I appreciate your point, one that I have emphasized to my graduate students many times over 30 years of teaching. Of course you are entirely correct.
On Tuesday, June 4, 2019, Kevin Birth <kevin.bi...@qc.cuny.edu> wrote: > When a clock is represented as only losing a second in billions of years > that is a statement packaged in a rhetorical fashion to impress readers. > Another way to think about the statement of such long-term accuracy is > that it is a improvement in reducing uncertainty about accuracy over time, > and that includes uncertainty in the short term at high levels of > precision. > > Consider that the SI second is 9,192,631,770 transitions of cesium, but > that when the number of cesium transitions per second was originally > measured, there was a plus or minus of 20 transitions. That means in > first generation cesium clocks there was a lurking uncertainty in accuracy > of at least plus or minus 20 not taking into account all the other factors > that can influence a clock¹s performance. Now if a clock¹s time was > uncertain by just a few transitions, then that could produce a 1 second > loss of accuracy over billions of years. > > So one way to look at the claim that a clock is accurate for billions of > years (although NIST-F2 is claimed for hundreds of millions of years) is > that it is a clock that has reduced the uncertainty in the short run, > making it not only precise, but accurate at high levels of precision over > short periods of time. > > Now that we live in a world where big data analysis (including data feeds > on Wall St) have ns levels of precision, reducing uncertainty in accuracy > in primary standards is highly valued. How precise does it need to be? > > Or, at least that is how I understand things. Thanks for your reply. > > Best, > > Kevin > > > -- > Kevin K. Birth, Professor > Department of Anthropology > Queens College, City University of New York > 65-30 Kissena Boulevard > Flushing, NY 11367 > telephone: 718/997-5518 > > "Tempus est mundi instabilis motus, rerumque labentium c/ursus." --Hrabanus To which I reply: Tunc temporis omnia consumit omnia iubeo. > We may live longer but we may be subject to peculiar contagion and > spiritual torpor or illiteracies of the imagination" --Wilson Harris > > > > > On 6/4/19, 12:43 PM, "time-nuts on behalf of William H. Fite" > <time-nuts-boun...@lists.febo.com on behalf of omni...@gmail.com> wrote: > > >EXTERNAL EMAIL: please report suspicious content to the ITS Help Desk. > > > > > >Warning: Potentially heretical material below > > > >Let me begin by saying I am neither an engineer nor a time expert. My PhD > >is in statistics and my spouse's PhD is in theoretical computer science, > >working on quantum computer algorithms. Neither of us claims any special > >expertise when it comes to time and frequency measurement. I am a radio > >amateur and I came to this group following a recommendation from John > >Ackermann, who very kindly answered some questions for me regarding the > >amateur radio frequency measurement test. I thoroughly enjoy the dialogue > >here and I think that I have learned a bit about the subject though, by > >any > >standard of this group, I am the rankest newbie. > > > >My question is a serious one. I am not trolling, nor am I trying to begin > >an argument, nor am I implying criticism of anyone or any endeavor, here > >or > >elsewhere. > > > >What useful purpose, if any, is served by the continuing evolution of > >clocks like NIST-F2 that now achieve accuracy along the lines of one > >second > >per many billions of years? Are there tangible benefits to be had? I > >consulted an astronomer friend who advised that the current generation of > >clocks would allow a suitable space vehicle to plant a probe squarely in > >the middle of Alpha Centauri, if rocket technology existed to do so. We > >have many friends in the academic computer science community who say that > >neither conventional nor quantum computers that exist at present or in the > >projectable future require anything like this kind of accuracy. > > > >By no means am I questioning the value of new knowledge qua knowledge. For > >theoreticians like the one to whom I am wedded, no justification is needed > >beyond the words of mountaineer George Mallory: "Because it's there." I'm > >sure that engineers and scientists in the field of time and frequency > >measurement feel the same. From that perspective, there need be no > >rationalization beyond the desire to do it just a little better than it > >has > >been done. > > > >Please don't lecture me about the value of science for its own sake. My > >career has largely been built on that principle. I'd like to be informed > >as > >to present or anticipated applications that require such accuracy. Are we > >developing these incredible devices just to push boundaries? Or do they > >have some practical purpose? > > > >I'll appreciate thoughtful answers. Dismissive and/or snarky replies will > >be deleted unread. > > > >Thanks for your help. > > > > > >-- > >Homo sum humani a me nihil alienum puto. > >_______________________________________________ > >time-nuts mailing list -- time-nuts@lists.febo.com > >To unsubscribe, go to > >http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > >and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to http://lists.febo.com/mailman/ > listinfo/time-nuts_lists.febo.com > and follow the instructions there. > -- Homo sum humani a me nihil alienum puto. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.