MIT physicists improve the precision of atomic clocks
1–10 of 43 posts
Re: MIT physicists improve the precision of atomic clocks
#2I’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.
Re: MIT physicists improve the precision of atomic clocks
#3"Improve" means nothing unless you give a number.
Re: MIT physicists improve the precision of atomic clocks
#4I’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 t…
Since their precision is essential to measuring relativistic effects, I'm not sure we're near that limit.
For your precise question, it may already be there.
Re: MIT physicists improve the precision of atomic clocks
#5When 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.
Re: MIT physicists improve the precision of atomic clocks
#6I’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 t…
I know that Google's Spanner[0] uses atomic clocks to help with consistency.
Re: MIT physicists improve the precision of atomic clocks
#7When 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 colle…
This topic of time being a western construct, it's impact on society and life is one of the subjects in the excellent book "Borderliners" [1] by Peter Høeg. A favorite of mine, though I never read the English translation.
It's a fascinating topic, and impacts our live more than we might be aware of or care to admit. I started thinking about it in a different way after reading this book.
Re: MIT physicists improve the precision of atomic clocks
#8"Improve" means nothing unless you give a number.
straight from the abstract:
> we can demonstrate quantum-amplified time-reversal spectroscopy on an optical clock transition that achieves directly measured 2.4(7) dB metrological gain and 4.0(8) dB improvement in laser noise sensitivity beyond the standard quantum limit.
Re: MIT physicists improve the precision of atomic clocks
#9I’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 t…
It hit diminishing returns for most things long, long ago, but this physics is directly related to stuff in quantum computing and studying gravity.
Re: MIT physicists improve the precision of atomic clocks
#10I’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 t…
I guess very few systems have better absolute time than a few microseconds. Those systems are probably exclusively found in HFT and experimental physics.
This past week I tried synchronizing the time of an embedded Linux board with a GPS PPS signal via GPIO. Turns out the kernel interrupt handler already delays the edge by 20 us compared to busy polling the state of the pin. Stuff then gets hard to measure at sub microsecond scales.