In Our Time (BBC Radio 4)

Melvyn Bragg and his guests discuss imaginary numbers. In the sixteenth century, a group of mathematicians in Bologna found a solution to a problem that had puzzled generations before them: a completely new kind of number. For more than a century this discovery was greeted with such scepticism that the great French thinker Rene Descartes dismissed it as an "imaginary" number.The name stuck - but so did the numbers. Long dismissed as useless or even fictitious, the imaginary number i and its properties were first explored seriously in the eighteenth century. Today the imaginary numbers are in daily use by engineers, and are vital to our understanding of phenomena including electricity and radio waves. With Marcus du SautoyProfessor of Mathematics at Oxford University Ian StewartEmeritus Professor of Mathematics at the University of WarwickCaroline SeriesProfessor of Mathematics at the University of WarwickProducer: Thomas Morris.

Melvyn Bragg and his guests discuss the Delphic Oracle, the most important source of prophecies in the ancient world. In central Greece, on the flank of Mount Parnassus, lies the ruined city of Delphi. For over a thousand years, between approximately 800 BC and 400 AD, this was the most sacred place in the ancient world. Its chief attraction was the Delphic Oracle, which predicted the future and offered petitioners advice.Travellers journeyed for weeks for a chance to ask the oracle a question. The answers, given by a mysterious priestess called the Pythia, were believed to come straight from the god Apollo. At the height of Greek civilisation the oracle was revered, and its opinion sought in some of the most significant conflicts of the age. Its activities were documented by historians including Xenophon and Plutarch, and it was regularly depicted in Greek tragedy, most famously Sophocles's masterpiece Oedipus the King.With: Paul CartledgeA G Leventis Professor of Greek Culture at Cambridge UniversityEdith HallProfessor of Classics and Drama at Royal Holloway, University of LondonNick LoweReader in Classical Literature at Royal Holloway, University of London.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the Spanish Armada. On May 28th, 1588, a fleet of a hundred and fifty-one Spanish ships set out from Lisbon, bound for England. Its mission was to transport a huge invasion force across the Channel: the Spanish King, Philip II, was determined to remove Elizabeth from the throne and return the English to the Catholic fold. Two months later the mighty Spanish Armada was sighted off the coast of Cornwall. Bad weather, poor planning and spirited English resistance defeated the Spaniards: after a brief battle the remnants of their fleet fled. This tale of religious dispute, shifting political alliance and naval supremacy has entered our folklore - although some historians argue it changed nothing.With:Diane PurkissFellow and Tutor at Keble College, OxfordMia Rodriguez-SalgadoProfessor in International History at the London School of EconomicsNicholas RodgerSenior Research Fellow at All Souls College at the University of OxfordProducer: Thomas Morris.

Melvyn Bragg and his guests discuss the artistic movement known as Sturm und Drang.In the 1770s a small group of German writers started to produce plays, poetry and novels which were radically different from what had gone before. These writers were all young men, and they rejected the values of the Enlightenment, which they felt had robbed art of its spontaneity and feeling. Their work was passionate, ignored existing conventions and privileged the individual's free will above the constraints of society.The most prominent member of the movement was Johann von Goethe, whose novel The Sorrows of Young Werther became its most notable success, translated into more then thirty languages. Despite this and other successes including Schiller's play The Robbers, the Sturm und Drang disappeared almost as quickly as it had emerged; by the mid-1780s it was already a thing of the past.With:Tim BlanningEmeritus Professor of Modern European History at Cambridge UniversitySusanne KordProfessor of German at University College, LondonMaike Oergel Associate Professor of German at the University of NottinghamProducer: Thomas Morris.

Melvyn Bragg and his guests discuss the history of logic. Logic, the study of reasoning and argument, first became a serious area of study in the 4th century BC through the work of Aristotle. He created a formal logical system, based on a type of argument called a syllogism, which remained in use for over two thousand years. In the nineteenth century the German philosopher and mathematician Gottlob Frege revolutionised logic, turning it into a discipline much like mathematics and capable of dealing with expressing and analysing nuanced arguments. His discoveries influenced the greatest mathematicians and philosophers of the twentieth century and considerably aided the development of the electronic computer. Today logic is a subtle system with applications in fields as diverse as mathematics, philosophy, linguistics and artificial intelligence.With:A.C. GraylingProfessor of Philosophy at Birkbeck, University of LondonPeter MillicanGilbert Ryle Fellow in Philosophy at Hertford College at the University of OxfordRosanna KeefeSenior Lecturer in Philosophy at the University of Sheffield.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the unicorn. In the 5th century BC a Greek historian, Ctesias, described a strange one-horned beast which he believed to live in a remote area of India. Later classical scholars, including Aristotle and Pliny, added to his account of this animal which they called the monoceros, a vicious ass-like creature with a single horn in the middle of its forehead.For centuries the monoceros or unicorn was widely accepted to be a real - if rarely seen - beast. It appears in the Bible, and in the Middle Ages became a powerful Christian symbol. It continued to be represented in art and literature throughout the Renaissance, when 'unicorn horn' became one of the most valuable commodities on earth, thanks to its supposed properties as an antidote to poison. As late as the seventeenth century, scientists believed they had found conclusive proof of the existence of unicorns. It was some time before the animal was shown to be a myth; four hundred years on, the unicorn retains much of its fascination and symbolic power.With:Juliette WoodAssociate Lecturer in Folklore at Cardiff UniversityLauren KassellLecturer in the History and Philosophy of Science at the University of CambridgeDavid EkserdjianProfessor of the History of Art and Film at the University of Leicester.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the role played by women in Enlightenment science. During the eighteenth century the opportunities for women to gain a knowledge of science were minimal. Universities and other institutions devoted to research were the preserve of men. Yet many important contributions to the science of the Enlightenment were made by women. These ranged from major breakthroughs like those of the British astronomer Caroline Herschel, the first woman to discover a comet, to important translations of scientific literature such as Emilie du Chatelet's French version of Newton's Principia - and all social classes were involved, from the aristocratic amateur botanists to the women artisans who worked in London's workshops manufacturing scientific instruments. The image above, of Emilie du Chatelet, is attributed to Maurice Quentin de La Tour.

With

Patricia Fara Senior Tutor at Clare College, University of Cambridge

Karen O'Brien Professor of English at the University of Warwick

Judith Hawley Professor of 18th Century Literature at Royal Holloway, University of London

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the Volga Vikings. Between the 8th and the 10th centuries AD, fierce Scandinavian warriors raided and then settled large swathes of Europe, particularly Britain, Ireland and parts of northern France. These were the Vikings, and their story is well known today. Far fewer people realise that groups of Norsemen also travelled east.These Volga Vikings, also known as the Rus, crossed the Baltic into present-day Russia and the Ukraine and founded settlements there. They traded commodities including furs and slaves for Islamic silver, and penetrated so far east as to reach Baghdad. Their activities were documented by Arab scholars: one, Ahmad ibn Fadlan, recorded that the Volga Vikings he met were perfect physical specimens but also "the filthiest of God's creatures". Through trade and culture they brought West and East into regular contact; their story sheds light on both Scandinavian and early Islamic history.With:James MontgomeryProfessor of Classical Arabic at the University of CambridgeNeil PriceProfessor of Archaeology at the University of AberdeenElizabeth RoweLecturer in Scandinavian History of the Viking Age at Clare Hall, University of CambridgeProducer: Thomas Morris.

Melvyn Bragg and his guests discuss John Foxe and his book Actes and Monuments, better known today as Foxe's Book of Martyrs. Born in 1517, John Foxe was an early Protestant who was forced to flee the persecutions which ensued when the Catholic Mary came to the English throne in 1553. He was a horrified observer on the Continent as more than three hundred of his countrymen were burnt at the stake. In exile he began work on a substantial work of scholarship, bringing together eyewitness accounts of these horrifying deaths.First published in 1563, Foxe's Book of Martyrs was one of the most elaborate early books produced, and thanks to vivid woodcut illustrations reached an audience far beyond the literate elite. Its stories of Protestant martyrdom became powerful Church propaganda in the late sixteenth century and were used by those who wished to banish Catholicism from England permanently. But despite its use as an instrument of religious factionalism, Foxe's work remains one of the key and most read books of the early modern period. With:Diarmaid MacCullochProfessor of Church History at the University of OxfordJustin ChampionProfessor of the History of Early Modern Ideas at Royal Holloway, University of LondonElizabeth EvendenLecturer in Book History at Brunel UniversityProducer: Thomas Morris.

Melvyn Bragg and his guests discuss the history of metaphor. In Shakespeare's As You Like It, the melancholy Jaques declares: "All the world's a stage/And all the men and women merely players." This is a celebrated use of metaphor, a figure of speech in which one thing is used to describe another. Metaphor is a technique apparently as old as language itself; it is present in the earliest surviving work of literature, the Epic of Gilgamesh. Homer developed it into an art form, and his invention of the epic simile was picked up by later writers including Milton. In the Middle Ages the device of allegory underpinned much of French and English writing, while the Metaphysical poets employed increasingly elaborate metaphorical conceits in the sixteenth century. In the age of the novel the metaphor once again evolved, while the Modernist writers used it to subvert their readers' expectations. But how does metaphor work, and what does this device tell us about the way our minds function?With:Steven ConnorProfessor of Modern Literature and Theory at Birkbeck, University of LondonTom HealyProfessor of Renaissance Studies at the University of SussexJulie SandersProfessor of English Literature and Drama at the University of NottinghamProducer: Thomas Morris.

Melvyn Bragg and his guests discuss Cleopatra. The last pharaoh to rule Egypt, Cleopatra was a woman of intelligence and charisma, later celebrated as a great beauty. During an eventful life she was ousted from her throne and later restored to it with the help of her lover Julius Caesar. A later relationship with another Roman statesman, Mark Antony - and Cleopatra's subsequent death at her own hands - provided Shakespeare with the raw material for one of his greatest plays. Today Cleopatra is still an object of fascination, her story revealing as much about the Roman world as it does about the end of the age of the Pharaohs.With:Catharine EdwardsProfessor of Classics and Ancient History at Birkbeck, University of LondonMaria WykeProfessor of Latin at University College LondonSusan WalkerKeeper of Antiquities at the Ashmolean Museum at the University of OxfordProducer: Thomas Morris.

Melvyn Bragg and his guests discuss the innovations and influence of Thomas Edison, one of the architects of the modern age.Edison is popularly remembered as the man who made cheap electric light possible. Born in 1847, he began his career working in the new industry of telegraphy, and while still in his early twenties made major improvements to the technology of the telegraph. Not long afterwards he invented a new type of microphone which was used in telephones for almost a century. In the space of three productive years, Edison developed the phonograph and the first commercially viable light bulb and power distribution system. Many more inventions were to follow: he also played a part in the birth of cinema in the 1890s. When he died in 1931 he had patented no fewer than 1093 devices - the most prolific inventor in history. As the creator of the world's first industrial research laboratory he forever changed the way in which innovation took place.With:Simon SchafferProfessor of the History of Science, University of CambridgeKathleen BurkProfessor of History, University College LondonIwan MorusReader in History, University of AberystwythProducer: Thomas Morris.

