Time flying! Earth rotating faster than usual; timekeepers ponder deleting a second
BusinessToday.In January 7, 2021
Earth is rotating faster than its normal speed in the last half-century, according to scientists. The international timekeepers observed that July 19, 2020, was the shortest day since scientists began keeping records in the 1960s. July 19, 2020, was 1.4602 milliseconds shorter than the full 24 hours, according to a report in The Telegraph.
It is not an alarming thing as such as the planet's rotation varies due to ocean currents, atmospheric pressure, and movement of the core.
However, it is inconvenient for international timekeepers who use ultra-accurate atomic clocks to metre out Coordinated Universal Time (UTC) by which everyone sets their clocks.
When the time is taken by Earth to take a full rotation deviates from the UTC by more than 0.4 seconds, then timekeepers adjust UTC.
Until now, global timekeepers have added "leap second", which happened either on June-end or December-end. Like leap years, leap seconds are time adjustments. Since 1972, scientists have added leap seconds about every year-and-a-half, on average to keep atomic time in line with solar time, thereby keeping satellites and communications equipment in sync.
The last addition came in 2016, when on New Year's Eve at 23 hours, 59 minutes and 59 seconds, an extra "leap second" was added.
This is because the Earth has taken slightly longer than 24 hours to complete a rotation for decades.
Now, due to this unusual changes, world timekeepers are debating whether to delete a second from time, also known as "negative leap second" in order to bring time passage back into line with the rotation of the Earth.
That's because the average length of a day is 86,400 seconds, but an astronomical day in 2021 will clock in 0.05 milliseconds shorter, on average. Over the course of the year, that will add up to a 19 millisecond lag in atomic time.
Physicist Peter Whibberley of the National Physics Laboratory told the daily that a 'negative leap second' will be needed if the Earth's rotation rate increases further, adding, "but it's too early to say if this is likely to happen".