Thursday 21 Jan 2021

Earth is spinning faster than it has in 50 years. Why?

Scientists believe that days have become shorter than the standard 24 hours because the earth is spinning faster. What could the reason be?

| JANUARY 08, 2021, 09:42 PM IST
Earth is spinning faster than it has in 50 years. Why?

Scientists think days are getting shorter than 24 hours because the planet is spinning faster than it has in 50 years and a full day has been taking less than normal since last year. 

According to sources, July 19, 2020, was the shortest day since scientists began keeping records in the 1960s - 1.4602 milliseconds shorter than the full 24 hours. 

It is a retreat from previous records showing that for decades, the Earth took slightly longer than 24 hours to complete a rotation.

The International Earth Rotation and Reference Systems Service (IERS) in Paris announced in July last year that no “leap second” would be added to the world’s official timekeeping in December 2020. 

Leap seconds are time adjustments like leap years and timekeepers at IERS have added leap seconds to 27 days since the 1970s, with the most recent on December 31, 2016. 

According to reports, they keep atomic time in line with solar time, thereby keeping satellites and communications equipment in sync. 

The next possible date for a leap second is June 30, 2021, as  leap seconds are always added on the last day of June or December.

According to scientists, the days are on average about 0.5 seconds shorter than 24 hours. Though the time difference is noticed only at the atomic level, experts say its impact could be significant. 

World timekeepers are debating whether to delete a second from time — called a “negative leap second” — to account for the change and bring time passage back into line with the rotation of the Earth.

Peter Whibberley of the National Physical Laboratory in the UK said, while speaking to the Telegraph, that the Earth is spinning faster now than at any time in the last 50 years. 

“It’s quite possible that a negative leap second will be needed if the Earth’s rotation rate increases further, but it’s too early to say if this is likely to happen. There are also international discussions taking place about the future of leap seconds, and it’s also possible that the need for a negative leap second might push the decision towards ending leap seconds for good,” Whibberley, a senior research scientist, said.

A study published in Science Advances in 2015 suggests global warming may be the reason behind the Earth’s speedier rotation.



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