Melvyn Bragg and his guests discuss Daoism. An ancient Chinese tradition of philosophy and religious belief, Daoism first appeared more than two thousand years ago. For centuries it was the most popular religion in China; in the West its religious aspects are not as well known as its practices, which include meditation and Feng Shui, and for its most celebrated text, the Daodejing.The central aim in Daoism is to follow the 'Dao', a word which roughly translates as 'The Way'. Daoists believe in following life in its natural flow, what they refer to as an 'effortless action'. This transcendence can be linked to Buddhism, the Indian religion that came to China in the 2nd century BC and influenced Daoism - an exchange which went both ways. Daoism is closely related to, but has also at times conflicted with, the religion of the Chinese Imperial court, Confucianism. The spirit world is of great significance in Daoism, and its hierarchy and power often take precedence over events and people in real life. But how did this ancient and complex religion come to be so influential?With:Tim Barrett Professor of East Asian History at the School of Oriental and African Studies, University of LondonMartin PalmerDirector of the International Consultancy on Religion, Education and CultureHilde De WeerdtFellow and Tutor in Chinese History at Pembroke College, University of Oxford Producer: Natalia Fernandez.

Melvyn Bragg and his guests discuss the Pelagian Controversy.In the late 4th century a British monk, Pelagius, travelled to Rome, where he became a theologian and teacher, revered for his learning and ascetic lifestyle. But he soon aroused the ire of some of the Church's leading figures, preaching a Christian doctrine which many regarded as heretical. Pelagius believed that mankind was not inherently depraved, and disputed the necessity of original sin. His opinions were highly controversial and led to fierce division. Pelagius's most prominent opponent was the African bishop St Augustine of Hippo. Their dispute resulted in the persecution and eventual condemnation of Pelagius and his followers, and was to be of long-lasting significance to the future of the Church.With:Martin PalmerDirector of the International Consultancy on Religion, Education, and CultureCaroline HumfressReader in History at Birkbeck College, University of LondonJohn MilbankProfessor in Religion, Politics and Ethics and the Director of the Centre for Theology and Philosophy at Nottingham UniversityProducer: Thomas Morris.

Melvyn Bragg and his guests discuss the Hippocratic Oath. The Greek physician Hippocrates, active in the fifth century BC, has been described as the father of medicine, although little is known about his life and some scholars even argue that he was not one person but several. A large body of work originally attributed to him, the Hippocratic Corpus, was disseminated widely in the ancient world, and contains treatises on a wide variety of subjects, from fractures to medical ethics.Today we know that the Hippocratic Corpus cannot have been written by a single author. But many of its texts shaped Western medicine for centuries. The best known is the Hippocratic Oath, an ethical code for doctors. Celebrated in the ancient world, and later referred to by Arabic scholars, it offers medics guidance on how they should behave. Although it has often been revised and adapted, the Hippocratic Oath remains one of the most significant and best known documents of medical science - but there is little evidence that it was routinely sworn by doctors until modern times. With:Vivian NuttonEmeritus Professor of the History of Medicine at University College LondonHelen KingProfessor of Classical Studies at the Open UniversityPeter PormannWellcome Trust Associate Professor in Classics and Ancient History at the University of WarwickProducer: Thomas Morris.

Melvyn Bragg and his guests discuss the Etruscan civilisation.Around 800 BC a sophisticated civilisation began to emerge in the area of Italy now known as Tuscany. The Etruscans thrived for the next eight hundred years, extracting and trading copper and developing a sophisticated culture. They were skilled soldiers, architects and artists, and much of their handiwork survives today. They are also believed to have given us the alphabet, an innovation they imported from Greece. Eventually the Etruscan civilisation was absorbed into that of Rome, but not before it had profoundly influenced Roman art and religion, and even its politics.With:Phil PerkinsProfessor of Archaeology at the Open UniversityDavid RidgwaySenior Research Fellow at the Institute of Classical Studies at the University of LondonCorinna RivaLecturer in Mediterranean Archaeology at University College London.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the work of the philosopher David Hume. A key figure in the Scottish Enlightenment of the eighteenth century, Hume was an empiricist who believed that humans can only have knowledge of things they have themselves experienced. Hume made a number of significant contributions to philosophy. He saw human nature as a manifestation of the natural world, rather than something above and beyond it. He gave a sceptical account of religion, which caused many to suspect him of atheism. He was also the author of a bestselling History of England. His works, beginning in 1740 with A Treatise of Human Nature, have influenced thinkers from Adam Smith to Immanuel Kant and Charles Darwin, and today he is regarded by some scholars as the most important philosopher ever to write in English.With:Peter MillicanProfessor of Philosophy at the University of OxfordHelen BeebeeProfessor of Philosophy at the University of BirminghamJames HarrisSenior Lecturer in Philosophy at the University of St AndrewsProducer: Thomas Morris.

Melvyn Bragg and his guests discuss the Ming Voyages. In 1405 a Chinese admiral, Zheng He, set sail with an enormous fleet of ships carrying more than 27,000 people. This was the first of seven voyages of discovery which took Zheng and his ships all over the known world, from India to the Gulf of Persia and as far as East Africa. They took Chinese goods, evidence of the might of the Ming Empire, to the people they visited; and they also returned to China with treasure from the places they visited, and exotic items including a live giraffe. These seven voyages were an expression of the might of the Ming Dynasty; but they were regarded by some Chinese courtiers as a wasteful extravagance, and after internal disputes they came to an end in 1433. These extraordinary journeys live on in the imagination and the historical record - and had a profound effect on China's relationship with the rest of the world.With:Rana MitterProfessor of the History and Politics of Modern China at the University of OxfordJulia LovellLecturer in Chinese History at Birkbeck College, University of LondonCraig ClunasProfessor of the History of Art at the University of Oxford.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss Delacroix's painting Liberty Leading the People. In 1830 revolution once more overtook France, when a popular uprising toppled the French king Charles X. A few months later, the artist Eugene Delacroix immortalised the events of the July Revolution in a painting which remains one of the icons of the age. His allegorical depiction of a Paris barricade, with the figure of Liberty clutching a tricolore while standing on a pile of corpses, is a powerful image which has provoked much debate in the years since it was first unveiled to an enthusiastic public.Producer: Natalia Fernandez.

Melvyn Bragg and his guests discuss the Siege of Tenochtitlan. In 1521 the Spanish conquistador Hernan Cortes led an army of Spanish and native forces against the city of Tenochtitlan, the spectacular island capital of the Aztec civilisation. At first Cortes had been welcomed by the Aztec leader, Moctezuma, and he and his men were treated like kings. But their friendship proved short-lived, and soon celebrations turned into vicious fighting. After a prolonged siege and fierce battle, in which many thousands died, the city finally fell. This major confrontation between Old and New Worlds precipitated the downfall of the Aztec Empire, and marked a new phase in European colonisation of the Americas.With:Alan Knight Professor of the History of Latin America at the University of OxfordElizabeth GrahamProfessor of Mesoamerican Archaeology at University College, LondonCaroline Dodds Pennock Lecturer in International History at the University of Sheffield Producer: Natalia Fernandez.

Melvyn Bragg and his guests discuss the origins, science and mythology of the moon. Humans have been fascinated by our only known satellite since prehistory. In some cultures the Moon has been worshipped as a deity; in recent centuries there has been lively debate about its origins and physical characteristics. Although other planets in our solar system have moons ours is, relatively speaking, the largest, and is perhaps more accurately described as a 'twin planet'; the past, present and future of the Earth and the Moon are locked together. Only very recently has water been found on the Moon - a discovery which could prove to be invaluable if human colonisation of the Moon were ever to occur. Mankind first walked on the Moon in 1969, but it is debatable how important this huge political event was in developing our scientific knowledge. The advances of space science, including data from satellites and the moon landings, have given us some startling insights into the history of our own planet, but many intriguing questions remain unanswered. With:Paul MurdinVisiting Professor of Astronomy at Liverpool John Moores UniversityCarolin CrawfordGresham Professor of Astronomy at the University of Cambridge Ian CrawfordReader in Planetary Science and Astrobiology at Birkbeck College, London.Producer: Natalia Fernandez.

Melvyn Bragg and his guests discuss the Continental-Analytic split in Western philosophy. Around the beginning of the last century, philosophy began to go down two separate paths, as thinkers from Continental Europe explored the legacy of figures including Friedrich Nietzsche and Martin Heidegger, while those educated in the English-speaking world tended to look to more analytically-inclined philosophers like Bertrand Russell and Gottlob Frege. But the divide between these two schools of thought is not clear cut, and many philosophers even question whether the term 'Continental' is accurate or useful.The Analytic school favours a logical, scientific approach, in contrast to the Continental emphasis on the importance of time and place. But what are the origins of this split and is it possible that contemporary philosophers can bridge the gap between the two? With:Stephen MulhallProfessor of Philosophy at New College, University of OxfordBeatrice Han-PileProfessor of Philosophy at the University of EssexHans Johann-Glock Professor of Philosophy at the University of ZurichProducer: Natalia Fernandez.

Melvyn Bragg and his guests discuss the ancient Greek astronomer and mathematician Ptolemy, and consider how and why his geocentric theory of the universe held sway for so many centuries. In his seminal astronomical work, the Almagest, written in the 2nd century AD, Ptolemy proposed that the Earth was at the centre of the universe and explained all the observed motions of the Sun, Moon, planets and stars with a system of uniform circular motions which he referred to as 'epicycles'. But Ptolemy was a polymath and did not confine his study of the stars to mathematical equations. He was also interested in astrology and his book on this topic, the Tetrabiblos, tackled the spiritual aspects of the cosmos and its influence on individual lives and personalities.Ptolemy's model of the universe remained the dominant one for over a thousand years. It was not until 1543, and Copernicus's heliocentric theory of the world, that the Ptolemaic model was finally challenged, and not until 1609 that Johannes Kepler's New Astronomy put an end to his ideas for good. But how and why did Ptolemy's system survive for so long?With:Liba TaubProfessor of History and Philosophy of Science at Cambridge UniversityJim BennettDirector of the Museum of the History of Science at the University of OxfordCharles BurnettProfessor of the History of Islamic Influences on Europe at the Warburg Institute, University of LondonProducer: Natalia Fernandez.

Melvyn Bragg and his guests discuss the revolutionary Jewish leader Judas Maccabeus. Born in the second century BC, Judas led his followers, the Maccabees, in a rebellion against the Seleucid Empire, which was attempting to impose the Greek culture and religion on the Jews. After a succession of battles he succeeded and the Seleucid king granted the Jews religious freedom. But even after that freedom was granted the struggle for political independence continued, and it was not until twenty years after Judas's death that Judaea finally became an independent state. Thanks to an extensive, if often confused, historical record of these events, the story of the Maccabees is well known. Judas Maccabeus has become a celebrated folk hero, and one of his achievements, the restoration and purification of the Temple of Jerusalem after its desecration by the Seleucids, is commemorated every year at the Jewish festival of Hanukkah.With: Helen Bond, Senior Lecturer in the New Testament at Edinburgh University Tessa Rajak, Emeritus Professor of Ancient History at the University of ReadingPhilip Alexander, Emeritus Professor of Jewish Studies at the University of ManchesterProducer: Natalia Fernandez.

