Soviet agent Sergei Skipal in England, Andrea weaves archive with interviews with key figures in the ongoing campaign to control and ban the use of such weapons and he asks how science educators can prepare young chemists for the moral hazard posed by this particular class of weapon.

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 War by both sides. More substances were developed in the 1930s and 1940s but weren’t used in the battlefield in World War 2. Andrea Sella tells the stories of the chemists behind these developments. Picture: GB Army soldiers train for biological and chemical warfare, Credit: BBC