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British scientists preparing to fight to keep mean time at Greenwich
British scientists are prepared to launch a defence of Greenwich Mean Time ahead of an international decision on whether the world should move to strict atomic time instead.
The move would eliminate the need for 'leap seconds', which are quietly added to global timekeeping systems every few years to ensure we remain exactly in sync with the rotation of the Earth.
At a meeting of the International Telecommunications Union in Geneva next week, representatives from 190 countries will gather to vote on whether or not to stop using this system and align ourselves strictly with atomic time.
This would mean that every 80 years or so we would move about a minute further away from GMT, the method first adopted in Britain in 1847 and used by the rest of the world before the introduction of Coordinated Universal Time (UTC) – essentially the same measurement – in 1972.
It would cut the link between our time and the rising and setting of the Sun, and cause us to gradually drift away from Greenwich Mean Time, judged by when the Sun crosses the Greenwich Meridian.
The problem lies in the fact that the Earth's rotation is irregular and is gradually slowing down by about two thousandths of a second every day.
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This means that atomic clocks, which measure the length of a second with extreme accuracy based on reactions in caesium atoms, are ever so slightly out of kilter with astronomical time.
Additional seconds are added to the time signal when needed to account for this deviation, with 24 having been used since they were first introduced in 1972.
Britain remains determined to defend the traditional method of timekeeping, insisting that the inconvenience of adding leap seconds is nothing compared with the difficulty of adding additional minutes or hours further down the line when our gradual deviation from astronomical time would become noticeable.
But a host of other countries including the USA and China are set to vote in favour of the move because it would eliminate the need to regularly update the world's clocks.
Debate on the issue has been rife for many years but it is thought that this meeting could finally mark the demise of GMT with the majority of nations favouring the move.
Peter Whibberley of the National Physical Laboratory, who will represent the UK at next week's meeting, said the switch would mean we could no longer refer to UK time as GMT.
"One you break that link UTC would just drift away from GMT and you would have to refer to it as UTC", he said.
"The problem is, once you have broken that link there is no way to restore it, it is just too difficult.
"We have had leap seconds for the last 40 years so we can handle them, but there is no equipment in the world that could handle a leap minute or hour ... it could be 200 years down the line but it would be just impossible."
British scientists are prepared to launch a defence of Greenwich Mean Time ahead of an international decision on whether the world should move to strict atomic time instead.
The move would eliminate the need for 'leap seconds', which are quietly added to global timekeeping systems every few years to ensure we remain exactly in sync with the rotation of the Earth.
At a meeting of the International Telecommunications Union in Geneva next week, representatives from 190 countries will gather to vote on whether or not to stop using this system and align ourselves strictly with atomic time.
This would mean that every 80 years or so we would move about a minute further away from GMT, the method first adopted in Britain in 1847 and used by the rest of the world before the introduction of Coordinated Universal Time (UTC) – essentially the same measurement – in 1972.
It would cut the link between our time and the rising and setting of the Sun, and cause us to gradually drift away from Greenwich Mean Time, judged by when the Sun crosses the Greenwich Meridian.
The problem lies in the fact that the Earth's rotation is irregular and is gradually slowing down by about two thousandths of a second every day.
Related Articles
This means that atomic clocks, which measure the length of a second with extreme accuracy based on reactions in caesium atoms, are ever so slightly out of kilter with astronomical time.
Additional seconds are added to the time signal when needed to account for this deviation, with 24 having been used since they were first introduced in 1972.
Britain remains determined to defend the traditional method of timekeeping, insisting that the inconvenience of adding leap seconds is nothing compared with the difficulty of adding additional minutes or hours further down the line when our gradual deviation from astronomical time would become noticeable.
But a host of other countries including the USA and China are set to vote in favour of the move because it would eliminate the need to regularly update the world's clocks.
Debate on the issue has been rife for many years but it is thought that this meeting could finally mark the demise of GMT with the majority of nations favouring the move.
Peter Whibberley of the National Physical Laboratory, who will represent the UK at next week's meeting, said the switch would mean we could no longer refer to UK time as GMT.
"One you break that link UTC would just drift away from GMT and you would have to refer to it as UTC", he said.
"The problem is, once you have broken that link there is no way to restore it, it is just too difficult.
"We have had leap seconds for the last 40 years so we can handle them, but there is no equipment in the world that could handle a leap minute or hour ... it could be 200 years down the line but it would be just impossible."
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