Nist Greg Hoth and Vladislav Gerginov scientists work at Nist-F4, the new Nist clock-one of the most accurate atomic clocks ever created
The new cesium clock of the National Institute of Standards and Technology is one of the most accurate atomic clocks ever created. It only delays 1 second in every 100 million years.
Scientists have developed one of the most accurate atomic clocks ever built and plan to use it as a reference watch to define its own time.
The new atomic clock NIST-F4 It is based on the climb and descent of cesium atoms under a microwave beam.
This clock is so reliable that if it had started to work when dinosaurs existed 100 million years ago, it would have a detour less than one second today.
Watchmakers, scientists from the National Institute of Standard and Technology (NIST) in Colorado (USA), recently, in Metrology magazine, the details about the functioning of NIST-F4.
In operation since April 2025, the new clock is now waiting for approval before joining about 450 other watches around the world in defining the Coordinated Universal Time (UTC) – the overall system to measure the ultra -prepressive beat of a second.
As explained by, Nist-F4 is a type of atomic clock known as a source clock, which contains a cloud of thousands of cooled cesium atoms up to almost the absolute zero using lasers. Atoms are thrown up under the impulse supplied by a pair of laser beams and then fall under their own weight as they pass a tuned microwave beam to make the atoms oscillate.
Tell this frequency (which occurs 9,192,631,770 times per second) Allows scientists accurately define the second international.
But this is the relatively simple part, points the same magazine.
To ensure the reliability of NIST-F4, scientists had to take into account all tiny noise sources that could affect cesium atom vibrations. These include quantum interference with other atoms; microwave escape and lens effects; and subtle distortions in the electromagnetic fields generated by lasers.
In, Nist clarified that the result was a watch with a Total systematic uncertainty of 2.2 × 10⁻¹⁶ – A precision that means he loses less than one second every 140 million years.
