Year 2021 is set to FLY by as the Earth is spinning faster than at any time in the past 50 years – prompting scientists to call for the addition of a ‘negative leap second’
- Atomic clocks accurately record how long every day is at millisecond level
- Since invention in 1970s the days have been slightly longer than 24 hours
- But since mid-2020 the Earth’s spin has accelerated and is now, on average, 0.5milliseconds a day shorter than 24 hours
Time is passing quicker now than at any point in the last half century, official data reveals.
Earth’s rotation is faster than normal and, as a result, the length of a day is currently ever-so-slightly shorter than the regulation 24 hours.
The world’s timekeepers are now debating whether to delete a second from time to account for the change, and bring the precise passing of time back into line with the the rotation of the Earth.
While the addition of a so-called ‘negative leap second’ has never been done before, a total of 27 ‘leap seconds’ have been added since the 1970s, in order to keep atomic time in line with solar time.
This is because, for decades, the Earth has taken slightly longer than 24 hours to complete a rotation, but since last year it has been taking taking slightly less.
Earth’s rotation is faster than normal and as a result the length of a day is currently consistently shorter than the regulation 24 hours. The world’s timekeepers are now debating whether to delete a second from time to account for the change (stock image)
Since the 1960s, atomic clocks have been keeping ultra-precise records of day length and found that, for the past 50 years, Earth has taken a fraction less than 24 hours (86,400 seconds) to complete one rotation.
However, in the middle of 2020, this long-standing trend was reversed and days are now regularly shorter than 86,400 seconds.
On 19 July 2020, the day was 1.4602 milliseconds shorter than the full 24 hours – the shortest day since records began.
Prior to 2020, the shortest day occurred in 2005, but this record has been shattered a staggering 28 times in the last 12 months.
Some of the web’s most popular sites were laid low on July 1, 2012 after the world’s timekeepers added an extra second to the day.
Sites including Reddit, FourSquare, Yelp, LinkedIn, Gawker and StumbleUpon came crashing down after the extra second played havoc with their servers and source code.
An extra second is added to Coordinated Universal Time (UTC) – the benchmark time agreed internationally – every few years to keep it in line with the time as determined by the Earth’s rotation.
However, many computer applications and digital systems cannot take this into account.
Working on the assumption that every minute always lasts 60 seconds they go haywire when, during a leap-second insertion, they find themselves in a situation they did not expect.
On average, the days are now passing 0.5 seconds shy of 24 full hours.
This diminutive loss of time is only detectable at the atomic level but has wide-reaching implications.
Satellites and communications equipment rely on the true time aligning with solar time, which is determined by the positions of the stars, moon and the sun.
In order to keep this harmonious relationship intact, timekeepers at the Paris-based International Earth Rotation Service have previously added so-called ‘leap seconds’ to a day.
This has happened 27 times since the 70s, with the last one on New Year’s Eve 2016.
However, as Earth has been consistently slowing and not accelerating its spin, there has never before been a need to add a negative leap second.
Now, there is a debate over whether one may be needed to rectify the growing disparity.
‘It is certainly correct that the Earth is spinning faster now than at any time in the last 50 years’, Peter Whibberley, senior research scientist with National Physical Laboratory’s time and frequency group, told The Telegraph.
‘It’s quite possible that a negative leap second will be needed if the Earth’s rotation rate increases further, but it’s too early to say if this is likely to happen.
‘There are also international discussions taking place about the future of leap seconds, and it’s also possible that the need for a negative leap second might push the decision towards ending leap seconds for good.’
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