Aiguille du Midi is 3842m IIRC (cable car base station at about 1000m). Dave
-----Original Message----- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of jimlux Sent: 22 March 2017 14:57 To: time-nuts@febo.com Subject: Re: [time-nuts] Time Dilation tinkering On 3/22/17 4:04 AM, Angus wrote: > On Tue, 21 Mar 2017 13:08:56 +0100, you wrote: > >> On Tue, 21 Mar 2017 13:38:51 +1100 >> Hugh Blemings <h...@blemings.org> wrote: >> >>> This got me to wondering if a Rubidium based standard might do the >>> trick >>> - the Efratom SLCR-101s seem readily available for ~USD$200 mark. >> >> As TvB wrote, a single one will not do the trick. You will need a >> stability 1e-14 @1d. IIRC most Rb standards floor out at 1e-12 to >> 1e-13 somewhere between 1k and 100k seconds. Even the Super-5065 has >> a floor of about 3-4e-14 (unless our friends here improved on this already). >> >> There will be a few things that you will need to do, if you want to >> go with Rubidiums: >> 1) Stabilize or compensate for environmental effects (temperature, >> air pressure) >> 2) Build ensembles of Rb clocks. >> > > Hi, > > Looking back at an old plot I did of a temperature controlled and air > pressure compensated LPRO against an M12+T, the Hadamard Deviation of > the 1000s averages of the 1PPS measurement was about 5E-14 at 1 day. > A large part of that was likely the GPS, so with a better rubidium > like an FRK-H in a sealed and temperature controlled enclosure you > might be around 1E-14 at 1 day. > > The bit that I'm not so sure about is the travelling. A long period of > movement, vibration, magnetic fields, etc. all adding in could > obscure the effects of time dilation. > > It might be quite possible, although a nearby mountain and a friend > with a helicopter would make it a lot easier! > No tall mountains in Australia, but... Pikes Peak in the US is 14114 ft, 4304m and has a road to the top. Of course the base is at about 5000 ft/1600 m In EU, there's probably a Seilbahn of some sort pretty high up in the Alps, although probably not to 4000m. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.