Many people are hoping that the bad year of 2020 will pass quickly, as if the Earth thinks so too. The beautiful blue planet has been rotating extra fast lately, so much so that the days are getting shorter. The year has 28 of the shortest days since 1960.
On average, the Earth rotates once every 86,400 seconds relative to the Sun, or 24 hours or one solar day, according to the Time and Date website.
But the speed of the Earth’s rotation is not fixed; it often changes due to complex factors such as the oceans or the atmosphere, so the length of each day can vary by as little as a millisecond (thousandth of a second).
Before the start of 2020, the shortest day since 1973 was July 5, 2005, which rotated in 1.0516 milliseconds less than 86,400 seconds.
But by the middle of 2020, the Earth breaks this record at least 28 times, that is, there are 28 days shorter, and the shortest day is July 19, which rotates in 1.4602 milliseconds less than 86,400 seconds.
If the Earth’s rotation is out of sync with the very precise atomic clocks and varies considerably, people use plus or minus leap seconds to make adjustments to keep it in line.
Since the leap second system was introduced in 1972, the Earth’s rotation has been a little slower. So far, people have used 27 leap seconds, and all of them have been positive. In other words, all 27 seconds have been added to our clocks so that the Earth can catch up.
However, the Earth’s rotation has gotten faster in recent years, so there is no need to adjust the time with leap seconds from 2016 onward. If the Earth’s rotation continues to get faster, people may need to use negative leap seconds, that is, clocks minus leap seconds, in order to catch up with the overtaking Earth.
So why don’t people feel the Earth’s rotation getting faster? This is because people and everything on the Earth follow the Earth’s rotation, so they don’t feel it spinning, and certainly don’t feel it increasing in speed.
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