Year 2021 is set to fly by, 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.
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.
By Joe Pinkstone