Melvyn Bragg and his guests discuss the life and work of the Victorian poet Christina Rossetti. Rossetti was born into an artistic family and her siblings included Dante Gabriel, one of the leading lights of the Pre-Raphaelite Brotherhood, to whose journal, 'The Germ', Christina contributed poems. She was a devout Anglican all her life and her religious beliefs are a recurring theme in her work. Christina never married, although she was engaged twice - one of her fiancés was the Pre-Raphaelite painter, James Collinson. She spent her time writing and volunteering for charitable works. It is said she even considered going to the Crimea with Florence Nightingale, but in the end ill health prevented her from doing so. Best known for her ballads and long narrative poems, she also wrote some prose and children's verses. Christina was admired by contemporaries including Swinburne, Tennyson and Elizabeth Barrett Browning. Her work was to have an influence on later writers such as Virginia Woolf and Gerard Manley Hopkins. Rossetti's poetry has a spirituality and sensitivity that has led to her redisovery in recent decades, not least by feminist critics who praise her powerful and independent poetic voice. With:Dinah BirchProfessor of English Literature and Pro-Vice Chancellor for Research at Liverpool University Rhian WilliamsLecturer in Nineteenth-Century English Literature at the University of GlasgowNicholas ShrimptonEmeritus Fellow of Lady Margaret Hall, University of Oxford Producer: Natalia Fernandez.

Melvyn Bragg and his guests discuss the ancient Greek philosopher Heraclitus. Writing in the 5th century BC, Heraclitus believed that everything is constantly changing or, as he put it, in flux. He expressed this thought in a famous epigram: "No man ever steps into the same river twice." Heraclitus is often considered an enigmatic thinker, and much of his work is complex and puzzling. He was critical of the poets Homer and Hesiod, whom he considered to be ignorant, and accused the mathematician Pythagoras (who may have been his contemporary) of making things up. Heraclitus despaired of men's folly, and in his work constantly strove to encourage people to consider matters from alternative perspectives. Donkeys prefer rubbish to gold, he observed, pointing out that the same thing can have different meanings to different people.Unlike most of his contemporaries he was not associated with a particular school or disciplinary approach, although he did have his followers. At times a rationalist, at others a mystic, Heraclitus is an intriguing figure who influenced major later philosophers and movements such as Plato and the Stoics.With:Angie HobbsAssociate Professor of Philosophy and Senior Fellow in the Public Understanding of Philosophy at the University of WarwickPeter AdamsonProfessor of Ancient and Medieval Philosophy at King's College LondonJames WarrenSenior Lecturer in Classics and a Fellow of Corpus Christi College, University of CambridgeProducer: Natalia Fernandez.

Melvyn Bragg and his guests discuss the Concordat of Worms. This treaty between the papacy and the Holy Roman Empire, signed in 1122, put an end, at least for a time, to years of power struggle and bloodshed. The wrangling between the German kings and the Church over who had the ultimate authority to elect bishops, use the ceremonial symbols of office in his coronation and even choose the pope himself, was responsible for centuries of discord. The hatred between the two parties reached such a pinnacle that it resulted in the virtual destruction of Rome at the hands of the Normans in 1084.Nearly forty years later Emperor Henry V and Pope Calixtus II came to a compromise; their agreement became known as the Concordat of Worms, named after the town where they met and signed the treaty. The Concordat created a historic distinction between secular power and spiritual authority, and more clearly defined the respective powers of monarchs and the Church. Although in the short term the Concordat failed to prevent further conflict, some historians believe that it paved the way for the modern nation-state.With:Henrietta LeyserEmeritus Fellow of St Peter's College, University of OxfordKate CushingReader in Medieval History at Keele University John Gillingham Emeritus Professor of History at the London School of Economics and Political Science Producer: Natalia Fernandez.

Melvyn Bragg and his guests discuss Daniel Defoe's novel Robinson Crusoe. Published in 1719, it was an immediate success and is considered the classic adventure story. There are several incidents that may have inspired the tale, although none of them exactly mirrors Defoe's thrilling yet didactic narrative. The plot is now universally known - the sailor stranded on a desert island who learns to tame the environment and the native population. The character of Friday, Crusoe's trusty companion and servant, has become almost as famous as Crusoe himself and their master-servant relationship forms one of the principal themes in the novel. Robinson Crusoe has been interpreted in myriad ways, from colonial fable to religious instruction manual to capitalist tract; although arguably above all of these, it is perhaps best known today as a children's story. With:Karen O'BrienPro-Vice Chancellor for Education at the University of Birmingham Judith HawleyProfessor of Eighteenth-Century Literature at Royal Holloway, University of LondonBob OwensEmeritus Professor of English Literature at the Open UniversityProducer: Natalia Fernandez.

Melvyn Bragg and guests discuss the giant molecules that form the basis of all life. Macromolecules, also known as polymers, are long chains of atoms. They form the proteins that make up our bodies, as well as many of the materials of modern life. Man's ability to mimic the structure of macromolecules has led to the invention of plastics such as nylon, paints and adhesives. Most of our clothes are made of macromolecules, and our food is macromolecular. The medical sciences are making increasingly sophisticated use of macromolecules, from growing replacement skin and bone to their increasing use in drug delivery. One of the most famous macromolecules is DNA, an infinitely more complex polymer than man has ever managed to produce. We've only known about macromolecules for just over a century, so what is the story behind them and how might they change our lives in the future?With:Tony RyanPro-Vice Chancellor for the Faculty of Science at the University of SheffieldAthene DonaldProfessor of Experimental Physics at the University of Cambridge and a Fellow of Robinson CollegeCharlotte WilliamsReader in Polymer Chemistry and Catalysis at Imperial College, London Producer: Natalia Fernandez.

Melvyn Bragg and his guests discuss the Safavid Dynasty, rulers of the Persian empire between the 16th and 18th centuries.In 1501 Shah Ismail, a boy of fifteen, declared himself ruler of Azerbaijan. Within a year he had expanded his territory to include most of Persia, and founded a ruling dynasty which was to last for more than two hundred years. At the peak of their success the Safavids ruled over a vast territory which included all of modern-day Iran. They converted their subjects to Shi'a Islam, and so created the religious identity of modern Iran - although they were also often ruthless in their suppression of Sunni practices. They thrived on international trade, and their capital Isfahan, rebuilt by the visionary Shah Abbas, became one of the most magnificent cities in the world. Under Safavid rule Persia became a cultural centre, producing many great artists and thinkers. With:Robert GleaveProfessor of Arabic Studies at the University of ExeterEmma LoosleySenior Lecturer at the School of Arts, Histories and Cultures at the University of ManchesterAndrew NewmanReader in Islamic Studies and Persian at the University of Edinburgh.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss 1848, the year that saw Europe engulfed in revolution. Across the continent, from Paris to Palermo, liberals rose against conservative governments. The first stirrings of rebellion came in January, in Sicily; in February the French monarchy fell; and within a few months Germany, Austria, Hungary and Italy had all been overtaken by revolutionary fervour. Only a few countries, notably Britain and Russia, were spared.The rebels were fighting for nationalism, social justice and civil rights, and were prepared to fight in the streets down to the last man. Tens of thousands of people lost their lives; but little of lasting value was achieved, and by the end of the year the liberal revolutions had been soundly beaten.With: Tim BlanningEmeritus Professor of History at the University of CambridgeLucy RiallProfessor of History at Birkbeck, University of LondonMike RapportSenior Lecturer in History at the University of Stirling.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the evolution of the Scientific Method, the systematic and analytical approach to scientific thought. In 1620 the great philosopher and scientist Francis Bacon published the Novum Organum, a work outlining a new system of thought which he believed should inform all enquiry into the laws of nature. Philosophers before him had given their attention to the reasoning that underlies scientific enquiry; but Bacon's emphasis on observation and experience is often seen today as giving rise to a new phenomenon: the scientific method.The scientific method, and the logical processes on which it is based, became a topic of intense debate in the seventeenth century, and thinkers including Isaac Newton, Thomas Huxley and Karl Popper all made important contributions. Some of the greatest discoveries of the modern age were informed by their work, although even today the term 'scientific method' remains difficult to define.With: Simon SchafferProfessor of the History of Science at the University of CambridgeJohn WorrallProfessor of the Philosophy of Science at the London School of Economics and Political ScienceMichela MassimiSenior Lecturer in the Philosophy of Science at University College London.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the Kama Sutra, one of the most celebrated and often misunderstood texts of Indian literature. Probably composed during the reign of the Gupta dynasty around 1800 years ago, the work is a collection of writings about the art of love and sensual pleasure. Although it is best known today for a single chapter devoted to sexual pleasure, this important Sanksrit collection contains much besides. In particular it teaches the attainment of Kama (pleasure), one of the central goals of Hinduism. The Kama Sutra is a manual to a life of fulfilment, offering advice on such subjects as finding a spouse and how to behave in marriage; it has had a profound influence on Indian culture and thought. With:Julius LipnerProfessor of Hinduism and the Comparative Study of Religion at the University of CambridgeJessica FrazierLecturer in Religious Studies at the University of Kent and Research Fellow at the Oxford Centre for Hindu StudiesDavid SmithReader in South Asian Religions at the University of Lancaster.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the life and work of the Dutch humanist scholar Desiderius Erasmus. In his lifetime Erasmus was almost universally recognised as the greatest classical scholar of his age, the translator and editor of numerous Latin and Greek texts. But above all he was a religious scholar who published important editions of the Bible which expunged many corruptions to the texts of the Scriptures. He was an outspoken critic of the Church, whose biting satire on its excesses, In Praise of Folly, was famed throughout Europe.When the Reformation began in 1517, however, Erasmus chose to remain a member of the Catholic Church rather than side with Martin Luther and the reformers, and a few years later he engaged in a celebrated debate with Luther on the subject of free will. Through his writings on the Church, on education and the wide gamut of humanist scholarship, Erasmus is remembered today as one of the greatest thinkers of the northern Renaissance.With:Diarmaid MacCullochProfessor of the History of the Church at the University of OxfordEamon DuffyProfessor of the History of Christianity at the University of CambridgeJill KrayeProfessor of the History of Renaissance Philosophy and Librarian at the Warburg Institute, University of London.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the An Lushan Rebellion, a major uprising against the imperial rule of the Chinese Tang Dynasty. In 755 AD a senior general, An Lushan, orchestrated a plot against Emperor Xuanzong, taking the regime's capital city before declaring a rival dynasty in northern China. The rebellion lasted eight years but was eventually put down by Tang forces. Although the dynasty's authority was restored, it never regained the prosperity of previous generations. The An Lushan Rebellion displaced millions of people and killed many more. It changed the relationship between the Chinese state and neighbouring powers; but it also left a rich cultural legacy in the poetry memorialising this seismic event.With:Frances WoodLead Curator of Chinese at the British LibraryNaomi StandenProfessor of Medieval History at the University of BirminghamHilde de WeerdtFellow and Lecturer in Chinese History at Pembroke College, Oxford.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the physics of electrical conduction. Although electricity has been known for several hundred years, it was only in the early twentieth century that physicists first satisfactorily explained the phenomenon. Electric current is the passage of charged particles through a medium - but a material will only conduct electricity if its atomic structure enables it to do so. In investigating electrical conduction scientists discovered two new classes of material. Semiconductors, first exploited commercially in the 1950s, have given us the transistor, the solar cell and the silicon chip, and have revolutionised telecommunications. And superconductors, remarkable materials first observed in 1911, are used in medical imaging and at the Large Hadron Collider in Geneva. With:Frank CloseProfessor of Physics at the University of OxfordJenny NelsonProfessor of Physics at Imperial College LondonLesley CohenProfessor of Solid State Physics at Imperial College LondonProducer: Thomas Morris.

