Discovery

Why do birds sing?

<p>"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.</p><p>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.</p><p>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.</p><p>Bird Song</p><p>"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 elaborate?" asks Tony Fulford from Cambridgeshire in the UK.</p><p>We find out how birds produce multiple notes at once, which one has the widest repertoire of songs, and why males like to show off quite so much. Plus, we talk to researcher Lauryn Benedict about the project which aims to solve the mystery of why female birds sing.</p><p>Featuring interviews with RSPB president and nature presenter Miranda Krestovnikoff, and world-renowned birdsong expert and sound recordist, Don Kroodsma from the University of Massachusetts. TV archive courtesy of The One Show, BBC TV.</p><p>Please send your cases for consideration for the next series to <a href="mailto:curiouscases@bbc.co.uk">curiouscases@bbc.co.uk</a>.</p><p>Presenters: Adam Rutherford, Hannah Fry Producer: Michelle Martin.</p><p>(Photo: Eurasian Wren (Troglodytes troglodytes). Credit: Getty Images)</p>

Does infinity exist?

<p>“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. </p><p>First, we investigate the concept of infinity in mathematics with a story of mathematics, music and murder from Steven Strogatz from the Cornell University.</p><p>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.</p><p>Next we turn to physics to see if we can find something in the Universe that is truly infinite. </p><p>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.</p><p>But if we’re looking for something that is infinite, how about the Universe itself? We find out how physicists measure the shape of the Universe, with the help of an orange and a game of Asteroids. However, if the Universe is not infinite, and it has an edge, what is on the other side?</p><p>Presenters: Hannah Fry, Adam Rutherford Producer: Michelle Martin</p><p>(Photo: The Infinity symbol in an exploding cloud of data. Credit: Wigglestick/Getty Images)</p>

Why do we get déjà vu?

<p>4/6 Part 1: Déjà vu</p><p>"Do we know what causes déjà vu?" asks Floyd Kitchen from Queenstown in New Zealand.</p><p>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.</p><p>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.</p><p>Part 2: Randomness</p><p>"Is anything truly random, or is everything predetermined?" asks Darren Spalding from Market Harborough.</p><p>Hannah and Adam go in search of random events, from dice throws to lava lamps. Can we predict the outcome of any event? </p><p>"How do computers manage to pick random numbers?" asks Jim Rennie from Mackinaw in Illinois. Random numbers are vital for things like cyber security and banking. But true randomness is surprisingly hard to produce, as the team discover.</p><p>Joining them for this case we have a random selection of experts: mathematician Colva Roney-Dougal, technology journalist Bill Thompson, Science Museum Curator Tilly Blyth and quantum physicist Jim AlKhalili.</p><p>Presenters: Hannah Fry, Adam Rutherford Producer: Michelle Martin</p><p>Main Image: A fan of the New York Yankees holds up a sign which reads "It's Deja Vu" at the Yankee Stadium, New York City 29 Oct 2009. Credit: Jed Jacobsohn / Getty Images</p>

Will we ever find alien life?

<p>3/6 In this instalment of The Curious Cases of Rutherford &amp; 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. </p><p>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?</p><p>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?</p><p>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.</p><p>Send your Curious Cases for consideration in to <a href="mailto:curiouscases@bbc.co.uk">curiouscases@bbc.co.uk</a></p><p>Presenters: Hannah Fry, Adam Rutherford Producer: Michelle Martin.</p><p>Main Image: This image obtained from NASA on November 25, 2013 shows several images that were taken by the Hubble Space Telescope of the spiral NGC 4921 from the Coma Cluster of Galaxies. Copyright: NASA / Hubble / ESA / Handout</p>

Why people have different pain thresholds

<p>2/6 "How fast can a human run and would we be faster as quadrapeds?" This question flew in via Twitter from Greg Jenner.</p><p>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.</p><p>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?</p><p>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.</p><p>"Why do people experience pain differently when they go through the same event?" asks Claire Jenkins from Cwmbran in Wales.</p><p>Professor of Pain Research, Irene Tracey, welcomes Adam in to the room she calls her 'Torture Chamber'. Burning, electrocuting, lasering and piercing are all on the menu, but which will hurt the most?</p><p>Hannah speaks to Steve Pete from Washington who has a rare genetic condition which means he does not feel pain. For chronic sufferers, this sounds like heaven, but a life without pain has brought untold suffering to him and his family, including the tragic story of his brother, Chris.</p><p>We look at how the body creates pain, why some people feel it more than others, and how this knowledge could help scientists treat pain more effectively in the future.</p><p>Presenters: Hannah Fry, Adam Rutherford Producer: Michelle Martin</p><p>(Photo: A runner beats the pain to make it over the finishing line in the Hong Kong Marathon 12 February 2006. Credit: Martin Chan/South China Morning Post/Getty Images)</p>

How do instruments make music?

