Discovery

Ignaz Semmelweiss: The hand washer

<p>Lindsey Fitzharris tells the story of Ignaz Semmelweiss, the hand washer. In a world that had no understanding of germs, he tried to apply science to halt the spread of infection. Ignaz Semmelweis observed that many young medical students at his hospital in Vienna went directly from an autopsy, still covered in contaminated dead flesh, to attend pregnant women. Could this be the reason for such high maternal mortality rates from conditions like puerperal fever? Believing that the disease was caused by “infective material” from a dead body, Semmelweiss set up a basin filled with chlorinated lime solution in his hospital and began saving women’s lives with three simple words: ‘wash your hands’. He was demonised by his colleagues for his efforts, but today, he is known as the “Saviour of Mothers.”</p><p>Lindsey Fitzharris discusses some of the common myths surrounding the story of Semmelweiss with Dr Barron H. Lerner of New York University Langone School of Medicine. And she talks to Professor Val Curtis, Director of the Environmental Health Group at the London School of Hygiene and Tropical Medicine, who has studied the amount of hand washing by medical staff in hospitals today.</p><p>Picture: Victorian boy washing his hands in a stream, Credit: whitemay</p>

Madame Lavoisier's Translation of Oxygen

<p>Philip Ball tells the story of Madame Lavoisier; translator of oxygen. At a time when science was almost a closed book to women, Madame Marie Anne Lavoisier’s skills were indispensable. A translator, illustrator and critic of scientific papers, she learnt chemistry herself and helped her husband Antoine Lavoisier develop his theory of the role played by oxygen in combustion. As modern science was taking shape it lacked any universal language, so communication in many tongues was vital to stay ahead of the game. Even today there is debate as to who can really be considered the discoverer of oxygen, but Madame Lavoisier’s gift for translation helped her husband compete against English rivals and banish their theories. Come the French Revolution however, Anton was branded a traitor to the state and sentenced to death. By a cruel twist of fate Marie lost both husband and father to the guillotine on the same day.</p><p>Philip Ball talks to Patricia Fara at the University of Cambridge, about the largely unrecognised contribution that women like Marie Anne Lavoisier made to the early days of modern science, and to Michael Gordin of Princeton University about the importance of scientific translation in the past and how it features today,</p><p>Picture: French chemist Antoine Laurent Lavoisier, Credit: Getty Images</p>

Galileo's lost letter

<p>Galileo famously insisted in the early 17th Century that the Earth goes round the Sun and not vice versa – an idea that got him into deep trouble with the Catholic Church. In 1633 Galileo was put on trial for heresy by the Inquisition, and was threatened with imprisonment, or worse, if he did not recant. Galileo spent the rest of his days under house arrest and is now seen by some as a near-martyr to science in the face of unyielding religious doctrine. But the discovery of a letter questions the received version of events. Philip Ball tells the story of the relationship between Galileo, the church and his fellow professors.</p><p>Philip talks to science historians professor Paula Findlen of Stanford University and professor Mary Jane Rubenstein of Wesleyan University about Galileo's time and about the history of the relationship between science and religion.</p><p>(Picture: Galileo demonstrating his telescope. Credit: Getty Images)</p>

Robin Dunbar

<p>Maintaining friendships is one of the most cognitively demanding things we do, according to Professor of Evolutionary Psychology Robin Dunbar. So why do we bother? </p><p>Robin has spent his life trying to answer this deceptively simple question. For most of his twenties, he lived with a herd of five hundred gelada monkeys in the Ethiopian highlands. He studied their social behaviour and concluded that an ability to get on with each other was just as important as finding food, for the survival of the species. Animals that live in large groups are less likely to get eaten by predators. When funding for animal studies dried up in the 1980s, he turned his attention to humans. and discovered there’s an upper limit to the number of real friends we can have, both in the real world and on social media.</p>

Katherine Joy

<p>Katherine Joy studies moon rock. She has studied lunar samples that were brought to earth by the Apollo missions (382kg in total) and hunted for lunar meteorites in Antarctica, camping on ice for weeks on end and travelling around on a skidoo. Working at the forefront of the second wave of lunar exploration, she studied remote sensing data from Europe’s first mission to the moon, Smart 1 which launched in 2003 and data from many subsequent missions. She tells Jim Al-Khalili why she believes the moon is the most exciting destination in our solar system and explains what it can tell us about the long history of planet earth. Beneath the magnificent desolation of the moon’s surface, multicoloured rocks contain vital clues about the history of our solar system. Every crater on the moon is evidence of a collision and the chemistry of these rocks tells us when these collisions took place. Katherine’s research supports the idea that a period known as the late heavy bombardment was a particularly turbulent time. Could the late heavy bombardment explain the origin of life on earth?</p>