Melvyn Bragg and his guests discuss the life and work of Benjamin Franklin. A printer, statesman, diplomat, writer and scientist, Franklin was one of the most remarkable individuals of the eighteenth century. His discoveries relating to the nature of electricity, and in particular a celebrated experiment which involved flying a kite in a thunderstorm, made him famous in Europe and America. His inventions include bifocal spectacles, and a new type of stove. In the second half of his life he became prominent as a politician and a successful diplomat. As the only Founding Father to have signed all three of the fundamental documents of the United States of America, including its Declaration of Independence and Constitution, Benjamin Franklin occupies a unique position in the history of the nation. With:Simon MiddletonSenior Lecturer in American History at the University of SheffieldSimon NewmanSir Denis Brogan Professor of American History at the University of GlasgowPatricia FaraSenior Tutor at Clare College, University of Cambridge.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss Lyrical Ballads, the collection of poems by William Wordsworth and Samuel Coleridge first published in 1798. The work was conceived as an attempt to cast off the stultifying conventions of formal 18th-century poetry. Wordsworth wrote that the poems it contains should be "considered as experiments. They were written chiefly with a view to ascertain how far the language of conversation in the middle and lower classes of society is adapted to the purpose of poetic pleasure."Lyrical Ballads contains some of the best-known work by Coleridge and Wordsworth, including The Rime of the Ancient Mariner and Tintern Abbey - and is today seen as a point of radical departure for poetry in English.With:Judith HawleyProfessor of Eighteenth-Century Literature at Royal Holloway, University of LondonJonathan BateProvost of Worcester College, OxfordPeter SwaabReader in English Literature at University College London.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss Vitruvius' De Architectura. Written almost exactly two thousand years ago, Vitruvius' work is a ten-volume treatise on engineering and architecture, the only surviving work on the subject from the ancient world. This fascinating book offers unique insights into Roman technology and contains discussion of the general principles of architecture, the training of architects and the design of temples, houses and public buildings.The rediscovery of this seminal treatise in the 15th century provided the impetus for the neoclassical architectural movement, and Vitruvius exerted a significant influence on the work of Renaissance architects including Palladio, Brunelleschi and Alberti. It remains a hugely important text today, two millennia after it was written.With:Serafina CuomoReader in Roman History at Birkbeck, University of LondonRobert TavernorEmeritus Professor of Architecture and Urban Design at the London School of EconomicsAlice KoenigLecturer in Latin and Classical Studies at the University of St Andrews.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the work and influence of the eighteenth-century philosopher Moses Mendelssohn. A prominent figure at the court of Frederick the Great, Mendelssohn was one of the most significant thinkers of his age. He came from a humble, but culturally rich background and his obvious intelligence was recognised from a young age and nurtured by the local rabbi where he lived in the town of Dessau in Prussia. Moses's learning earned him the sobriquet of the 'German Socrates' and he is considered to be one of the principal architects of the Haskala, the Jewish Enlightenment, and widely regarded as having helped bring Judaism into the mainstream of European culture. Mendelssohn is perhaps best remembered today for his efforts to bring Jewish and German culture closer together and for his plea for religious toleration.With:Christopher ClarkProfessor of Modern European History at the University of CambridgeAbigail GreenTutor and Fellow in History at the University of OxfordAdam SutcliffeSenior Lecturer in European History at King's College, London Producer: Natalia Fernandez.

Melvyn Bragg and his guests discuss the measurement of time. Early civilisations used the movements of heavenly bodies to tell the time, but even in the ancient world more sophisticated timekeeping devices such as waterclocks were known. The development of mechanical clocks in Europe emerged in the medieval period when monks used such devices to sound an alarm to signal it was the hour to pray, although these clocks did not tell them the time. For hundreds of years clocks were inaccurate and it proved hard to remedy the problems, let alone settle on a standard time that the country should follow. It was with the advent of the railways that time finally became standardised in Britain in the mid-19th century and only in 1884 that Greenwich became the prime meridian of the world. Atomic clocks now mark the passing of the days, hours, and minutes and they are capable of keeping time to a second in 15 million years. With:Kristen LippincottFormer Director of the Royal Observatory, GreenwichJim BennettDirector of the Museum of the History of Science at the University of OxfordJonathan BettsSenior Curator of Horology at the Royal Observatory, GreenwichProducer: Natalia Fernandez.

Melvyn Bragg and his guests discuss the origins of Quakerism. In the mid-seventeenth century an itinerant preacher, George Fox, became the central figure of a group known as the Religious Society of Friends, whose members believed it was possible to obtain contact with Christ without priestly intercession. The Quakers, as they became known, rejected the established Church and what they saw as the artificial pomp and artifice of its worship. They argued for religious toleration and for the equality of men and women. Persecuted for many years, particularly after the Restoration of Charles II in 1660, the Quakers survived to become an influential religious group, known for their pacifism and philanthropy. With:Justin ChampionProfessor of the History of Early Modern Ideas at Royal Holloway, University of LondonJohn CoffeyProfessor of Early Modern History at the University of LeicesterKate PetersFellow in History at Murray Edwards College at the University of Cambridge.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the emergence of geology as a scientific discipline. A little over two hundred years ago a small group of friends founded the Geological Society of London. This organisation was the first devoted to furthering the discipline of geology - the study of the Earth, its history and composition. Although geology only emerged as a separate area of study in the late eighteenth century, many earlier thinkers had studied rocks, fossils and the materials from which the Earth is made. Ancient scholars in Egypt and Greece speculated about the Earth and its composition. And in the Renaissance the advent of mining brought further insight into the nature of objects found underground and how they got there. But how did such haphazard study of rocks and fossils develop into a rigorous scientific discipline?With:Stephen PumfreySenior Lecturer in the History of Science at Lancaster UniversityAndrew ScottProfessor of Applied Palaeobotany at Royal Holloway, University of LondonLeucha VeneerResearch Associate at the Centre for the History of Science, Technology and Medicine at the University of Manchester.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss Neoplatonism, the school of thought founded in the 3rd century AD by the philosopher Plotinus. Born in Egypt, Plotinus was brought up in the Platonic tradition, studying and reinterpreting the works of the Greek thinker Plato. After he moved to Rome Plotinus became the most influential member of a group of thinkers dedicated to Platonic scholarship. The Neoplatonists - a term only coined in the nineteenth century - brought a new religious sensibility to bear on Plato's thought. They outlined a complex cosmology which linked the human with the divine, headed by a mysterious power which they called the One. Neoplatonism shaped early Christian, Jewish and Muslim religious scholarship, and remained a dominant force in European thought until the Renaissance. With:Angie HobbsAssociate Professor of Philosophy and Senior Fellow in the Public Understanding of Philosophy at the University of WarwickPeter AdamsonProfessor of Ancient and Medieval Philosophy at King's College LondonAnne SheppardProfessor of Ancient Philosophy at Royal Holloway, University of LondonProducer: Thomas Morris.

Melvyn Bragg and his guests discuss the Battle of Bosworth Field, the celebrated encounter between Lancastrian and Yorkist forces in August 1485. The battle, the penultimate of the Wars of the Roses, resulted in the death of Richard III. The victory of Henry Tudor enabled him to succeed Richard as monarch and establish the Tudor dynasty which was to rule for over a century. These events were immortalised by Shakespeare in Richard III, and today the battle is regarded as one of the most important to have taken place on English soil. But little is known about what happened on the battlefield, and the very location of the encounter remains the subject of much debate.With:Anne CurryProfessor of Medieval History and Dean of Humanities at the University of SouthamptonSteven GunnTutor and Fellow in Modern History at Merton College, OxfordDavid GrummittLecturer in British History at the University of Kent.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss Voltaire's novel Candide. First published in 1759, the novel follows the adventures of a young man, Candide, and his mentor, the philosopher Pangloss. Candide was written in the aftermath of a major earthquake in Lisbon and the outbreak of the Seven Years' War, events which caused such human suffering that they shook many people's faith in a benevolent God. Voltaire's masterpiece piles ridicule on Optimism, the fashionable philosophical belief that such disasters are part of God's plan for humanity - that 'all is for the best in this best of all possible worlds'.Often uproariously funny, the novel is a biting satire whose other targets include bad literature, extremist religion and the vanity of kings and politicians. It captivated contemporary readers and has proved one of French literature's most enduring classics.With:David WoottonAnniversary Professor of History at the University of YorkNicholas CronkProfessor of French Literature and Director of the Voltaire Foundation at the University of OxfordCaroline WarmanLecturer in French and Fellow of Jesus College at the University of Oxford.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss game theory, the mathematical study of decision-making. First formulated in the 1940s, the discipline entails devising 'games' to simulate situations of conflict or cooperation. It allows researchers to unravel decision-making strategies, and even to establish why certain types of behaviour emerge. Some of the games studied in game theory have become well known outside academia - they include the Prisoner's Dilemma, an intriguing scenario popularised in novels and films, and which has inspired television game shows. Today game theory is seen as a vital tool in such diverse fields as evolutionary biology, economics, computing and philosophy. With:Ian StewartEmeritus Professor of Mathematics at the University of WarwickAndrew ColmanProfessor of Psychology at the University of LeicesterRichard BradleyProfessor of Philosophy at the London School of Economics and Political Science.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss On War, a treatise on the theory and practice of warfare written by the Prussian soldier and intellectual Carl von Clausewitz. First published in 1832, Clausewitz's magnum opus is commonly regarded as the most important book about military theory ever written. Informed by its author's experience of fighting against the mighty armies of Napoleon, the work looks not just at the practicalities of warfare, but offers a subtle philosophical analysis of the nature of war and its relationship with politics. Notions such as the Clausewitzian Trinity have had an enormous effect on later military leaders. But its influence is felt today not just on the battlefield but also in politics and business.With:Saul DavidProfessor of War Studies at the University of BuckinghamHew StrachanChichele Professor of the History of War at the University of OxfordBeatrice HeuserProfessor of International Relations at the University of Reading.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the celebrated Venetian explorer Marco Polo. In 1271 Polo set off on an epic journey through Asia. He was away for more than twenty years, and when he returned to Venice he told extraordinary tales of his adventures. He had visited the court of the Mongol Emperor Kublai Khan, and acted as his emissary, travelling through many of the remote territories of the Far East. An account of Marco Polo's travels was written down by his contemporary Rustichello da Pisa, a romance writer he met after being imprisoned during a war against the neighbouring Genoese.The Travels of Marco Polo was one of the most popular books produced in the age before printing. It was widely translated, and many beautifully illustrated editions made their way to the collections of the rich and educated. It was much read by later travellers, and Polo's devotees included Christopher Columbus and Henry the Navigator. For centuries it was seen as the first and best account of life in the mysterious East; but today the accuracy and even truth of Marco Polo's work is often disputed.With:Frances WoodLead Curator of Chinese Collections at the British LibraryJoan Pau RubiesReader in International History at the London School of Economics and Political ScienceDebra Higgs StricklandSenior Lecturer in the History of Art at the University of GlasgowProducer: Thomas Morris.

