The Earth witnessed its fastest days on record since 1960 in 2020. Scientists found out that the Earth completed its fastest revolutions around its axis in the year just gone by.
While this news should not be unnerving, as different conditions such as the atmospheric pressure, winds, and ocean current may cause the Earth to rotate at a different pace, it can be problematic for timekeepers who use the atomic clocks to adjust the Coordinated Universal Time – the benchmark time for everyone else.
The astronomical time is the time it takes for the Earth to make a full rotation. When this time deviates by over 0.4 seconds, the UTC may have to be adjusted. Before now, these adjustments were made by adding leap seconds at the end of June or December so that the atomic time and astronomical time may align.
However, a change has occurred, brought on by the fast-spinning rotation of the Earth. So, instead of the regular addition international timekeepers are used to, we may be talking about a subtraction here. That is, instead of the addition of a leap second, timekeepers may need to subtract one. An average astronomical day in 2021 is touted to be 0.05 milliseconds shorter. So making additions to the atomic time is very necessary, Livescience reports.
Peter Whibberley, a senior scientist at the National Physics Laboratory, United Kingdom, said it was possible that we might have on our hands a negative leap second if the Earth continues at its current fast-moving pace. However, Whibberley admitted it was still too early to say if this would happen. According to Whibberley, stakeholders are having a discussion about putting an end to leap seconds.
Prior to 2020, the shortest astronomical day was in 2005. However, in 2020, this record was broken about 28 times. The shortest day in 2020 occurred on July 19, with the Earth completing one full circle 1.4602 milliseconds faster than 86,400 seconds – the average length of a day.
Leap seconds has its own positives sides and drawbacks. For one, they are very necessary to ensure that the astronomical time is in tune with the atomic time. On the other hand, they can be problematic for telecommunication facilities and other time-sensitive data applications. To reduce the disruptions caused to telecommunication systems, scientists have suggested that the gap in the timeframe between the astronomical time and atomic time be allowed to stretch to an hour (leap hour).
The International Earth Rotation Service (IERS) in Paris has been tasked with adding or subtracting a leap year, which must be done six months in advance.
Source: jpost.com