Scientific principles, theory, and the role of key figures in the advancement of science.
The Manhattan Project
48:20Melvyn Bragg and guests discuss the race to build an atom bomb in the USA during World War Two. Before the war, scientists in Germany had discovered the potential of nuclear fission and scientists in Britain soon argued that this could be used to make an atom bomb, against which there could be no defence other than to own one. The fear among the Allies was that, with its head start, Germany might develop the bomb first and, unmatched, use it on its enemies. The USA took up the challenge in a huge engineering project led by General Groves and Robert Oppenheimer and, once the first bomb had been exploded at Los Alamos in July 1945, it appeared inevitable that the next ones would be used against Japan with devastating results. The image above is of Robert Oppenheimer and General Groves examining the remains of one the bases of the steel test tower, at the atomic bomb Trinity Test site, in September 1945. With Bruce Cameron Reed The Charles A. Dana Professor of Physics Emeritus at Alma College, Michigan Cynthia Kelly Founder and President of the Atomic Heritage Foundation And Frank Close Emeritus Professor of Theoretical Physics at the University of Oxford and a Fellow of Exeter College, Oxford Producer: Simon Tillotson
The Evolution of Crocodiles
53:07Melvyn Bragg and guests discuss the remarkable diversity of the animals that dominated life on land in the Triassic, before the rise of the dinosaurs in the Jurassic, and whose descendants are often described wrongly as 'living fossils'. For tens of millions of years, the ancestors of alligators and Nile crocodiles included some as large as a bus, some running on two legs like a T Rex and some that lived like whales. They survived and rebounded from a series of extinction events but, while the range of habitats of the dinosaur descendants such as birds covers much of the globe, those of the crocodiles have contracted, even if the animals themselves continue to evolve today as quickly as they ever have. With Anjali Goswami Research Leader in Life Sciences and Dean of Postgraduate Education at the Natural History Museum Philip Mannion Lecturer in the Department of Earth Sciences at University College London And Steve Brusatte Professor of Palaeontology and Evolution at the University of Edinburgh Producer Simon Tillotson
50:28Melvyn Bragg and guests discuss the search for Longitude while at sea. Following efforts by other maritime nations, the British Government passed the Longitude Act in 1714 to reward anyone who devised reliable means for ships to determine their longitude at sea. Mariners could already calculate how far they were north or south, the Latitude, using the Pole Star, but voyaging across the Atlantic to the Caribbean was much less predictable as navigators could not be sure how far east or west they were, a particular problem when heading for islands. It took fifty years of individual genius and collaboration in Britain and across Europe, among astronomers, clock makers, mathematicians and sailors, for the problem to be resolved. With Rebekah Higgitt Principal Curator of Science at National Museums Scotland Jim Bennett Keeper Emeritus at the Science Museum And Simon Schaffer Professor of History and Philosophy of Science at the University of Cambridge Producer: Simon Tillotson
48:10Melvyn Bragg and guests discuss Laplace (1749-1827) who was a giant in the world of mathematics both before and after the French Revolution. He addressed one of the great questions of his age, raised but side-stepped by Newton: was the Solar System stable, or would the planets crash into the Sun, as it appeared Jupiter might, or even spin away like Saturn threatened to do? He advanced ideas on probability, long the preserve of card players, and expanded them out across science; he hypothesised why the planets rotate in the same direction; and he asked if the Universe was deterministic, so that if you knew everything about all the particles then you could predict the future. He also devised the metric system and reputedly came up with the name 'metre'. With Marcus du Sautoy Simonyi Professor for the Public Understanding of Science and Professor of Mathematics at the University of Oxford Timothy Gowers Professor of Mathematics at the College de France And Colva Roney-Dougal Professor of Pure Mathematics at the University of St Andrews Producer: Simon Tillotson
The Late Devonian Extinction
49:05Melvyn Bragg and guests discuss the devastating mass extinctions of the Late Devonian Period, roughly 370 million years ago, when around 70 percent of species disappeared. Scientists are still trying to establish exactly what happened, when and why, but this was not as sudden as when an asteroid hits Earth. The Devonian Period had seen the first trees and soils and it had such a diversity of sea life that it’s known as the Age of Fishes, some of them massive and armoured, and, in one of the iconic stages in evolution, some of them moving onto land for the first time. One of the most important theories for the first stage of this extinction is that the new soils washed into oceans, leading to algal blooms that left the waters without oxygen and suffocated the marine life. The image above is an abstract group of the huge, armoured Dunkleosteus fish, lost in the Late Devonian Extinction With Jessica Whiteside Associate Professor of Geochemistry in the Department of Ocean and Earth Science at the University of Southampton David Bond Professor of Geology at the University of Hull And Mike Benton Professor of Vertebrate Paleontology at the School of Life Sciences, University of Bristol.
Emilie du Châtelet
49:50Melvyn Bragg and guests discuss one of the outstanding French mathematicians and natural philosophers of the 18th Century, celebrated across Europe. Emilie du Châtelet, 1706-49, created a translation of Newton’s Principia from Latin into French that helped spread the light of mathematics on the emerging science, and her own book Institutions de Physique, with its lessons on physics, was welcomed as profound. She had the privileges of wealth and aristocracy, yet had to fight to be taken seriously as an intellectual in a world of ideas that was almost exclusively male. With Patricia Fara Emeritus Fellow of Clare College, Cambridge David Wootton Anniversary Professor of History at the University of York And Judith Zinsser Professor Emerita of History at Miami University of Ohio and biographer of Emilie du Châtelet. Producer: Simon Tillotson
50:31Melvyn Bragg and guests discuss solar eclipses, some of life’s most extraordinary moments, when day becomes night and the stars come out before day returns either all too soon or not soon enough, depending on what you understand to be happening. In ancient China, for example, there was a story that a dragon was eating the sun and it had to be scared away by banging pots and pans if the sun were to return. Total lunar eclipses are more frequent and last longer, with a blood moon coloured red like a sunrise or sunset. Both events have created the chance for scientists to learn something remarkable, from the speed of light, to the width of the Atlantic, to the roundness of Earth, to discovering helium and proving Einstein’s Theory of General Relativity. With Carolin Crawford Public Astronomer based at the Institute of Astronomy, University of Cambridge and a fellow of Emmanuel College Frank Close Emeritus Professor of Physics at the University of Oxford And Lucie Green Professor of Physics and a Royal Society University Research Fellow at Mullard Space Science Laboratory at University College London Producers: Simon Tillotson and Julia Johnson
53:08Melvyn 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. With Leslie Ann Goldberg Professor of Computer Science and Fellow of St Edmund Hall, University of Oxford Simon Schaffer Professor of the History of Science at the University of Cambridge and Fellow of Darwin College And Andrew Hodges Biographer of Turing and Emeritus Fellow of Wadham College, Oxford Producer: Simon Tillotson
50:47Melvyn 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, Cambridge Valerie Gibson Professor of High Energy Physics at the University of Cambridge and Fellow of Trinity College And David Berman Professor of Theoretical Physics at Queen Mary University of London Producer: Simon Tillotson
The Evolution of Horses
50:10Melvyn 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 Exeter Christine Janis Honorary Professor in Palaeobiology at the University of Bristol and Professor Emerita in Ecology and Evolutionary Biology at Brown University And John Hutchinson Professor in Evolutionary Biomechanics at the Royal Veterinary College Producer: Simon Tillotson