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Earth's Day Lengthens By Two Milliseconds a Century, Astronomers Find (theguardian.com)
Researchers at Durham University and the UK's Nautical Almanac Office compiled nearly 3,000 years of celestial records and found that with every passing century, the day on Earth lengthens by two milliseconds as the planet's rotation gradually winds down. The Guardian reports: The split second gained since the first world war may not seem much, but the time it takes for a sunbeam to travel 600km towards Earth can cost an Olympic gold medal, as the American Tim McKee found out when he lost to Sweden's Gunnar Larsson in 1972. For those holding out for a whole extra hour a day, be prepared for a long wait. Barring any change in the rate of slowing down, an Earth day will not last 25 hours for about two million centuries more. Researchers at Durham University and the UK's Nautical Almanac Office gathered historical accounts of eclipses and other celestial events from 720BC to 2015. The oldest records came from Babylonian clay tablets written in cuneiform, with more added from ancient Greek texts, such as Ptolemy's 2nd century Almagest, and scripts from China, medieval Europe and the Arab dominions. The ancient records captured the times and places that people witnessed various stages of solar and lunar eclipses, while documents from 1600AD onwards described lunar occultations, when the moon passed in front of particular stars and blocked them from view. To find out how the Earth's rotation has varied over the 2,735-year-long period, the researchers compared the historical records with a computer model that calculated where and when people would have seen past events if Earth's spin had remained constant. The astronomers found that Earth's spin would have slowed down even more had it not been for a counteracting process. Since the end of the most recent ice age, land masses that were once buried under slabs of frozen water have been unloaded and sprung back into place. The shift caused the Earth to be less oblate -- or squished -- on its axis. And just as a spinning ice skater speeds up when she pulls in her arms, so the Earth spins faster when its poles are less compressed. Changes in the world's sea levels and electromagnetic forces between Earth's core and its rocky mantle had effects on Earth's spin too, according to the scientists' report in Proceedings of the Royal Society.
I suggest we tie a string around the equator, then launch a mighty rocket into space that we've tied to the end.
I foresee no problems with this plan.
More irrefutable evidence of God's magnificence.
Earth spinning slows down? Must be a conspiracy theory from liberal lizard people. As far as we know, the flat plate known as the Earth haven't moved a bit at all, since its creation ~6000 years ago!
Is this a new record low for poor writing on slashdot? Gold medal for most tortured use of an tenuous comparison in a pointless comparison? Our judges are very excited...
We just passed a century mark.
"The split second gained since the first world war may not seem much, but the time it takes for a sunbeam to travel 600km towards Earth can cost an Olympic gold medal, as the American Tim McKee found out when he lost to Sweden's Gunnar Larsson in 1972."
The reason he lost was that he was slower. Its was just so little that with todays measuring it would be a tie since you do not measure in thousand any more. Trying to make it like he lost to a technicality is just sad.
my life? my pay? my vacation? all a lie?
atlast... I can enjoy my free days longer... oh sorry this aint 9gag....
Interestingly, this also has an effect on the moon. The reason why the earth's rotation is slowing are the tidal forces. Part of the energy lost from the Earth's momentum goes into the Moon's own orbit. As a result, the moon is actually getting further and further away from us, at a rate of 38 mm (1.5 in) per year. Somewhat counter-intuitively, the Moon actually gets slower that way, despite the energy put in is in the prograde direction, i.e. increases its velocity. The reason is the higher orbit. Sources:
Tidal effects on the Moon
Earth's rotation
Raising 39 trillion kilograms of water 175 meters above sea level will increase the Earthâ(TM)s moment of inertia and thus slow its rotation. However, the effect would extremely small. NASA scientists calculated that shift of such as mass would increase the length of day by only 0.06 microseconds and make the Earth only very slightly more round in the middle and flat on the top. It would shift the pole position by about two centimeters (0.8 inch). Note that a shift in any objectâ(TM)s mass on the Earth relative to its axis of rotation will change its moment of inertia, although most shifts are too small to be measured (but they can be calculated). http://www.businessinsider.com...
Howlin' Wolf asked How Many More Years?
Now I'm gonna ask how many more milliseconds!
I'm not sure I really understand the use of the Babylonian clay tablets for this - at best they'll tell you what day it happened, but we're talking about ~6000 years ago, so 60 centuries times 2 milliseconds, that's ... Did the Babylonians really calculate time in 1/100s of a second?
-=This sig has nothing to do with my comment. Move along now=-
I'd really like to see the end of using the AD and BC. We have BCE and CE that do not require invoking a mythological being.
