The Earth Is Spinning Faster Than It Has in 50 Years
- par Amanda Heroux
- dans Science
- — Jan 9, 2021
Through this, scientists have figured out that 444-419 million years ago, the Earth span 420 times a year, while a few million years later it slowed to 410.
Our clocks are falling out of sync, but instead of running slow like they usually do, they're starting to run a bit fast.
Because of the constant changes in the conditions that aid in determining the speed that the planet spins, scientists have enough reasons to believe that every day is taking less than it is supposed to be.
"But in the middle of 2020, the Earth beat that record no less than 28 times".
However, scientists are now contemplating adding a "negative leap second" to 2021's timekeeping, as a day is now slightly shorter than 24 hours. By looking at ancient corals, however, we can figure out that this wasn't always the case, and the Earth used to spin a lot faster than it does now. Scientists around the world are considering whether to delete a second from time.
That's not particularly alarming - the planet's rotation varies slightly all the time, driven by variations in atmospheric pressure, winds, ocean currents and the movement of the core.
To be clear, we're talking about really tiny numbers.
Our planet is recognised as a reliable timekeeper, as it rotates on average once every 86,400 seconds - the equivalent of 24 hours - with respect to the Sun. That's a difference of 0.1769 ms, so yeah, minuscule stuff.
This means that our days are slightly shorter than usual.
If 2020 felt like a drag, you may be surprised to discover it actually went faster than you thought ... and this year is set to be even speedier. The shortest of these was on July 19, when Earth's rotation was 1.4602 ms below the mean solar day.
That's because the average length of a day is 86,400 seconds, but an astronomical day in 2021 will clock in 0.05 milliseconds shorter, on average. However, no single institution can just modify the system and add a leap second on the official timekeeping when they want it.
While the addition of a so-called "negative leap second" has never been done before, a total of 27 "leap seconds" have been added since the 1970s, in order to keep atomic time in line with solar time. Researchers around the globe are also considering deleting a second in a bid to keep the passage of time in sync with the Earth's rotation.
The last time this happened was in 2016. "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", says Peter Whibberley, senior research scientist with National Physical Laboratory's time and frequency group. In 2012, the additional leap second caused server crashes across a number of websites, including Reddit, Yelp, and LinkedIn, with those who use Linux operating systems and their software disabled using Javascript.
The changes to the length of a standard day were only discovered after highly accurate atomic clocks were developed in the 1960s and compared to fixed stars in the sky. That said, the International Earth Rotation and Reference Systems Service, which decides on such matters, now has no plans to do so.
