There are problems that are easy to solve in theory, but impossible to solve in practice. Intrigued? Then join us on a journey through the world of complexity, all the way to the famous P versus NP conjecture.
David Spiegelhalter, one of our favourite experts on statistics, recently joined David Attenborough, Bill Bryson and other eminent contributors on the Royal Society's People of Science series. You can watch the video here.
In 1915 a cook in California accidentally infected 93 people with typhoid. Over 100 years on mathematicians shed light on a long-standing mystery surrounding this and other outbreaks of infectious diseases.