Global time change is a lie created by the Chinese to fool westerners. They'll pretend they have two more milliseconds in the day, and do high-frequency trading during that time. After a long enough time, the Chinese calendar will no longer agree with the western one! It will mean chaos!
Earth's Day Lengthens By Two Milliseconds a Century, Astronomers Find
How could they let this happen? Damn right they should be fined!
systemd is Roko's Basilisk.
Everybody run towards the east, as fast as you can!
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
"every action has an equal and opposite reaction" space launches to the east use less fuel at the cost of slowing our spin.
https://www.quora.com/Why-are-satellites-launched-from-east-coast
Also one class of "free" energy device creates energy at the cost of causing drag to our planets dynamo, slowly slowing us.
Note not all free energy devices cause problems so don't automatically bash free energy, just understand how something works before creating it; for example a simple copper cone can create slight movement from quantum noise because particles that hit the inside bounce off it twice.
I must be missing something. The oldest records they observed were from 3000 years ago, i.e. 30 centuries, or 60 milli-seconds. How in heavens sake do they decide that the recorded eclipse was off by that little? Their article mentions "thousands of observations". Even assuming 10,000 observations, the time accuracy for statistically meaningful results would seem to be sqrt(10,000)*60ms or 6sec. No way the ancient observations were so accurate.
So ... that means by the law of opposites, the right lies by invention?
Well, it would explains religion and pizzagate, I give you that...
We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
Surely that means that current timekeeping practice is doomed in the fairly short term because we don't currently have a mechanism for adding more than two leap seconds in a year...
Righties lie by making false assertions and then saying "Prove it didn't happen". That's why they are such liars and fools.
I really wish the kerfuffle around "fake news" would shine a light on the fact that a lot of science "reporting" on the intertubes is mischaracterized or just plain wrong. This article is a perfect example. Every article I've seen on sites that are not hard science reports it as if the fact that the earth is slowing is a new discovery. It's not, we've known for decades (at least) that this was the case. The linked Guardian article doesn't even mention that until ten sentences into a fourteen sentence piece and about half the articles I've seen don't mention it at all. It's a result of tidal forces and can be worked out with newtonian dynamics. The news is that they updated the rate at which it's slowing.
I know a lot of people will rate this as a pedantic rant but the drive for "click bait" headlines is just as prevalent in mainstream reporting as it is in "fake news", "alt news", etc. and it has the same effect. People who are just skimming headlines (or even the first few paragraphs in most cases) are going to walk away with a information that is just wrong. For all the hype about the internet making information available to the masses a lot of times it seems it's actually dumbing down the world in general (but hey, we all know that Kim Kardashian can balance a champagne glass on her butt, so there's that).
There are no good US presidents. The presidency is a sham office. But if you want Biblical proof, Jesus said there is none good but God.
Tim McKee got silver in the 1972 Olympics (didn't qualify for a tie-breaker) because he was slower than his competitor... by less than a hundredth of a second.
But this really couldn't have much less to do with the story. It's a random fact, not on topic. TFA: WTF?
Did you use biblical and proof in the same sentance?
Now THAT is funny.
The article says 2 milliseconds per century, but we've already added 27 leap seconds since 1972 ..
So, what am I missing..?
ITYM west. Running the opposite way to how he turns will speed it up right?
"The split second gained since the first world war may not seem much, but the time it takes for a sunbeam to travel 600km towards Earth can cost an Olympic gold medal, "
What he/she said was, "Being second by a small amount of time will cause you to not be first"
I'm pretty sure being second by any amount of time, large or small, will cause you to not be first too.
I'm confused now. Top half run to the left, bottom half go right!
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
Comment removed based on user account deletion
Everybody run towards the east, as fast as you can!
We need to run east then suddenly all stop at the same time.
Top?
He's getting rather old, but he's a good mouse.
lettuce return to 1969
2 ms / yr = 5000 years for 1 second. How many leap seconds have been added?
Didn't Superman spin the Earth backwards by flying around it opposite to the rotation? That seems like it would work to speed it up if he flew the other way. Just need to contact Clark.
Overtime pay. But you can add it up and pay out just once a century.
Relatively speaking, there were some very good presidents. Relative to God's original creation, you're absolutely right.
I don't understand this:
"And just as a spinning ice skater speeds up when she pulls in her arms, so the Earth spins faster when its poles are less compressed"
Less compressed is spreading out, so the spin would be slower, not faster.
Atari rules... ermm... ruled.
Where the ice is!
Why would you contact Clark? He's just a reporter.
2 million centuries? Dang, that's like 2,000 kiloyears.
