How the U.S. Built the World's Most Ridiculously Accurate Atomic Clock

Throw out that lame old atomic clock that's only accurate to a few tens of quadrillionths of a second. Atomic clocks are responsible for synchronizing time for much of our technology, including electric power grids, GPS, and the watch on your iPhone. 3, the National Institute of Standards and Technology in Boulder, Colorado officially launched their newest standard for measuring time using the NIST-F2 atomic clock, which has been under development for more than a decade. “NIST-F2 is accurate to one second in 300 million years,” said Thomas O’Brian, who heads NIST's time and frequency division, during a press conference Apr. Your smartphone doesn’t display the time to the sixteenth decimal place, but it still relies on the frequency standards coming from NIST's clocks, which make their measurements while living in a tightly controlled lab environment.