The cesium atomic clock in Braunschweig, Germany, is in error by one second every two million years.
Physicists have measured and compared the world’s most accurate atomic clocks to an unprecedented level of accuracy, which is important for exploring dark matter, spacecraft communications and more.
An atomic clock is a device that calculates and maintains Time accuracy at the frequency of atomic oscillations. It is now the world’s most accurate timekeeping device and the benchmark for international time and frequency conversion, and signals such as television, radio and Global Positioning System (GPS) satellites are controlled by atomic clocks.
Researchers at the National Institute of Standards and Technology (NIST) and the Boulder Atomic Clock and Light Network (BACON) have collaborated to compare, for the first time, atomic clocks that use three different atoms to calculate time, raising the ratio of the differences between them to nearly ten times their previous levels. The results of this experiment were published March 24 in the journal Nature.
For this experiment, the aluminum and ytterbium clocks were located in two rooms inside the National Institute of Standards and Technology building in Boulder, Colorado, and the strontium clock was located 1.5 kilometers away at the Joint Institute for Laboratory Astrophysics (JILA), another physics research facility also in Boulder. Institute (JILA), also in Boulder.
David Hume of the National Institute of Standards and Technology, the study’s lead author, said in a press release, “These results are the most advanced results available today from comparisons performed both in fiber optics and airborne propagation, and are both about 10 times more accurate than any atomic clock comparison previously used.”
What is a second
Conventional atomic clocks commonly use cesium atoms, which oscillate about 9 billion times per second. The new atomic clocks introduced in this experiment are much faster, at about trillions of times per second.
So fast that it is no longer possible to count with conventional electronic devices. One of the participants in this study is located in New Mexico Space Dynamics Laboratory (Space Dynamics Laboratory) physicist Leopardi (Holly Leopardi), said they designed a method to convert these ultra-high frequency light waves into a controlled, easy to measure form.
Frequency ratios of different classes of atomic clocks
Using this method, researchers can compare the ratios of the oscillation frequencies of different atomic clocks. In simple terms, for example, if one device oscillates three times and another oscillates twice in the same amount of time, then the frequency ratio of the two devices is 1.5.
The researchers operate these atomic clocks continuously for 10 to 17 days, constantly measuring and comparing their frequencies, and raise this ratio from the current 17 decimal places, to 18 decimal places.
What is the use of such a comparison?
Satellites and global positioning systems (GPS) now rely on atomic clocks to determine precise time. Lead contributor Hume says, “You won’t feel any difference in everyday Life, but there is an important role for the precise definition of a second of time.”
The oscillation ratio between different types of atomic clocks should be fixed, so the ratio of ytterbium to strontium atomic clock frequencies should be the same in Boulder as in any other part of the world. This has important implications for the calibration of all atomic clocks located around the world.
Exploring dark matter
Scientists believe that up to 85 percent of the matter in the universe is not made up of matter that science has now detected, which is collectively referred to as “dark matter. However, to date, no single substance or particle has been identified as making up dark matter.
The research suggests that dark matter, as it travels through the Earth at the speed of light, is likely to slightly change some fundamental physical constants, such as the value of the fine structure constant, and that such changes could be detected by atomic clocks deployed around the world.