In Our Time

Duration: 45 minutes
First broadcast: Thursday 18 November 2004

Melvyn Bragg and guests discuss the Higgs Boson particle. One weekend in 1964 the Scottish scientist Peter Higgs was walking in the Cairngorm Mountains. On his return to his laboratory in Edinburgh the following Monday, he declared to his colleagues that he had just experienced his ‘one big idea’ and now had an answer to the mystery of how matter in the universe got its mass. That big idea took many years of refining, but it has now generated so much international interest and has such an important place in physics that well over one billion pounds is being spent in the hope that he was right. It’s the biggest science project on Earth; the quest to find the ‘Higgs Boson’, a fundamental constituent of nature that – if it does exist – has such a central role in defining the universe that it’s also known as the God Particle.

What is the Higgs Boson? Why is it so important to scientists and how are they planning to find it?

With Jim Al-Khalili, Senior Lecturer in Physics at the University of Surrey; David Wark, Professor of Experimental Physics at Imperial College London and the Rutherford Appleton Laboratory; Professor Roger Cashmore, former Research Director at CERN and now Principal of Brasenose College, Oxford.

http://www.bbc.co.uk/programmes/p004y2b7

Duration: 45 minutes
First broadcast: Thursday 27 May 2004

Melvyn Bragg and guests discuss our knowledge of the planets in both our and other solar systems. Tucked away in the outer Western Spiral arm of the Milky Way is a middle aged star, with nine, or possibly ten orbiting planets of hugely varying sizes. Roughly ninety-two million miles and third in line from that central star is our own planet Earth, in thrall to our Sun, just one of the several thousand million stars that make up the Galaxy.

Ever since Galileo and Copernicus gave us a scientific model of our own solar system, we have assumed that somewhere amongst the myriad stars there must be other orbiting planets, but it took until 1995 to find one. ‘51 Pegasus A’ was discovered in the Pegasus constellation and was far bigger and far closer to its sun than any of our existing theories could have predicted. Since then 121 new planets have been found. And now it is thought there may be more planets in the skies than there are stars.

What causes a planet to form? How do you track one down? And how likely is there to be another one out there with properties like the Earth’s?

With Paul Murdin, Senior Fellow at the Institute of Astronomy in Cambridge; Hugh Jones, planet hunter and Reader in Astrophysics at Liverpool John Moores University; Carolin Crawford, Royal Society Research Fellow at the Institute of Astronomy in Cambridge

http://www.bbc.co.uk/programmes/p004y25b

Duration: 45 minutes
First broadcast: Thursday 25 March 2004

Melvyn Bragg and guests discuss the 30 year search to solve all the biggest questions in physics. At the end of the last century, brave voices were predicting that all the big questions of physics were on the verge of being answered by a Theory of Everything. The disparity between the physics of the very small would finally be reconciled with the very large, and the four forces of nature would finally be united with a single set of equations. It was suggested that with such a theory we might solve the riddle of black holes, unlock the secrets of the Big Bang, probe other universes and even uncover the mystery of travelling through time. But Stephen Hawking, who once said that with a Theory of Everything “we would know the m mind of God”, has changed his mind and now says that it may not be possible after all.

So what are the prospects for a Theory of Everything? Why do we need one? How do we get one? And what would it mean if we did?

With Brian Greene, Professor of Physics and Mathematics at Columbia University and author of The Fabric of the Cosmos; John Barrow, Professor of Mathematical Sciences at the University of Cambridge and author of The Constants of Nature; Dr Val Gibson, particle physicist from the Cavendish Laboratory and Fellow of Trinity College, Cambridge

http://www.bbc.co.uk/programmes/p004y24b

Duration: 45 minutes
First broadcast: Thursday 27 March 2003

Melvyn Bragg and guests discuss the life cycle of stars. In his poem Bright Star John Keats wrote, “Bright Star, would I were steadfast as thou art”. For Keats the stars were symbols of eternity- they were beautiful and ordered and unchanging – but modern astronomy tells a very different story. Stars, like everything else in the universe, are subject to change. They are born among vast swirls of gas and dust and they die in the stunning explosions we call supernovae. They create black holes and neutron stars and, in the very beginning of the universe, they forged the elements from which all life is made. But how do stars keep burning for millions of years, why do they self-destruct with such ferocity and what will happen to the universe when they all go out?

