3 ms·

Crappy article. Sure, the more precise your oscillator is the more you need to worry about other effects. Basic cesium beam clocks are precise enough the altit

by nullc 12y ago

Crappy article. Sure, the more precise your oscillator is the more you need to worry about other effects. Basic cesium beam clocks are precise enough the altitude based corrections for relativity are required to achieve full accuracy. Each km of altitude is about 10ns/day of slew, ... I can measure this myself with equipment I have at home (I have an unusual home). So sure, when you start making optical clocks with accuracy in the 1e-18 land then external effects may well be much harder to correct for, e.g. tides have an effect at the 1e-17 level ... but such a device could still keep time better than prior techniques. The "They just may not be able to tell us the time" is rubbish hyperbole that just serves to confuse readers who don't already know the subject well.

wuliwong 12y ago
The comment where the man makes a comparison to measuring electric current but tries to make it seem like we understand time better than electric current annoyed me. As if we have a greater fundamental understanding of what an electric charge "is" vs. time.
- jacquesm 12y ago
  I love this page on that subject: http://amasci.com/elect/charge1.html http://amasci.com/elect/charge1.html It's not exactly 100% current (pun intended) but it makes the point nicely.
healsjnr1 12y ago
This is the worst kind of comment and what is wrong with Hacker News. No one cares about your intellectual superiority, or the fact this might be a special interest for you. This article wasn't written for you, you already know and understand its content. There is literally nothing you could have got from it. I on the other hand enjoyed the article. This isn't a field I'm familiar, so in general my knowledge was increased. That some concepts are misrepresented and dumbed down is obvious, but this is far out weighed by the general knowledge that was imparted. Writing is all about picking an audience and conveying it effectively to the audience. It's fine to point out inaccuracy or build on the finer points, but don't be aggressive about it and don't insult the article because it offended your superior intellect.
- nullc 12y ago
  I'm glad you enjoyed it, but in my opinion the article was misleading. Not just simplified. I didn't go on and on in detail about systemic and random effects, linking to NIST tech reports on all the corrections they have to do on primary standards (http://tf.boulder.nist.gov/general/pdf/1846.pdf?origin=publication_detail http://tf.boulder.nist.gov/general/pdf/1846.pdf?origin=publi... on the redshift error at NISTs boulder facilities; and http://tf.boulder.nist.gov/general/pdf/2704.pdf http://tf.boulder.nist.gov/general/pdf/2704.pdf on the sources of error in the F2 primary reference, see section 3.2 on relativistic effects), or pointing out people's amateur time keeping experiments where they demonstrate relativistic influence on decades old hardware ( http://leapsecond.com/ptti2006/tvb-project-great-ptti-ppt.pdf http://leapsecond.com/ptti2006/tvb-project-great-ptti-ppt.pd... (this presentation is long and a ton of fun)), etc. or all the other bits of trash I could have pulled out to demonstrate knowing something here... because that wasn't my goal, the only point I was trying to make is that the article was likely to make many readers _less_ knowledgeable about the subject. (But I will give those links now, because this argument is boring and time is neat!) Perhaps you have enough background that you were not thrown off by the seeming claim that improved accuracy somehow makes these experimental references _less useful_, and you already know that relativistic effects aren't unique to optical lattice clocks and already must be compensated for, but I am sure that this is not universally the case. What I get from the article isn't nothing... Potentially I get community around me which is less informed than they started and all that entails. Perhaps that's compensated for the fun they had reading about an interesting subject? or the additional learning they do after? I don't know, but I think the article could have been just as enjoyable without the bogus mystique that makes it misleading. But if pointing out an article was, in my opinion, potentially misleading makes me everything that is wrong about Hacker News, I'll wear that proudly. I, for one, think it's more likely the case that crappy shock headlines like "end time as we know it", constructed drama, and false freshness are a bigger drag on HN (and wider society) than any of my posts are likely to be... but to each his own.
  - foobarian 12y ago
    For what it's worth, the new thing I got from the article is the unexpected idea that one could usefully measure non-time phenomena with a really precise clock, such as gravity or altitude. Definitely more thought inspiring than many other articles, in spite of the way it was written.
physonaught 12y ago
I though the article was cute, but I wouldn't go so far as to say it was crappy. The essence of the article was on point. You can't just report the time anymore, once special and general relativity become important, you have to report space-time. Sure, other effects are going to become important as well, but the essence of the article: time is not absolute, and this has practical difficulties for clock-makers, was well communicated.
- ObviousScience 12y ago
  You already can't do that, though. This isn't some new problem experienced only by this clock, though it's more sensitive to it. The GPS satellites already had to correct for the passage of time being different for them relative to the surface of the planet. Decades ago.

