Main content

The Photon

Melvyn Bragg and his guests discuss the photon, the fundamental particle associated with light.

Melvyn Bragg and his guests discuss the photon, one of the most enigmatic objects in the Universe. Generations of scientists have struggled to understand the nature of light. In the late nineteenth century it seemed clear that light was an electromagnetic wave. But the work of physicists including Planck and Einstein shed doubt on this theory. Today scientists accept that light can behave both as a wave and a particle, the latter known as the photon. Understanding light in terms of photons has enabled the development of some of the most important technology of the last fifty years.


Frank Close
Professor Emeritus of Physics at the University of Oxford

Wendy Flavell
Professor of Surface Physics at the University of Manchester

Susan Cartwright
Senior Lecturer in Physics and Astronomy at the University of Sheffield.

Producer: Thomas Morris.

Available now

43 minutes

Last on

Thu 12 Feb 2015 21:30


Reading list 

Frank Close, The Infinity Puzzle: Quantum Field Theory and the Hunt for an Orderly Universe (Basic Books, 2013)

Richard Feynman, QED: The Strange Theory of Light and Matter (Penguin, 1990)

Manjit Kumar, Quantum: Einstein, Bohr and the Great Debate About the Nature of Reality (Icon Books Ltd, 2009)

Useful websites

International Year of Light 2015 - UNESCO

The American Physical Society celebrates the International Year of Light

Scientists slow the speed of light - BBC News 

Milestones – photons - Nature

Applications of lasers - Nobel Prizes

The 2012 Nobel Prize in Physics (awarded for developing ground-breaking methods for measuring and manipulating single photons)    




Role Contributor
Presenter Melvyn Bragg
Interviewed Guest Frank Close
Interviewed Guest Wendy Flavell
Interviewed Guest Susan Cartwright
Producer Thomas Morris


  • Thu 12 Feb 2015 09:00
  • Thu 12 Feb 2015 21:30

Featured in...

In Our Time podcasts

In Our Time podcasts

Every episode of In Our Time is available to download.

The In Our Time Listeners' Top 10

The In Our Time Listeners' Top 10

If you’re new to In Our Time, this is a good place to start.

Arts and Ideas podcast

Arts and Ideas podcast

Download the best of Radio 3's Free Thinking programme.