The True Nature of Time

Time... it rules our lives, and we all wish we had more of it. Businesses make money out of it, and scientists can measure it with astonishing accuracy.

Earlier this year, American researchers unveiled an atomic clock accurate to better than one second since the Big Bang 14 billion years ago.

But what, exactly, is time? Despite its familiarity, its ineffability has defied even the greatest thinkers.

Over 1,600 years ago the philosopher Augustine of Hippo admitted defeat with words that still resonate: “If no-one asks me, I know what it is. If I wish to explain it to him who asks, I do not know.”

Yet according to theoretical physicist Lee Smolin, the time has come to grapple with this ancient conundrum: “Understanding the nature of time is the single most important problem facing science,” he says.

As one of the founders of the Perimeter Institute for Theoretical Physics in Ontario, Canada, which specialises in tackling fundamental questions in physics, Professor Smolin has spent more time pondering deep questions than most.

So why does he think the nature of time is so important? Because, says Smolin, it is central to the success of attempts to understand reality itself.

To most people, this may sound a bit overblown. Since reality in all its forms, from the Big Bang to the Sunday roast, depends on time, isn’t it obvious that we should take time seriously? And didn’t scientists sort out its mysteries centuries ago?