Sir Gregory Winter

<p>In an astonishing story of a scientific discovery, Greg Winter tells Jim Al-Khalili how decades of curiosity-driven research led to a revolution in medicine.</p><p>Forced to temporarily abandon his work in the lab when a road rage incident left him with a paralysed right arm, Greg Winter spent several months looking at the structure of proteins. Looking at the stunning computer graphics made the pain in his arm go away. It also led him to a Nobel Prize winning idea: to ‘humanise’ mouse antibodies. A visit to an old lady in hospital made Greg determined to put his research to good use. He fought hard to ensure open access to the technology he invented and set up a start up company to encourage the development of therapeutic drugs. It took years to persuade anyone to fund his Nobel Prize winning idea that led to the creation of an entirely new class of drugs, known as monoclonal antibodies. In 2018, the market for these drugs, which include Humira for rheumatoid arthritis and Herceptin for breast cancer, was worth $70 billion.</p>

Turi King: Solving the mystery of Richard III through DNA

<p>When a skeleton was unearthed in 2012 from under the tarmac of a car park in Leicester in the English East Midlands, Turi King needed to gather irrefutable evidence to prove that this really was the body of Richard III, England's infamous medieval monarch. Under the microscope was not only the king's genetic identity, but his entire reputation. Was Richard a ruthless villain, as depicted by Shakespeare? Or did the incoming Tudors spread 'fake news' to besmirch his name? As presenter Jim al-Khalili discovers, clues in his skeletal remains have helped to solve some of these mysteries, and reveal the real Richard III. When she was young, Turi King wanted to be the next Indiana Jones. Her love of archaeology led her to study genetics so she could use ancient DNA to solve historic mysteries. She tells Jim how genetic testing, of both the dead skeleton and his living relatives, provided the vital evidence they needed to identify Richard III. But first, she had to extract his DNA, by pulling out one of his teeth.</p><p>Main Image: Turi King Credit: Jonathan Sisson</p>

Plastic pollution with Richard Thompson

<p>A Professor of Marine Biology who was not particularly academic at school, Richard Thompson went to university after running his own business selling greetings cards for seven years. When the rest of the world was waking up to the harm caused to marine life by larger plastic items, such as plastic bags, he searched for tiny fragments of plastic, some no bigger than a human hair; and found them in oceans and on beaches all over the world. He has spent decades studying the harm these micro-plastics might cause to marine life and is concerned. His work on plastics in cosmetics led to a UK ban on micro-beads in shower gels and exfoliating scrubs. And he advised government to ban single use plastic bags from supermarkets. Rather than demonize plastic, however, he believes we need to learn to love it more. Often plastic it is the best material for the job. Now we need to make sure that all plastic products are designed so that they can be easily recycled at the end of their useful life.</p><p>Picture: Plastic water bottles pollution in ocean, credit: chaiyapruek2520/Getty Images</p>

Protecting heads in sports

<p>The death last week of boxer Patrick Day, four days after he was stretchered out of the ring in a coma, is the latest reminder of how vulnerable sportsmen and women are to traumatic brain injury. During the latest Ashes series the Australian batsman Steve Smith was temporarily retired for one test after being struck on the helmet by a bouncer. The current World Cup Rugby has been affected too, with Welsh fly half Dan Biggar withdrawn from a game against Uruguay having received head injuries in two previous matches. </p><p>In this edition of Discovery, Roland Pease talks to engineers at Imperial College and Loughborough University using the latest techniques to understand the dynamics of blows to the head, and to improve helmet protection. And to experts and Rugby players at Swansea University seeking to make precision measurements of real-life head movements with the help of gum shields stuffed with electronics.</p><p>Picture credit: Mazdak Ghajari</p>

