Melvyn Bragg and guests discuss the attempt to define humanity’s part in the natural world. In Childe Harold’s Pilgrimage Lord Byron wrote:“There is a pleasure in the pathless woods, There is a rapture on the lonely shore,There is society where none intrudes,By the deep Sea, and music in its roar:I love not man the less, but Nature more.” In the Bible’s book of Genesis, ‘nature’ was the paradise of Eden, but for the philosopher Thomas Hobbes it was a place of perpetual war, where the life of man was “solitary, poore, nasty, brutish and short”. The defining of Nature, whether “red in tooth and claw” or as the fount of all innocence, is an attempt to define man’s origins and purpose and humanity’s part in the natural world. With Jonathan Bate, Professor of English Literature at the University of Warwick; Roger Scruton, Professor of Philosophy at the University of Buckingham; Karen Edwards, Lecturer in English at the University of Exeter.

Melvyn Bragg and guests discuss the formation of volcanoes. In 79AD Mount Vesuvius erupted on the Bay of Naples, buried Pompeii in ash and drowned nearby Herculaneum in lava. The great letter writer Pliny the Younger was staying with his uncle in Misenum and was a witness to the cataclysm. He described it to the historian Tacitus, It seemed as though the sea was being sucked backwards, as if it were being pushed back by the shaking of the land. Certainly the shoreline moved outwards, and many sea creatures were left on dry sand. Behind us were frightening dark clouds, rent by lightning twisted and hurled, opening to reveal huge figures of flame. These were like lightning but bigger. This eruption, which claimed the life of Pliny's uncle, is one of about 500 volcanoes to have erupted in the last two thousand years, some of which are now categorised by vulcanologists as Plinian, after Pliny's famous description.What causes volcanoes? What role do they play in the formation and maintenance of our planet? And is it ever possible to predict when and where they are about to erupt?With Hilary Downes, Professor of Geochemistry at Birkbeck, University of London; Steve Self, Professor of Vulcanology at the Open University; Bill McGuire, Benfield Professor of Geophysical Hazards at University College London.

Melvyn Bragg and guests discuss the Lunar Society. In the late 18th century, with the ascendant British Empire centred on London, a small group of friends met at a house on the crossroads outside Birmingham and applied their minds to the problems of the age. Between them they managed to launch the Industrial Revolution, discover oxygen, harness the power of steam and pioneer the theory of evolution. They were the Lunar Society, a gathering of free and fertile minds centred on the remarkable quartet of Matthew Boulton, James Watt, Joseph Priestly and Erasmus Darwin. The potter Josiah Wedgwood, another member, summed up the ethos of this group when he said that they were ‘living in an age of miracles in which anything could be achieved’.But how did the Lunar Society operate? What was the blend of religious dissent, entrepreneurial spirit and intellectual adventure that proved so fertile and how did their discoveries permanently change the shape and character of this country?With Simon Schaffer, Reader in History and Philosophy of Science at the University of Cambridge; Jenny Uglow, Honorary Visiting Professor at the University of Warwick and author of The Lunar Men: The Friends who Made the Future; Peter Jones, Professor of French History at the University of Birmingham.

Melvyn Bragg and guests discuss the function and significance of memory. The great writer of remembrance, Marcel Proust, declared “We are able to find everything in our memory, which is like a dispensary or chemical laboratory in which chance steers our hand, sometimes to a soothing drug and sometimes to a dangerous poison”. The memory is vital to life and without it we could not be the people we are, but can it really contain the sum of all our experience? Is it a repository constantly mounting events waiting to be plucked to consciousness, or if not, then under what criteria are memories turfed out?With Martin Conway, Professor of Psychology at Durham University; Mike Kopelman, Professor of Neuropsychiatry at King's College London and St Thomas’ Hospital; Kim Graham, Senior Scientist at the Medical Research Council’s Cognition and Brain Sciences Unit.

Melvyn Bragg and guests discuss blood. For more than 1500 years popular imagination, western science and the Christian Church colluded in a belief that blood was the link between the human and the divine. The Greek physician, Galen, declared that it was blood that contained the force of life and linked the body to the soul, the Christian Church established The Eucharist – the taking of the body and blood of Christ. In our blood was our individuality, it was thought, our essence and our blood lines were special. Transfusion threatened all that and now itself is being questioned.Why is it that blood was used to define both man and messiah? And how has the tradition of blood in religious thought been affected by the progress of medicine?With Miri Rubin, Professor of European History at Queen Mary, University of London; Dr Anne Hardy, Reader in the History of Medicine at the Wellcome Trust Centre for the History of Medicine at University College London; Jonathan Sawday, Professor of English Studies at the University of Strathclyde.

