Earth has set a new record for the shortest day. Even if we humans couldn’t feel the difference, we can fool ourselves that at least it was a work day.
The length of the day on June 29, 2022, as measured by the International Earth Rotation and Reference Systems Service, was 159 milliseconds shorter than 24 full hours.
This is the shortest day since scientists began using atomic clocks to measure Earth’s rotation speed.
Earth recorded its shortest day in two years
In general, the Earth makes a complete rotation on its axis once every 24 hours. However, the length of the day varies due to several factors, which can make it longer or shorter.
The tidal forces between the Earth and the Moon tend to make the day longer. Every 100 years, the Earth needs a few extra milliseconds to complete one rotation on its axis. The internal motion of the planet and atmosphere also alters the length of the day, as does the motion of our satellites, he writes IFL Science.
But in the last few years, the length of the day seems to be getting shorter. Earth has broken a lot of speed records since 2020. In fact, 2020 has seen 28 of the shortest days since the 1960s so far.
Why are the days shorter?
No one knows for sure why this happens, but one suggestion is related to the variability of the spin axis, which hasn’t wobbled as much in the last five years.
Understanding the planet’s complex motions, especially if they are related to long-term cycles, could take some time, but fortunately most of the effects of these variations are negligible. If after several months or even years any significant difference occurs, a “leap” second may be added (or subtracted) from the official time and date.
The internet giants (Facebook, Google, Amazon and Microsoft) would like to give up this second because it could cause bugs in the software.
The last extra second was added to the day on December 31, 2016. No extra second is forecast to be added in 2022.