If you’ve always thought that there are exactly 24 hours in a day and not a second more or less, you may be surprised to discover that this is hardly the truth – the speed of the Earth’s rotation is never constant, and there are variances worth microseconds in the lengths of our days. Recently, scientists have been stumped after finding out that our planet’s days are actually seemingly longer, despite the fact that June 29, 2022 was the shortest day recorded since we’ve had the technology (atomic clocks) to measure time down to the smallest microsecond. It was discovered that the Earth’s days were actually getting shorter until 2020, when it all reversed and our days began getting longer.
The exact reason for this change has yet to be determined, with experts claiming the change to be the most drastic in the last 50 years (which is also since when we’ve been able to measure the planet’s spin with accuracy). So far, scientists have made attempts at guessing the reason for this change, with some factors already known to be a fact. For example, we definitely know that the Earth’s rotation has slowed down considerably since the age of the dinosaurs, and our days are now about half-an-hour longer in comparison.
A few billion years ago, the Earth’s day was only about 19 hours. Experts have pointed out one possible reason for the slowing down of the spin – the relationship between our planet and the Moon, with its exerted gravitational forces slowly removing energy and causing Earth to slow down. This takes about 2.
3 milliseconds off the length of each day per century. But over the last 20,000 years, there have been forces that have actually caused the Earth to speed up, such as the melting polar ice sheets that have reduced the planet’s surface pressure, which caused the Earth’s mantle to steadily start moving towards the poles. This was illustrated as a ballet dancer bringing their hands closer inside towards their body as they spun, with their rotation only growing faster the closer their hands came closer inside.
Alongside this, there are also other factors and events that have caused our planet to speed up its rotation over the course of time – like Japan’s Great Tōhoku earthquake of 2011 which was thought to have sped up the planet’s rotation by about 1. 8 microseconds. Other cited reasons include climate change and weather events on the extreme end, such as major storms that release massive volumes of water closer to the equator – which happens to slow down the spin, while snowfall at higher elevations will cause the opposite effect until the ice melts and the water trickles back down to the oceans.
All in all, you can see just how there’s a myriad of reasons and factors that end up changing the spin rate of the planet. Right now, however, scientists are still stumped to the exact reason why the trajectory has shifted in favor of the Earth spinning more slowly since 2020. Previously, when the planet’s days were seemingly growing shorter, there were calls by some to introduce leap seconds – a concept that would have seen the removal of a second from a day to coordinate and account for the time lost (from 23:00:58 to 00:00:00).
But now, it seems that it may no longer be needed. Your secret Twitter account may no longer be secret Meta accuses Malaysian police of running online troll farm that targeted the public The reason Malaysian kids become ‘Mat Rempits’ is peer pressure, study says Kind-hearted woman turns her flat into ‘nursing home’ for sick cats Apple Pay is finally in Malaysia with availability for select credit cards Cover image sourced from Discover Magazine and Freepik . .
From: mashable
URL: https://sea.mashable.com/life/21089/days-on-earth-have-been-getting-longer-since-2020-and-scientists-dont-know-why