Image: © mykolastock/Stock.adobe.com
There are theories that the ‘Chandler wobble’ could be linked to the Earth’s rotation speeding up, which could lead to the first ever negative leap second.
Do you ever feel like the days are passing by at a faster rate? Recent findings suggest this may actually be the case.
Scientists have said that the Earth is spinning at a faster rate than usual, with a recent date being the shortest day recorded since accurate measurements using atomic clocks began in the 1960s.
On 29 June, the Earth completed a full spin in 1.59ms less than 24 hours, according to International Earth Rotation and Reference Systems Service. This record was nearly beaten last month, as the length of the day was 1.50ms shorter than 24 hours on 26 July.
The Earth’s rotation has been speeding up in recent years. In 2020, the planet hit a new record by having its 28 shortest days since accurate atomic clock measuring began. The Earth continued to spin at a faster-than-usual rate last year, though its shortest day failed to break any new records.
The Chandler wobble
There are a number of theories as to why this speed-up is occurring, such as changes in climate, tides and earthquakes.
One theory is that the shorter days are linked to a phenomenon called the ‘Chandler wobble’. This is the name given to an irregular movement of Earth’s geographical poles across the surface of the globe.
“The normal amplitude of the Chandler wobble is about three to four meters at Earth’s surface,” Leonid Zotov of Lomonosov Moscow State University, who recently published a study on what might cause the changes in Earth’s rotation, told TimeandDate.com.
“But from 2017 to 2020 it disappeared.”
A negative leap second
Our methods of timekeeping aren’t perfect, as scientists have had to make slight alterations in the past to keep our time consistent with how the Earth has rotated.
The leap second is a time adjustment added to Coordinated Universal Time (UTC) in order to keep atomic clocks synchronised with astronomical time. Since the introduction of the leap second in 1972, UTC has been updated 27 times.
There are theories that if the Earth continues on a faster rotation, it could lead to the first ever negative leap second. This would mean UTC would be adjusted to skip one second.
However, leap seconds have been known to cause disruptions to various precise systems, leading to data corruption and site crashes. In 2012, a leap second change caused Reddit to go offline and there were issues affecting Mozilla, LinkedIn, Yelp and BuzzFeed. At the start of 2017, a leap second issue at Cloudflare caused some of its customers’ servers to go offline.
Last month, Meta said it is backing an industry effort with other tech giants to abolish the leap second, referring to it as a “risky practice that does more harm than good”.
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