Melvyn Bragg and his guests discuss the Trojan War, one of the best known events of Greek mythology. According to the traditional version of the story, the war began when a Trojan prince, Paris, eloped with the Spartan queen Helen. A Greek army besieged Troy for ten years before the city was finally overrun and destroyed. Some of the most familiar names of Greek mythology are associated with the war, including Achilles and Hector, Odysseus and Helen of Troy - and it has also given us the story of the Trojan Horse.The war is the backdrop for Homer's epic poem The Iliad, and features in many other works from classical antiquity. For centuries it was assumed to be a mythical event. But in the nineteenth century a series of archaeological discoveries provided startling evidence that Troy might really have existed, leading some scholars to conclude that there could even be some truth behind the myth. So does the Trojan War story have any basis in fact? And why has it proved such an enduring legend?With:Edith HallProfessor of Classics at King's College LondonEllen AdamsLecturer in Classical Art and Archaeology at King's College LondonSusan SherrattLecturer in Archaeology at the University of SheffieldProducer: Thomas Morris.

Melvyn Bragg and his guests discuss the biblical king Solomon, celebrated for his wisdom and as the architect of the First Temple in Jerusalem. According to the Old Testament account of his life, Solomon was chosen as his father David's successor as Israelite king, and instead of praying for long life or wealth asked God for wisdom. In the words of the Authorised Version, "And there came of all people to hear the wisdom of Solomon, from all kings of the earth, which had heard of his wisdom." Solomon is an important figure in Judaism, Islam and Christianity alike, and is also credited with the authorship of several scriptural texts. His name is associated with the tradition of wisdom literature and with a large number of myths and legends. For many centuries Solomon was seen as the archetypal enlightened monarch, and his example influenced notions of kingship from the Middle Ages onwards.With:Martin PalmerDirector of the International Consultancy on Religion, Education, and CulturePhilip AlexanderEmeritus Professor of Jewish Studies at the University of ManchesterKatharine DellSenior Lecturer in Old Testament Studies at the University of Cambridge, and Fellow of St Catherine's College, CambridgeProducer: Thomas Morris.

Melvyn Bragg and his guests discuss James Joyce's novel Ulysses. First published ninety years ago in Paris, Joyce's masterpiece is a sprawling and startlingly original work charting a single day in the life of the Dubliner Leopold Bloom. Some early readers were outraged by its sexual content and daringly scatalogical humour, and the novel was banned in most English-speaking countries for a decade after it first appeared. But it was soon recognised as a genuinely innovative work: overturning the ban on its publication, an American judge described Ulysses as "a sincere and serious attempt to devise a new literary method for the observation and description of mankind."Today Ulysses is widely regarded as the greatest example of literary modernism, and a work that changed literature forever. It remains one of the most discussed novels ever written.Steven ConnorProfessor of Modern Literature and Theory at Birkbeck, University of LondonJeri JohnsonSenior Fellow in English at Exeter College, OxfordRichard BrownReader in Modern English Literature at the University of LeedsProducer: Thomas Morris.

Melvyn Bragg and his guests discuss the life of the prominent 19th-century social reformer Annie Besant. Born in 1847, Annie Besant espoused a range of causes including secularism, women's rights, Socialism, Irish Home Rule, birth control and better conditions for workers. Described by Beatrice Webb as having "the voice of a beautiful soul", Besant became an eloquent public speaker as well as writing numerous campaigning articles and pamphlets. She is perhaps most famous for the key role she played in the successful strike by female workers at the Bryant and May match factory in East London in 1888, which brought the appalling working conditions of many factory workers to greater public attention.

Later in life she became a follower of theosophy, a belief system bringing together elements of Hinduism, Buddhism and other Eastern religions. She moved to India, its main base, and took on a leading role in the Indian self-rule movement, being appointed the first female president of the Indian National Congress in 1917.

With:

Lawrence Goldman Fellow in Modern History at St Peter's College, University of Oxford

David Stack Reader in History at the University of Reading

Yasmin Khan Senior Lecturer in Politics and International Relations at Royal Holloway, University of London.

Producer: Victoria Brignell.

Melvyn Bragg and his guests discuss the life and work of the Arab philosopher al-Kindi. Born in the early ninth century, al-Kindi was heavily influenced by Greek philosophy and supervised the translation of many works by Aristotle and others into Arabic. The author of more than 250 works, he wrote on many different subjects, from optics to mathematics, music and astrology. He was the first significant thinker to argue that philosophy and Islam had much to offer each other and need not be kept apart. Today al-Kindi is regarded as one of the greatest scholars of the medieval Islamic world.

With:

Hugh Kennedy Professor of Arabic at SOAS, University of London

James Montgomery Sir Thomas Adams's Professor of Arabic Elect at the University of Cambridge

Amira Bennison Senior Lecturer in Middle Eastern and Islamic Studies at the University of Cambridge.

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss Scepticism, the idea that it may be impossible to know anything with complete certainty. Scepticism was first outlined by ancient Greek philosophers: Socrates is reported to have said that the only thing he knew for certain was that he knew nothing. Later, Scepticism was taught at the Academy founded by Plato, and learnt by students who included the Roman statesman Cicero. The central ideas of Scepticism were taken up by later philosophers and came to the fore during the Renaissance, when thinkers including Rene Descartes and Michel de Montaigne took up its challenge. A central plank of the philosophical system of David Hume, Scepticism had a powerful influence on the religious and scientific debates of the Enlightenment.

With:

Peter Millican Professor of Philosophy at Hertford College, Oxford

Melissa Lane Professor of Politics at Princeton University

Jill Kraye Professor of the History of Renaissance Philosophy and Librarian at the Warburg Institute, University of London.

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss Hadrian's Wall, the largest Roman structure and one of the most important archaeological monuments in Britain. Stretching for eighty miles from the mouth of the River Tyne to the Solway Firth and classified today as a World Heritage Site, it has been a source of fascination ever since it came into existence. It was built in about 122 AD by the Emperor Hadrian, and a substantial part of it still survives today. Although its construction must have entailed huge cost and labour, the Romans abandoned it within twenty years, deciding to build the Antonine Wall further north instead. Even after more than a century of excavations, many mysteries still surround Hadrian's Wall, including its exact purpose. Did it have a meaningful defensive role or was it mainly a powerful emperor's vanity project?

With:

Greg Woolf Professor of Ancient History at the University of St Andrews

David Breeze Former Chief Inspector of Ancient Monuments for Scotland and Visiting Professor of Archaeology at the University of Durham

Lindsay Allason-Jones Former Reader in Roman Material Culture at the University of Newcastle

Producer: Victoria Brignell.

Melvyn Bragg and his guests discuss the cell, the fundamental building block of life. First observed by Robert Hooke in 1665, cells occur in nature in a bewildering variety of forms. Every organism alive today consists of one or more cells: a single human body contains up to a hundred trillion of them.

The first life on Earth was a single-celled organism which is thought to have appeared around three and a half billion years ago. That simple cell resembled today's bacteria. But eventually these microscopic entities evolved into something far more complex, and single-celled life gave rise to much larger, complex multicellular organisms. But how did the first cell appear, and how did that prototype evolve into the sophisticated, highly specialised cells of the human body?

With:

Steve Jones Professor of Genetics at University College London

Nick Lane Senior Lecturer in the Department of Genetics, Evolution and Environment, University College London

Cathie Martin Group Leader at the John Innes Centre and Professor in the School of Biological Sciences at the University of East Anglia

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the Druids, the priests of ancient Europe. Active in Ireland, Britain and Gaul, the Druids were first written about by Roman authors including Julius Caesar and Pliny, who described them as wearing white robes and cutting mistletoe with golden sickles. They were suspected of leading resistance to the Romans, a fact which eventually led to their eradication from ancient Britain. In the early modern era, however, interest in the Druids revived, and later writers reinvented and romanticised their activities. Little is known for certain about their rituals and beliefs, but modern archaeological discoveries have shed new light on them.

With:

Barry Cunliffe Emeritus Professor of Archaeology at the University of Oxford

Miranda Aldhouse-Green Professor of Archaeology at Cardiff University

Justin Champion Professor of the History of Early Modern Ideas at Royal Holloway, University of London

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the Ontological Argument. In the eleventh century St Anselm of Canterbury proposed that it was possible to prove the existence of God using reason alone. His argument was ridiculed by some of his contemporaries, but was analysed and improved by later thinkers including Descartes, Spinoza and Leibniz. Other philosophers have been less kind, with the Enlightenment thinker David Hume offering one possible refutation. But the debate continued, fuelled by interventions from such heavyweights as Immanuel Kant and Kurt Gödel; and it remains one of the most discussed problems in philosophy.

With:

John Haldane Professor of Philosophy at the University of St Andrews

Peter Millican Professor of Philosophy at the University of Oxford

Clare Carlisle Lecturer in Philosophy of Religion at King's College London

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the medieval scholar Gerald of Wales. Born around the middle of the twelfth century, Gerald was a cleric and courtier. For much of his life he was close to Henry II and the Church hierarchy, and wrote accounts of official journeys he made around Wales and Ireland in their service. Both Anglo-Norman and Welsh by parentage, he had a unique perspective on the political strife of his age. Gerald's Journey Around Wales and Description of Ireland are among the most colourful and informative chronicles of the Middle Ages, and had a powerful influence on later historians.

With:

Henrietta Leyser Emeritus Fellow of St Peter's College, University of Oxford

Michelle Brown Professor Emerita of Medieval Manuscript Studies at the School of Advanced Study, University of London

Huw Pryce Professor of Welsh History at Bangor University

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the life and achievements of Hannibal. One of the most celebrated military leaders in history, Hannibal was the Carthaginian general who led an entire army, complete with elephants, across the Alps in order to attack the Roman Republic. He lived at a time of prolonged hostility between the two great Mediterranean powers, Rome and Carthage, and was the Carthaginians' inspirational leader during the Second Punic War which unfolded between 218 and 202 BC. His career ended in defeat and exile, but he achieved such fame that even his enemies the Romans erected statues of him. Centuries later his tactical genius was admired and studied by generals including Napoleon and Wellington.

With:

Ellen O'Gorman Senior Lecturer in Classics at the University of Bristol

Mark Woolmer Senior Tutor in the Department of Classics and Ancient History at the University of Durham

Louis Rawlings Senior Lecturer in Ancient History at Cardiff University.

Producer: Natalia Fernandez.

