To keep things in perspective, a vertical shift of a few centimeters could be measured if two of these clocks were placed next to each other, just by the lesser gravity/time dilation at the increased "altitude".
It's an amazing time to be alive. While not this precise, you can have atomic cesium beam clocks of your own for a few thousand dollars each, and some elbow grease.
Wondering if we could spatially place a bunch of these to make a time based gravitational wave detectors. A single location could infer magnitude, and direction of a gravitational wave.
I propose calling it TIGO(Time Interferometer Gravitational-Wave Observatory) ;-)
I wonder how many more orders of magnitude of precision will be realistically possible. I wonder if we'd ever be able to use gravity to "see" things at non-cosmological scales, like if you could resolve the gravitational waves and interference patterns caused by a person walking by.
The article is very good and has some cool pictures of the device. Aluminum is apparently just better than cesium but harder to use and now they have solved the problems preventing it from being the standard.
Somewhat topical: in case you want authenticated access to NIST NTP servers, you need to send a letter to NIST using the US mail or FAX machine (e-mail is not acceptable).
NIST will reply with a key number and a key value. The reply will be by US mail only, e-mail will never be used.
The office that normally receives US mail and FAX messages currently has limited access, which may result in significant delays in processing requests
I left a comment on the first that summarizes the second one, which describes how they're working on a new type of atomic "nuclear" clock based on the atomic nucleus instead of electron orbitals. It doesn't mention the accuracy, I wonder how it would compare to this "ion" clock.
That's great and all, but stepping back a bit: the US (and the West?) seems to be falling behind in distribution and resiliency. For high-accuracy timing stuff, China has space (BeiDou), terrestrial broadcast (eLoran), and fiber in production:
If I'm not mistaken this improves a critical bottleneck on GPS precision, solutions to which will open up amazing applications. Driving lane boundaries just being one example.
as a layman, wouldn't you need a more-accurate clock to measure the accuracy of a clock? How is clock accuracy measured when the clock is the most accurate clock?
24 comments
[ 2.9 ms ] story [ 48.4 ms ] threadIt's an amazing time to be alive. While not this precise, you can have atomic cesium beam clocks of your own for a few thousand dollars each, and some elbow grease.
I propose calling it TIGO(Time Interferometer Gravitational-Wave Observatory) ;-)
https://arxiv.org/abs/2504.13071 ("High-Stability Single-Ion Clock with $5.5\times10^{-19}$ Systematic Uncertainty")
NIST will reply with a key number and a key value. The reply will be by US mail only, e-mail will never be used.
The office that normally receives US mail and FAX messages currently has limited access, which may result in significant delays in processing requests
https://www.nist.gov/pml/time-and-frequency-division/time-se...
(things you discover when you implement fedramp)
New atomic fountain clock joins group that keeps the world on time (nist.gov) | 118 points | 76 days ago | 33 comments | https://news.ycombinator.com/item?id=43831792
Major leap for nuclear clock paves way for ultraprecise timekeeping (nist.gov) | 12 points | 7 months ago | 10 comments | https://news.ycombinator.com/item?id=42362215
I left a comment on the first that summarizes the second one, which describes how they're working on a new type of atomic "nuclear" clock based on the atomic nucleus instead of electron orbitals. It doesn't mention the accuracy, I wonder how it would compare to this "ion" clock.
* https://rntfnd.org/2024/10/03/china-completes-national-elora...
As we've seen regularly, GPS/GNSS has major risks with it, and it seems to have become a single point of failure:
* https://gpsjam.org
* https://www.marineinsight.com/shipping-news/msc-container-sh...
* https://gcaptain.com/gps-jamming-in-strait-of-hormuz-raises-...
Please don't let them embezzle the future of scientific innovation.
> NIST researchers have made the most accurate atomic clock to date — one that can measure time down to the 19th decimal place.
That's precision, not accuracy.
I briefly worked at NOAA, on this same campus, and I loved walking around NIST. Such a cool building. The entire campus is at risk -> https://www.cpr.org/2025/07/01/proposed-noaa-budget-would-cl...
Is there a meaningful pattern or logic to explain the combination of potential closures alongside new construction?