An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
The rate of clocks, according to Einstein's theory of relativity, is influenced by the gravitational potential and relative motion of the clocks. A grid of
Gregory Hoth, Bijunath Patla, Neil Ashby, Vladislav Gerginov
The microwave cavities of NIST-F1, the cesium fountain primary frequency standard at the National Institute of Standards and Technology (NIST), have been
Gregory Hoth, Bijunath Patla, Neil Ashby, Vladislav Gerginov
We are in the process of re-evaluating NIST-F1, the cesium fountain primary frequency standard at the National Institute of Standards and Technology (NIST)