Dark matter is thought to make up around a quarter of the universe, but so far it has eluded detection by all scientific instruments. Scientists know it must exist because of the ways galaxies move and it also explains the large-scale structure of the modern universe. But no-one knows what dark matter actually is.

Scientists have been hunting for dark matter particles for decades, but have so far had no luck. At the annual meeting of the American Association for the Advancement of Science, held recently in Denver, a new generation of researchers presented their latest tools, techniques and ideas to step up the search for this mysterious substance. Will they finally detect the undetectable?

Host: Alok Jha, The Economist’s science and technology editor. Contributors: Don Lincoln, senior scientist at Fermi National Accelerator Laboratory; Christopher Karwin, a fellow at NASA’s Goddard Space Flight Center; Josef Aschbacher, boss of the European Space Agency; Michael Murra of Columbia University; Jodi Cooley, executive director of SNOLAB; Deborah Pinna of University of Wisconsin and CERN.

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