<p>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.</p><p>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.</p><p>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.</p><p>Presenters: Adam Rutherford, Hannah Fry Producer: Michelle Martin</p><p>Main 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, 1817, Paris. Credit: De Agostini Editorial / Getty Images</p>

A sense of time

<p>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? </p><p>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.</p><p>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?</p><p>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, biologically?' When birds have to dodge through forests and catch flies on the wing, or when flies have to avoid those birds, it would seem that a faster temporal resolution would be a huge advantage. </p><p>Geoff meets physicist Carlo Rovelli and asks him to jump outside of physics to answer questions on biology and philosophy. Geoff explores the mind of a bat with Professor Yossi Yovel in Israel, and dissects birdsong at super slow speeds with BBC wildlife sound recordist, Chris Watson. Getting deep into the minds of animals he questions whether our seconds feel like swordfish seconds, or a beetles' or birds' or bats..?</p><p>Presenter: Geoff Marsh Producer: Rory Galloway</p><p>Picture: Violaceous Euphonia (Euphonia violacea) male flying from branch, Itanhaem, Brazil Credit: Getty images</p>

Cat Hobaiter on communication in apes

<p>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. </p><p>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.</p><p>(Photo: Dr Catherine Hobaiter)</p>

Carlo Rovelli on rethinking the nature of time

<p>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. </p><p>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, than it was to overthrow the government.</p><p>Picture: Carlo Rovelli. Credit: BBC Producer: Anna Buckley</p>

Corinne Le Quéré on carbon and climate

<p>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. </p><p>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.</p>

Ken Gabriel on why your smartphone is smart

<p>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.</p><p>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.</p><p>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 yet to go into production.</p><p>Producer: Julian Siddle</p>

Donna Strickland and extremely powerful lasers

<p>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. </p><p>Producer: Anna Buckley</p>

Unbottling the past

<p>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.</p><p>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, and teach him how to mix a scent. And in constructing Soir de Paris, he learns about Constantin Weriguine, his grandfather ‘Rex’, and discovers if his skills as a chemist are enough to turn him into a top perfumer, or is fragrance more of an art than a science?</p><p>Presenter: Andrew Holding Producer: Katy Takatsuki.</p><p>Image: Patricia de Nicolaï</p>

California burning

<p>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. </p><p>Producer: Roland Pease</p><p>Image: A man watches the Thomas Fire above Carpinteria, California, Credit: Getty Images</p>

ShakeAlertLA - California’s earthquake early warning system

<p>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.</p><p>Picture: An apartment after the Northridge earthquake in 1994 Credit: Getty Images</p>

From the Cold War to the present day

<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 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.</p><p>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.</p><p>(Photo: Mock up of Novichok agent (A-234), Credit: WoodyAlec/Getty Images)</p>

From the Crimean War to the end of World War Two

<p>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. </p><p>Picture: GB Army soldiers train for biological and chemical warfare, Credit: BBC</p>

Tracks across time

<p>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.</p><p>Picture: Footprints made by a sauropod as it walked across a mudflat 95 million years ago, Credit: Australian Broadcasting Corporation/Belinda Smith</p>

Trouble in paradise

<p>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 mosquitoes to try to rid this motu of the disease-carrying pest. Join Carl Smith from ABC Australia for the third episode of The Chase: a special four-part series about science on the run.</p><p>Picture: The Pacific rat (Rattus exulans) is smaller than many other invasive rat species, but it’s still been linked to localised extinctions of island birds, Credit: Carl Smith</p>

Back from the Dead

<p>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.</p><p>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.</p><p>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.</p><p>(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)</p>

Eye in the Sky

<p>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.</p><p>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.</p><p>(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)</p>

