To mark the time, you can track the height of the sun in the sky or the seasons. Or, you…
To mark the time, you can track the height of the sun in the sky or the seasons. Or, you can measure vibration of an atom.
This is what researchers have done at the National Institute of Standards and Technology (NIST) in Maryland, creating two bells, each of which precipitates 1000 atoms of ytterbium element in laser networks. These lasers can measure the vibration of the atoms with almost perfect accuracy (there is about one billionth of a billion chance.)
Scientists have measured time in nuclear vibration, not only to prove themselves, but because the scientific definition of one second is determined by the frequency of these vibrations. As Katherine Foley wrote in Quartz, researchers in 1
967 defined a second as “9 192 631 770 radiation periods” of an atom of the isotope cesium-133 atom at absolute zero temperatures.
The research behind the atomic watches, published in Nature on November 28, shows that not only the units are very accurate, they also stand out in other clock evaluation measures: Stability (how much the clock’s frequency changes over time) and reproducibility (how close are the two bells at the same frequency). The scientists behind these watches have created atomic watches earlier, but their latest version is even more accurate, thanks to partial thermal and electrical shielding, which protects atoms from external electric fields.
In fact, they are so accurate that they show the gravity effect, as predicted by Einstein’s theory of relativity: the stronger gravity’s traits are, the slower the vibrations of atoms and the passage of time. This means that the watches not only show time, but also their distance from a center of gravity. They effectively measure the space-time continuum.
This means that they can, for example, be used to measure the shape of the earth perfectly, as gravity becomes stronger as you get closer to the core of the earth. The clock’s sensitivity to gravity also theoretically means that they can be used to detect the presence of dark matter. We do not know what dark matter is, but we know it is distorting gravity, and these bells can potentially retrieve it.
Currently, these watches are too big for transport. But NIST researchers build a portable version that can be used to measure time around the world. Effectively, they will be able to show exactly where time goes slower, down to the slightest vibration of the atomic era.