Dark Matter

Melvyn Bragg and his guests discuss dark matter, the mysterious and invisible substance which is believed to make up most of the Universe. In 1932 the Dutch astronomer Jan Oort noticed that the speed at which galaxies moved was at odds with the amount of material they appeared to contain. He hypothesized that much of this 'missing' matter was simply invisible to telescopes. Today astronomers and particle physicists are still fascinated by the search for dark matter and the question of what it is. With Carolin Crawford Public Astronomer at the Institute of Astronomy, University of Cambridge and Gresham Professor of Astronomy Carlos Frenk Ogden Professor of Fundamental Physics and Director of the Institute for Computational Cosmology at the University of Durham Anne Green Reader in Physics at the University of Nottingham Producer: Simon Tillotson.

Om Podcasten

Spanning history, religion, culture, science and philosophy, In Our Time from BBC Radio 4 is essential listening for the intellectually curious. In each episode, host Melvyn Bragg and expert guests explore the characters, events and discoveries that have shaped our world. History fans can learn about pivotal wars and societal upheavals, such as the rise and fall of Napoleon, the Sack of Rome in 1527, and the political intrigue of the Russian Revolution. Those fascinated by the lives of kings and queens can journey to Versailles to meet Marie Antoinette and Louis XIV the Sun King, or to Ancient Egypt to meet Cleopatra and Nerfertiti. Or perhaps you’re looking to explore the history of religion, from Buddhism’s early teachings to the Protestant Reformation. If you’re interested in the stories behind iconic works of art, music and literature, dive in to discussions on the artistic genius of Michelangelo's Sistine Chapel and Van Gogh’s famous Sunflowers. From Gothic architecture to the works of Shakespeare, each episode of In Our Time offers new insight into humanity’s cultural achievements. Those looking to enrich their scientific knowledge can hear episodes on black holes, the Periodic Table, and classical theories of gravity, motion, evolution and relativity. Learn how the discovery of penicillin revolutionised medicine, and how the death of stars can lead to the formation of new planets. Lovers of philosophy will find episodes on the big issues that define existence, from free will and ethics, to liberty and justice. In what ways did celebrated philosophers such as Mary Wollstonecraft and Karl Marx push forward radical new ideas? How has the concept of karma evolved from the ancient Sanskrit texts of Hinduism to today? What was Plato’s concept of an ideal republic, and how did he explore this through the legend of the lost city of Atlantis? In Our Time celebrates the pursuit of knowledge and the enduring power of ideas.