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China's Atomic Clock in Space Will Stay Accurate For a Billion Years (rt.com)
The space laboratory that China launched earlier this week has an atomic clock in it which is more accurate than the best timepiece operated by America's National Institute of Standards and Technology, according to Chinese engineers. The atomic called, dubbed CACS or Cold Atomic Clock in Space, will slow down by only one second in a billion years. In comparison, the NIST's F2 atomic clock, which serves as the United States' primary time and frequency standard, loses a second every 300 million years. From an RT report:"It is the world's first cold atomic clock to operate in space... it will have military and civilian applications," said Professor Xu Zhen from the Shanghai Institute of Optics and Fine Mechanics, who was involved in the CACS project. An atomic clock uses vibrations of atoms to measure time, which are very consistent as long as the atoms are held at constant temperature. In fact, since 1967 the definition of second has been "9,192,631,770 vibrations of a cesium-133 atom." In a cold atomic clock, the atoms are cooled down with a laser to decrease the effect of atom movement on the measurements. CACS goes even further and eliminates the pull of Earth's gravity by being based in orbit.
Well the atomic clock won't last that long see that second offset!
Because the satellite will come down in 10 years, maybe 20 anyhow.
CACS goes even further and eliminates the pull of Earth's gravity by being based in orbit.
Yeah, spot the glaring contradiction in that sentence. Hint: you can be free of the pull of Earth's gravity, or you can be in orbit around Earth... but not both!
AntiFA: An abbreviation for Anti First Amendment.
I don't want to be late for my dentist appointment in the year 1,000,002,017.
This must be a pet project of White Rose.
Can you read the time in chinese?
Why did they put it in a satellite lasting under a millennium in lifespan?
So are our electronic devices going to be able to receive a signal and sync wirelessly?
The description is incorrect: CACS is more accurate than the NIST F2 but is 15 times less accurate than NIST's strontium clock. See the article below and the referenced journal article.
http://www.theverge.com/2015/4/22/8466681/most-accurate-atomic-clock-optical-lattice-strontium
No it won't. It will be broken within 30 months. Count on it.
It sync with your smartphone using the new BluTooth LEO standard
So, how do they compensate for space time dilation?
I don't read your sig. Why are you reading mine?
The atomic called, dubbed CACS or Cold Atomic Clock in Space, will slow down by only one second in a billion years.
If they know it's going to slow down, and by one second, why don't they just add a billionth of a second a year?
I assume what was meant was "drift by at most one second."
systemd is Roko's Basilisk.
Mr. President, we must not allow an atomic clock gap!
If Slashdot were chemistry it would look like this:Cadaverine
The key to successful journalism is understanding that adding "...in space" to anything makes it more interesting. If I say, "I just drank a bottle of beer", it's boring. If I say, "I just drank a bottle of beer...in space" it's suddenly more interesting.
Try it yourselves at home. Make a boring declarative statement and add, "...in space" to the end and see if it hasn't become more interesting.
Now that I think about it, adding "...for a billion years" will have the same effect. If I say, "I just took a nap on the sofa", it's like, who cares? But "I just took a nap on my sofa...for a billion years" and it gets your attention.
Now, having said all that, this Chinese clock...in space that will last...a billion years, like who the hell is going to check that this clock is going to still be accurate in a billion years? You might as well say, "a Chinese clock built in space will turn into a galaxy-sized replica of a vagina in...a billion years". You would be approximately as accurate as this stupid-ass headline.
You are welcome on my lawn.
In the coming decades, the Chinese will easily eclipse the US in being insufferable, jingoistic dicks.
It probably won't stay that accurate for that long either if it is in space because it is in a different frame of reference and so relativistic effects, including those from general relativity, will build up. This is why the GPS satellites have to have their clocks corrected to stay accurate within the tolerances required. The shift per day for GPS is around 38 microseconds per day which if it is the same for this satellite means that in 26,316 years the clock will be off by one second. This is still a long time but a lot, lot less than 1 billion years.
