In Our Time: Science

Melvyn Bragg and guests talk about blood, black bile, yellow bile and phlegm. These are the four humours, a theory of disease and health that is among the most influential ideas aver conceived. According to an 11th century Arabic book called the Almanac of Health, an old man went to the doctor complaining of a frigid complexion and stiffness in winter. The doctor, after examining his condition, prescribed a rooster. Being a hot and dry bird it was the perfect tonic for a cold and rheumatic old man. This is medicine by the four humours. The idea that the body is a concoction of these four essential juices is one of the oldest on record. From the Ancient Greeks to the 19th century it explained disease, psychology, habit and personality. When we describe people as being choleric, sanguine or melancholic we are still using the language of the humours today. It also explains why, in the long and convoluted history of medical practice, pigeon livers were an aphrodisiac, blood letting was a form of heroism (and best done in spring) and why you really could be frightened to death. The theory was dismantled from the 17th century but in its belief that the mind and body are intimately connected and that health requires equilibrium the humours retain an influence to this dayWith David Wootton, Anniversary Professor of History at the University of York; Vivian Nutton, Professor of the History of Medicine at University College London; Noga Arikha, Visiting Fellow at the Institut Jean-Nicod in Paris

Melvyn Bragg and guests discuss mutation in genetics and evolution. When lying mortally ill with cancer, the British geneticist J.B.S. Haldane penned the following lines: Cancer's a Funny Thing:I wish I had the voice of HomerTo sing of rectal carcinoma,Which kills a lot more chaps, in fact,Than were bumped off when Troy was sacked...Haldane knew better than most that many cancers, and many other diseases, are caused by genetic mutation. A mutation is an error in reproduction between one generation and the next as the copying mechanism that allows you to inherit your parent’s genes goes awry. Mutations are almost always bad news for the organism that suffers them and yet mutation is also a giver of life. Without it there would be no natural selection, no evolution and, arguably, no life on this planet. It’s not unreasonable to see life itself as a mutation and to understand this may also hold the key to aging and disease. It is, in the Darwinian view of life, the raw material of evolution.With Steve Jones, Professor of Genetics in the Galton Laboratory, University College London; Adrian Woolfson, lectures in Medicine at Cambridge University; Linda Partridge, Weldon Professor of Biometry at University College LondonTags

Melvyn Bragg and guests discuss the Fibonacci Sequence. Named after a 13th century Italian Mathematician, Leonardo of Pisa who was known as Fibonacci, each number in the sequence is created by adding the previous two together. It starts 1 1 2 3 5 8 13 21 and goes on forever. It may sound like a piece of mathematical arcania but in the 19th century it began to crop up time and again among the structures of the natural world, from the spirals on a pinecone to the petals on a sunflower.The Fibonacci sequence is also the mathematical first cousin of the Golden Ratio – a number that has haunted human culture for thousands of years. For some, the Golden ratio is the essence of beauty found in the proportions of the Parthenon and the paintings of Leonardo Da Vinci. With Marcus du Sautoy, Professor of Mathematics at the University of Oxford; Jackie Stedall, Junior Research Fellow in History of Mathematics at Queen’s College, Oxford; Ron Knott, Visiting Fellow in the Department of Mathematics at the University of Surrey

Melvyn Bragg discusses the discovery of Oxygen by Joseph Priestley and Antoine Lavoisier. In the late 18th century Chemistry was the prince of the sciences – vital to the economy, it shaped how Europeans fought each other, ate with each other, what they built and the medicine they took. And then, in 1772, the British chemist, Joseph Priestley, stood in front of the Royal Society and reported on his latest discovery: “this air is of exalted nature…A candle burned in this air with an amazing strength of flame; and a bit of red hot wood crackled and burned with a prodigious rapidity. But to complete the proof of the superior quality of this air, I introduced a mouse into it; and in a quantity in which, had it been common air, it would have died in about a quarter of an hour; it lived at two different times, a whole hour, and was taken out quite vigorous.” For the British dissenting preacher, Joseph Priestley, and the French aristocrat, Antoine Lavoisier, Chemistry was full of possibilities and they pursued them for scientific and political ends. But they came to blows over oxygen because they both claimed to have discovered it, provoking a scientific controversy that rattled through the laboratories of France and England until well after their deaths. To understand their disagreement is to understand something about the nature of scientific discovery itself. With Simon Schaffer, Professor in History and Philosophy of Science at the University of Cambridge; Jenny Uglow, Honorary Visiting Professor at the University of Warwick; Hasok Chang, Reader in Philosophy of Science at University College London.

