In Our Time: Science Folgen

Melvyn Bragg and guests discuss Carbon. It forms the basis of all organic life and has the amazing ability to bond with itself and a wide range of other elements, forming nearly 10 million known compounds. It is in the food we eat, the clothes we wear, the shampoo we use and the petrol that fuels our cars. Because carbon has the largest range of subtle bonding capabilities, 95% of everything that exists in the universe is made up of carbon atoms that are stuck together. It is an extraordinary element for many reasons: the carbon-nitrogen cycle provides some of the energy produced by the Sun and the stars; it has the highest melting point of all the elements; and its different forms include one of the softest and one of the hardest substances known. What gives carbon its great ability to bond with other atoms? What is the significance of the recent discovery of a new carbon molecule - the C60? What role does carbon play in the modern chemistry of nanotechnology? And how should we address the problem of our diminishing carbon energy sources? With Harry Kroto, Professor of Chemistry at Florida State University; Monica Grady, Professor of Planetary and Space Sciences at the Open University; Ken Teo, Royal Academy of Engineering Research Fellow at Cambridge University.

Melvyn Bragg and guests discuss the heart. Aristotle considered the heart to be the seat of thought, reason and emotion. The Roman physician Galen located the seat of the passions in the liver, the seat of reason in the brain, and considered the heart to be the seat of the emotions. It was not until the 17th century that the physician William Harvey wrote in the preface to his thesis On the Motion of the Heart and Blood in Animals, a letter addressed to King Charles I. 'The heart of animals is the foundation of their life, the sovereign of everything within them...from which all power proceeds. The King, in like manner, is the foundation of his kingdom, the sun of the world around him, the heart of the republic, the foundation whence all power, all grace doth flow'. Harvey was probably wise to address the King in this manner, for what he laid out in his groundbreaking text challenged scientific wisdom that had gone unquestioned for centuries about the true function of the heart. Organs had been seen in a hierarchical structure with the heart as the pinnacle. But Harvey transformed the metaphor into something quite different: the heart as a mechanistic pumping device. How had the Ancient Greeks and Islamic physicians understood the heart? What role did the bodily humours play in this understanding? Why has the heart always been seen as the seat of emotion and passion? And why was it that despite Harvey's discoveries about the heart and its function, this had limited implications for medical therapy and advancement? With David Wootton, Anniversary Professor of History at the University of York; Fay Bound Alberti, Research Fellow at the Wellcome Unit for the History of Medicine at the University of Manchester; Jonathan Sawday, Professor of English Studies at the University of Strathclyde.

Melvyn Bragg and guests discuss the relationship between astronomy and the British Empire. The 18th century explorer and astronomer James Cook wrote: 'Ambition leads me not only farther than any other man has been before me, but as far as I think it possible for man to go'. Cook's ambition took him to the far reaches of the Pacific and led to astronomical observations which measured the distance of Venus to the Sun with unprecedented accuracy. Cook's ambition was not just personal and astronomical. It represented the colonial ambition of the British Empire which was linked inextricably with science and trade. The discoveries about the Transit of Venus, made on Cook's voyage to Tahiti, marked the beginning of a period of expansion by the British which relied on maritime navigation based on astronomical knowledge. With Simon Schaffer, Professor in History and Philosophy of Science at the University of Cambridge; Kristen Lippincott, former Director of the Royal Observatory, Greenwich; Allan Chapman, Historian of Science at the History Faculty at Oxford University.