The NIST Time and Frequency Division is one of the unsung heros of physics. Their senior guy, Wineland, got the 2012 Nobel Prize. I remember when the current P

The NIST Time and Frequency Division is one of the unsung heros of physics. Their senior guy, Wineland, got the 2012 Nobel Prize. I remember when the current Primary Standard, NIST-F1, was meeting the press in the late 90s. I was in undergrad and one of their junior guys came through interviewing for a faculty job. His lecture remains one of the most memorable hours of my life. Probably helped by the fact that I had just heard about the F1 in Scientific American a few weeks prior. It is unclear that this particular clock will take over as the Primary Standard, whose data is compared to a competing project in France and coordinated with the astronomical measurements at the US Naval Observatory to construct the Universal Coordinated Time standard. That is then what the USNO transmits to coordinate the GPS satellites, radio services, etc. http://www.nist.gov/pml/div688/ http://www.nist.gov/pml/div688/