Kepler's Snowflake

<p>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.</p>

Lucretius, Sheep and Atoms

<p>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. </p><p>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 power to surprise. He’s saying that there are no supernatural forces controlling our lives, no fate pulling the strings, if there are gods they’re made of atoms just like everything else. There is nothing else. Naomi discusses the life of Lucretius and his poem with classicist Dr Emma Woolerton of Durham University. And she talks to particle physicist Professor Jonathan Butterworth of UCL about which of his theories still holds water today.</p><p>Picture: Gathered sheep, Credit: Chris Strickland, Getty Images</p>

Eddington's eclipse and Einstein's celebrity

<p>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.</p><p>Picture: Image of the 1919 Solar eclipse taken by Arthur Eddington (1882-1944), Credit: Science Photo Library</p><p>Producer: Erika Wright</p>

Earthrise

<p>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. </p><p>“Oh my God. Look at that picture over there. Here’s the earth coming up. Wow, isn’t that pretty.”</p><p>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 added value of going into space: taking pictures of our home planet. </p><p>Stewart Brand was part of both the counterculture and the environmental movement; he’d hung out with Ken Kesey and his merry pranksters and put on happenings. He went on to found the Whole Earth Catalog, which brought together all kinds of alternative thinkers. Stewart Brand put the Earthrise photo on the front cover of one of the editions of the Whole Earth Catalog. </p><p>Gaia Vince talks to Stewart Brand, and to scientists and artists, about the continuing importance of seeing Earth from above. </p><p>Picture: Earthrise - The rising Earth is about five degrees above the lunar horizon in this telephoto view taken from the Apollo 8 spacecraft on December 24th 1968, Credit: Nasa</p><p>Presenter: Gaia Vince Producer: Deborah Cohen</p>

The Supercalculators

<p>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.</p><p>Picture: The Supercalculators, Credit: Alex Bellos</p>

The China Syndrome

<p>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.</p><p>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.</p><p>Picture: Bike loaded with empty plastic bottles. Shanghai China, Credit: typhoonski/Getty Images</p>

How Much Plastic Can We Recycle?

<p>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 change. But it won't be easy. One major area that needs an overhaul is recycling. In the UK only 14% of plastic collected is recycled. Europe tends to burn our waste for energy, and plastic has a calorific value similar to that of coal. But proponents of the circular economy say we should never consider plastic as waste at all and we should think of it as 'Buried Sunshine' - a resource that needs conserving - by reusing and recycling again and again.</p><p>Picture: Production line for the processing of plastic waste in the factory, Credit: Getty Images</p>

Why We Fell In Love with Plastic

<p>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 One: First Flush of Love We may not be on speaking terms right now. But we do have a love affair with plastic, in fact it can be all consuming. Adaptable, lightweight, cheap and hygienic - fantastic plastics started to win our affection back in the late 19th century. Bakelite was an early plastic invented to replace expensive wood. Celluloid was one of the earliest plastics, failing to replace ivory in billiard balls, but revolutionising the world as movie film. Plastic really did change our world. Plastic radar insulation played a role in helping the Allied forces win the Second World War and after the conflict, factories start to churn out cheap, mass-produced goods in the new synthetic polymers. But some of the key virtues of plastic may now have paradoxically poisoned the relationship. Being virtually indestructible, has led to a build-up of toxic micro-plastic in the oceans and environment. We've grown to regard many plastics as cheap and disposable, we take it for granted, rely on it too much, value it too little and are too ready to cast it aside after one single use.</p><p>Producer: Fiona Roberts</p><p>Picture: The Bakelite Museum, Credit: Getty Images</p>

Finding the Coelacanths

<p>The first Coelacanth was discovered by a woman in South Africa in 1938. The find, by the young museum curator, was the fish equivalent of discovering a T- Rex on the Serengeti, it took the Zoological world by storm. Presenter Adam Hart tells the story of this discovery, and the steps taken by Coelacanth biologists in the decades since to find more fish, in other populations, and record them for science. Adam hears personal accounts from a deep diver who swam with Coelacanths, Eve Marshall, conservationist Dr Mark Erdman, and geneticist Professor Axel Meyer.</p><p>Picture: 3 Coelacanths at 116 metres depth in Sodwana Bay, South Africa, Credit: Eve Marshall</p><p>Producer: Rory Galloway</p>