Melvyn Bragg and guests discuss the life cycle of stars. In his poem Bright Star John Keats wrote, "Bright Star, would I were steadfast as thou art". For Keats the stars were symbols of eternity- they were beautiful and ordered and unchanging - but modern astronomy tells a very different story. Stars, like everything else in the universe, are subject to change. They are born among vast swirls of gas and dust and they die in the stunning explosions we call supernovae. They create black holes and neutron stars and, in the very beginning of the universe, they forged the elements from which all life is made. But how do stars keep burning for millions of years, why do they self-destruct with such ferocity and what will happen to the universe when they all go out?With Paul Murdin, Senior Fellow at the Institute of Astronomy, Cambridge; Janna Levin, Advanced Fellow in Theoretical Physics in the Department of Applied Mathematics & Theoretical Physics at the University of Cambridge; Phil Charles, Professor of Astronomy at Southampton University.

Melvyn Bragg and guests discuss meteorology. The Book of Genesis resounds with a terrible act of vengeance, carried out by an angry God seeking to punish his people. And the mechanism with which this is carried out - a catastrophic flood which wipes out evil on earth. In fact, many ancient civilisations believed extreme meteorological phenomena like thunder and lightning, hailstones and even meteors were acts of divine intervention. Running parallel with this belief, however, was also a desire to understand and explain the natural world through rational enquiry and observation. This complex relationship – between the natural world and divinity – has fascinated philosophers, artists and scientists alike from antiquity to our own time. Aristotle, for example, coined the phrase meteorology but to what extent did he link meteorological events to the cosmos and the Gods? How did the development of instrumentation during the Renaissance aid the prediction of weather events? Why did 18th century writers such as Keats feel that these scientific advances stripped the skies of its mystique and romance? And why does meteorology continue to fascinate and mystify to this day? With Vladimir Jankovic, Wellcome Research Lecturer at the Centre for the History of Science, Technology and Medicine at Manchester University;Richard Hamblyn, writer; Liba Taub, Director of the Whipple Museum of the History of Science at Cambridge University.

Melvyn Bragg and guests discuss the theories of a grand design in the universe. The late evolutionary biologist Stephen Jay Gould argued that if you re-ran the tape of evolutionary history, an entirely different set of creatures would emerge. Man would not exist because the multitude of random changes that resulted in us would never be repeated exactly the same way. Others disagree, arguing that there is a pattern that points to some kind of direction – even, perhaps, a design, a sense that some things are pre-ordained. Who were the original proponents of the idea of a grand design? Were they deliberately setting out to find a scientific theory that could sit alongside religious faith? On the other hand, can the concept of contingency – or the randomness of evolution - be compatible with a belief in God? With Simon Conway Morris, Professor of Evolutionary Palaeobiology at Cambridge University and author of The Crucible of Creation – the Burgess Shale and the Rise of Animals; Sandy Knapp, botanist at the Natural History Museum; John Brooke, Andreas Idreos Professor of Science and Religion at Oxford University.

Melvyn Bragg and guests discuss the calendar, which shapes the lives of millions of people. It is an invention that gives meaning to the passing of time and orders our daily existence. It links us to the arcane movements of the heavens and the natural rhythms of the earth. It is both deeply practical and profoundly sacred. But where does this strange and complex creation come from? Why does the week last seven days but the year twelve months? Who named these concepts and through them shaped our lives so absolutely? The answers involve Babylonian Astronomers and Hebrew Theologians, Roman Emperors and Catholic Popes. If the calendar is a house built on the shifting sands of time, it has had many architects. With Robert Poole, Reader in History at St Martin’s College Lancaster and author of Time’s Alteration, Calendar Reform in Early Modern England; Kristen Lippincott, Deputy Director of the National Maritime Museum in Greenwich; Peter Watson, Research Associate at the McDonald Institute for Archaeological Research at Cambridge University and author of A Terrible Beauty – A History of the People and Ideas that Shaped the Modern Mind.

Melvyn Bragg and guests discuss man and disease. The Book of Exodus makes clear that when God wants to strike humankind, he does so with plague and disease. For millennia epidemics were understood exactly that way - as acts of divine retribution, a force of nature that could devastate empires and annihilate great swathes of population at a stroke. From the bubonic plague to measles, from cholera to smallpox, epidemics have constantly reshaped our world, leaving destruction and huge social upheaval in their wake. Before advanced science, what defences did humankind have? How much did the ancient Greeks understand of the root causes of disease - or did they simply explain it as an imbalance of the four humours that governed the body? What were the social and political consequences of The Black Death of 14th century Europe which wiped out a third of the population? How did the scientific breakthroughs of the 19th century - and the discovery of germ theory - alter people's perception of disease? And is it possible to live in a disease free society? How have we understood these afflictions, how have we fought against them and is it a war we can ever win?With Dr Anne Hardy, Reader in the History of Medicine at the Wellcome Trust Centre at University College London; David Bradley, Professor of Tropical Hygiene at the London School of Hygiene and Tropical Medicine; Dr Chris Dye, epidemiologist with the World Health Organisation.