Early diagnosis and research

<p>James Parkinson described a condition known as the “shaking palsy” over 200 years ago. Today there are many things that scientists still don’t understand explaining why diagnosis, halting the progression or finding a cure for Parkinson’s can seem elusive. But how close are researchers to developing better treatments?</p><p>Better understanding seems to suggest that Parkinson’s is not one condition but several, with different causes and symptoms in different people. Many researchers think that early diagnosis and greater recognition of the non motor symptoms such as loss of smell, sleep disorders and depression is to be encouraged, while others say without effective treatments then there are ethical issues to consider.</p><p>Jane visits a brain bank and sees the changes in a Parkinson’s brain that causes many of the symptoms and she takes a test which examines the sense of smell. Could this be a new tool to identify early stages of the condition? Plus repurposing of existing drugs, i.e. drugs that have been developed for one condition but being tested in another are having promising results in Parkinson’s and genetic studies are leading to a greater understanding of the mechanisms involved in PD which in turn is leading to new therapies.</p><p>(Photo: Man smelling hops in his hands. Credit: Ales-A/Getty Images)</p>

Exercise

<p>Can exercise help people living with Parkinson’s, a neurodegenerative condition, with symptoms such as loss of balance, difficulty walking and stiffness in the arms and legs.</p><p>Jane Hill travels to the Netherlands to meet Mariëtte Robijn and Wim Rozenberg, coaches at Rock Steady Boxing Het Gooi and co-founders of ParkinsonSport.nl, a unique sports club ran 100% by and for people with Parkinson’s. It doesn’t take long before a transformation begins to take place in the gym.</p><p>Boxing is popular in the US as well, says Professor Lisa Shulman, Director of the Parkinson’s Centre at the University of Maryland. She has been encouraging her patients to exercise for the last 25 years.</p><p>Results from over 200 studies suggest that exercise is a good way to empower people as well as having physical benefits such as delaying disability.</p><p>In Ghana many people receive a late diagnosis. Sheila Klufio a physiotherapist at Korle Bu Hospital in Accra works with people to help them deal with some of the more common symptoms such as freezing when walking so they feel more confident to go out.</p><p>And it seems all types of exercise can help, Alan Alda and Michael J Fox both box, ballet dancing is popular, walking, cycling and Tai Chi have benefits and it’s never too late to start. </p><p>Picture credit: Wim Rozenberg at Wimages.nl</p>

Living with Parkinson's

<p>BBC newsreader Jane Hill knows all about Parkinson’s. Her father was diagnosed in t1980s and lived with the condition for ten years — her uncle had it, too. She’s spoken about the dreadful experience of watching helplessly as the two men were engulfed by the degenerative disease, losing their independence and the ability to do the things that they once enjoyed. “I remember feeling how cruel Parkinson’s is.</p><p>The number of people living with Parkinson’s disease is set to double over the next few decades as we all live longer; it is the only long-term neurological condition that is increasing globally.</p><p>In this series Jane Hill looks at what it means to be given a diagnosis of Parkinson’s and the reality of living with the condition. She and her cousin Steve remember how their fathers adopted a British stiff upper lip at a time when there was little awareness. In contrast she meets highly successful comedy writer Paul Mayhew Archer, whose reaction to his diagnosis was to create a one-man show exploring the lighter side of living with Parkinson’s.</p><p>Actors Michael J Fox and Alan Alda both discuss the early symptoms of the disease and their diagnosis.</p><p>Most people are diagnosed in their sixties but Dutch blogger Mariette Robijn talks about accepting a life changing diagnosis in her forties.</p><p>Picture: Dopaminergic neuron, 3D illustration. Degeneration of this brain cells is responsible for development of Parkinson's disease, Credit: Dr Microbe</p><p>Presenter: Jane Hill Producer: Geraldine Fitzgerald</p>

Preventing pesticide poisoning

<p>Thanks to a ban on several hazardous pesticides Sri Lanka has seen a massive reduction in deaths from pesticide poisoning, and the World Health Organisation is recommending other countries should follow this example. </p><p>As Health Correspondent Matthew Hill discovers, hospitals which used to deal with many pesticide related deaths are now seeing fewer cases, and more survivors. However, a lack of mental health services means, for many in rural communities, taking pesticides is still a way of drawing attention to a variety of personal issues - sometimes with tragic consequences.</p><p>Image: Rural pesticide shop, Sri Lanka (Credit: BBC)</p>

