The Earth is spinning faster and has the shortest day on record

Forbes

Earth recorded fastest day on June 29, 2022

As reported by TimeAndDate.com, on June 29 the Earth set a new record – as far as scientists can tell – for having completed one rotation, with 1.59 milliseconds slower. Expect! The Earth takes exactly 24 hours to once rotate on its axis, doesn’t it? Almost, yes, but not quite.

What about “leap seconds”? Until a few years ago, it was thought that the Earth’s rotation was slowing down after several successive measurements by atomic clocks since 1973.
The IERS (International Service for Earth Rotation and Reference Systems) had even started adding leap seconds from time to time to compensate for the slower rotation (this last happened on December 31, 2016).

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Over a longer period of time, this may still be the case – the Earth’s rotation may, in general, still slow down.

After all, the Moon is gradually slowing down the Earth’s rotation. Its gravitational pull causes tides and makes Earth’s orbital path around the Sun slightly elliptical.

How fast does the Earth spin?

However, in recent years, atomic clocks have shown that the Earth’s rotation is accelerating. In fact, we could start a period of 50 years of shorter days.

In 2020, scientists recorded the shortest 28 days since 1960. Last year, this trend did not continue, with the shortest day in 2021 being longer than the year before.

However, on June 29, 2022, our planet completed its fastest rotation ever, followed quickly by a 1.50 millisecond shorter day on July 26, 2022.

The previous record for the shortest rotation was July 19, 2020, when Earth’s rotation occurred at 1.4602 milliseconds in less than 24 hours.

Why is the Earth accelerating?

The cause of the difference in Earth’s rotational speed is unknown, but theories abound:

  • melting glaciers mean less weight at the poles.
  • movements of the molten inner core of our planet.
  • seismic activity.
  • the “Chandler wobble” – the movement of the geographical poles of the Earth on its surface.

Why Earth’s Rotational Speed ​​Matters

The acceleration of the Earth’s rotation has consequences because atomic clocks – which are used in GPS satellites – do not take into account the change in the Earth’s rotation.

If the Earth rotates faster, it will arrive at the same position a little sooner. Half a millisecond equals 10 inches or 26 centimeters at the equator. In short, the GPS satellites – which already need to be corrected for the effect of the theory of general relativity (the curve of space and time) – will quickly become useless.

There are also potentially confusing consequences for smartphones, computers and communication systems, which are synchronized with NTP (Network Time Protocol). It is defined as the number of seconds since 00:00:00 UTC on January 1, 1970.

To solve all this, international timekeepers may need to add a negative leap second – a “decreasing second”. Although the Earth is already spinning faster than ever, with an inevitable slowdown.

Only time will tell.

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