Melvyn Bragg and his guests discuss the life and influence of William Caxton, the merchant who brought the printing press to the British Isles. After spending several years working as a printer in Bruges, Caxton returned to London and in 1476 set up his first printing press in Westminster, and also imported and sold other printed books. Caxton concentrated on producing popular books that he knew would sell, such as Chaucer's 'Canterbury Tales' and small liturgical 'books of hours'. The standard of Caxton's printing may have lagged behind that on the continent, but he was a skilful businessman and unusually for printers at the time, he managed not to go bankrupt. The advent of print is now seen as one of the great revolutions in intellectual history - although many scholars believe it was a revolution that took many generations to have an effect.

With:

Richard Gameson Professor of the History of the Book at the University of Durham

Julia Boffey Professor of Medieval Studies in the English Department at Queen Mary, University of London

David Rundle Member of the History Faculty at the University of Oxford

Producer: Natalia Fernandez.

Melvyn Bragg and his guests discuss Fermat's Last Theorem. In 1637 the French mathematician Pierre de Fermat scribbled a note in the margin of one of his books. He claimed to have proved a remarkable property of numbers, but gave no clue as to how he'd gone about it. "I have found a wonderful demonstration of this proposition," he wrote, "which this margin is too narrow to contain". Fermat's theorem became one of the most iconic problems in mathematics and for centuries mathematicians struggled in vain to work out what his proof had been. In the 19th century the French Academy of Sciences twice offered prize money and a gold medal to the person who could discover Fermat's proof; but it was not until 1995 that the puzzle was finally solved by the British mathematician Andrew Wiles.

With:

Marcus du Sautoy Professor of Mathematics & Simonyi Professor for the Public Understanding of Science at the University of Oxford

Vicky Neale Fellow and Director of Studies in Mathematics at Murray Edwards College at the University of Cambridge

Samir Siksek Professor at the Mathematics Institute at the University of Warwick.

Producer: Natalia Fernandez.

Melvyn Bragg and his guests discuss The Anarchy, the civil war that took place in mid-twelfth century England. The war began as a succession dispute between the Empress Matilda, daughter of Henry I, and her cousin, Stephen of Blois. On Henry's death Stephen seized the English throne and held it for a number of years before Matilda wrestled it from him, although she was chased out of London before she could be crowned.

The Anarchy dragged on for nearly twenty years and is so called because of the chaos and lawlessness that characterised the period. Yet only one major battle ever took place, the Battle of Lincoln in 1141, and any other fighting associated with the conflict was fairly localised. This has led historians to question the accuracy of labelling the civil war as The Anarchy, a name only bestowed on the era in the 19th century. But why did Matilda fail to become the monarch, and what impact did it have on the way England was ruled in centuries to come?

With:

John Gillingham Emeritus Professor of History at the London School of Economics and Political Science

Louise Wilkinson Reader in Medieval History at Canterbury Christ Church University

David Carpenter Professor of Medieval History at Kings College London.

Producer: Natalia Fernandez.

Melvyn Bragg and his guests discuss the Upanishads, the ancient sacred texts of Hinduism. Dating from about 700 BC, the Upanishads were passed down through an oral tradition in priestly castes and were not written down until the 6th century AD. They constitute the final part of the Vedas, the collection of texts which form the foundation of the Indian Hindu world, and were originally spoken during sacrificial rituals.

Yet the Upanishads go beyond incantations performed during sacrifices, and ask profound questions about human existence and man's place in the cosmos. The concepts of Brahman (the universal cosmic power) and Atman (the deeper soul of the individual) are central to the understanding of the Upanishads. Each individual treatise has its own character. Some are poetic; some are scientific; others are dialogues between kings and sages or metaphysical reflections. More than one hundred Upanishads were produced, thirteen of which are regarded as the canonical scriptures of Hinduism.

With:

Jessica Frazier Lecturer in Religious Studies at the University of Kent and a Research Fellow at the Oxford Centre for Hindu Studies at the University of Oxford

Chakravarthi Ram-Prasad Professor of Comparative Religion and Philosophy at Lancaster University

Simon Brodbeck Lecturer in Religious Studies at the University of Cardiff

Producer: Natalia Fernandez.

Melvyn Bragg and his guests discuss the French philosopher and social activist Simone Weil. Born in Paris in 1909 into a wealthy, agnostic Jewish family, Weil was a precocious child and attended the prestigious Ecole Normale Superieure in Paris, achieving the top marks in her class (Simone de Beauvoir came second).

Weil rejected her comfortable background and chose to work in fields and factories to experience the life of the working classes at first hand. She was acutely sensitive to human suffering and devoted her life to helping those less fortunate than herself. Despite her belief in pacifism she volunteered on the Republican side during the Spanish Civil War and later joined the French Resistance movement in England.

Her philosophy was both complex and intense. She argued that the presence of evil and suffering in the world was evidence of God's love and that Man has no right to ask anything of God or of anyone whom they love. Love which expects reward was not love at all in Weil's eyes.

Weil died of TB in Kent at the age of only 34. Her strict lifestyle and self-denial may have contributed to her early death. T.S Eliot said "she was not just a woman of genius, but was a genius akin to that of a saint"; Albert Camus believed she was "the only great spirit of our time."

With:

Beatrice Han-Pile Professor of Philosophy at the University of Essex

Stephen Plant Runcie Fellow and Dean of Trinity Hall at the University of Cambridge

David Levy Teaching Fellow in the Department of Philosophy at the University of Edinburgh

Producer: Natalia Fernandez.

Melvyn Bragg and his guests discuss the Borgias, the most notorious family in Renaissance Italy. Famed for their treachery and corruption, the Borgias produced two popes during their time of dominance in Rome in the late 15th century. The most well-known of these two popes is Alexander VI, previously Cardinal Rodrigo Borgia. He was accused of buying votes to elect him to the papacy and openly promoted his children in positions of power. Rodrigo's daughter, Lucrezia, is widely remembered as a ruthless poisoner; his son, Cesare, as a brutal soldier.

Murder, intrigue and power politics characterised their rule, but many of the stories now told about their depraved behaviour and evil ways emerged after their demise and gave rise to the so-called 'Black Legend'. The sullied reputation of the Borgia dynasty endures even today and their lives have provided a major theme for plays, novels and over forty films.

With:

Evelyn Welch Professor of Renaissance Studies at Queen Mary, University of London

Catherine Fletcher Lecturer in Public History at the University of Sheffield

Christine Shaw Honorary Research Fellow at Swansea University

Producer: Natalia Fernandez.

Melvyn Bragg and his guests discuss the history of crystallography, the study of crystals and their structure. The discovery in the early 20th century that X-rays could be diffracted by a crystal revolutionised our knowledge of materials. This crystal technology has touched most people's lives, thanks to the vital role it plays in diverse scientific disciplines - from physics and chemistry, to molecular biology and mineralogy. To date, 28 Nobel Prizes have been awarded to scientists working with X-ray crystallography, an indication of its crucial importance.

The history of crystallography began with the work of Johannes Kepler in the 17th century, but perhaps the most crucial leap in understanding came with the work of the father-and-son team the Braggs in 1912. They built on the work of the German physicist Max von Laue who had proved that X-rays are a form of light waves and that it was possible to scatter these rays using a crystal. The Braggs undertook seminal experiments which transformed our perception of crystals and their atomic arrangements, and led to some of the most significant scientific findings of the last century - such as revealing the structure of DNA.

With:

Judith Howard Director of the Biophysical Sciences Institute and Professor of Chemistry at the University of Durham

Chris Hammond Life Fellow in Material Science at the University of Leeds

Mike Glazer Emeritus Professor of Physics at the University of Oxford and Visiting Professor of Physics at the University of Warwick

Producer: Natalia Fernandez.

Melvyn Bragg and his guests discuss the influential British philosopher Bertrand Russell. Born in 1872 into an aristocratic family, Russell is widely regarded as one of the founders of Analytic philosophy, which is today the dominant philosophical tradition in the English-speaking world. In his important book The Principles of Mathematics, he sought to reduce mathematics to logic. Its revolutionary ideas include Russell's Paradox, a problem which inspired Ludwig Wittgenstein to pursue philosophy. Russell's most significant and famous idea, the theory of descriptions, had profound consequences for the discipline.

In addition to his academic work, Russell played an active role in many social and political campaigns. He supported women's suffrage, was imprisoned for his pacifism during World War I and was a founder of the Campaign for Nuclear Disarmament. He wrote a number of books aimed at the general public, including The History of Western Philosophy which became enormously popular, and in 1950 he was awarded the Nobel Prize in Literature. Russell's many appearances on the BBC also helped to promote the public understanding of ideas.

With:

AC Grayling Master of the New College of the Humanities and a Supernumerary Fellow of St Anne's College, Oxford

Mike Beaney Professor of Philosophy at the University of York

Hilary Greaves Lecturer in Philosophy and Fellow of Somerville College, Oxford

Producer: Victoria Brignell.

Melvyn Bragg and his guests discuss the epic poem the Shahnameh of Ferdowsi, the 'Book of Kings', which has been at the heart of Persian culture for the past thousand years. The poem recounts a legendary history of Iran from the dawn of time to the fall of the Persian Empire in the 7th century and serves, in a sense, as a creation myth for the Persian nation.

The Shahnameh took Ferdowsi thirty years to write and, consisting of over 50,000 verses, is said to be the longest poem ever written by a single author. Laced with tragedy, Ferdowsi's epic chronicles battles, romances, family rifts and Man's interior struggle with himself. Although the stories may not always be true they have a profound resonance with Iranians even today, and the poem has been referred to as both the 'encyclopaedia of Iranian culture' and the identity card of the Persian people.

With:

Narguess Farzad Senior Fellow in Persian at SOAS, University of London

Charles Melville Professor of Persian History at Pembroke College at the University of Cambridge

Vesta Sarkhosh Curtis Curator of Middle Eastern Coins at the British Museum

Producer: Natalia Fernandez.

Melvyn Bragg and his guests discuss The South Sea Bubble, the speculation mania in early 18th-century England which ended in the financial ruin of many of its investors. The South Sea Company was founded in 1711 with a view to restructuring government debt and restoring public credit. The company would ostensibly trade with South America, hence its name; and indeed, it did trade in slaves for the Spanish market even after the Bubble burst in 1720.

People from all walks of life bought shares in the South Sea Company, from servants to gentry, and it was said the entire country was gripped by South Sea speculation mania. When the shares crashed and the company collapsed there was a public outcry and many people faced financial ruin, although some investors sold before the crash and made substantial amounts of money. For example, the bookseller Thomas Guy made his fortune and founded a hospital in his name the following year.

But how did such a financial crisis develop and were there any lessons learnt following this early example of a stock market boom and bust?

With:

Anne Murphy Senior Lecturer in History at the University of Hertfordshire

Helen Paul Lecturer in Economics and Economic History at the University of Southampton

Roey Sweet Head of the School of History at the University of Leicester

Producer: Natalia Fernandez.

Melvyn Bragg and his guests discuss the cult of Mithras, a mystery religion that existed in the Roman Empire from the 1st to the 4th centuries AD. Also known as the Mysteries of Mithras, its origins are uncertain. Academics have suggested a link with the ancient Vedic god Mitra and the Iranian Zoroastrian deity Mithra, but the extent and nature of the connection is a matter of controversy.

