In Our Time: Science Folgen

Melvyn Bragg and his guests discuss the measurement of time. Early civilisations used the movements of heavenly bodies to tell the time, but even in the ancient world more sophisticated timekeeping devices such as waterclocks were known. The development of mechanical clocks in Europe emerged in the medieval period when monks used such devices to sound an alarm to signal it was the hour to pray, although these clocks did not tell them the time. For hundreds of years clocks were inaccurate and it proved hard to remedy the problems, let alone settle on a standard time that the country should follow. It was with the advent of the railways that time finally became standardised in Britain in the mid-19th century and only in 1884 that Greenwich became the prime meridian of the world. Atomic clocks now mark the passing of the days, hours, and minutes and they are capable of keeping time to a second in 15 million years. With:Kristen LippincottFormer Director of the Royal Observatory, GreenwichJim BennettDirector of the Museum of the History of Science at the University of OxfordJonathan BettsSenior Curator of Horology at the Royal Observatory, GreenwichProducer: Natalia Fernandez.

Melvyn Bragg and his guests discuss the physics of electrical conduction. Although electricity has been known for several hundred years, it was only in the early twentieth century that physicists first satisfactorily explained the phenomenon. Electric current is the passage of charged particles through a medium - but a material will only conduct electricity if its atomic structure enables it to do so. In investigating electrical conduction scientists discovered two new classes of material. Semiconductors, first exploited commercially in the 1950s, have given us the transistor, the solar cell and the silicon chip, and have revolutionised telecommunications. And superconductors, remarkable materials first observed in 1911, are used in medical imaging and at the Large Hadron Collider in Geneva. With:Frank CloseProfessor of Physics at the University of OxfordJenny NelsonProfessor of Physics at Imperial College LondonLesley CohenProfessor of Solid State Physics at Imperial College LondonProducer: Thomas Morris.

Melvyn Bragg and his guests discuss the evolution of the Scientific Method, the systematic and analytical approach to scientific thought. In 1620 the great philosopher and scientist Francis Bacon published the Novum Organum, a work outlining a new system of thought which he believed should inform all enquiry into the laws of nature. Philosophers before him had given their attention to the reasoning that underlies scientific enquiry; but Bacon's emphasis on observation and experience is often seen today as giving rise to a new phenomenon: the scientific method.The scientific method, and the logical processes on which it is based, became a topic of intense debate in the seventeenth century, and thinkers including Isaac Newton, Thomas Huxley and Karl Popper all made important contributions. Some of the greatest discoveries of the modern age were informed by their work, although even today the term 'scientific method' remains difficult to define.With: Simon SchafferProfessor of the History of Science at the University of CambridgeJohn WorrallProfessor of the Philosophy of Science at the London School of Economics and Political ScienceMichela MassimiSenior Lecturer in the Philosophy of Science at University College London.Producer: Thomas Morris.