Discovery

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

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 of the four-part series The Chase, science journalist Belinda Smith from the ABC in Australia discovers what footprints can tell us about the ancient beasts that once roamed this land, and follows a team racing against time and the elements to save this once-in-a-lifetime find. Because even though these tracks have lasted the best part of 100 million years, they may not survive another one.Picture: Footprints made by a sauropod as it walked across a mudflat 95 million years ago, Credit: Australian Broadcasting Corporation/Belinda Smith

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 bird species off some of the islands. Meanwhile introduced mosquitoes have thrived in the warm conditions, and now act as vectors for diseases such as the Zika virus. Rat eradication experts have travelled to one of the uninhabited islands in the atoll, called Reiono, to attempt an experimental eradication of thousands of rats with one mammoth poison bait drop. They’re also using this as an opportunity to better understand why eradication attempts have been less effective on tropical islands. At the same time, on another island in the chain called Onetahi, researchers are releasing swarms of sterilised male mo

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 arid plains of Australia’s vast arid interior, but it took another seven years for a single photograph of a live bird.Incredibly, a population of night parrots had survived. Their exact location is kept secret, and people are still looking for more – or more precisely, listening for more, using acoustic traps to identify calls.Dr Ann Jones from ABC Australia takes a huge microphone for a spin in the desert to join the hunt for the legendary Night Parrot.(Photo: Ullala Boss is a Birriliburu Indigenous Ranger, Elder and Traditional Owner and knows the dreaming stories of the Night Parrot. Credit: Dr Ann Jones)

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 reveal a large, custom-built telescope – carefully engineered to work inside a moving jet plane. Its full name is the Stratospheric Observatory for Infrared Astronomy, and it’s a joint project of Nasa and the German space agency, DLR. The catch? That shadow is moving across the earth at 22 kilometres per second. Join Dr Jonathan Webb from the ABC in Australia for episode one of The Chase - a special four-part series about science on the run.(Photo: SOFIA is a heavily modified 747SP which was acquired by Nasa in the mid-1990s after spending 20 years as a passenger jet. (Credit: Wayne Williams)

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. He was a precocious mathematician who became an adviser to Emperor Rudolf II in 1600. Although he contributed to the idea that the sun, not the earth, was the centre of the solar system, his role at the court was to be an astrologer. Philip brings the story of the shape of the snowflakes up to date. It was only 20 years ago with the development of the maths of fractals that we got to understand the formation of the myriad patterns of snowflakes.

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 believe they were sheep who had to follow those in power. Naomi discovers that the poem is an epic, beautiful and persuasive piece of work. It begins with a discussion of atoms. Lucretius, like Epicurus, followed the Greek tradition in believing that the universe is composed of tiny, indivisible particles. De Rerum Natura asks us to consider that all that really exists in the universe are these atoms and the void between them. Atoms are indestructible, the number of atoms in the universe is infinite and so is the void in which the atoms move. What Lucretius is saying here was revolutionary then – and still has the pow

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 celebrity. But this is also a tale of how a Quaker tried to use science to unite countries. The reparations imposed on Germany after the war extended into science too as many in Great Britain and other Allied nations felt that German science should be ostracised from the international community. As a Quaker, Eddington wanted just the opposite: to see peaceful cooperation restored among nations.Picture: Image of the 1919 Solar eclipse taken by Arthur Eddington (1882-1944), Credit: Science Photo LibraryProducer: Erika Wright

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 understanding of our place in the universe. “Oh my God. Look at that picture over there. Here’s the earth coming up. Wow, isn’t that pretty.”Bill Anders was on the fourth of the ten orbits of the moon on Apollo 8, along with James Lovell and Frank Borman. Bill had spotted the earth through one of the hatch windows and grabbed his camera to take a black and white photo. But just in time, he picked up another camera with a colour film loaded, and the rest is history. When they returned from space – the first mission to orbit the moon – Nasa used Bill Anders’ image of Earthrise in its publicity. Nasa had understood there was an a

Alex Bellos is brilliant at all things mathematical, but even he can't hold a candle to the amazing mathematical feats of the supercalculators. Alex heads to Wolfsburg in Germany to meet the contestants at this year's Mental Calculation World Cup. These men and women are the fastest human number crunchers on the planet, able to multiply and divide large numbers with no need to reach for a smart phone, computer or calculator. So how do they do it, and is it a skill that any of us can learn? Alex talks to Robert Fountain, the UK's two-time winner of this prestigious prize, about his hopes for this year's competition and the mathematical magicians of the past who have inspired him. He also meets Rachel Riley, Countdown's number queen, to find out what it takes to beat the countdown clock.Picture: The Supercalculators, Credit: Alex Bellos

Plastic waste and pollution have become a global problem but is there any sign of a global solution? And how did we allow this to happen in the first place? Materials scientist and broadcaster, Professor Mark Miodownik, explores how we fell in love with plastic, why we've ended up with oceans of waste blighting the environment and what science and society can do about it.Programme Three: Roland Pease hears from Kenya where one of the most stringent bans on plastic bags has been in force for nearly two years, from the US where the reuseable cup has taken off and from Sweden where reverse vending machines give you money back when you return your plastic bottles. And he looks at places where plastic is the best material for the job.Picture: Bike loaded with empty plastic bottles. Shanghai China, Credit: typhoonski/Getty Images

Plastics are fantastically versatile materials that have changed our lives. It is what we do with them, when we no longer want them, that has resulted in the global plastic crisis. Mark Miodownik explores our love hate relationship with plastics. Programme Two: Things begin to go stale Plastic waste has been a global crisis waiting to happen. To date it's estimated that around 8.3 billion tonnes of waste plastic exists. That's 25 Empire State Buildings or 1 billion elephants. Incredibly around half of this has been generated in just the last 14 years, despite mass production having begun in the 1950s. Events such as China's recent refusal to take any more "foreign rubbish" from the west and Sir David Attenborough's graphic portrayal of the devastation that plastic waste is causing in our oceans, has prompted political and media discussion like never before. We are at a critical moment where, if we're to turn the tide on plastic pollution, it will require science and society to come together to create real