Why has a kids TV show about a mad man with a box that can travel anywhere in time and space become the BBC's longest running TV drama - and one of Britain's biggest brands?

On its 50th anniversary, lifelong fan Matthew Sweet argues you ignore Doctor Who at your peril. It may be a piece of children's television, but he believes it's one of the most important cultural artefacts of modern Britain. Put simply, Doctor Who matters.

In this hour-long Culture Show special, BBC Two's flagship arts programme explores with wit, authority and affection, why Doctor Who has become entrenched in British life. Matthew Sweet traces the 50 years of extraordinary social change and uncertainty that sent generations of children scuttling behind the sofa. How did a pepper pot, the Nazis and a sink plunger result in the scariest adversaries of our time - the Daleks?

Sweet argues how in turn the show became a cultural force in its own right, influencing music, design and storytelling - whether pioneering electronica (Delia Derbyshire), or giving the unknown Douglas Adams a crucial break. Matthew meets both famous faces as well as cast, crew and Doctors past and present (from current Doctor Matt Smith to Richard Martin, the maverick director who first brought the Daleks to screens in 1964) to find out how Doctor Who has changed our culture.