Marcus du Sautoy explores the history of Le Grand K - the world's master kilogramme - and the race to replace it now that it has been discovered to be losing weight. Show more
Discover 11,128,835 listings and 279,777 playable programmes from the BBC
Marcus du Sautoy explores the history of Le Grand K - the world's master kilogramme - and the race to replace it now that it has been discovered to be losing weight. Show more