Melvyn Bragg and his guests discuss nuclear fusion, the process that powers stars. In the 1920s physicists predicted that it might be possible to generate huge amounts of energy by fusing atomic nuclei together, a reaction requiring enormous temperatures and pressures. Today we know that this complex reaction is what keeps the Sun shining. Scientists have achieved fusion in the laboratory and in nuclear weapons; today it is seen as a likely future source of limitless and clean energy.Guests:Philippa Browning, Professor of Astrophysics at the University of ManchesterSteve Cowley, Chief Executive of the United Kingdom Atomic Energy AuthorityJustin Wark, Professor of Physics and fellow of Trinity College at the University of OxfordProducer: Thomas Morris.

Melvyn Bragg and his guests discuss the Haitian Revolution. In 1791 an uprising began in the French colonial territory of St Domingue. Partly a consequence of the French Revolution and partly a backlash against the brutality of slave owners, it turned into a complex struggle involving not just the residents of the island but French, English and Spanish forces. By 1804 the former slaves had won, establishing the first independent state in Latin America and the first nation to be created as a result of a successful slave rebellion. But the revolution also created one of the world's most impoverished societies, a legacy which Haiti has struggled to escape.ContributorsKate Hodgson, Postdoctoral Research Fellow in French at the University of LiverpoolTim Lockley, Reader in American Studies at the University of WarwickKaren Salt, Fellow in History in the School of Language and Literature at the University of AberdeenProducer: Luke Mulhall.

Melvyn Bragg and his guests discuss the life and work of Rudyard Kipling. Born in Bombay in 1865, Kipling has been described as the poet of Empire, celebrated for fictional works including Kim and The Jungle Book. Today his poem 'If--' remains one of the best known in the English language. Kipling was amongst the first writers in English to develop the short story as a literary form in its own right, and was the first British recipient of a Nobel Prize for Literature. A literary celebrity of the Edwardian era, Kipling's work for the Commonwealth War Graves Commission played a major role in Britain's cultural response to the First World War.Contributors:Howard Booth, Senior Lecturer in English Literature at the University of ManchesterDaniel Karlin, Winterstoke Professor of English Literature at the University of BristolJan Montefiore, Professor of Twentieth Century English Literature at the University of KentProducer: Luke Mulhall.

Melvyn Bragg and his guests discuss the Battle of Talas, a significant encounter between Arab and Chinese forces which took place in central Asia in 751 AD. It brought together two mighty empires, the Abbasid Caliphate and the Tang Dynasty, and although not well known today the battle had profound consequences for the future of both civilisations. The Arabs won the confrontation, but the battle marks the point where the Islamic Empire halted its march eastwards, and the Chinese stopped their expansion to the west. It was also a point of cultural exchange: some historians believe that it was also the moment when the technology of paper manufacture found its way from China to the Western world.GUESTSHilde de Weerdt, Professor of Chinese History at Leiden UniversityMichael Höckelmann, British Academy Postdoctoral Fellow in the Department of History at King's College LondonHugh Kennedy, Professor of Arabic at SOAS, University of LondonProducer: Thomas Morris.

Melvyn Bragg and his guests discuss the life, work and reputation of Julius Caesar. Famously assassinated as he entered the Roman senate on the Ides of March, 44 BC, Caesar was an inspirational general who conquered much of Europe. He was a ruthless and canny politician who became dictator of Rome, and wrote The Gallic Wars, one of the most admired and studied works of Latin literature. Shakespeare is one of many later writers to have been fascinated by the figure of Julius Caesar.With:Christopher Pelling Regius Professor of Greek at the University of OxfordCatherine Steel Professor of Classics at the University of GlasgowMaria Wyke Professor of Latin at University College LondonProducer: Thomas Morris.

Melvyn Bragg and his guests discuss Euler's number, also known as e. First discovered in the seventeenth century by the Swiss mathematician Jacob Bernoulli when he was studying compound interest, e is now recognised as one of the most important and interesting numbers in mathematics. Roughly equal to 2.718, e is useful in studying many everyday situations, from personal savings to epidemics. It also features in Euler's Identity, sometimes described as the most beautiful equation ever written. With:Colva Roney-Dougal Reader in Pure Mathematics at the University of St AndrewsJune Barrow-Green Senior Lecturer in the History of Maths at the Open UniversityVicky Neale Whitehead Lecturer at the Mathematical Institute and Balliol College at the University of OxfordProducer: Thomas Morris.

Melvyn Bragg and his guests discuss the Sun. The object that gives the Earth its light and heat is a massive ball of gas and plasma 93 million miles away. Thanks to the nuclear fusion reactions taking place at its core, the Sun has been shining for four and a half billion years. Its structure, and the processes that keep it burning, have fascinated astronomers for centuries. After the invention of the telescope it became apparent that the Sun is not a placid, steadily shining body but is subject to periodic changes in its appearance and eruptions of dramatic violence, some of which can affect us here on Earth. Recent space missions have revealed fascinating new insights into our nearest star.With:Carolin Crawford Gresham Professor of Astronomy and Fellow of Emmanuel College, CambridgeYvonne Elsworth Poynting Professor of Physics at the University of BirminghamLouise Harra Professor of Solar Physics at UCL Mullard Space Science LaboratoryProducer: Thomas Morris.

Melvyn Bragg and his guests discuss Virginia Woolf's novel Mrs Dalloway. First published in 1925, it charts a single day in the life of Clarissa Dalloway, a prosperous member of London society, as she prepares to throw a party. Writing in her diary during the writing of the book, Woolf explained what she had set out to do: 'I want to give life and death, sanity and insanity. I want to criticize the social system, and to show it at work at its most intense.' Celebrated for its innovative narrative technique and distillation of many of the preoccupations of 1920s Britain, Mrs Dalloway is now seen as a landmark of twentieth-century fiction, and one of the finest products of literary modernism.With:Professor Dame Hermione Lee President of Wolfson College, OxfordJane Goldman Reader in English Literature at the University of GlasgowKathryn Simpson Senior Lecturer in English Literature at Cardiff Metropolitan University.

Melvyn Bragg and his guests discuss one of the most remarkable figures of the Middle Ages, Hildegard of Bingen. The abbess of a Benedictine convent, Hildegard experienced a series of mystical visions which she documented in her writings. She was an influential person in the religious world and much of her extensive correspondence with popes, monarchs and other important figures survives. Hildegard was also celebrated for her wide-ranging scholarship, which as well as theology covered the natural world, science and medicine. Officially recognised as a saint by the Catholic Church in 2012, Hildegard is also one of the earliest known composers. Since their rediscovery in recent decades her compositions have been widely recorded and performed.With:Miri Rubin Professor of Medieval and Early Modern History and Head of the School of History at Queen Mary, University of LondonWilliam Flynn Lecturer in Medieval Latin at the Institute for Medieval Studies at the University of LeedsAlmut Suerbaum Professor of Medieval German and Fellow of Somerville College, Oxford.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the philosophy of solitude. The state of being alone can arise for many different reasons: imprisonment, exile or personal choice. It can be prompted by religious belief, personal necessity or a philosophical need for solitary contemplation. Many thinkers have dealt with the subject, from Plato and Aristotle to Hannah Arendt. It's a philosophical tradition that takes in medieval religious mystics, the work of Montaigne and Adam Smith, and the great American poets of solitude Thoreau and Emerson.With:Melissa Lane Professor of Politics at Princeton UniversitySimon Blackburn Professor of Philosophy at the New College of the Humanities and Fellow of Trinity College, CambridgeJohn Haldane Professor of Philosophy at the University of St AndrewsProducer: Thomas Morris.