Hi The CSAC is not a cesium in the conventional sense. It is much closer to a telecom Rb than anything else. There likely are telecom Rb’s that would do a better job. Would they do a good enough job? …. likely not ….
Bob > On Nov 27, 2021, at 5:11 PM, Lux, Jim <[email protected]> wrote: > > On 11/27/21 12:37 PM, Thomas Valerio wrote: >> I think that Tom's GREAT adventure is kind of what sealed the deal making >> me a time-nut or at least a time-nuts lurker, a lot of this stuff is still >> little over my head, but I keep reading. >> >> If anyone is inclined and has the clocks and the kids ( I don't have >> either ), there is always Mount Evans and Pikes Peak, although you may >> have to leave the clocks behind overnight. Mount Evans is still on my >> bucket list but without clocks and two or three days of time to monitor >> them, I don't think I will be doing the Mount Evans edition of GREAT. For >> anyone that is flush enough to afford or can beg, borrow or steal access >> to a Microsemi chip scale atomic clock, I think a Mount Evans edition >> would be an awesome addition to Tom's original work. >> >> Thomas Valerio >> > I don't think a CSAC would be good enough. > > Tom's experiment was 22 ns out of 42 hours or about 1.45E-13. That's quite a > bit smaller than a CSAC adev over that period. > > There's a variety of roads that go to ~12,000 ft in Colorado, about ~10,000 > in CA (Tioga Pass isn't closed yet), so you can get about 3x change, but > still you're talking <1E-12. > > Mammoth Mtn has a gondola to the top, but it's only 11,000. There may be a > ski resort in CO that's higher. > > >>> For newcomers to time-nuts, Andy is asking about my DIY gravitational >>> time dilation experiment(s). >>> >>> > What am I missing? >>> >>> It looks like you used the wrong value (or wrong units) for "h". >>> >>> The summit of Mt Rainier is 14411 ft (4400 m), but the highest point on >>> Mt Rainier that is accessible by road is the Paradise visitors center at >>> 5400 ft. Our house is at 1000 ft elevation so the net difference in >>> elevation of the clocks was 4400 ft (1340 m). >>> >>> The clock(s) on the mountain ran fast by gh/c² = 9.8 × 1340 / (3e8)² = >>> 1.5e-13. Fast clocks gain time. We stayed for about 42 hours so the net >>> time dilation was 42×3600 × gh/c² = 22 ns. >>> >>> ---- >>> >>> For more information see the Project G.R.E.A.T. 2005 page: >>> >>> http://leapsecond.com/great2005/ >>> >>> Better yet, these two recent talks from 2018 and 2020 cover all 3 GREAT >>> experiments: >>> >>> <http://web.stanford.edu/group/scpnt/pnt/PNT18/presentation_files/I08-VanBaak-GPS_Flying_Clocks_and_Relativity.pdf> >>> >>> <http://leapsecond.com/ptti2020/2020-PTTI-tvb-Atomic-Timekeeping-Hobby.pdf> >>> >>> Lots of time nutty photos in both of those! >>> >>> /tvb >>> >>> >>> On 11/27/2021 7:33 AM, Andy Talbot wrote: >>>> Just been reading your adventures with 3 Cs clocks, a mountain and 3 >>>> kids, >>>> but I can't make the estimate of time dilation work out. >>>> You measured ~ 23ns and say it agrees with calculation >>>> >>>> The equation quoted in a related reference, for "low elevations" is >>>> g.h/c² >>>> which if you plug in g = 9.81 m/s² and h = 4300m for Mt Rainer gives >>>> an >>>> expected value of 4.7 * 10^-16. >>>> Over 2 days, 2 * 86400s, that would be 81 ns in total, four times your >>>> value >>>> >>>> What am I missing? >>>> >>>> Was just speculating what Ben Nevis at a mere 1340m height might offer >>>> >>>> Andy >>>> www.g4jnt.com >>>> _______________________________________________ >>>> time-nuts mailing list -- [email protected] -- To unsubscribe >>>> send an email to [email protected] >>>> To unsubscribe, go to and follow the instructions there. >>> _______________________________________________ >>> time-nuts mailing list -- [email protected] -- To unsubscribe send >>> an email to [email protected] >>> To unsubscribe, go to and follow the instructions there. >>> >> _______________________________________________ >> time-nuts mailing list -- [email protected] -- To unsubscribe send an >> email to [email protected] >> To unsubscribe, go to and follow the instructions there. >> > _______________________________________________ > time-nuts mailing list -- [email protected] -- To unsubscribe send an > email to [email protected] > To unsubscribe, go to and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] -- To unsubscribe send an email to [email protected] To unsubscribe, go to and follow the instructions there.
