Post by dividavi on Jan 15, 2021 1:57:37 GMT
Jerusalem Post Health & Science
Earth is spinning faster: Time flies in 50-year record
The planet is speeding up and a negative leap second may soon be needed so atomic clocks can align correctly with the turning world.
By SARAH CHEMLA JANUARY 6, 2021 13:17Email Twitter Facebook fb-messenger
What if the feeling that time flies were actually true?
Indeed, the Earth has been spinning abnormally quick lately, reported The Telegraph. The planet is now completing its rotation in 1.4602 milliseconds less than the usual 86,400 seconds.
The speed of the Earth's rotation varies constantly because of the complex motion of its molten core, oceans and atmosphere, as well as the effect of celestial bodies such as the Moon.
The friction of the tides and the change in distance between the Earth and the Moon all make for daily variations in the speed the planet rotates on its axis, the Telegraph reported, adding that even the snow building up on mountains and melting in the summer can shift the rotation.
July 19, 2020 was recorded as the shortest day since records began in the 1960s after highly accurate atomic clocks were developed and compared the length of a standard day to fixed stars in the sky.
According to The Telegraph, the previous shortest day in 2005 was beaten 28 times in 2020, and 2021 is expected to be the fastest year ever, with the average day passing 0.5 milliseconds faster than usual.
The planet is speeding up and a negative leap second may soon be needed so atomic clocks can align correctly with the turning world, and it would be the first time ever that a second has been removed from global clocks.
“It is certainly correct that the Earth is spinning faster now than at any time in the last 50 years," Peter Whibberley, senior research scientist with National Physical Laboratory’s time and frequency group, told The Telegraph, adding that “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.”
On Sunday, the solar day lasted just 23 hours, 59 minutes and 59.9998927 seconds, then slowed down on Monday to a little more than 24 hours.
However, in the course of 2021, atomic clocks are expected to accumulate a lag of about 19 milliseconds.
While it would take hundreds of years for the difference to become obvious to most people, modern satellite communication and navigation systems rely on time being consistent with the conventional positions of the Sun, Moon and stars.
It is the task of scientists and officials at the International Earth Rotation Service, based in Paris, to monitor the planet's rotation and inform countries when leap seconds must be added or taken away six months in advance.
