The end of time? GMT under threat

Did 2008 seem like a long year to you? Well, technically it was – one second longer in fact.

Today, we use atomic clocks to provide an accurate measurement of time, but the clocks are so accurate that they’re more reliable than the rotation of the earth – the traditional measurement we use for hours, minutes and seconds.

To correct this mis-match, every year or so, a leap-second is added, and one such leap second was added on the 31st of December 2008. This has been done since 1972.

As so many devices rely on precise timekeeping and atomic clocks, there’s some work involved in compensating for these leap-seconds. So – a group within the International Telecommunications Union is planning to abolish the leap-second, instead having a leap-hour every 600 years.

Seems logical? Yes indeed – however…

This change will effectively end the bond between timekeeping and the sun – meaning that we’d no longer be able to gauge time from the position of the sun and the stars – sundials would get increasingly inaccurate, and there’d be problems for astronomers.

The biggie for those of us in the UK, would that GMT (Greenwich Mean Time) would start to drift, and London would lose its status as the centre of the world’s timezone, as GMT would be replaced by UTC (Universal Time).

There’s a vote on the future of the leap-second, and GMT, in 2011. If you want GMT to stay, sign the petition at http://www.ipetitions.com/petition/save_gmt/