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I’ve spent a decent chunk of my career wrestling with time sync — NTP/PTP, GPS, timezones, all that fun stuff. For real world network time infrastructure, where do we actually hit diminishing returns with clock precision? Like, at what point does making clocks more precise stop helping in practice?

Asking partly out of curiosity, I have been toying with a future pet project ideas around portable atomic clocks, just to skip some of the headaches of distributed time sync altogether. Curious how folks who’ve worked on GPS or timing networks think about this.

"Improve" means nothing unless you give a number.

Is this (the OT [1]) with ytterbium a more or less efficient way to count clock ticks with high precision than is described in [2]?

[1] "Quantum-amplified global-phase spectroscopy on an optical clock transition" (2025) https://www.nature.com/articles/s41586-025-09578-8

[2] "Quantum watch and its intrinsic proof of accuracy" (2022) https://journals.aps.org/prresearch/abstract/10.1103/PhysRev...

When I was in anthropology, many of the cultures I studied had very vague concepts of time (sunrise/sunset, passage of stars and constellations, different seasons). One of my professors spent two weeks about how time was a Western construct and how people want to go to such great lengths to have such precise measurement of it.

The very lengthy discussion around the concept was fascinating to me as a 23 year old college student who only knew it from one perspective.

They mention a "quantum noise limit", that must be the ultimate precision that is physically possible, right?

What is this ultimate precision? I imagine that at some point, even the most modest relative motion at ordinary velocities would introduce measurable time dilation at fine enough clock precision.