It seems that the wishes of many people have actually been fulfilled during the difficult year of 2020: The year went by. Or rather, Rotation Planet Earth was fast, and scientists recorded 28 shortest days in history.
The planet works with great accuracy, and the day is on average 86,400 seconds – or equal to Twenty four hours. This means that, every 24 hours, the Earth completes a circle around it with respect to the Sun.
The rotation speed of the Earth constantly changes due to many reasons, especially its complex movement of molten cores, oceans and atmosphere.
But since Atomic clocks Were developed in 1960, Scientists are able to monitor changes over time High accuracy, And began to notice that the length of a day might be To change In the order of milliseconds (Or equal to 0.001 seconds).
By then, it was the shortest day on record 5 July 2005, When the Earth revolved Is 1,0516 Milliseconds less. But in 2020, the planet broke a record that is no less than none 28 times. New full record in 19 July 2020, When the earth took over Is 1,4602 Milliseconds to complete its rotation less than normal
When we talk about change very small Over time, it may seem that they are not so important – but add change, and much less than this desire Taking atomic clocks out of sync like Astronomical time.
How atomic clocks are defined Coordinated global time (U.T. C), Which is basically what we know for everyone on the planet to use and agree on time, can mean A. Big problem.
When atomic clocks deviate from an astronomical time greater than 0.4 seconds, the coordinated universal time Need to read unjustly All over the world.
Currently, these measurements are done by International Earth Rotation Service and Reference System (Irish). To determine the exact duration of a day, IERS determine the precise speed of the Earth by scientific measurements. Exact moment In which one Star Passes through a certain place in the sky.
According to current calculations, days 2021 Trend should follow and continue Faster than normal. 2021 will be an average day 0,05 ms Smaller than normal. This means that the year 2021 will be Smallest in decades – The last such thing happened in 1937.
With all Leap day, If the Earth’s rotation goes out of sync with the super-stable beat of atomic clocks, then A Second jump Positives or negatives can be used to bring them back into alignment. The last time a leap second was added was on New Year’s Eve 2016.
However, with the increase in the rotation speed of the Earth, it will soon be necessary Subtract one second from time, Which means that our clocks will give up one second to maintain the momentum of the Earth. This will happen first time That a one second shortfall will occur story.