Melvyn Bragg and guests discuss Antimatter, a type of particle predicted by the British physicist, Paul Dirac. Dirac once declared that “The laws of nature should be expressed in beautiful equations”. True to his word, he is responsible for one of the most beautiful. Formulated in 1928, it describes the behaviour of electrons and is called the Dirac equation. But the Dirac equation is strange. For every question it gives two answers – one positive and one negative. From this its author concluded that for every electron there is an equal and opposite twin. He called this twin the anti-electron and so the concept of antimatter was born.Despite its popularity with Science Fiction writers, antimatter is relatively mundane in physics – we have created antimatter in the laboratory and we even use it in our hospitals. But one fundamental question remains – why isn’t there more antimatter in the universe. Answering that question will involve developing new physics and may take us closer to understanding events at the origin of the universe. With Val Gibson, Reader in High Energy Physics at the University of Cambridge; Frank Close, Professor of Physics at Exeter College, University of Oxford; Ruth Gregory, Professor of Mathematics and Physics at the University of Durham

Melvyn Bragg and guests discuss the Permian-Triassic boundary. 250 million years ago, in the Permian period of geological time, the most ferocious predators on earth were the Gorgonopsians. Up to ten feet in length, they had dog-like heads and huge sabre-like teeth. Mammals in appearance, their eyes were set in the side of their heads like reptiles. They looked like a cross between a lion and giant monitor lizard and were so ugly that they are named after the gorgons from Greek mythology – creatures that turned everything that saw them to stone. Fortunately, you’ll never meet a gorgonopsian or any of their descendants because they went extinct at the end of the Permian period. And they weren’t alone. Up to 95% of all life died with them. It’s the greatest mass extinction the world has ever known and it marks what is called the Permian-Triassic boundary. But what caused this catastrophic juncture in life, what evidence do we have for what happened and what do events like this tell us about the pattern and process of evolution itself?With Richard Corfield, Senior Lecturer in Earth Sciences at the Open University; Mike Benton, Professor of Vertebrate Palaeontology in the Department of Earth Sciences at the University of Bristol; Jane Francis, Professor of Palaeoclimatology at the University of Leeds

Melvyn Bragg and guests discuss Renaissance Astrology. In Act I Scene II of King Lear, the ne’er do well Edmund steps forward and rails at the weakness and cynicism of his fellow men:This is the excellent foppery of the world, that,when we are sick in fortune, - often the surfeitof our own behaviour, - we make guilty of ourdisasters the sun, the moon, and the stars: asif we were villains by necessity.The focus of his attack is astrology and the credulity of those who fall for its charms. But the idea that earthly life was ordained in the heavens was essential to the Renaissance understanding of the world. The movements of the heavens influenced many things from the practice of medicine to major political decisions. Every renaissance court had its astrologer including Elizabeth Ist and the mysterious Dr. John Dee who chose the most propitious date for her coronation. But astrologers also worked in the universities and on the streets, reading horoscopes, predicting crop failures and rivalling priests and doctors as pillars of the local community. But why did astrological ideas flourish in the period, how did astrologers interpret and influence the course of events and what new ideas eventually brought the astrological edifice tumbling down? With Peter Forshaw, Lecturer in Renaissance Philosophies at Birkbeck, University of London; Lauren Kassell, Lecturer in the History and Philosophy of Science at the University of Cambridge; and Jonathan Sawday, Professor of English Studies at the University of Strathclyde.

