Not enough hours in a day? There used to be just 18!

FOR anyone who feels there are not enough hours in the day this may come as a welcome surprise – the Earth’s days are steadily getting longer.

A study analysing the effect of the moon’s pull on the earth shows that 1.4billion years ago, a day lasted just over 18 hours.

It has got steadily lengthier in the intervening centuries to reach the current 24 hours. But any change in the length of days is unlikely to be noticed in our lifetime – as the increase is about a millisecond or so every century.

Part of the reason for the lengthening day is that the moon was once much closer. Having the moon orbiting much nearer sped up the Earth’s rotation – and as it moves away, the Earth slows down. Stephen Meyers, professor of geoscience at the University of Wisconsin-Madison, co-wrote the study published in the Proceedings of the National Academy of Sciences.

Professor Meyers said: ‘As the moon moves away, the Earth is like a spinning figure skater who slows down as they stretch their arms out.’ The moon is currently moving away from the Earth at a rate of .82cm (1.5inches) per year.

Using geological data, and astronomical theory, the scientists assessed the direction of the axis of rotation of the earth and the shape of its orbit 55million years ago compared with 1.4billion years ago.

This allowed them to calculate the length of a day and the distance between the Earth and the moon.