SETI researcher Seth Shostak bets that we will find extraterrestrial life in the next twenty-four years, or he’ll buy you a cup of coffee. At TEDxSanJoseCA, he explains why new technologies and the laws of probability make the breakthrough so likely — and forecasts how the discovery of civilizations far more advanced than ours might affect us here on Earth.
Is there more than one universe? In this visually rich, action-packed talk, Brian Greene shows how the unanswered questions of physics (starting with a big one: What caused the Big Bang?) have led to the theory that our own universe is just one of many in the “multiverse.”
Brian Greene is perhaps the best-known proponent of superstring theory, the idea that minuscule strands of energy vibrating in a higher dimensional space-time create every particle and force in the universe
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.
Professor of the History of Science at the University of Cambridge
Professor of the Philosophy of Science at the London School of Economics and Political Science
Senior Lecturer in the Philosophy of Science at University College London.
15:54 Posted: May 2011
14:41 Posted: May 2011
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.
Professor of Physics at Exeter College at the University of Oxford
Senior Lecturer in Particle Physics and Astrophysics at the University of Sheffield
Professor of Particle Physics at Imperial College, London, and the Rutherford Appleton Laboratory.
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.
Astronomer Royal and Emeritus Professor of Cosmology and Astrophysics at the University of Cambridge
Member of the Institute of Astronomy and Fellow of Emmanuel College at the University of Cambridge
Director of the Institute for Computational Cosmology at the University of Durham.