Followers of Mithras are thought to have taken part in various rituals, most notably communal meals and a complex seven-stage initiation system. Typical depictions of Mithras show him being born from a rock, enjoying food with the sun god Sol and stabbing a bull. Mithraic places of worship have been found throughout the Roman world, including an impressive example in London. However, Mithraism went into decline in the 4th century AD with the rise of Christianity and eventually completely disappeared. In recent decades, many aspects of the cult have provoked debate, especially as there are no written accounts by its members. As a result, archaeology has been of great importance in the study of Mithraism and has provided new insights into the religion and its adherents.

With:

Greg Woolf Professor of Ancient History at the University of St Andrews

Almut Hintze Zartoshty Professor of Zoroastrianism at SOAS, University of London

John North Acting Director of the Institute of Classical Studies, University of London.

Producer: Victoria Brignell.

Melvyn Bragg and his guests discuss Thomas Malory's "Le Morte Darthur", the epic tale of King Arthur and his knights of the Round Table. Sir Thomas Malory was a knight from Warwickshire, a respectable country gentleman and MP in the 1440s who later turned to a life of crime and spent various spells in prison. It was during Malory's final incarceration that he wrote "Le Morte Darthur", an epic work which was based primarily on French, but also some English, sources.

Malory died shortly after his release in 1470 and it was to be another fifteen years before "Le Morte Darthur" was published by William Caxton, to immediate popular acclaim. Although the book fell from favour in the seventeenth century, it was revived again in Victorian times and became an inspiration for the Pre-Raphaelite movement who were entranced by the chivalric and romantic world that Malory portrayed.

The Arthurian legend is one of the most enduring and popular in western literature and its characters - Sir Lancelot, Guinevere, Merlin and King Arthur himself, are as well-known today as they were then; and the book's themes - chivalry, betrayal, love and honour - remain as compelling.

With:

Helen Cooper Professor of Medieval and Renaissance English at the University of Cambridge

Helen Fulton Professor of Medieval Literature and Head of Department of English and Related Literature at the University of York

Laura Ashe CUF Lecturer and Tutorial Fellow at Worcester College at the University of Oxford

Producer: Natalia Fernandez.

Melvyn Bragg and his guests discuss comets, the 'dirty snowballs' of the Solar System. In the early 18th century the Astronomer Royal Sir Edmond Halley compiled a list of appearances of comets, bright objects like stars with long tails which are occasionally visible in the night sky. He concluded that many of these apparitions were in fact the same comet, which returns to our skies around every 75 years, and whose reappearance he correctly predicted. Halley's Comet is today the best known example of a comet, a body of ice and dust which orbits the Sun. Since they contain materials from the time when the Solar System was formed, comets are regarded by scientists as frozen time capsules, with the potential to reveal important information about the early history of our planet and others.

With:

Monica Grady Professor of Planetary and Space Sciences at the Open University

Paul Murdin Senior Fellow at the Institute of Astronomy at the University of Cambridge

Don Pollacco Professor of Astronomy at the University of Warwick

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss Romulus and Remus, the central figures of the foundation myth of Rome. According to tradition, the twins were abandoned by their parents as babies, but were saved by a she-wolf who found and nursed them. Romulus killed his brother after a vicious quarrel, and went on to found a city, which was named after him.

The myth has been at the core of Roman identity since the 1st century AD, although the details vary in different versions of the story. For many Roman writers, the story embodied the ethos and institutions of their civilisation. The image of the she-wolf suckling the divinely fathered twins remains a potent icon of the city even today.

With:

Mary Beard Professor of Classics at the University of Cambridge Peter Wiseman Emeritus Professor of Classics and Ancient History at the University of Exeter Tim Cornell Emeritus Professor of Ancient History at the University of Manchester.

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the War of 1812, the conflict between America and the British Empire sometimes referred to as the second American War of Independence. In June 1812, President James Madison declared war on Britain, angered by the restrictions Britain had imposed on American trade, the Royal Navy's capture of American sailors and British support for Native Americans. After three years of largely inconclusive fighting, the conflict finally came to an end with the Treaty of Ghent which, among other things, helped to hasten the abolition of the global slave trade. Although the War of 1812 is often overlooked, historians say it had a profound effect on the USA and Canada's sense of national identity, confirming the USA as an independent country. America's national anthem, The Star-Spangled Banner began life as a poem written after its author, Francis Scott Key, witnessed the British bombardment of Fort McHenry during the Battle of Baltimore. The war also led to Native Americans losing hundreds of thousands of acres of land in a programme of forced removal. With: Kathleen Burk Professor of Modern and Contemporary History at University College London Lawrence Goldman Fellow in Modern History at St Peter's College, University of Oxford Frank Cogliano Professor of American History at the University of Edinburgh Producer: Victoria Brignell.

Angie Hobbs, David Sedley and James Warren join Melvyn Bragg to discuss Epicureanism, the system of philosophy based on the teachings of Epicurus and founded in Athens in the fourth century BC. Epicurus outlined a comprehensive philosophical system based on the idea that everything in the Universe is constructed from two phenomena: atoms and void. At the centre of his philosophy is the idea that the goal of human life is pleasure, by which he meant not luxury but the avoidance of pain. His followers were suspicious of marriage and politics but placed great emphasis on friendship. Epicureanism became influential in the Roman world, particularly through Lucretius's great poem De Rerum Natura, which was rediscovered and widely admired in the Renaissance.

With:

Angie Hobbs Professor of the Public Understanding of Philosophy at the University of Sheffield

David Sedley Laurence Professor of Ancient Philosophy at the University of Cambridge

James Warren Reader in Ancient Philosophy at the University of Cambridge

Producer: Thomas Morris.

Jane Francis, Richard Corfield and Carrie Lear join Melvyn Bragg to discuss ice ages, periods when a reduction in the surface temperature of the Earth has resulted in ice sheets at the Poles. Although the term 'ice age' is commonly associated with prehistoric eras when much of northern Europe was covered in ice, we are in fact currently in an ice age which began up to 40 million years ago. Geological evidence indicates that there have been several in the Earth's history, although their precise cause is not known. Ice ages have had profound effects on the geography and biology of our planet.

With:

Jane Francis Professor of Paleoclimatology at the University of Leeds

Richard Corfield Visiting Research Fellow in the Department of Earth Sciences at Oxford University

Carrie Lear Senior Lecturer in Palaeoceanography at Cardiff University.

Producer: Thomas Morris.

David Bradshaw, John Bowen and Ann Pasternak Slater join Melvyn Bragg to discuss Evelyn Waugh's comic novel Decline and Fall. Set partly in a substandard boys' public school, the novel is a vivid, often riotous portrait of 1920s Britain. Its themes, including modernity, religion and fashionable society, came to dominate Waugh's later fiction, but its savage wit and economy of style were entirely new. Published when Waugh was 24, the book was immediately celebrated for its vicious satire and biting humour.

With:

David Bradshaw Professor of English Literature at Worcester College, Oxford

John Bowen Professor of Nineteenth-Century Literature at the University of York

Ann Pasternak Slater Senior Research Fellow at St Anne's College, Oxford.

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the life and work of the Victorian anthropologist and archaeologist Augustus Pitt-Rivers. Over many years he amassed thousands of ethnographic and archaeological objects, some of which formed the founding collection of the Pitt Rivers Museum at Oxford University. Inspired by the work of Charles Darwin, Pitt-Rivers believed that human technology evolved in the same way as living organisms, and devoted much of his life to exploring this theory. He was also a pioneering archaeologist whose meticulous records of major excavations provided a model for later scholars.

With:

Adam Kuper Visiting Professor of Anthropology at Boston University

Richard Bradley Professor in Archaeology at the University of Reading

Dan Hicks University Lecturer & Curator of Archaeology at the Pitt Rivers Museum at the University of Oxford.

Producer: Thomas Morris.

In a programme first broadcast in 2013, Melvyn Bragg and his guests discuss absolute zero, the lowest conceivable temperature.  In the early eighteenth century the French physicist Guillaume Amontons suggested that temperature had a lower limit.  The subject of low temperature became a fertile field of research in the nineteenth century, and today we know that this limit - known as absolute zero - is approximately minus 273 degrees Celsius.  It is impossible to produce a temperature exactly equal to absolute zero, but today scientists have come to within a billionth of a degree.  At such low temperatures physicists have discovered a number of strange new phenomena including superfluids, liquids capable of climbing a vertical surface.

With:

Simon Schaffer Professor of the History of Science at the University of Cambridge

Stephen Blundell Professor of Physics at the University of Oxford

Nicola Wilkin Lecturer in Theoretical Physics at the University of Birmingham

Producer: Thomas Morris

Melvyn Bragg and his guests discuss the life and work of Anton Chekhov. Born in 1860, Chekhov trained as a doctor and for most of his adult life divided his time between medicine and writing. Best known for plays including The Cherry Orchard and Three Sisters, he is also celebrated today as one of the greatest of short story writers. His works are often powerful character studies and chronicle the changing nature of Russian society in the late nineteenth century.

With:

Catriona Kelly Professor of Russian at the University of Oxford

Cynthia Marsh Emeritus Professor of Russian Drama and Literature at the University of Nottingham

Rosamund Bartlett Founding Director of the Anton Chekhov Foundation and former Reader in Russian at the University of Durham.

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the work of Alfred Russel Wallace, a pioneer of evolutionary theory. Born in 1823, Wallace travelled extensively, charting the distribution of animal species throughout the world. This fieldwork in the Amazon and later the Malay Archipelago led him to formulate a theory of evolution through natural selection. In 1858 he sent the paper he wrote on the subject to Charles Darwin, who was spurred into the writing and publication of his own masterpiece On the Origin of Species. Wallace was also the founder of the science of biogeography and made important discoveries about the nature of animal coloration. But despite his visionary work, Wallace has been overshadowed by the greater fame of his contemporary Darwin.

With:

Steve Jones Emeritus Professor of Genetics at University College London

George Beccaloni Curator of Cockroaches and Related Insects and Director of the Wallace Correspondence Project at the Natural History Museum

Ted Benton Professor of Sociology at the University of Essex

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss one of the simplest and most remarkable of all molecules: water. Water is among the most abundant substances on Earth, covering more than two-thirds of the planet. Consisting of just three atoms, the water molecule is superficially simple in its structure but extraordinary in its properties. It is a rare example of a substance that can be found on Earth in gaseous, liquid and solid forms, and thanks to its unique chemical behaviour is the basis of all known life. Scientists are still discovering new things about it, such as the fact that there are at least fifteen different forms of ice.

Hasok Chang Hans Rausing Professor of History and Philosophy of Science at the University of Cambridge

Andrea Sella Professor of Chemistry at University College London

Patricia Hunt Senior Lecturer in Chemistry at Imperial College London.

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss Japan's Sakoku period, two centuries when the country deliberately isolated itself from the Western world. Sakoku began with a series of edicts in the 1630s which restricted the rights of Japanese to leave their country and expelled most of the Europeans living there. For the next two hundred years, Dutch traders were the only Westerners free to live in Japan. It was not until 1858 and the gunboat diplomacy of the American Commodore Matthew Perry that Japan's international isolation finally ended. Although historians used to think of Japan as completely isolated from external influence during this period, recent scholarship suggests that Japanese society was far less isolated from European ideas during this period than previously thought.