Global warming or climate change or what every they are calling it this month. Has nothing on earth slowing down. We are all going to fly off into space soon.
So 7,100 years from now we're gonna need one leap second per week, or 50 leap seconds at once at the end of each year, whichever is easier to organise. That's gonna be tough.
The article says 2 milliseconds per century, but we've already added 27 leap seconds since 1972 ..
So, what am I missing..?
Leap seconds (and leap years) are due to the number of rotations of the earth in a year not being exactly 365. If you think about it, why would they be. There is no reason the earth should rotate exactly 365 time in one trip around the sun. So, to keep December from gradually creeping into the summer, we have to fiddle a bit with the calendar.
In this case, we are just talking about the rotation speed of the earth. In a closed system, the rotation speed can be changed by moving the mass around the Earth, such as from the equator to the poles or from the the earth surface to under the surface. Changing the shape of the Earth is essentially the same as moving the mass around so would also affect speed (going from sphere to pair shape to ellipsoid).
Since we don't live in a closed system (e.g. the moon is out there), one can also change the earths rotation speed by adding (or in our case with the moon) taking away momentum. So this also affects the rotation speed.
Microseconds, not milliseconds. Here's a good read about the impact of major quakes on the Earth's rotation
For all intensive purposes, "whom" is no longer a word. That begs the question, "who cares"?
I believe the article is missing a clear indication that "2ms/century" is the rate at which the length of a _day_ is increasing. So it really means "the lengthening of a day is accelerating by 2ms/day/century". And like in distance, the acceleration doesn't tell you how much something changed by itself, you have to know what the starting rate of change was.
was!
NB: The message above might reflect my opinion right now, but not necessarily tomorrow or next year.
Presumably such an event was newsworthy.
Actually, just get a big bulldozer and shove a few mountains away from the equator.
Fixed!
Didn't Superman spin the Earth backwards by flying around it opposite to the rotation? That seems like it would work to speed it up if he flew the other way. Just need to contact Clark.
I always thought that too, but apparently from reading articles about the movie more recently, they were trying to show him flying so fast that he went back in time (supposedly just going around the Earth so he didn't get lost).
Didn't Superman spin the Earth backwards by flying around it opposite to the rotation? That seems like it would work to speed it up if he flew the other way. Just need to contact Clark.
I always thought that too, but apparently from reading articles about the movie more recently, they were trying to show him flying so fast that he went back in time (supposedly just going around the Earth so he didn't get lost).
So how did they explain away the Earth actually stopping, then reversing its rotation, which would have been more disastrous than the nuke detonating on the San Andreas Fault?
This space unintentionally left blank.
Didn't Superman spin the Earth backwards by flying around it opposite to the rotation? That seems like it would work to speed it up if he flew the other way. Just need to contact Clark.
I always thought that too, but apparently from reading articles about the movie more recently, they were trying to show him flying so fast that he went back in time (supposedly just going around the Earth so he didn't get lost).
That's how Superman travelling backwards in time would see the Earth. As time stopped for him, so would the spinning of the Earth. As he moved backwards in time, the Earth would appear to move in reverse and all the actions would be shown like a movie being played backwards as they appeared in the film.
So how did they explain away the Earth actually stopping, then reversing its rotation, which would have been more disastrous than the nuke detonating on the San Andreas Fault?
The bit where Australia isn't.
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
Is it possible that the slowing down side or direct effect is effecting climate? That slowing down would manifest itself as resulting in hotter summers and colder winters.
No. Climate would happen anyway.
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
Erm... A century contains 36500 days... not 365. That's a year. And every 4th year has 366 days. So that's 25*366 +75*365 = 36575 days in a century.
You may want to correct the rest of your maths to account for there being more than 100 times more days in that period than you counted.
You might want to double check your math too. Just saying. (36525)
There are sporadic shifts in the position of the rotation axis too - each major earthquake moves the axis, and this has been detected repeatedly since the 1960s whenever there is a large (M8+) earthquake.
Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
2 milliseconds per day per century,
A change of 2ms per day would add up to a difference of 1s in about 500 days.
I make the Julian Day for 1972-01-01 (ISO8601) to be 2441318 and for 2017-01-01 to be 2457755 (because I've done the legwork previously for calculating Julian Days) for a difference of 16437 days. At about 1 second per 500 days, then there should have been about 32 or 33 leap seconds since 1972-01-01.
given that tidal couping between Earth and Moon is somewhat variable (it depends on what you could well describe as the friction between the oceans and their coastlines, which is at least weather dependent. Shape of the Erth (therefore earthquakes) have a noticeable effect too.
Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"