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You can find the current article at its original source at https://www.theguardian.com/uk-news/2016/dec/30/new-years-eve-countdown-to-take-second-longer-than-normal
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| New Year's Eve countdown to take second longer than normal | |
| (35 minutes later) | |
| Counting down to 2017 will take longer than usual this New Year’s Eve as horologists compensate for a slowdown in the Earth’s rotation. | Counting down to 2017 will take longer than usual this New Year’s Eve as horologists compensate for a slowdown in the Earth’s rotation. |
| To be precise, it will last an extra second. The National Physical Laboratory (NPL) is to introduce a “leap second” after 23.59:59 on 31 December. | To be precise, it will last an extra second. The National Physical Laboratory (NPL) is to introduce a “leap second” after 23.59:59 on 31 December. |
| As a result, clocks striking 00:00:00 will actually be recording a time of 23:59:60 - delaying midnight by a second. | As a result, clocks striking 00:00:00 will actually be recording a time of 23:59:60 - delaying midnight by a second. |
| It will be the 27th occasion the NPL has brought in a leap second to ensure that time based on the Earth’s rotation does not lag behind time kept by atomic clocks. | It will be the 27th occasion the NPL has brought in a leap second to ensure that time based on the Earth’s rotation does not lag behind time kept by atomic clocks. |
| The extra seconds are occasionally necessary because of unpredictable changes in the speed at which the Earth turns on its axis. | The extra seconds are occasionally necessary because of unpredictable changes in the speed at which the Earth turns on its axis. |
| Typically, they are added every two or three years, although the last one was inserted just 18 months ago in June 2015. | Typically, they are added every two or three years, although the last one was inserted just 18 months ago in June 2015. |
| NPL, based in Teddington, London, is Britain’s national measurement institute and the birthplace of atomic time. The laboratory is responsible for providing the UK’s national time scale – known as UTC(NPL) – which is controlled by atomic clocks that are among the most accurate in the world. | NPL, based in Teddington, London, is Britain’s national measurement institute and the birthplace of atomic time. The laboratory is responsible for providing the UK’s national time scale – known as UTC(NPL) – which is controlled by atomic clocks that are among the most accurate in the world. |
| Peter Whibberley, senior research scientist with NPL’s time and frequency group, said: “Atomic clocks are more than a million times better at keeping time than the rotation of the Earth, which fluctuates unpredictably. | Peter Whibberley, senior research scientist with NPL’s time and frequency group, said: “Atomic clocks are more than a million times better at keeping time than the rotation of the Earth, which fluctuates unpredictably. |
| “Leap seconds are needed to prevent civil time drifting away from Earth time. Although the drift is small – taking around 1,000 years to accumulate a one-hour difference – if not corrected it would eventually result in clocks showing midday before sunrise.” | “Leap seconds are needed to prevent civil time drifting away from Earth time. Although the drift is small – taking around 1,000 years to accumulate a one-hour difference – if not corrected it would eventually result in clocks showing midday before sunrise.” |
| Leap seconds can be a headache for communication networks, financial systems and other applications that rely on precise timing, and must be programmed into computers to avoid mistakes. | Leap seconds can be a headache for communication networks, financial systems and other applications that rely on precise timing, and must be programmed into computers to avoid mistakes. |
| The extra seconds are introduced in the last minute of either December or June, or rarely March or September. | The extra seconds are introduced in the last minute of either December or June, or rarely March or September. |
| It is also possible for a second to be removed from the UTC (universal coordinated time) timescale, although this has never happened. | It is also possible for a second to be removed from the UTC (universal coordinated time) timescale, although this has never happened. |
| The International Earth Rotation and Reference Systems Service (IERS), based at the Paris Observatory in France, tracks the Earth’s rotation and announces when a leap second is needed roughly six months in advance. | The International Earth Rotation and Reference Systems Service (IERS), based at the Paris Observatory in France, tracks the Earth’s rotation and announces when a leap second is needed roughly six months in advance. |