‘This century is special’: Astronomer Royal Martin Rees on the vast span of time

IN OUR everyday lives, time is a precious commodity. We can gain it or lose it. We can save, spend or waste it. If our crimes are revealed, we risk doing time.

But it is, of course, something we can measure. Indeed, clocks have, over the centuries, been the high-tech artefacts of their era – the water clock, the pendulum clock, Harrison’s chronometer, all the way up to the incredible precision of atomic clocks.

Before there was a reliable calendar of…