In Our Time

Absolute Zero

absolute zero
Duration: 43 minutes
First broadcast: Thursday 07 March 2013

Melvyn Bragg and his guests discuss absolute zero, the lowest conceivable temperature. In the early eighteenth century the French physicist Guillaume Amontons suggested that temperature had a lower limit. The subject of low temperature became a fertile field of research in the nineteenth century, and today we know that this limit – known as absolute zero – is approximately minus 273 degrees Celsius. It is impossible to produce a temperature exactly equal to absolute zero, but today scientists have come to within a billionth of a degree. At such low temperatures physicists have discovered a number of strange new phenomena including superfluids, liquids capable of climbing a vertical surface.

With:

Simon Schaffer
Professor of the History of Science at the University of Cambridge

Stephen Blundell
Professor of Physics at the University of Oxford

Nicola Wilkin
Lecturer in Theoretical Physics at the University of Birmingham

Producer: Thomas Morris

http://www.bbc.co.uk/programmes/b01r113g

 

 

Relativity

Duration: 43 minutes
First broadcast: Thursday 06 June 2013

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 University

Martin Rees
Astronomer Royal and Emeritus Professor of Cosmology and Astrophysics at the University of Cambridge

Roger Penrose
Emeritus Rouse Ball Professor of Mathematics at the University of Oxford.

http://www.bbc.co.uk/programmes/b02144gl

Cosmic rays

Duration: 43 minutes
First broadcast: Thursday 16 May 2013

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.

http://www.bbc.co.uk/programmes/b01sdnkg

The Scientific Method

Duration: 45 minutes
First broadcast: Thursday 26 January 2012

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 Schaffer
Professor of the History of Science at the University of Cambridge

John Worrall
Professor of the Philosophy of Science at the London School of Economics and Political Science

Michela Massimi
Senior Lecturer in the Philosophy of Science at University College London.

http://www.bbc.co.uk/programmes/b01b1ljm

The Neutrino

Duration: 45 minutes

First broadcast: Thursday 14 April 2011

Melvyn Bragg and his guests discuss the neutrino.

In 1930 the physicist Wolfgang Pauli proposed the existence of an as-yet undiscovered subatomic particle. He also bet his colleagues a case of champagne that it would never be detected. He lost his bet when in 1956 the particle, now known as the neutrino, was first observed in an American nuclear reactor.

Neutrinos are some of the most mysterious particles in the Universe. The Sun produces trillions of them every second, and they constantly bombard the Earth and everything on it. Neutrinos can pass through solid rock, and even stars, at almost the speed of light without being impeded, and are almost impossible to detect. Today, experiments involving neutrinos are providing insights into the nature of matter, the contents of the Universe and the processes deep inside stars.

With:
Frank Close
Professor of Physics at Exeter College at the University of Oxford

Susan Cartwright
Senior Lecturer in Particle Physics and Astrophysics at the University of Sheffield

David Wark
Professor of Particle Physics at Imperial College, London, and the Rutherford Appleton Laboratory.

http://www.bbc.co.uk/programmes/b0106tjc

The Age of the Universe

Duration: 45 minutes
First broadcast: Thursday 03 March 2011

Melvyn Bragg and his guests discuss the age of the Universe.

Since the 18th century, when scientists first realised that the Universe had existed for more than a few thousand years, cosmologists have debated its likely age. The discovery that the Universe was expanding allowed the first informed estimates of its age to be made by the great astronomer Edwin Hubble in the early decades of the twentieth century. Hubble’s estimate of the rate at which the Universe is expanding, the so-called Hubble Constant, has been progressively improved.

Today cosmologists have a variety of other methods for ageing the Universe, most recently the detailed measurements of cosmic microwave background radiation – the afterglow of the Big Bang – made in the last decade. And all these methods seem to agree on one thing: the Universe has existed for around 13.75 billion years.

With:
Martin Rees
Astronomer Royal and Emeritus Professor of Cosmology and Astrophysics at the University of Cambridge

Carolin Crawford
Member of the Institute of Astronomy and Fellow of Emmanuel College at the University of Cambridge

Carlos Frenk
Director of the Institute for Computational Cosmology at the University of Durham.

http://www.bbc.co.uk/programmes/b00yz3gy

Logic

Duration: 45 minutes
First broadcast: Thursday 21 October 2010

Melvyn Bragg and his guests discuss the history of logic.

