Plot: What is only 100 years old? What were the French finally forced to accept? And why do King Charles II, Sir Isaac Newton, Captain Cook, Admiral Sir Clowdisley Shovel, the Great Western Railway and an American called Charles Dowd share a vital part in an institution of which we in Britain can be justly proud? Patrick Moore takes an affectionate look at the stories behind the centenary of Greenwich Mean Time; asks why it incurred the wrath of the law and discovers why astronauts and space men - like mere earthlings - would be lost without Greenwich Mean Time.