In Our Time: Science Folgen

Melvyn Bragg and guests discuss Alan Turing (1912-1954) whose 1936 paper On Computable Numbers effectively founded computer science. Immediately recognised by his peers, his wider reputation has grown as our reliance on computers has grown. He was a leading figure at Bletchley Park in the Second World War, using his ideas for cracking enemy codes, work said to have shortened the war by two years and saved millions of lives. That vital work was still secret when Turing was convicted in 1952 for having a sexual relationship with another man for which he was given oestrogen for a year, or chemically castrated. Turing was to kill himself two years later. The immensity of his contribution to computing was recognised in the 1960s by the creation of the Turing Award, known as the Nobel of computer science, and he is to be the new face on the £50 note.WithLeslie Ann Goldberg Professor of Computer Science and Fellow of St Edmund Hall, University of OxfordSimon Schaffer Professor of the History of Science at the University of Cambridge and Fellow of Darwin CollegeAnd Andrew Hodges Biographer of Turing and Emeritus Fellow of Wadham College, OxfordProducer: Simon Tillotson

Melvyn Bragg and guests discuss the theoretical physicist Dirac (1902-1984), whose achievements far exceed his general fame. To his peers, he was ranked with Einstein and, when he moved to America in his retirement, he was welcomed as if he were Shakespeare. Born in Bristol, he trained as an engineer before developing theories in his twenties that changed the understanding of quantum mechanics, bringing him a Nobel Prize in 1933 which he shared with Erwin Schrödinger. He continued to make deep contributions, bringing abstract maths to physics, beyond predicting anti-particles as he did in his Dirac Equation.With Graham Farmelo Biographer of Dirac and Fellow at Churchill College, CambridgeValerie Gibson Professor of High Energy Physics at the University of Cambridge and Fellow of Trinity CollegeAndDavid Berman Professor of Theoretical Physics at Queen Mary University of LondonProducer: Simon Tillotson

Melvyn Bragg and guests discuss the origins of horses, from their dog sized ancestors to their proliferation in the New World until hunted to extinction, their domestication in Asia and their development since. The genetics of the modern horse are the most studied of any animal, after humans, yet it is still uncertain why they only have one toe on each foot when their wider family had more, or whether speed or stamina has been more important in their evolution. What is clear, though, is that when humans first chose to ride horses, as well as eat them, the future of both species changed immeasurably.With Alan Outram Professor of Archaeological Science at the University of ExeterChristine Janis Honorary Professor in Palaeobiology at the University of Bristol and Professor Emerita in Ecology and Evolutionary Biology at Brown UniversityAnd John Hutchinson Professor in Evolutionary Biomechanics at the Royal Veterinary CollegeProducer: Simon Tillotson