Discovery

The human gut has around 100 trillion bacterial cells from up to 1,000 different species. Every person's microbiota (the body's bacterial make-up) is different as a result of the effects of diet and lifestyle, and the childhood source of bacteria. What is it about the microbes in our guts that can have such an impact on our lives? Scientists are learning more and more about the importance of these bacteria, as well as the viruses, fungi and other microbes that live in our gastrointestinal tracts. Without them, our digestion, immune system and overall health would be compromised. Adam Hart talks to researchers who are discovering how important a balanced and robust gut microflora is for our health. And he asks how this can be maintained and what happens when things go wrong.(Image: Gut Microbiota Copyright: Getty Images)

Journalist and numbers obsessive Alex Bellos travels around India to explore the fundamental numerical gifts which early Indian mathematicians gave to the world and asks whether the great religions of ancient India - Hinduism, Buddhism and Jainism - had any part in their origins. The number system which the world uses today originated in India in the early centuries of the first millennium AD. It is usually called the Arabic numeral system, but in the Middle East the scheme employing the symbols 0 to 9 is correctly referred to as the Indian system. The designation of zero as a number in its own right by South Asian thinkers was arguably the greatest conceptual leap in the history of mathematics. During his numerical odyssey, Alex visits a temple in Gwalior, containing the earliest zero in India with a known date. He is also granted an audience with one of Hinduism's most revered gurus, who is also an author of books on numbers. His Holiness, the Shankaracharya of Puri tells Alex that the study of mathematics

Australian geneticist Jenny Graves discusses her life pursuing sex genes in her country's weird but wonderful fauna, the end of men and singing to her students in lectures.(Image: Jenny Graves, BBC copyright)

Life on earth has gone through a series of mass extinctions. Mike Benton talks about his fascination with ancient life on the planet and his work on the Bristol Dinosaur Project.Image: Mike Benton BBC Copyright

Joanna Haigh, Professor of Atmospheric Physics at Imperial College, London, studies the influence of the sun on the Earth's climate using data collected by satellites. She talks to Jim al-Khalili about how she got started on her career in climate physics: she can trace her interest in it back to her childhood when she built herself a home weather station. Jo Haigh explains why we need to know how the sun affects the climate: it's so scientists can work out what contribution to warming is the result of greenhouse gases that humans produce, and what is down to changes in the energy coming from the sun. She has sat on the Intergovernmental Panel on Climate Change and discusses with Jim how it delivers its reports. And as a prominent scientist who speaks out about the dangers of increasing man made greenhouse gases in the atmosphere, she explains how she responds to climate change deniers. Image: Joanna Haigh Credit: BBC

Russell Foster, professor of circadian neuroscience at Oxford University, is obsessed with biological clocks. He talks to Jim al-Khalili about how light controls our wellbeing from jet lag to serious mental health problems. Professor Foster explains how he moved from being a poor student at school to the scientist who discovered a new way in which animals detect light. Image: Russell Foster Copyright: BBC

Adam Hart investigates yet another threat to the ash trees of Europe. In the last programme he found out about the latest research developments to save ash trees from ash dieback, a disease that has already devastated trees across Europe, but now it seems that another threat could be on its way from Russia – the emerald ash borer. This beetle already targets ash trees in the USA and kills 99% of the trees it infests. But, what is it, how great is the threat and is there any way to stopping it spreading to Europe?Image: Emerald Ash Borer Traces Credit: Cornelia Schaible

Professor Adam Hart looks at the disease that has devastated ash trees in Europe – ash dieback. Over the last 20 years the fungus that causes ash dieback has been spreading westwards across the continent and last year it was found in the UK for the first time. At the moment there is no cure for the disease and only a tiny fraction of trees seem to be able to survive it. In this programme, he investigates the very latest scientific research into this deadly disease and asks if it will be enough to save this important species.(Image: Professor Adam Hart in Trolleholm seed orchard in Sweden where ash dieback has infected many of the trees. Credit: BBC)

