Time
When we switch on the television to watch the All Blacks playing on the other side of the world, none of us thinks we might miss the broadcast because we’ve got the time wrong. In common with the inhabitants of most countries, we depend on an accurate knowledge of the time for just about everything we do. Modern life could barely be sustained without it, and we take it so much for granted that we hardly ever think about it. However, the assumption that the precise time can always be known dates back little more than a century.