Scientists are still astonished as to why the Earth has been spinning faster than ever in recent years.
While you might think that the planet we live on has always taken 24 hours to complete a rotation, the length of the day varies.
While these changes are minor, the Earth was closer to the moon more than a billion years ago, causing it to rotate much faster than it does now – as a result, there were only 19 hours in a day.
As the planet’s position in the solar system has shifted, so has its rotation speed, and a full spin on its axis now takes about 24 hours.
We now have a better understanding of the cycles thanks to atomic clocks, which scientists began using in the 1960s to take accurate daily measurements of the Earth’s rotation.
These instruments, which sound like something out of a science fiction film, work by monitoring time with extreme precision by using atom resonance frequencies.
In recent years, scientists have discovered an unusual trend: the Earth has been speeding up, with 2020 having 28 of the shortest days since these clocks were installed.
On that year’s shortest day, July 19, the Earth span 1.47 milliseconds less than 24 hours.
On June 29, 2022, a new record was set at 1.59 milliseconds less, demonstrating that our planet rarely reaches the 86,400-second mark for a full rotation.
Despite these increasing speeds, the overall trajectory shows that the days are getting longer – need I remind you of the 19-hour day?
According to Time and Date, Earth takes a couple of milliseconds or so longer to complete one rotation every century.
So, what exactly is causing these changes? Scientist Leonid Zotov believes the recent decrease in the length of the day is due to the ‘Chandler wobble.’
The term refers to a small and irregular movement of the earth’s geographical poles across its surface.
“The normal amplitude of the Chandler wobble at Earth’s surface is about three to four metres, but it vanished from 2017 to 2020,” Zotov told the outlet.
If the Earth’s rotation continues to accelerate in the short term, it could result in a negative leap second, which is suppressed from our clocks to keep them in sync.
Concerns have been expressed that this change may cause IT system glitches, but Zotov reassured: “I think there’s a 70% chance we’re at the minimum and we won’t need a negative leap second.”
Other theories propose that the planet’s inner or outer layers, oceans, tides, or even climate may influence Earth’s speed.
But, as of now, there is no definitive answer; no one knows whether or not the days will continue to change on a larger scale.