[time-nuts] Time Dilation tinkering

Angus not.again at btinternet.com
Wed Mar 22 07:04:53 EDT 2017

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.


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!


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