For centuries , humans have followed different scales of measuring time.
Be it the lunar calendar to keep track of the days or the sundials to keep track of the hours within the day.
Humans have always had this innate drive to track time and of course without it, our civilization wouldn’t be able to stand where it is.
But with recent discoveries in the field of science, many concepts and theories have been upturned by new ones and so does in the case of tracking time.
In the ’60s scientist invented the atomic clock. Even though being a clock, this device functions on a relatively different concept than our normal clocks.
A normal day on earth has 86,400 seconds. But on an atomic clock, a second isn’t defined as one 86,400th part of an earth day but rather as the time it takes a Cesium-133 atom at the ground state to oscillate precisely 9,192,631,770 times. Making it a much precise measure of time.
Well, atomic clocks deviate by 1 second only in 100 million years. While on the other hand the earth time or Universal time is quite unreliable due to the deviations in the speed of the earth’s rotations due to terrestrial and cosmic events.
Usually, an earth day is .002 seconds longer than the previous one and if we consider this to keep on going, then in 1.5 years a day would increase by 1 second.
And for this very purpose scientists came up with the concept of a leap second.
The entire world follows the UTC or Coordinated universal time, which is measured with the help of the atomic clock. The fact that atomic clocks only deviate by 1 second in 100 million years puts us all in a tough spot when the year increases by 1 second on average every 1.5 years.
That’s where the leap second comes in. Every time the earth time is about to cross the 1 second difference, a leap second or an extra 1 sec is added to the watches around the globe to keep up with the difference.
In history, this has been accomplished 27 times since 1962. But recently , sometime in 2016 it has been discovered that the earth’s speed of rotation hasn’t been decreasing but increasing. Which resulted in the shortening of the day.
For example, a Sunday in January only lasted for 23 hours, 59 minutes, and 59.9998927 seconds. In fact, 2021 is expected to be 19 milliseconds shorter than 2020.
Even though the amount is very small, it Is yet a deviation from the equilibrium set between the UTC and the universal earth time.
And though some scientists say that it will take a while for the deviation to substantially increase if the same trend of shorter days continues but the international community is wondering that whether or not a negative leap second would be needed.
A negative leap second would work on the same concepts as that of a positive one, but instead of adding a second to the year it shall reduce it by 1 and reduce a minute to 59 seconds.
Of course, this would have massive implications on the industries and projects that need precise measures of time such as satellites, aviation systems, servers, etc.
As a matter of fact, the addition of a leap second in 2012 resulted in multiple worldwide server crashes.
But the international community is still uncertain about the decision and an official word from the timekeepers is still awaited.