With:

Richard Bowring Emeritus Professor of Japanese Studies at the University of Cambridge

Andrew Cobbing Associate Professor of History at the University of Nottingham

Rebekah Clements Research Fellow of Queens' College and Research Associate at the Faculty of Asian and Middle Eastern Studies at the University of Cambridge.

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the Amazons, a tribe of formidable female warriors first described in Greek literature. They appear in the Homeric epics and were described by Herodotus, and featured prominently in the decoration of Greek vases and public buildings. In later centuries, particularly in the Renaissance, the Amazons became a popular theme of literature and art. After the discovery of the New World, the largest river in South America was named the Amazon, since the warlike tribes inhabiting the river's margins reminded Spanish pioneers of the warriors of classical myth.

With:

Paul Cartledge A.G. Leventis Professor of Greek Culture at Cambridge University

Chiara Franceschini Teaching Fellow at University College London and an Academic Assistant at the Warburg Institute

Caroline Vout University Senior Lecturer in Classics and Fellow and Director of Studies at Christ's College, Cambridge.

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the Putney Debates. For several weeks in late 1647, after the defeat of King Charles I in the first hostilities of the Civil War, representatives of the New Model Army and the radical Levellers met in a church in Putney to debate the future of England. There was much to discuss: who should be allowed to vote, civil liberties and religious freedom. The debates were inconclusive, but the ideas aired in Putney had a considerable influence on centuries of political thought.

With:

Justin Champion Professor of the History of Early Modern Ideas at Royal Holloway, University of London

Ann Hughes Professor of Early Modern History at Keele University

Kate Peters Fellow in History at Murray Edwards College, Cambridge.

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the Essays of Michel de Montaigne. Born near Bordeaux in 1533, Montaigne retired from a life of public service aged 38 and began to write. He called these short works 'essais', or 'attempts'; they deal with an eclectic range of subjects, from the dauntingly weighty to the apparently trivial. Although he never considered himself a philosopher, he is often now seen as one of the most outstanding Sceptical thinkers of early modern Europe. His approachable style, intelligence and subtle thought have made him one of the most widely admired writers of the Renaissance.

With:

David Wootton Anniversary Professor of History at York University

Terence Cave Emeritus Professor of French Literature at the University of Oxford

Felicity Green Chancellor's Fellow in History at the University of Edinburgh.

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss Gnosticism, a sect associated with early Christianity. The Gnostics divided the universe into two domains: the visible world and the spiritual one. They believed that a special sort of knowledge, or gnosis, would enable them to escape the evils of the physical world and allow them access to the higher spiritual realm. The Gnostics were regarded as heretics by many of the Church Fathers, but their influence was important in defining the course of early Christianity. A major archaeological discovery in Egypt in the 1940s, when a large cache of Gnostic texts were found buried in an earthenware jar, enabled scholars to learn considerably more about their beliefs.

With:

Martin Palmer Director of the International Consultancy on Religion, Education, and Culture

Caroline Humfress Reader in History at Birkbeck College, University of London

Alastair Logan Honorary University Fellow of the Department of Theology and Religion at the University of Exeter

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the Icelandic Sagas. First written down in the 13th century, the sagas tell the stories of the Norse settlers of Iceland, who began to arrive on the island in the late 9th century. They contain some of the richest and most extraordinary writing of the Middle Ages, and often depict events known to have happened in the early years of Icelandic history, although there is much debate as to how much of their content is factual and how much imaginative. Full of heroes, feuds and outlaws, with a smattering of ghosts and trolls, the sagas inspired later writers including Sir Walter Scott, William Morris and WH Auden.

With:

Carolyne Larrington Fellow and Tutor in Medieval English Literature at St John's College, Oxford

Elizabeth Ashman Rowe University Lecturer in Scandinavian History at the University of Cambridge

Emily Lethbridge Post-Doctoral Researcher at the Árni Magnússon Manuscripts Institute in Reykjavík

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss cosmic rays. In 1912 the physicist Victor Hess discovered that the Earth is under constant bombardment from radiation coming from outside our atmosphere. These so-called cosmic rays have been known to cause damage to satellites and electronic devices on Earth, but most are absorbed by our atmosphere. The study of cosmic rays and their effects has led to major breakthroughs in particle physics. But today physicists are still trying to establish where these highly energetic subatomic particles come from.

With:

Carolin Crawford Gresham Professor of Astronomy and a member of the Institute of Astronomy at the University of Cambridge

Alan Watson Emeritus Professor of Physics at the University of Leeds

Tim Greenshaw Professor of Physics at the University of Liverpool.

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the work of the anthropologist Claude Lévi-Strauss. One of twentieth-century France's most celebrated intellectuals, Lévi-Strauss attempted to show in his work that thought processes were a feature universal to humans, whether they lived in tribal rainforest societies or in the rich intellectual life of Paris. During the 1930s he studied native Brazilian tribes in the Amazonian jungle, but for most of his long career he preferred the study to the field. He was the leading exponent of structuralism, a school of thought which was influential for decades, and was involved in a famous debate with his friend Jean-Paul Sartre, who resisted many of his ideas. His books about the nature of myth, human thought and kinship are now seen as some of the most important anthropological texts written in the twentieth century.

With:

Adam Kuper Visiting Professor of Anthropology at Boston University

Christina Howells Professor of French at Oxford University

Vincent Debaene Associate Professor of French Literature at Columbia University

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss Queen Zenobia, a famous military leader of the ancient world. Born in around 240 AD, Zenobia was Empress of the Palmyrene Empire in the Middle East. A highly educated, intelligent and militarily accomplished leader, she claimed descent from Dido and Cleopatra and spoke many languages, including Egyptian. Zenobia led a rebellion against the Roman Empire and conquered Egypt before being finally defeated by the Emperor Aurelian. Her story captured the imagination of many Renaissance writers, and has become the subject of numerous operas, poems and plays.

With:

Edith Hall Professor of Classics at King's College, London

Kate Cooper Professor of Ancient History at the University of Manchester

Richard Stoneman Honorary Visiting Professor in the Department of Classics and Ancient History at the University of Exeter.

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss Einstein's theories of relativity. Between 1905 and 1917 Albert Einstein formulated a theoretical framework which transformed our understanding of the Universe. The twin theories of Special and General Relativity offered insights into the nature of space, time and gravitation which changed the face of modern science. Relativity resolved apparent contradictions in physics and also predicted several new phenomena, including black holes. It's regarded today as one of the greatest intellectual achievements of the twentieth century, and had an impact far beyond the world of science.

With:

Ruth Gregory Professor of Mathematics and Physics at Durham University

Martin Rees Astronomer Royal and Emeritus Professor of Cosmology and Astrophysics at the University of Cambridge

Roger Penrose Emeritus Rouse Ball Professor of Mathematics at the University of Oxford.

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the meaning and significance of prophecy in the Abrahamic religions. Prophets, those with the ability to convey divinely-inspired revelation, are significant figures in the Hebrew Bible and later became important not just to Judaism but also to Christianity and Islam. Although these three religions share many of the same prophets, their interpretation of the nature of prophecy often differs.

With:

Mona Siddiqui Professor of Islamic and Interreligious Studies at the University of Edinburgh

Justin Meggitt University Senior Lecturer in the Study of Religion and the Origins of Christianity at the University of Cambridge

Jonathan Stökl Post-Doctoral Researcher at Leiden University.

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the Physiocrats, an important group of economic thinkers in eighteenth-century France. The Physiocrats believed that the land was the ultimate source of all wealth, and crucially that markets should not be constrained by governments. Their ideas were important not just to economists but to the course of politics in France. Later they influenced the work of Adam Smith, who called Physiocracy "perhaps the nearest approximation to the truth that has yet been published upon the subject of political economy."

With:

Richard Whatmore Professor of Intellectual History & the History of Political Thought at the University of Sussex

Joel Felix Professor of History at the University of Reading

Helen Paul Lecturer in Economics and Economic History at the University of Southampton.

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the Romance of the Three Kingdoms, widely regarded as one of the greatest works of Chinese literature. Written 600 years ago, it is an historical novel that tells the story of a tumultuous period in Chinese history, the 2nd and 3rd centuries AD. Partly historical and partly legend, it recounts the fighting and scheming of the feudal lords and the three states which came to power as the Han Dynasty collapsed. The influence of Romance of the Three Kingdoms in East Asia has been likened to that of Homer in the West, and this warfare epic remains popular in China today.

With:

Frances Wood Former Lead Curator of Chinese Collections at the British Library

Craig Clunas Professor of the History of Art at the University of Oxford

Margaret Hillenbrand University Lecturer in Modern Chinese Literature at the University of Oxford and Fellow of Wadham College

Producer: Victoria Brignell.

Melvyn Bragg and his guests discuss the invention of radio. In the early 1860s the Scottish physicist James Clerk Maxwell derived four equations which together describe the behaviour of electricity and magnetism. They predicted the existence of a previously unknown phenomenon: electromagnetic waves. These waves were first observed in the early 1880s, and over the next two decades a succession of scientists and engineers built increasingly elaborate devices to produce and detect them. Eventually this gave birth to a new technology: radio. The Italian Guglielmo Marconi is commonly described as the father of radio - but many other figures were involved in its development, and it was not him but a Canadian, Reginald Fessenden, who first succeeded in transmitting speech over the airwaves.

With:

Simon Schaffer Professor of the History of Science at the University of Cambridge

Elizabeth Bruton Postdoctoral Researcher at the University of Leeds

John Liffen Curator of Communications at the Science Museum, London

Producer: Thomas Morris.

Melvyn Bragg and his guests begin a new series of the programme with a discussion of the French polymath Blaise Pascal. Born in 1623, Pascal was a brilliant mathematician and scientist, inventing one of the first mechanical calculators and making important discoveries about fluids and vacuums while still a young man. In his thirties he experienced a religious conversion, after which he devoted most of his attention to philosophy and theology. Although he died in his late thirties, Pascal left a formidable legacy as a scientist and pioneer of probability theory, and as one of seventeenth century Europe's greatest writers.

With:

David Wootton Anniversary Professor of History at the University of York

Michael Moriarty Drapers Professor of French at the University of Cambridge

Michela Massimi Senior Lecturer in the Philosophy of Science at the University of Edinburgh.

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the Mamluks, who ruled Egypt and Syria from about 1250 to 1517. Originally slave soldiers who managed to depose their masters, they went on to repel the Mongols and the Crusaders to become the dominant force in the medieval Islamic Middle Eastern world. Although the Mamluks were renowned as warriors, under their rule art, crafts and architecture blossomed. Little known by many in the West today, the Mamluks remained in power for almost 300 years until they were eventually overthrown by the Ottomans.

With:

Amira Bennison Reader in the History and Culture of the Maghrib at the University of Cambridge and Fellow of Magdalene College

Robert Irwin Former Senior Research Associate in the Department of History at SOAS, University of London

Doris Behrens-Abouseif Nasser D Khalili Professor of Islamic Art and Archaeology at SOAS, University of London

Producer: Victoria Brignell.