[time-nuts] "When you google word ..."

[Tom Van Baak]

Azelio,

Right, OCXO are not stable enough at the desired tau to do a blueshift 
experiment. So that's why atomic (and now, optical) clocks are used. But 
note that many experimental confirmations of general relativity, from 
planets to black holes, do not involve clocks, per se. See, for example:

https://en.wikipedia.org/wiki/Pound%E2%80%93Rebka_experiment

Here's a historical summary of GR experiments from a Physics textbook:

https://www.relativity.li/uploads/pdf/English/I_en.pdf

Another good list:

https://en.wikipedia.org/wiki/Tests_of_general_relativity

And Clifford Will's classic:

https://link.springer.com/article/10.12942/lrr-2014-4

https://arxiv.org/abs/1403.7377

/tvb


On 10/30/2020 7:44 AM, Azelio Boriani wrote:
> Was the blueshift only ever tested by using atomic clocks? OK, OCXOs
> alone are not stable enough to try and we can't go that far from our
> planet with the necessary equipment.
>
> On Fri, Oct 30, 2020 at 2:27 PM Bob kb8tq <kb8tq at n1k.org> wrote:
>> Hi
>>
>> So there might be a reason (other than NIST) to believe that frequency and
>> gravity are related to each other ? :)
>>
>> Bob
>>
>>> On Oct 30, 2020, at 7:28 AM, Tom Van Baak <tvb at LeapSecond.com> wrote:
>>>
>>>> Time Too Good to Be True, Daniel Kleppner
>>>> Physics Today, March 2006, page 10
>>>> https://physicstoday.scitation.org/doi/10.1063/1.2195297
>>> An adventure in relative time-keeping, Tom Van Baak
>>> Physics Today, March 2007, page 16
>>> https://physicstoday.scitation.org/doi/10.1063/1.2718741
>>>
>>> /tvb
>>>
>>>
>>>