Timelords adjust the clocks

Click to follow
The Independent Online
(First Edition)

INSOMNIACS listening to BBC radio at one o'clock tomorrow ie 1am Fridaymorning will hear not six but seven 'pips' as , at the behest of a group of French scientists, the Greenwich Time signal adds a 'leap second' to the length of the day.

The additional 'pip' which makes tomorrow 1 Julywill therefore be officially the longest day of the year summer's long balmy days. This is not some new version of Euromadness being foisted on Britain in revenge for Mr Major's veto at last week's European summit, but an international agreement to prevents highly accurate atomic clocks getting out of step with the rotation of the earth.

For the first half of the century, the best mechanical clocks were accurate to within a few seconds every five years. However, the advent in the mid-1950s of atomic clocks based on vibrations of the element caesium brought time measurement accurate to within one second in 300,000 years.

The earth is slowing down and the days are getting longer by about three hours during the past 600 million years So accurate is the beat of modern which means that so accurate that the slowing of the earth's rotation has meant that periodic adjustments are necessary to keep atomic clocks in step.

become embarrassing and the clocks have to be adjusted to keep in step.

Tomorrow's leap second, the 19th nineteenth since 1972, They have all been added seconds indicating that the earth is still slowing.

In 1972, therefore, Universal Time was replaced in favour of 'Co-ordinated Universal Time' which is kept by has added at the behest of the world's official timekeepers the International Earth Rotation Service at the Paris Observatory.