by nullc 12y ago

wuliwong 12y ago

The comment where the man makes a comparison to measuring electric current but tries to make it seem like we understand time better than electric current annoyed me. As if we have a greater fundamental understanding of what an electric charge "is" vs. time.

jacquesm 12y ago
I love this page on that subject: http://amasci.com/elect/charge1.html http://amasci.com/elect/charge1.html It's not exactly 100% current (pun intended) but it makes the point nicely.

healsjnr1 12y ago

This is the worst kind of comment and what is wrong with Hacker News. No one cares about your intellectual superiority, or the fact this might be a special interest for you. This article wasn't written for you, you already know and understand its content. There is literally nothing you could have got from it. I on the other hand enjoyed the article. This isn't a field I'm familiar, so in general my knowledge was increased. That some concepts are misrepresented and dumbed down is obvious, but this is far out weighed by the general knowledge that was imparted. Writing is all about picking an audience and conveying it effectively to the audience. It's fine to point out inaccuracy or build on the finer points, but don't be aggressive about it and don't insult the article because it offended your superior intellect.

nullc 12y ago
I'm glad you enjoyed it, but in my opinion the article was misleading. Not just simplified. I didn't go on and on in detail about systemic and random effects, linking to NIST tech reports on all the corrections they have to do on primary standards (http://tf.boulder.nist.gov/general/pdf/1846.pdf?origin=publication_detail http://tf.boulder.nist.gov/general/pdf/1846.pdf?origin=publi... on the redshift error at NISTs boulder facilities; and http://tf.boulder.nist.gov/general/pdf/2704.pdf http://tf.boulder.nist.gov/general/pdf/2704.pdf on the sources of error in the F2 primary reference, see section 3.2 on relativistic effects), or pointing out people's amateur time keeping experiments where they demonstrate relativistic influence on decades old hardware ( http://leapsecond.com/ptti2006/tvb-project-great-ptti-ppt.pdf http://leapsecond.com/ptti2006/tvb-project-great-ptti-ppt.pd... (this presentation is long and a ton of fun)), etc. or all the other bits of trash I could have pulled out to demonstrate knowing something here... because that wasn't my goal, the only point I was trying to make is that the article was likely to make many readers _less_ knowledgeable about the subject. (But I will give those links now, because this argument is boring and time is neat!) Perhaps you have enough background that you were not thrown off by the seeming claim that improved accuracy somehow makes these experimental references _less useful_, and you already know that relativistic effects aren't unique to optical lattice clocks and already must be compensated for, but I am sure that this is not universally the case. What I get from the article isn't nothing... Potentially I get community around me which is less informed than they started and all that entails. Perhaps that's compensated for the fun they had reading about an interesting subject? or the additional learning they do after? I don't know, but I think the article could have been just as enjoyable without the bogus mystique that makes it misleading. But if pointing out an article was, in my opinion, potentially misleading makes me everything that is wrong about Hacker News, I'll wear that proudly. I, for one, think it's more likely the case that crappy shock headlines like "end time as we know it", constructed drama, and false freshness are a bigger drag on HN (and wider society) than any of my posts are likely to be... but to each his own.
- foobarian 12y ago
  For what it's worth, the new thing I got from the article is the unexpected idea that one could usefully measure non-time phenomena with a really precise clock, such as gravity or altitude. Definitely more thought inspiring than many other articles, in spite of the way it was written.

physonaught 12y ago

I though the article was cute, but I wouldn't go so far as to say it was crappy. The essence of the article was on point. You can't just report the time anymore, once special and general relativity become important, you have to report space-time. Sure, other effects are going to become important as well, but the essence of the article: time is not absolute, and this has practical difficulties for clock-makers, was well communicated.

ObviousScience 12y ago
You already can't do that, though. This isn't some new problem experienced only by this clock, though it's more sensitive to it. The GPS satellites already had to correct for the passage of time being different for them relative to the surface of the planet. Decades ago.