Prepare for the ‘leap second’

IF life is often a matter of split seconds - the train door that closes in your face, the chance encounter with the love of your life - then the universe is about to bestow upon us a generous gift: the leap second.

On Saturday, at exactly midnight, one second will be added to our record of time: Co-ordinated Universal Time, kept by atomic clocks worldwide, certified by the International Bureau of Weights and Measures in Paris.

The reason for the extra second is simple: the Earth is slowing down. Since the days of Isaac Newton, scientists have understood the time it takes for the Earth to make a full rotation is getting longer. The gradual deceleration is caused by the gravitational pull of the moon. The same force that brings the tides is putting the brakes on the earth, albeit very slowly.