If it feels like you’re losing time in the day, you may be right.
Scientists claim that on June 29, 2022, the Earth spun faster than normal, making it the shortest day recorded since the 1960s.
The average day is 24 hours long (or exactly 86,400 seconds). According to CBS, who spoke to Leonid Zotov, a scientist at the Sternberg Astronomical Institute of Lomonosov Moscow State University, June 29 was 1.59 millisecond shorter.
Zotov and a team of scientists recently published a study outlining possible hypotheses for Earth’s new accelerated rotation.
They reported that the Earth has been turning faster since 2016. According to the Guardian, 2020 had 28 of the shortest days recorded in the last 50 years. (Not every day, however, is shorter than 24 hours.)
The increased rotational speed came as a surprise to scientists who, as Zotov and his peers wrote in the study, previously believed the Earth had been decelerating over the past centuries.
Scientists have not been able to say for certain what is causing the increased speed, though Zotov and other scientists will present their research and theories at the Asia Oceania Geosciences Society conference this month.
Zotov told CBS he believes the Earth’s tides may play a factor in why the planet is spinning faster.
According to Forbes (who also spoke to Zotov), a decay in the “Chandler Wobble” may be what is causing the change in acceleration. The Chandler Wobble involves the movement of geographical poles across the surface of the globe, as Earth is a living, moving planet.
(The normal amplitude of the Chandler wobble is about three to four metres at Earth’s surface, but from 2017 to 2020 it disappeared, according to numerous scientific reports.)
“Polar motion is caused by geophysical processes in the Earth systems, in particular currents in the ocean, winds in the atmosphere, internal processes inside the Earth,” Zotov told Forbes. He told the outlet he believes “something is happening inside the Earth to the core and mantle.”
Whatever is happening to Earth’s core and mantle is what is decaying the Chandler Wobble and causing Earth’s acceleration, Zotov claims.
There are also other factors potentially at play, including natural weather occurrences. NASA has previously claimed that changes in atmospheric pressure and strong winds (like that of the El Niño years) can slow the speed of Earth’s rotation. Alternatively, events like earthquakes can speed up rotation.
This is not the first time the length of Earth’s days has changed. Scientists believe that more than 1.4 billion years ago, days on Earth were less than 19 hours long.
Still, despite there being no concrete answer for Earth’s rising speed, scientists and various professionals around the world are now disputing the best method to cope with the time shift.
Zotov said if Earth continues to rotate faster, atomic time — the universal way time is measured on Earth — may need to change.
One such proposal is to introduce a negative leap second. First proposed in the 1970s, a negative leap second would see one second removed from clocks to maintain Coordinated Universal Time (CUT). Leap seconds are usually implemented either on the last day of June or the last day of December.
While a negative leap second has never been used, there have been, in total, 27 positive leap seconds (one second added to clocks) implemented about every year and a half (on average), according to the National Institute of Standards and Technology (NIST).
Some engineers strongly oppose the use of negative leap seconds, claiming it could cause widespread technological issues.
Meta, the tech giant that owns Facebook, shared a blog post by engineers Oleg Obleukhov and Ahmad Byagowi in July, insisting that leap seconds should be a thing of the past. They claim in the blog post that leap seconds mainly benefit “scientists and astronomers as it allows them to observe celestial bodies using UTC (Coordinated Universal Time) for most purposes.”
Obleukhov and Byagowi wrote that a negative leap second could cause IT programs to crash and may corrupt data on an international level, as seen in simulations the company claims to have run.
“Introducing new leap seconds is a risky practice that does more harm than good, and we believe it is time to introduce new technologies to replace it,” they continued.
The Meta-affiliated engineers believe the melting and refreezing of ice caps on the world’s tallest mountains may be a factor in Earth’s increased rotational speed.
“This phenomenon can be simply visualized by thinking about a spinning figure skater, who manages angular velocity by controlling their arms and hands,” they wrote. “As they spread their arms the angular velocity decreases, preserving the skater’s momentum. As soon as the skater tucks their arms back in the angular velocity increases.”
All in all, scientists, engineers and other time and Earth science-related professionals are now arguing whether time should continue to be defined by the movement of the planet.
What’s to be done about the increased speed of Earth, then? Only time can tell.