In Our Time: Science Folgen

Melvyn Bragg and his guests discuss the invention of radio. In the early 1860s the Scottish physicist James Clerk Maxwell derived four equations which together describe the behaviour of electricity and magnetism. They predicted the existence of a previously unknown phenomenon: electromagnetic waves. These waves were first observed in the early 1880s, and over the next two decades a succession of scientists and engineers built increasingly elaborate devices to produce and detect them. Eventually this gave birth to a new technology: radio. The Italian Guglielmo Marconi is commonly described as the father of radio - but many other figures were involved in its development, and it was not him but a Canadian, Reginald Fessenden, who first succeeded in transmitting speech over the airwaves.With:Simon Schaffer Professor of the History of Science at the University of CambridgeElizabeth Bruton Postdoctoral Researcher at the University of LeedsJohn Liffen Curator of Communications at the Science Museum, LondonProducer: Thomas Morris.

Melvyn Bragg and his guests discuss Einstein's theories of relativity. Between 1905 and 1917 Albert Einstein formulated a theoretical framework which transformed our understanding of the Universe. The twin theories of Special and General Relativity offered insights into the nature of space, time and gravitation which changed the face of modern science. Relativity resolved apparent contradictions in physics and also predicted several new phenomena, including black holes. It's regarded today as one of the greatest intellectual achievements of the twentieth century, and had an impact far beyond the world of science.With:Ruth Gregory Professor of Mathematics and Physics at Durham UniversityMartin Rees Astronomer Royal and Emeritus Professor of Cosmology and Astrophysics at the University of CambridgeRoger Penrose Emeritus Rouse Ball Professor of Mathematics at the University of Oxford.Producer: Thomas Morris.

Melvyn Bragg and his guests discuss cosmic rays. In 1912 the physicist Victor Hess discovered that the Earth is under constant bombardment from radiation coming from outside our atmosphere. These so-called cosmic rays have been known to cause damage to satellites and electronic devices on Earth, but most are absorbed by our atmosphere. The study of cosmic rays and their effects has led to major breakthroughs in particle physics. But today physicists are still trying to establish where these highly energetic subatomic particles come from.With:Carolin Crawford Gresham Professor of Astronomy and a member of the Institute of Astronomy at the University of Cambridge Alan Watson Emeritus Professor of Physics at the University of Leeds Tim Greenshaw Professor of Physics at the University of Liverpool.Producer: Thomas Morris.