With Paul Murdin, Senior Fellow at the Institute of Astronomy, Cambridge; Janna Levin, Advanced Fellow in Theoretical Physics in the Department of Applied Mathematics & Theoretical Physics at the University of Cambridge; Phil Charles, Professor of Astronomy at Southampton University.

http://www.bbc.co.uk/programmes/p00548w8

Duration: 45 minutes
First broadcast: Thursday 16 May 2002

Melvyn Bragg examines whether world is a fundamentally chaotic or orderly place. When Newton published his Principia Mathematica in 1687 his work was founded on one simple message: Nature has laws and we can find them. His explanation of the movements of the planets, and of gravity, was rooted in the principle that the universe functions like a machine and its patterns are predictable.

Newton’s equations not only explained why night follows day but, importantly, predicted that night would continue to follow day for evermore. Three hundred years later Newton’s principles were thrown into question by a dread word that represented the antithesis of his vision of order: that word was Chaos.

According to Chaos Theory, the world is far more complicated than was previously thought. Instead of the future of the universe being irredeemably fixed, we are, in fact, subject to the whims of random unpredictability. Tiny actions can change the world by setting off an infinite chain of reactions: famously, if a butterfly flaps its wings in Brazil – it could cause a tornado in Berlin.

So what’s the answer? Is the universe chaotic or orderly? If it’s all so complicated, why does night still follow day? And what is going on in that most complex machine of all – the brain – to filter and construct our perception of the world?

With Susan Greenfield, Senior Research Fellow, Lincoln College, Oxford University; David Papineau, Professor of the Philosophy of Science, Kings College, London; Neil Johnson,University Lecturer in Physics at Oxford University.

http://www.bbc.co.uk/programmes/p00548f6

Duration: 45 minutes
First broadcast: Thursday 02 May 2002

Melvyn Bragg examines the physics of reality. When Quantum Mechanics was developed in the early 20th century reality changed forever. In the quantum world particles could be in two places at once, they disappeared for no reason and reappeared in unpredictable locations, they even acted differently according to whether we were watching them. It was so shocking that Erwin Schrodinger, one of the founders of Quantum Theory, said “I don’t like it and I’m sorry I ever had anything to do with it.” He even developed an experiment with a cat to show how absurd it was.

Quantum Theory was absurd, it disagreed with the classical physics of Newton and Einstein and it clashed with our experience of the everyday world. Footballs do not disappear without reason, cats do not split into two and shoes do not act differently when we are not looking at them. Or do they? Eighty years later we are still debating whether the absurd might actually be true.

But why are features of quantum physics not seen in our experience of everyday reality? Can the classical and quantum worlds be reconciled, and why should reality make sense to us?

With Roger Penrose, Emeritus Rouse Ball Professor of Mathematics, Oxford University; Fay Dowker, Lecturer in Theoretical Physics, Queen Mary, University of London; Tony Sudbery, Professor of Mathematics, University of York

http://www.bbc.co.uk/programmes/p00548dl

Duration: 45 minutes
First broadcast: Thursday 07 February 2002

Melvyn Bragg and guests discuss the shape of the universe. In the Beginning, runs one account, was the Big Bang. All matter in existence today originated around 13 billion years ago in a phenomenally hot, extraordinarily condensed primordial atom that exploded with incredible force. Hydrogen and helium were shot across the firmament, gravity caused the gases to condense into clouds and in these clouds the first stars were formed, then galaxies came and more galaxies in clusters, onwards and outwards, ever expanding. It is still expanding, runs the orthodox account, and may even be speeding up. It is still creating new galaxies and it continues to colonise more and more of infinite space, despite the fact that it is supposedly infinite itself.

So, if our universe is expanding, what is it expanding into? If it is already infinite how can it be getting any bigger? And is there really only one?

With Sir Martin Rees, Royal Society Research Professor in Astronomy and Physics, Cambridge University; Julian Barbour, Independent Theoretical Physicist; Janna Levin, Advanced Fellow in Theoretical Physics at the University of Cambridge

http://www.bbc.co.uk/programmes/p0054880