Melvyn Bragg and guests discuss mysterious phenomena called Gravitational Waves in contemporary physics. The rather un-poetically named star SN 2006gy is roughly 150 times the size of our sun. Last week it went supernova, creating the brightest stellar explosion ever recorded. But among the vast swathes of dust, gas and visible matter ejected into space, perhaps the most significant consequences were invisible – emanating out from the star like the ripples from a pebble thrown into a pond. They are called Gravitational Waves, predicted by Einstein and much discussed since, their existence has never actually been proved but now scientists may be on the verge of measuring them directly. To do so would give us a whole new way of seeing the cosmos. But what are gravitational waves, why are scientists trying to measure them and, if they succeed, what would a gravitational picture of the universe look like?With Jim Al-Khalili, Professor of Physics at the University of Surrey; Carolin Crawford, Royal Society Research Fellow at the Institute of Astronomy, Cambridge; Sheila Rowan, Professor in Experimental Physics in the Department of Physics and Astronomy at the University of Glasgow

Melvyn Bragg and guests discuss symmetry. Found in Nature - from snowflakes to butterflies - and in art in the music of Bach and the poems of Pushkin, symmetry is both aesthetically pleasing and an essential tool to understanding our physical world. The Greek philosopher Aristotle described symmetry as one of the greatest forms of beauty to be found in the mathematical sciences, while the French poet Paul Valery went further, declaring; “The universe is built on a plan, the profound symmetry of which is somehow present in the inner structure of our intellect”.The story of symmetry tracks an extraordinary shift from its role as an aesthetic model - found in the tiles in the Alhambra and Bach's compositions - to becoming a key tool to understanding how the physical world works. It provides a major breakthrough in mathematics with the development of group theory in the 19th century. And it is the unexpected breakdown of symmetry at sub-atomic level that is so tantalising for contemporary quantum physicists.So why is symmetry so prevalent and appealing in both art and nature? How does symmetry enable us to grapple with monstrous numbers? And how might symmetry contribute to the elusive Theory of Everything?With Fay Dowker, Reader in Theoretical Physics at Imperial College, London; Marcus du Sautoy, Professor of Mathematics at the University of Oxford; Ian Stewart, Professor of Mathematics at the University of Warwick.

Melvyn Bragg and guests discuss the history of anaesthetics, from laughing gas in the 1790s to the discovery of “blessed chloroform”. Remembering his unsuccessful stint at Edinburgh Medical school Charles Darwin described the horrors of surgery before anaesthetics : "I attended the operating theatre and saw two very bad operations... but I rushed away before they were completed. Nor did I ever attend again, for hardly any inducement would have been strong enough to make me do so; this being long before the blessed days of chloroform. The two cases fairly haunted me for many a long year."The suffering Darwin witnessed is almost unimaginable. In the 19th Century, a simple fracture often led to amputation carried out on a conscious patient, whose senses would be dulled only by brandy or perhaps some morphine. Many patients died of shock.The properties of gases like nitrous oxide or “laughing gas” held out hope. The chemist Humphrey Davy in the 1790s described it as “highly pleasurable, thrilling”. He also noticed his toothache disappeared. But he failed to apply his observations and it wasn't until the 1840s that there was a major breakthrough in anaesthetics, when an enterprising dentist in Boston managed to anaesthetize a patient with ether. It became known as the “Yankee Dodge”. Ether had its drawbacks and the search for a suitable alternative continued until chloroform was tried in 1847, winning many admirers including Queen Victoria, the first English royal to use it. So why did it take so long for inhaled gases to advance from providing merely recreational highs to providing an essential tool of humane surgery? What role did the development of the atomic bomb play in the development of anaesthetics? And how have society's changing attitudes to pain informed the debate?With David Wilkinson, Consultant Anaesthetist at St Bartholomew’s Hospital in London and President of the History of Anaesthesia Society; Stephanie Snow, Research Associate at the Centre for the History of Science, Technology & Medicine at the University of Manchester; Anne Hardy, Professor in the History of Modern Medicine at University College London