Fracking for gas is highly controversial in the US and the UK as it has been accused of contaminating water courses and causing earthquakes. Yet it provides a cheap source of energy. Beneath England there are thought to be considerable amounts of shale gas and the UK government is considering whether to allow fracking in these areas. Already there is opposition from residents, concerned about pollution and earth tremors. Gaia Vince talks to scientists to find out what fracking involves and what impact it has on the environment, and she discovers what other countries can learn from the pioneers of the technology, the United States.(Image: Views of the Cuadrilla Fracking Site at Balcombe. Credit: WPA Pool, Getty)

We all rely on GPS – the Global Positioning System network of satellites – whether we want to or not. From shipping to taxis to mobile phones, the goods we consume and the technology with which we run our lives depend upon a low-power, weak and vulnerable signal beamed from a few tonnes of electronics orbiting above our heads. This dependence is a new Achilles' heel for the world's financial, commercial and military establishments. From North Korea's concerted disruption of South Korea's maritime and airborne fleet, to white van drivers evading the boss's scrutiny over lunch, this signal is easy to jam - with disastrous consequences. Quentin Cooper meets the scientists and engineers developing alternative, resilient navigation systems.(Image: Captain David Millar, Senior Master, on the bridge of P&O Ferries’ MS Spirit of Britain. BBC copyright)

Deep brain stimulation (DBS) is a brain surgery technique involving electrodes being inserted to reach targets deep inside the brain. Those targets are then stimulated via the electrodes which are connected to a battery powered pacemaker surgically placed under the person's collar bone. Geoff Watts finds out how the technique has been used successfully for treating the movement disorders of Parkinson's disease, in patients with severe, intractable depression, in chronic pain and how it's also being trialled to see if it can also be successful in treating obsessive compulsive disorder (OCD), Tourette's syndrome and other disorders. Geoff meets patients who have had their lives changed by having deep brain stimulation. He also meets the surgeons at the operating table to find out how it works. At the moment no one has all the answers but one psychiatrist he meets says the success of deep brain stimulation means we should radically change the way we understand how the brain works: that the brain is governed by e

Lorna Stewart reports on the new and growing phenomenon of electronic cigarettes and asks if they really help smokers to stop smoking and if they are as safe as their manufacturers suggest. One billion people smoke worldwide and tobacco shortens the lives of half of all users. With consumption of tobacco products increasing globally, finding a way to help smokers to quit is vital. Electronic cigarettes, which contain nicotine in water vapour, are one new approach, but there is very little research into whether they have any harmful effects. As legislators worldwide start to rule on how to regulate them, there are concerns over who might use e-cigarettes; in some places they are proving popular with young people. Issues surrounding nicotine use and addiction have led regulatory bodies around the globe to act, and e-cigarettes are now banned in Brazil, Canada, Singapore, Panama and Lebanon.In this episode of Discovery for the BBC we hear from public health experts, psychologists, and e-cigarette enthusiast

In the 20 years since the release of the film Jurassic Park, DNA cloning technologies have advanced dramatically. Professor Adam Hart asks whether we could and should start bringing extinct animals back from the dead. The fossilised remains of dinosaurs are too degraded to hold any viable DNA, so Jurassic Park is unlikely to be a reality. But what about Pleistocene Park? Deep frozen remains of Arctic animals like the woolly mammoth or the Irish elk, have been shown to contain DNA - but is it in a good enough condition to rebuild the genome and attempt cloning these animals which became extinct nearly 4000 years ago? Some people think it could work. But should we even be considering it? With so many plants and animals threatened with extinction now, should we be wasting time and resources on bringing back animals that didn't make the cut? Adam Hart asks experts in ancient DNA whether the code for life could be resurrected in animals such as the mammoth, the passenger pigeon, the dodo, the marsupial tiger, or t

Earlier this year the BBC organised a ‘science festival’ in Uganda. One of the practical outcomes of this was to put physics teachers in East Africa in touch with physicists involved in the Higgs boson discovery at CERN. As a result, several teachers from the region visited CERN and took part in their international teacher programmes. In Discovery this week we look at the impact of their visit and ask how international ‘big science’ projects such as CERN can offer practical development help – especially in sub Saharan Africa.

