The arrival of negative leap seconds is possible if the Earth rotational speed keeps rising. On July 29, the Earth beat its previous record for the shortest day as it spun around in 1.59 milliseconds less time than it normally does in a 24-hour period.
The Independent claims that the globe has recently started speeding up. The shortest month on record for the planet since the 1960s occurred in 2020. The shortest day ever was recorded on July 19 of that year. It was shorter than an usual 24-hour day by 1.47 milliseconds.
The globe continued to spin faster overall the next year, but it didn’t set any new records. However, Interesting Engineering (IE) asserts that a 50-year era of shorter days may already be beginning.
It is still unclear what is causing the Earth’s spin to vary in speed. However, experts hypothesize that this might be caused by processes in the core’s inner or outer layers, oceans, tides, or even shifts in the climate.
The “Chandler wobble,” or the shifting of the Earth’s geographic poles across its surface, is another theory put out by certain experts as to why this might be the case. Scientists Leonid Zotov, Christian Bezoar, and Nikolay Sidorenko explain this by comparing it to the quiver one notices when a spinning top begins to pick up speed or slows down.
According to the Independent, the introduction of negative leap seconds might be necessary if the Earth’s rotational speed keeps rising in order to maintain the accuracy of atomic clock measurements.
The negative leap second would, however, have potentially perplexing effects for communications, computing, and smartphone systems. According to the publication, which cited a Meta blog, the jump second “primarily benefits scientists and astronomers,” but it is a “risky technique that does more harm than good.”
This is due to the fact that the clock advances from 23:59:59 to 23:59:60 before ceasing to function at 00:00:00. Because of the timestamps on the data storage, a time jump like this might destroy data and cause programmers to crash.
The clock will change from 23:59:58 to 00:00:00 if a negative leap second occurs, according to Meta, and this could have a “devastating effect” on software that uses timers and schedulers. International timekeepers might need to add a “drop second”—a negative leap second—to resolve this, claims IE.
Notably, Coordinated Universal Time (UTC), the fundamental time reference used to govern clocks and time throughout the world, has already undergone 27 leap second updates.