The power of peace

<p>“Nature red in tooth and claw”. “Dog eat dog”. “Fighting for survival". You may well think that the natural world is one dangerous, violent, lawless place, with every creature out for itself. And it can be, but it can also be peaceful, democratic and compassionate.</p><p>Lucy Cooke seeks out the animal communities that adopt a more peaceful and democratic way of life and asks why it works for them. Despite being fierce predators, African wild dogs are cooperative and compassionate within their packs, and they actually hold democratic votes on hunting decisions – one sneeze for yes, two sneezes for no! They are among the most effective predators in the world. They use extraordinary cooperation and teamwork to pursue, overhaul and bring down their prey. As a result 80% of their hunts end successfully, compared to lions' at 10%. This is nearly all a result of their pack coordination. They are also surprisingly non-aggressive; they don’t fight over food but instead beg to indicate their wish to eat. Adults will allow younger pack members to eat before them. And the African wild dogs are not alone: such societies are also common in insects, other mammals, and birds, but exist even in simple species like amoebas. </p><p>But what is the evolutionary advantage of this group cohesion? Why when nature selects for not just the individual but for the selfish gene, does it pay to be part of a complex social group? Lucy discovers that when the benefits of group-living outweigh the costs, it’s very much advantageous – when 10 pairs of eyes are better at spotting predators and pack strategies mean far more successful kills in a hunt, or when grooming not only strengthens bonds, but it also gets rid of your ticks and fleas. She also explores the different strategies of the highly complex social animals – the Great Apes – and asks whether Bonobos are truly the lovers and Chimpanzees the fighters?</p><p>This all touches on the complex social interactions we have as humans. We can be peaceful and we can be violent and war-like, and like every species, individual variation and circumstances can tip the balance of our behaviour. But anthropologist Agustin Fuentes questions the belief that humans are at their core violent, aggressive, and oversexed. Are these behaviours part of our genetic heritage? What can biology, evolution, and behaviour tell us about peace and aggression in everyday life?</p><p>Picture: African Hunting Dogs by Paul F Donald</p>

The power of petite

<p>Bigger is better, right? An ancient lore in biology, Cope's rule, states that animals have a tendency to get bigger as they evolve. Evolution has cranked out some absolutely huge animals. But most of these giants are long gone. And those that remain are amongst the most threatened with extinction. Scientists now believe that while evolution favours larger creatures, extinction seems to favour the small. If you look at mammals, at the time of the dinosaurs, they were confined to rodent-sized scavengers living on the periphery. But 66 million years ago, the dinosaurs went and allowed the mammals to evolve into some really big creatures - 30 metre long blue whales, the ten tonne steppe mammoth and a giant ground sloth that looked a bit like a hamster but was the size of an elephant with enormous hooks for hands. Now, only the blue whale remains and these have been shown to have shrunk to half the size of their Pleistocene ancestors. So is it better to be small? Smaller animals need fewer resources and smaller territories. With the planet in such peril - are more animals going to start shrinking? Well, perhaps...new research shows that in 200 years' time, the largest mammal might be the domestic cow. And of course the most successful organisms, in terms of biomass, on the planet are the smallest. Zoologist, Lucy Cooke examines the science of being small, and why size matters.</p><p>Producer: Fiona Roberts</p><p>(Photo: Honeybee sitting on a flower. Credit: Dr Paul F Donald)</p>

The power of deceit

<p>Lucy Cooke sets out to discover why honesty is almost certainly not the best policy, be you chicken, chimp or human being. It turns out that underhand behaviour is rife throughout the animal kingdom, and can be a winning evolutionary strategy. From sneaky squid, to cheating cuckoos, some species will resort to truly incredible levels of deception and deviousness to win that mate, or get more food. And when it comes to social animals like we humans, it turns out that lying, or at least those little white lies, may be the social glue that binds us all together.</p><p>Lucy heads to the RSPB cliffs at Bempton, with Professor Tim Birkhead to discover why so many bird species appear to be such proficient deceivers, as well as visiting the very crafty ravens at The Tower of London. She speaks to psychologist Richard Wiseman about how to spot when someone is lying, and finds out whether she is any good at it. In fact, can we trust any of what she says in this documentary at all?</p><p>Presenter Lucy Cooke Producer Alexandra Feachem</p><p>Main image: Raven Credit: Dr Paul F Donald</p>

Patient Undone

<p>Professor Deborah Bowman reveals how a diagnosis of cancer has transformed her view of medical ethics and what it means to be a patient.</p><p>As Professor of Ethics and Law at St George's, University of London, Deborah has spent the past two decades teaching and writing about medical ethics, the moral principles that apply to medicine.</p><p>It's taken her down countless hospital corridors, to the clinics and the wards where medical ethics plays out in practice, behind closed doors, supporting healthcare practitioners and their patients to negotiate uncertainty and conflict.</p><p>This is the field of clinical ethics and, each time, the 'patient' has been central to her response. </p><p>Yet in the autumn of 2017, everything changed. Deborah was diagnosed with breast cancer and it signalled the beginning of her undoing, not just personally but professionally too, playing havoc with what she thought she knew about clinical ethics. </p><p>Patient autonomy - literally 'self-rule'- is one of its cornerstones - a patient's right to make decisions about their healthcare. So what does autonomy mean if the 'self', she thought she knew, was so changeable and confusing? </p><p>Deborah returns to the Royal Marsden Hospital where she is a patient, to explore this - with both her personal and professional hats on. </p><p>Producer: Beth Eastwood</p><p>Main Image: Deborah Bowman. Copyright: Deborah Bowman</p>

