The Earth completed its shortest rotation in recorded history on June
29 this year, shaving 1.59 milliseconds off of the approximately
24-hour day. Generally, the Earth is slowing its spin ever so slightly,
so why it seems to be speeding up is a mystery.
"It's certainly odd," Matt King, a professor of geodesy at the
University of Tasmania, tells Genelle Weule of the Australian
Broadcasting Corporation (ABC). "Clearly something has changed, and
changed in a way we haven't seen since the beginning of precise radio
astronomy in the 1970s."
Because the Earth’s rotational speed varies, we use a standardized Coordinated Universal Time, or UTC, to make sure our clocks are in sync
across the world. Two components determine UTC: International Atomic
Time (TAI) and Universal Time (UT1).
UT1 is a time standard based on the Earth’s rotation, whereas TAI is a
time scale that provides the speed at which our clocks should tick. TAI
is based on the average of hundreds of precise atomic clocks in timing
labs across the world. It’s incredibly accurate, but it doesn’t take
into account slight variations in how the Earth spins.
"When you start looking at the real nitty gritty, you realize that
Earth is not just a solid ball that is spinning," Fred Watson,
Australia's astronomer-at-large, tells ABC. "It's got liquid on the
inside, it's got liquid on the outside, and it's got an atmosphere and
all of these things slosh around a bit.”
The Earth’s spin is generally slowing, so a leap second (an extra
second every 1.5 years or so) is added to allow it to catch up to the
clocks.
But now it seems the Earth is spinning quicker. In 2020, scientists
recorded 28 of the shortest days since 1960, per TimeandDate.com's
Graham Jones and Konstantin Bikos. On July 26, 2022, the Earth rotated
around in 1.5 milliseconds less than 24 hours, per ABC.
If the trend continues, scientists may need to consider skipping a
second, which would be the first deletion in history. But ABC reports
this likely wouldn’t happen for another eight to ten years at the
current rate.
Technology companies, such as Meta, have spoken out against the leap
second, saying it is bad for both digital applications and scientists,
who often use TAI or UT1.
“Every leap second is a major source of pain for people who manage
hardware infrastructures,” write Oleg Obleukhov and Ahmad Byagowi in a
Meta blog post. “The impact of a negative leap second has never been
tested on a large scale; it could have a devastating effect on the
software relying on timers or schedulers.”
Since the 1970s, the world has added 27 leap seconds, per ABC.
“I hope that Earth’s acceleration stops and we don’t need to subtract a second, but who knows?” Leonid Zotov at the Sternberg Astronomical
Institute of Lomonosov Moscow State University tells Forbes' Jamie
Carter. “Predicting variations in Earth’s rotation is almost as
difficult as predicting stock prices.”
https://www.smithsonianmag.com/smart-news/the-earth-had-its-shortest-day-in-recorded-history-180980521/
--
Internetado.
...
This is a message from God: "Rebooting the universe, please log out"
--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)