Atomic Clocks Make a Quantum Leap in Accuracy • Hacker News Board

Re: Atomic Clocks Make a Quantum Leap in Accuracy

#41

Post by MichaelGG » Wed, Jan 29, 2014, 9:24 AM UTC

grecy wrote: post #40

MichaelGG wrote: post #39

Earlier quoted context omitted.

Do you know of anything more accurate, especially under Hyper-V? I've tried installing ntpd and even using the most aggressive settings and host time sync off, they drift like mad and the system log is filled with kernel warnings about time changes.

If I have something that needs that level of accuracy, and the implied up time to go with it, I don't use Windows. Neither should you.

I guess I find it sort of amazing that Windows can ship in 2014 and not have close to ms accuracy.

Re: Atomic Clocks Make a Quantum Leap in Accuracy

#42

Post by dmd » Wed, Jan 29, 2014, 11:23 AM UTC

thearn4 wrote: post #4

Hate to be that guy when it comes to being pedantic about headlines, but wouldn't a `quantum leap` in accuracy be rather un-noteworthy?

You (and everyone else who is commented in reply to you so far) didn't read the article.

In this particular case it is a perfect use of the phrase, as the advance in accuracy is based on measurements of the atomic electron transitions, also known as quantum leaps.

Re: Atomic Clocks Make a Quantum Leap in Accuracy

#43

Post by grecy » Wed, Jan 29, 2014, 5:06 PM UTC

MichaelGG wrote: post #41

grecy wrote: post #40

Earlier quoted context omitted.

If I have something that needs that level of accuracy, and the implied up time to go with it, I don't use Windows. Neither should you.

I guess I find it sort of amazing that Windows can ship in 2014 and not have close to ms accuracy.

Not at all. I think that kind of thing highlights where Microsoft's priorities are with Windows, and therefore the kinds of things you should be doing with it.

If you buy a civic to take to the racetrack, you shouldn't be amazed it doesn't come with a roll cage. Civics are supposed to be on racetracks, and windows isn't supposed to be a serious-workload OS. It's no problem though, you have plenty of alternatives for both.

Re: Atomic Clocks Make a Quantum Leap in Accuracy

#44

Post by ChuckMcM » Wed, Jan 29, 2014, 6:16 PM UTC

Daniel_Newby wrote: post #36

ChuckMcM wrote: post #29

At this level of accuracy things are pretty strange. It used to bug me when you had to tune RF circuits at a distance with non-conductive tools because your body capacitance would throw the tuning off. Having a clock that just being near it will change what time it reads, well that is a whole different ballgame of weird is it not? On a science note, why isn't this a gravity wave detector anyway?

Gravity wave detectors get phase accuracy by comparing a photon to itself using an interferometer. SNR is improved by brightening the laser and averaging over more photons. The laser frequency is less important. It turns out there are some ultraviolet nuclear transitions. The line widths promise to be obscenely narrow. If they can get it working in a clock, they will be able to directly measure gravitational time dil…

Do you have a reference to the UV transitions? I'm sure the LIGO folks think of themselves as being in a race with advancing clock technology with regards to actually detecting gravity waves.

Re: Atomic Clocks Make a Quantum Leap in Accuracy

#45

Post by Daniel_Newby » Thu, Jan 30, 2014, 6:56 AM UTC

ChuckMcM wrote: post #44

Daniel_Newby wrote: post #36

Earlier quoted context omitted.

Gravity wave detectors get phase accuracy by comparing a photon to itself using an interferometer. SNR is improved by brightening the laser and averaging over more photons. The laser frequency is less important. It turns out there are some ultraviolet nuclear transitions. The line widths promise to be obscenely narrow. If they can get it working in a clock, they will be able to directly measure gravitational time dil…

Do you have a reference to the UV transitions? I'm sure the LIGO folks think of themselves as being in a race with advancing clock technology with regards to actually detecting gravity waves.

http://arxiv.org/abs/1110.0741

http://www.thorium.at/?page_id=4

I could not find many references, but I think clocks mainly make the instrument cheaper, or possible in the case of long-baseline satellite instruments.