[time-nuts] Time Dilation tinkering

David C. Partridge david.partridge at perdrix.co.uk
Wed Mar 22 12:39:59 EDT 2017

Aiguille du Midi is 3842m IIRC (cable car base station at about 1000m).


-----Original Message-----
From: time-nuts [mailto:time-nuts-bounces at febo.com] On Behalf Of jimlux
Sent: 22 March 2017 14:57
To: time-nuts at 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 <hugh at 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.

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