Earth Is Spinning Faster and Days Are Getting Shorter, for Now (nytimes.com) 22
An anonymous reader shares a report: This week has seen the shortest days of the year so far. According to data from the U.S. Naval Observatory and the International Earth Rotation and Reference Systems Service, Tuesday's rotation was about 1.34 milliseconds less than 24 hours. More quick spins are expected this week, later this month and in early August, according to predictions from the website Time and Date.
This isn't completely out of the ordinary: Our world's spins have been faster than usual lately. The average day has mostly shortened over the past decade, and within the past five years or so, the full rotation has clocked in at a hair less than 24 hours more often than not. Factors driving the change include movements at Earth's core, atmospheric changes and the moon's position.
But long-term trends do not suggest that the days will shorten in perpetuity. In fact, it is just the opposite. For many millenniums, the days have been growing longer. A Tyrannosaurus rex that lived 70 million years ago would have experienced an average daily rotation of about 23 1/2 hours, studies have found.
This isn't completely out of the ordinary: Our world's spins have been faster than usual lately. The average day has mostly shortened over the past decade, and within the past five years or so, the full rotation has clocked in at a hair less than 24 hours more often than not. Factors driving the change include movements at Earth's core, atmospheric changes and the moon's position.
But long-term trends do not suggest that the days will shorten in perpetuity. In fact, it is just the opposite. For many millenniums, the days have been growing longer. A Tyrannosaurus rex that lived 70 million years ago would have experienced an average daily rotation of about 23 1/2 hours, studies have found.
Re: wonder if ground water pumping had anything 2 (Score:2)
That would be moving mass outward from the axis. That would cause a slowdown not a speed up.
So would the icecaps melting and moving mass outward, btw.
Mass transfer to the polar regions on or near the surface would also cause a speed up. But my guess is all climate-related mass transfers on or near the surface pale in comparison to processes near the core.
Re: (Score:3)
Groundwater depletion doesn't slow the Earth's rotation, it increases it. When water is pumped from high altitudes and ends up in the ocean, it speeds up the rotation. But a bigger factor is when groundwater is pumped from tropical areas (India is the biggest pumper), and then spreads out over the global ocean, speeding up the rotation even more.
Melting mountain glaciers speed up the Earth's rotation, but melting polar glaciers slow it.
Thermal expansion of the oceans slows the Earth's rotation.
But the bigge
Re: wonder if ground water pumping had anything 2 (Score:1)
Is this feeble attempt to gesture at Thermodynamics predictive success as doomed to frustration as the prediction that the moon should be falling into the Earth but actually it's moving away from the Earth? How does Thermodynamics predict that mere movements on a gravitaional objects can contradict the often-taught principle that a body rotating another will eventually fall into it?
Re: (Score:3)
sounds suspiciously like people in the government doing science work and that's verboten. turn those nerds into ICE deputies.
"Sir, we need to know how fast the earth spins so we can aim our missiles."
Very well then. Carry on, ensign.
It just feels that way (Score:5, Funny)
Headline soon (Score:3)
T-Rex complained about there not being enough hours in a day to do everything. Wished days were about 1/2 hour longer!!!
impressive (Score:1, Funny)
It's the cats (Score:3)
"So far" ?! (Score:2)
So far this year ? This century ? Ever ?
Science articles deserve scientific language, FFS.
Re: (Score:2)
"the shortest days of the year so far."
So far this year ? This century ? Ever ?
I'm going to go with, since 1 Jan 2025, i.e., the year so far.
Science articles deserve scientific language, FFS.
It's the New York Times, not a scientific journal.
Re: (Score:2)
> It's the New York Times, not a scientific journal.
It's an article about climate science.
It's a "science article".
It deserves scientific language.
rotation is not 24 hours or anywhere near it (Score:2, Informative)
with respect to the background stars, the Earth's rotation is 23 hours, 56 minutes, and 4 seconds. Not some milliseconds less than 24 hours! I can't believe anyone thought it was 24 hours, such basic things were taught in school when I was a kid.
Re: (Score:1)
and if you go by "solar day", getting the sun to same position in sky, that varies because of the elliptical orbit around the sun, from 21 seconds less or 29 seconds more than 24 hours throughout the year.
Now the "mean solar day" is another matter and very near 24 hours, but the article didn't explain or mention that.
Re: (Score:2)
And that measurement will be equally shorter now too.
There are Possible Real-World Consequences (Score:2)
In 2023 this scientific article [insidegnss.com] concluded "we are almost as likely as not to experience a negative leap second in the next 12 years." Check out Figure 4 to see the UTC-UT1 line curve back downward in a way that's never happened before since atomic time started in 1972. It's currently back in negative territory at -0.05s and, if makes it far past -0.5s, we'll need a negative leap second. Even the occasional positive leap second has caused software glitches in the past so an unprecedented negative leap sec