Dr Kevin Fong concludes a two-part special looking back at the extraordinary events which unfolded a decade ago when the disease known as SARS first emerged onto an unsuspecting world. In a matter of days SARS had travelled around the globe from a hotel room in Hong Kong, and would go on to infect thousands of people, in dozens of countries. But standing between us and the virus were hundreds of healthcare workers who risked their lives to fight against and contain this unknown deadly disease, some of whom paid the ultimate price. Kevin travels to Hong Kong and Toronto to meet the survivors. With concerns rising over H7N9 and MERS, Kevin asks what lessons have we learned since the first SARS outbreak and would those who stepped up to protect us back then, do so again?

Dr Kevin Fong begins a two-part special looking back at the extraordinary events which unfolded a decade ago when the disease known as SARS (Severe Acute Respiratory Syndrome) first emerged onto an unsuspecting world.In a matter of days SARS had travelled around the globe from a hotel room in Hong Kong - and would go on to infect thousands of people, in dozens of countries. But standing between us and the virus were hundreds of healthcare workers who risked their lives to fight against and contain this unknown deadly disease, some of whom paid the ultimate price. With concerns rising over H7N9 and MERS, Kevin asks what lessons have we learned since the first SARS outbreak and would those who stepped up to protect us back then, do so again?(Image: Sign for the accident and emergency unit at the L'Hopital Francais de Hanoi. Credit: BBC copyright)

Tracey Logan goes underground to find out how Crossrail is using the latest engineering techniques to create 26 miles of tunnels below London's tube network, sewers and foundations - and through its erratic, sometimes unpredictable geology. She finds out about the latest science being used in Europe's biggest engineering project. London sits on a varied geology of deposits of fine-grained sand, flint gravel beds, mottled clay, shelly beds which are sometimes mixed with pockets of water. This sheer variety has presented a challenge to London's tunnel engineers since the early 1800s. Tracey goes on board one of the huge, 150 metre long, 1000 tonne tunnel boring machines as it makes its way beneath London's Oxford Street. At depths of up to 40 metres it can negotiate London's complex geology with incredible precision and can instantly adjust the pressure it applies at the cutting head to ensure there is no ground movement above. Its precision engineering means it also follows a route which avoids the many existi

The hormone oxytocin is involved in mother and baby bonding and in creating trust. Linda Geddes finds out if taking oxytocin can help people with autism become more sociable. Larry Young, professor in the Department of Psychiatry at Emory University in Atlanta, talks about the work in voles that demonstrated the role of oxytocin in pair bonding. Professor Markus Heinrichs, of Freiburg University in Germany, tells Linda Geddes about doing the first research on oxytocin in human subjects. He was one of the authors of an influential paper on the hormone and trust, published in Nature in 2005. As journalists for New Scientist, Linda and her husband, Nic, invited one of the other authors of that paper, Professor Paul Zak of Claremont Graduate University in Califormia, to carry out an oxytocin experiment at their wedding. At Cambridge University, Dr Bonnie Auyeung, is currently carrying out studies to find out if giving the hormone to adults with autism can improve their social skills. And, Professor Jennifer Bartz

Earthquakes can't be predicted. But millions of dollars are spent trying to forecast them - warning the public which regions are dangerous, what the chances are of a quake in the next number of years and how strong the shaking might be. But following the failures of the Japanese system to identify the danger on the north-east coast, struck by a giant tsunami in 2011, many experts are saying that the dream of hazard assessment is an illusion. We may never know enough about the mechanisms of the Earth to reliably foresee deadly shaking.Others maintain it's a matter of knowledge - the more geologists can learn about the history of earthquakes, about the mechanics of plate tectonics, the better society can prepare for when the ground begins to shake.Well over half a million have died in earthquakes and their resulting tsunamis in the past decade, so the issue is critical.Roland Pease, who reported from Japan in the aftermath of the 2011 earthquake and tsunami, speaks to experts on both sides of the argument to f

Earthquakes are feared for their destructive, deadly force. But they are part of a geological process - plate tectonics - that some scientists say is vital for the existence of life itself. Without the ever-changing land surfaces that plate tectonics produces, or the high continental masses raised above sea level by earthquake activity, planet Earth would atrophy into a lifeless mass, like our neighbour Mars. But why is Earth the only planet with plate tectonics? And, when did they start? The clues are so faint, the traces so ephemeral, that researchers are only now beginning to find tentative answers. Extraordinarily, some say that life itself has changed the forces in plate tectonics, and helped to shape the world.