These hours are so accurate they will lose only half a second if the age of the universe lasts. That's 14 billion years.
But they're not used to running trains on time. The perfect accuracy of the hours, which is today described in Nature, means they can measure how spatial time interferes with gravitational forces.
Astrophysicists could eventually get help in detecting mysterious dark matter.
Instantly, the clock could tell us what is happening within the country by accurately mapping the shocks and graves of our planet – if the watch is shortened.
Study co-author Will McGrew, a PhD student at the National Institute of Standards and Technology in the United States, said "clock ticking" is produced by oscillating radiation when electrons in ytterbi atones are excited by lasers.
It turns out that in near perfect similarity ticks 500 trillion times per second.
"Measuring time and frequency with such unbelievable precision provides a really powerful lens for viewing the natural world," said Mr. McGrew.
Atomic Time 101
The measurement time was based on astronomy. For example, the length of the day was determined by one rotation of the Earth on its axis.
But astronomical phenomena usually slow or accelerate.
Our days are extended by another 1.7 milliseconds of every century thanks to our gravity tang with moon.
So while astronomical time can do for timing and the like, science requires precision.
And that's the time when the atomic time is on.
Rather than looking at the heavens, this form of timing exercise in the waves of radiation interrupted atoms as they bathed in the laser light.
It sounds super futuristic, but atomic clocks are for over 60 years.
The first atomic clocks, which were accurate enough to be used to set time, were built in 1955 in the British National Physical Laboratory.
It was accurate to the other for 300 years.
About 12 years later, cesium atomic clocks have become an international time standard, and in time atomic clocks have become much more accurate.
Modern atomic clocks that use strontium or ytterbium instead of cesium lose one second every 300 million years.
More than time holders
Atomic clock accuracy means that they have tested the general theory of relativity by Albert Einstein, which predicts that time is running faster or slower under the influence of different gravitational forces.
In other words, clocks on a satellite orbiting Earth, which records a higher "gravitational potential", tick more quickly than hours at sea.
And there are already atomic clocks that appear on Earth on satellites that use this time-wasting effect.
The Global Positioning System or GPS should not be without them.
Another use of satellite atomic clocks is the precise mapping of the Earth's size, shape, orientation in space and mass distribution, collectively called "geodesy".
Satellite geodesy usually includes the timing of how long it takes light to make the way between distant points, for example, light up the laser to satellite and timing, how long it takes before it bounces back to the receiver on Earth.
GPS geodesy is accurate to about one centimeter, said Matt King, who uses the satellite geodetic at the University of Tasmania and did not participate in the study.
Clocks with a higher "tick" – that is, higher frequencies – should not use light at all. They can use the relativistic effects of gravity.
What Mr. McGrew and his colleagues wanted to achieve with atomic clocks.
Cesium instead used ytterbium. The radial waves emitted by ytterbia atoms oscillate almost five orders faster than cesium atoms.
In the article, it turned out that the hours are exceptionally stable – losing or getting time almost imperceptibly – almost perfectly quiet.
So by comparing the difference between two ytterbi clocks on separate continents, one could measure the height difference between hours below the centimeter.
Using precision ultra-sensitive atomic clock would be like having a "telescope that looks inside," said Professor King.
"Let's say you have an earthquake," he said.
"If you can do that, you can learn about the principles of the interior of a country, such as its viscosity or outburst."
As Earth reflects when the glaciers melt or fall when groundwater depletes, it can be watched by atomic clocks.
And when he sees how the country around the volcano rises and falls, even on a subcentile scale, Volcanologists can tell how the magma moves down, Professor King added.
"Combine it with seismology and get a real picture of what's going on inside."
Large applications, compact clocks
So what stops atomic clocks that are brought to volcanic and earthquake-risky places all over the world?
Simply, ytterbium clocks are great to move.
"[The clocks] basically taking over a relatively large lab, "said Mr. McGrew.
It's because they need a lot of big lasers to work.
Some lasers cool ytterbia atoms to a fraction above absolute zero (-273 degrees Celsius), while others keep the cooled atoms in place.
Mr. McGrew and his colleagues have already begun to work on shrinking systems.
Professor King is optimistic that ultra-precise atomic clocks will one day be compact enough to be used on Earth and in space.
"Computers were used to fill the room as well.
"We could be 20 years old, it could be earlier, but if it were [ytterbium clocks] can be miniaturized and if accuracy is still increasing, there is no lack of requests. "
Strange and beautiful
By the way, atomic clocks can be used for experiments that involve measuring the smallest deformations in space-time, such as incredibly fine stretching and crushing of mass caused by gravitational waves.
Take, for example, dark matter. Astrophysicists know that dark matter is out and that they make up about a quarter of all matter and energy in the universe.
But its "dark" nature – that does not seem to reflect, absorb or emit radiation – means it is very difficult to uncover it.
One model of dark matter suggests that it could interact with ordinary matter by changing basic natural constants, said Mr. McGrew.
And that's where atomic clocks can help astrophysics learn something about elusive things.
"Let's say there's a big dark matter object going through a lab that has yterbi's clocks and strontium," said Mr. McGrew.
"[The dark matter] would influence yterbium by some factor and then strontium by another factor.
"By measuring the difference between these two hours, you can determine the presence of the dark matter object.
"These are very fine effects, but when you can make measurements with 18 digits of accuracy, you can reveal them."
And, of course, there are intentions we have not even dreamed about.
"People who first made atomic clocks did not know they were building GPS devices," said Mr. McGrew.
"I think there is something similar to what can be said about atomic clocks – that their most important and most important applications have not yet been thought of."