4. This Train Has Been Delayed

Singapore, 2016. A high-tech driverless train system starts glitching in wild and unpredictable ways. The train company, the government, even the military are at a loss: no-one can figure out what is causing the problem. Until Jason Bay and his team of data scientists assemble an old-fashioned timetabling graph, first developed in 19th century France, which exposes an invisible culprit.

Behind every line on a graph, there lies an extraordinary human story. And mathematician Hannah Fry is here to tell us ten of them.

Hannah Fry tells a tale of data detectives and very naughty trains.

Episode Producer: Ilan Goodman Sound Design: Jon Nicholls Story Editor: John Yorke

A series for Radio 4 by BBC Science in Cardiff.

Om Podcasten

Hannah Fry follows the numbers on thrilling journeys of data and discovery. Along the way we meet the remarkable people who dug into the data and unearthed something extraordinary.