Physics and Cosmology

Exoplanets found orbiting former extragalactic star

An international team of astronomers has uncovered the most ancient habitable exoplanet found to date. The discovery is all the more interesting because the planet originated outside of our Milky Way galaxy. At around 11.5 billion years old, the super-Earth is more than twice as old as our own planet and shows that habitable worlds were around much earlier in the universe’s history than previously thought. What is more, at 11 light years from Earth, it is a near neighbour.

Read more from Physics World June 5 2014

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.


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




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.

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.

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.

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.

Brian Greene: Is our universe the only universe?

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