The Great Science Publishing Scandal

<p>Matthew Cobb, Professor of Zoology at the University of Manchester, explores the hidden world of prestige, profits and piracy that lurks behind scientific journals. </p><p>Each year, hundreds of thousands of articles on the findings on research are published, forming the official record of science. This has been going on since the 17th century, but recently a kind of war has broken out over the cost of journals to the universities and research institutions where scientists work, and to anyone else who wants to access the research, such as policy makers, patient support groups and the general public. </p><p>Traditionally journals charge their readers a subscription, but since the start of the 21st century there's been a move to what's called open access, where the authors pay to get their articles published but anyone can read them, without charge. In Europe Plan S has called for all research funded by the public purse to be open access, by 2021. If and when this is implemented it could have downsides on learned societies who depend on income from journal subscriptions to support young researchers and on scientists in the less developed world. </p><p>Some universities, and even countries, have recently refused to pay the subscriptions charged by some of the big science publishers. This has led to some scientists using a service run by a Russian hacker, which has effectively stolen the whole of the scientific literature and gives it away, free, on the internet. </p><p>Matthew Cobb looks back at how the scientific publishing industry got to its current state and asks how it could change. He argues that scientists themselves need to break their addiction to wanting their articles to appear in a few well known journals, and instead concentrate on the quality of their research.</p>

Erica McAlister

<p>Dr Erica McAlister, of London's Natural History Museum, talks to Jim Al-Khalili about the beautiful world of flies and the 2.5 million specimens for which she is jointly responsible. </p><p>According to Erica, a world without flies would be full of faeces and dead bodies. Unlike, for example, butterflies and moths, whose caterpillars spend their time devouring our crops and plants, fly larvae tend to help rid the world of waste materials and then, as adults, perform essential work as pollinators. Yet they are rather unloved by humans who tend to regard them as pests at best and disease vectors at worst. 2019 is international Year of the Fly, and dipterists and entomologists around the world are working to raise the profile of the many thousands of species so far known to science. Erica tells Jim about her work in the museum, cataloguing and identifying new species either sent in from other researchers or discovered by her and her colleagues on swashbuckling trips around the world. Modern gene sequencing techniques are revealing new chapters in the life histories of species, and her collection of 300 year old dead flies continues to expand our knowledge of how the world works. Perhaps in the future, she argues, we will all be eating pasta and bread made from fly-larvae protein, or using small tea-bag like packets of maggots in our wounds to clean out gangrenous infection.</p>

Richard Peto

<p>When Sir Richard Peto began work with the late Richard Doll fifty years ago, the UK had the worst death rates from smoking in the world. Smoking was the cause of more than half of all premature deaths of British men. The fact that this country now boasts the biggest decrease in tobacco-linked mortality is in no doubt partly due to Doll and Peto's thirty year collaboration.</p><p>Professor of Medical Statistics and Epidemiology at the University of Oxford and until last year co-director of the Clinical Trial Service Unit with Professor Sir Rory Collins, Richard Peto pioneered "big data", setting up enormous randomised clinical trials and then, in a novel approach, combining results in what became known as meta-analyses, amassing unequivocal evidence about how early death could be avoided. He showed how asprin could prevent heart attacks and how the oestrogen-blocking drug tamoxifen really did affect survival rates for breast cancer patients.</p><p>Results on paper saves lives in the real world, he says, and he's famous for catchphrases like: "death in old age is inevitable, but death before old age is not" and "you can avoid more deaths by a moderate reduction of a big cause, than by a big reduction in a small cause" as well as "take the big numbers seriously".</p><p>One of the world's leading epidemiologists, Richard Peto's landmark study with Alan Lopez at the World Health Organisation predicted that a billion people would die from diseases associated with tobacco this century, compared to a hundred million killed by tobacco in the 20th century. The chilling message galvanised governments around the world to adopt anti-smoking policies. And Professor Peto's studies about smoking cessation ("smoking kills, stopping works") provided the public health evidence needed to encourage smokers that, however long they had smoked for, it was always worth quitting.</p>