You mean that they haven't already, w/ those South China Sea islands, and all that?
Like, seriously, 1 second in 300 million year is more than enough. The difference it will make during our lifetime... or our children's lifetime.. and their children's lifetime, etc etc for at least 50+ generations, is so negligible it literally makes no difference at all. What could possibility need that Planck second difference to operate accurately... Beside, in a few years you just know some mcdbag somewhere will come up with an atomic clock that's supposedly accurate for 10 billion years rendering the current ones pointless anyway.
And for pedants: Yes, technically nothing in the observable universe is theoretically "free" of Earth's gravitational influence
Actually if you want to be extra pedantic that may not be quite true. Parts of the universe which we can observe today (and so are in the observable universe) may by now be causally disconnected from us due to the accelerating expansion of the universe and so no longer feel the Earth's gravity. Of course we really don't know too much about what is driving the acceleration so perhaps this does not apply but it just goes to show that it is best not to make sweeping statements about the universe when we know so little about it: at least 95% of what it is made of is so far unknown to science.
Want to bet?
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
their next missile to space to destroy a spy satellite they don't want falling to earth hits the clock instead of its intended target.
With relativity, it will actually stay accurate for 0 seconds relative to all other mass.
So they just have to correct it by a second 5 times before the Sun explodes.
"It is the world's first cold atomic clock to operate in space."
Is it really the worlds anything if it's in space??
120 characters ought to be enough for anyone
Any piece of shit tech made by the mother fucking asshole cheating liar fuck puke piece of shit low life scum asshole CHINESE motherfuckers wont last a day.
The fucking chinese are dog shit and motherfucker liars. Fuck Jack Ma. Fuck China. Fuck their plastic shit. FUCK YOU CHINA.
A chinese atomic clock that isnt stolen technology? It will be wrong every god damn time someone looks at it. FUCK YOU CHINA.
LEO (Low Earth Orbit) requires a velocity of 7.8 km/s. The surface of the Earth (at the equator) rotates at a bit under 0.5 km/s. So the relative difference in speed is 7.3 km/s.
At that speed, the time dilation effect due to relativity is sqrt(1 - v^2/c^2) = 0.99999999970353434
So an atomic clock in LEO will run slower than one on the ground, losing 1 second every 3373072286 seconds, or 1 second every 106.96 years. You can compensate for that with a math correction which takes into account relativity. But that kinda defeats the purpose of building an "accurate" atomic clock, no?
It's a gum cleaning
Table-ized A.I.
a) "accurate" is not tied to "1 second" it may be - depending on application - a microsecond or a millenium.
b) it will not stay accurate for a billion years because it will fail before that time - and probably it would have be maintained (power, helium etc) much ealier.
The Chinese plan to improve their BeiDou Navigation Satellite System with synchronization signals from the new orbital atomic clock.
I'm thinking a clock accurate to 1 second every 1,000,000 years would more than suffice. Am I wrong?
So it will break down from some stupid cheapness in material or manufacturing defect in a few months
It is not that in a billion it will lose 1 second. It is that the accuracy is +-1E-9 s/year.
No one cares if it lasts a billion years.
Calm. Down. Before. You. Explode. Thank. You.
Clocks... In... Sssspppppppaaaaaaaaacccccceeeee!!
I, likewise, have built a clock that will lose nary a second in a billion years. I offer it up now to the highest bidder, bidding starts at one million dollars, a pittance, I know.
I guarantee this clock will not lose even a single second over a billion years, employing such principles as the law of averages.
The clock may run fast or slow for periods during the interval, but, HOWEVER, on AVERAGE, it will not lose even a second over a thousand years.
You can file a claim for a grievance under the terms of the warranty, if AFTER a billion years, it has NOT kept accurate time.
Having worked on these, the MTBF was usually between 50 and 80 years, which is impressive but nowhere near a billion years.