Logic, the study of reasoning and argument, first became a serious area of study in the 4th century BC through the work of Aristotle. He created a formal logical system, based on a type of argument called a syllogism, which remained in use for over two thousand years.

In the nineteenth century the German philosopher and mathematician Gottlob Frege revolutionised logic, turning it into a discipline much like mathematics and capable of dealing with expressing and analysing nuanced arguments. His discoveries influenced the greatest mathematicians and philosophers of the twentieth century and considerably aided the development of the electronic computer. Today logic is a subtle system with applications in fields as diverse as mathematics, philosophy, linguistics and artificial intelligence.

With:
A.C. Grayling
Professor of Philosophy at Birkbeck, University of London

Peter Millican
Gilbert Ryle Fellow in Philosophy at Hertford College at the University of Oxford

Rosanna Keefe
Senior Lecturer in Philosophy at the University of Sheffield.

http://www.bbc.co.uk/programmes/b00vcqcx

The Cool Universe

Duration: 45 minutes
First broadcast: Thursday 06 May 2010

The Cool Universe is the name astronomers give to the matter between the stars.

These great clouds of dust and gas are not hot enough to be detected by optical telescopes.

But over the last few decades, they have increasingly become the focus of infrared telescopy.

Astronomers had long encountered dark, apparently starless patches in the night sky.

When they discovered that these were actually areas obscured by dust, they found a way to see through these vexing barriers, using infrared telescopes, to the light beyond.

However, more recently, the dust itself has become a source of fascination.

The picture now being revealed by infrared astronomy is of a universe that is dynamic.

In this dynamic universe, matter is recycled – and so the dust and gas of the Cool Universe play a vital role.

They are the material from which the stars are created, and into which they finally disintegrate, enriching the reservoir of cool matter from which new stars will eventually be formed.

As a result of the new research, we are now beginning to see first-hand the way our planet was formed when the solar system was born.

With:
Carolin Crawford
Member of the Institute of Astronomy, and Fellow of Emmanuel College, at the University of Cambridge

Paul Murdin
Visiting Professor of Astronomy at Liverpool John Moores University’s Astronomy Research Institute

Michael Rowan-Robinson
Professor of Astrophysics at Imperial College, London

http://www.bbc.co.uk/programmes/b00s7b6r

Calculus

Duration: 45 minutes
First broadcast: Thursday 24 September 2009

Melvyn Bragg discusses the epic feud between Sir Isaac Newton and Gottfried Leibniz over who invented an astonishingly powerful new mathematical tool – calculus. Both claimed to have conceived it independently, but the argument soon descended into a bitter battle over priority, plagiarism and philosophy.

Set against the backdrop of the Hanoverian succession to the English throne and the formation of the Royal Society, the fight pitted England against Europe, geometric notation against algebra. It was fundamental to the grounding of a mathematical system which is one of the keys to the modern world, allowing us to do everything from predicting the pressure building behind a dam to tracking the position of a space shuttle.

Melvyn is joined by Simon Schaffer, Professor of History of Science at the University of Cambridge and Fellow of Darwin College; Patricia Fara, Senior Tutor at Clare College, University of Cambridge; and Jackie Stedall, Departmental Lecturer in History of Mathematics at the University of Oxford.

http://www.bbc.co.uk/programmes/b00mrfwq

Logical Positivism

Duration: 45 minutes
First broadcast: Thursday 02 July 2009

Melvyn Bragg discusses Logical Positivism, the eye-wateringly radical early 20th century philosophical movement.

The Logical Positivists argued that much previous philosophy was built on very shaky foundations, and they wanted to go right back to the drawing board. They insisted that philosophy – and science – had to be much more rigorous before it started making grand claims about the world.

The movement began with the Vienna Circle, a group of philosophically-trained scientists and scientifically-trained philosophers, who met on Thursdays, in ‘Red Vienna’, in the years after the First World War. They were trying to remould philosophy in a world turned upside down not just by war, but by major advances in science. Their hero was not Descartes or Hegel but Albert Einstein.

The group’s new doctrine rejected great swathes of earlier philosophy, from meditations on the existence of God to declarations on the nature of History, as utterly meaningless. When the Nazis took power, they fled to England and America, where their ideas put down new roots, and went on to have a profound impact.

Melvyn is joined by Barry Smith, Professor of Philosophy at the University of London; Nancy Cartwright, Professor of Philosophy at the London School of Economics; and Thomas Uebel, Professor of Philosophy at Manchester University.

http://www.bbc.co.uk/programmes/b00lbsj3