Lovelock at 100: Gaia on Gaia

<p>James Lovelock is one of the most influential thinkers on the environment of the last half century. His grand theory of planet earth, Gaia, the idea that from the bottom of the earth's crust to the upper reaches of the atmosphere, planet earth is one giant inter-connected and self-regulating system, has had an impact way beyond the world of science. </p><p>As James Lovelock, celebrates his hundredth birthday (he was born on 26th July 1919) he talks to science writer Gaia Vince about the freedom and frustrations of fifty years spent working outside the scientific establishment. While working at the National Institute for Medical Research he invented the Electron Capture Detector - an exquisitely sensitive device for detecting the presence of the tiniest quantities of gases in the atmosphere and led to a global ban on CFCs. It also took him to NASA and via designing a detector to look for life on Mars gave him the idea of Gaia. </p><p>Public interest in Gaia proliferated after the publication of his first book Gaia: a new look at life on earth in 1979; but the scientific community remained highly sceptical. For decades Gaia was ignored, dismissed and even ridiculed as a scientific theory. To this day, evolutionary biologists, in particular, take issue with the notion of a self-regulating planet though some are coming round to the idea. </p><p>Gaia Vince talks to earth system scientists Professor Andrew Watson and Professor Tim Lenton of Exeter University who have both championed the Gaia theory, and to Professor Ford Doolittle of Dalhousie University, an evolutionary biologist who has changed his mind about the theory.</p><p>Producer: Deborah Cohen</p><p>Picture: British scientist James Lovelock poses on March 17, 2009 in Paris. Credit: Jacques Demarthon / AFP / Getty Images.</p>

What next for the Moon?

<p>The Moon rush is back on. And this time it’s a global race. The USA has promised boots on the lunar surface by 2024. But China already has a rover exploring the farside. India is on the point of sending one too. Europe and Russia are cooperating to deliver more robots. And that’s not to mention the private companies also getting into the competition. Roland Pease looks at the prospects and challenges for all the participants.</p><p>(Image caption: Chinese lunar probe and rover lands on the far side of moon. Credit: CNSA via EPA)</p>

Irene Tracey on pain in the brain

<p>Pain, as we know, is highly personal. Some can cope with huge amounts, while others reel in agony over a seemingly minor injury. Though you might feel the stab of pain in your stubbed toe or sprained ankle, it is actually processed in the brain.</p><p>That is where Irene Tracey, Nuffield Professor of Anaesthetic Science at Oxford University, has been focussing her attention. Known as the Queen of Pain, she has spent the past two decades unravelling the complexities of this puzzling sensation.</p><p>She goes behind the scenes, as it were, of what happens when we feel pain - scanning the brains of her research subjects while subjecting them to a fair amount of burning, prodding and poking.</p><p>Her work is transforming our understanding, revealing how our emotions influence our experience of pain, how chronic pain develops and even when consciousness is present in the brain.</p><p>Producer: Beth Eastwood</p>

Paul Davies on the origin of life and the evolution of cancer

<p>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 the principles of physics to these big questions and about how he has worked closely with religious thinkers.</p><p>Producer: Anna Buckley</p>

Can psychology boost vaccination rates?

<p>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. </p><p>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. </p><p>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. </p><p>Head of the Vaccine Confidence Project Heidi Larson applauds 18 year old American Ethan Lindenberger who decided to get vaccinated despite his own mother's anti-vax views which he says she got from reading church and internet anti-vaccination groups rather than from the medical profession. </p><p>Producer: Paula McGrath</p><p>Picture: A vial of measles, mumps and rubella vaccine and an information sheet, Boston Children's Hospital in Boston, Massachusetts February 26, 2015. Credit: Reuters / Brian Snyder / File Photo</p>

Global attitudes towards vaccines

<p>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.</p><p>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. </p><p>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 increase the risk of complications if they catch measles. Vitamin A supplements are being given to help the immune system to work properly. </p><p>Next week on Discovery – could compulsory vaccines or a more subtle, psychological approach help to address vaccine hesitancy? </p><p>Producer: Paula McGrath</p><p>Photo: Children walk past a sign advising about a measles outbreak in the Brooklyn Borough of New York. Credit: Reuters)</p>

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 curiouscases@bbc.co.uk.</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 curiouscases@bbc.co.uk</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>