https://phys.org/news/2025-04-compact-optical-clock-quantum-frequency.html
Someone answer a question? It said stability at 10 ^-11 at 10,000 second level. I did some arithmetic and came out with an accuracy of one second off in 30 million years. Does that sound right?
The atomic clocks we used at NASA in my job in the Apollo days, Apollo Timing and tracking, was accurate to about one second in 3000 or so years, off the shelf Hewlett Packard 5060A clocks. The need for atomic clock timing was just to allow switching of radio dishes so data would not be lost when Apollo would have to switch dishes, say from Africa to Goddard or whatever because the Earth turns on its axis so any given dish would lose signal and the switch time had to be done within 100 microseconds going from one dish to the next so those old 5060 HP clocks were plenty accurate enough for that job. Back then the data rates were really slow compared to today's sats and probes so the switch times between dishes now must be made in terms of nano seconds when the data rates are measured in millions of bits per second compared to thousands of bits per second in Apollo times.
So am I right this present work to chip level clocks really like way over a thousand times more accurate than those old HP clocks? Cesium beam clocks ATT.
Looking at a blurb about modern HP clocks, looks like the actual accuracy hasn't changed much, still using cesium beam technology and still 3K/ years per second accuracy.
I would have thought they would have evolved a lot more in 60 years. They first came on the market in 1964.
The newest tech use optical frequency combs and a portable unit clocks in at one second in 50 BILLION years:
https://physicsworld.com/a/portable-optical-atomic-clock-makes-its-commercial-debut/
But that is not chip level, more like the size of a hard drive. Still pretty damn good!
Clocks like that used in GPS could make GPS position accuracy measured in centimeters rather than a couple of meters as they sit now.
Don't know when these new optical clocks will hit the GPS systems though.