In Our Time With Melvyn Bragg Folgen

Melvyn Bragg and guests discuss one of the most important philosophers of the 20th century, Karl Popper whose ideas about science and politics robustly challenged the accepted ideas of the day. He strongly resisted the prevailing empiricist consensus that scientists' theories could be proved true.Popper wrote: “The more we learn about the world and the deeper our learning, the more conscious, specific and articulate will be our knowledge of what we do not know, our knowledge of our ignorance”. He believed that even when a scientific principle had been successfully and repeatedly tested, it was not necessarily true. Instead it had simply not proved false, yet! This became known as the theory of falsification.He called for a clear demarcation between good science, in which theories are constantly challenged, and what he called “pseudo sciences” which couldn't be tested. His debunking of such ideologies led some to describe him as the “murderer of Freud and Marx”. He went on to apply his ideas to politics, advocating an Open Society. His ideas influenced a wide range of politicians, from those close to Margaret Thatcher, to thinkers in the Eastern Communist bloc and South America.So how did Karl Popper change our approach to the philosophy of science? How have scientists and philosophers made use of his ideas? And how are his theories viewed today? Are we any closer to proving scientific principles are “true”?With John Worrall, Professor of Philosophy of Science at the London School of Economics; Anthony O'Hear, Weston Professor of Philosophy at Buckingham University; Nancy Cartwright, Professor of Philosophy at the LSE and the University of California

Melvyn Bragg and guests discuss Genghis Khan. Born Temujin in the 12th Century, he was cast out by his tribe when just a child and left to struggle for survival on the harsh Steppes of what is now Mongolia. From these beginnings he went on to become Genghis Khan, leader of the greatest continuous land-based empire the world has ever seen. His conquered territories stretched from the Caspian Sea to the borders of Manchuria, from the Siberian forest to what is now Afghanistan.He was a charismatic commander and a shrewd military tactician. He was swift to promote those who served him well, ignoring race or creed, but vengeful to those who crossed him, killing every inhabitant of resistant towns, even the cats and dogs. Generally regarded as barbarians by their enemies, the Mongol armies were in fact disciplined and effective.So how did Genghis create such an impressive fighting force? How did he draw together such diverse peoples to create a wealthy and successful Empire? And what was his legacy for the territories he conquered?With Peter Jackson, Professor of Medieval History at Keele University; Naomi Standen, Lecturer in Chinese History at Newcastle University;George Lane, Lecturer in History at the School of Oriental and African Studies

Melvyn Bragg and guests discuss the Greek mathematician Archimedes. Reputed to have shouted “Eureka!” as he leapt from his bath having discovered the principles of floating bodies. Whatever the truth of the myths surrounding the man, he was certainly one of the world’s great mathematicians. The practical application of his work in pulleys and levers created formidable weapons such as catapults and ship tilting systems, allowing his home city in Sicily to defend itself against the Romans. “Give me a place to stand and I will move the earth”, he declared.But despite these triumphs, his true love remained maths for maths sake. Plutarch writes: “He placed his whole affection and ambition in those purer speculations where there can be no reference to the vulgar needs of life.” His most important breakthroughs came in the field of geometry with his work on the areas and volumes of curved objects.So how did this Greek mathematician in the third century BC arrive at a calculation of Pi? Did he really create a Death Ray to fight off invading ships? And what does a recently discovered manuscript reveal about his methods?With Jackie Stedall, Junior Research Fellow in the History of Mathematics at Queen's College, Oxford; Serafina Cuomo, Reader in the History of Science at Imperial College London; George Phillips, Honorary Reader in Mathematics at St Andrews University