Melvyn 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.
Bruce Cameron Reed
The Charles A. Dana Professor of Physics Emeritus at Alma College, Michigan
Founder and President of the Atomic Heritage Foundation
Emeritus Professor of Theoretical Physics at the University of Oxford and a Fellow of Exeter College, Oxford
Producer: Simon Tillotson
The Evolution of Crocodiles
Melvyn 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.
Research Leader in Life Sciences and Dean of Postgraduate Education at the Natural History Museum
Lecturer in the Department of Earth Sciences at University College London
Professor of Palaeontology and Evolution at the University of Edinburgh
Producer Simon Tillotson
Melvyn 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.
Principal Curator of Science at National Museums Scotland
Keeper Emeritus at the Science Museum
Professor of History and Philosophy of Science at the University of Cambridge
Producer: Simon Tillotson
Melvyn 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'.
Marcus du Sautoy
Simonyi Professor for the Public Understanding of Science and Professor of Mathematics at the University of Oxford
Professor of Mathematics at the College de France
Professor of Pure Mathematics at the University of St Andrews
Producer: Simon Tillotson
The Late Devonian Extinction
Melvyn 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
Associate Professor of Geochemistry in the Department of Ocean and Earth Science at the University of Southampton
Professor of Geology at the University of Hull
Professor of Vertebrate Paleontology at the School of Life Sciences, University of Bristol.