[time-nuts] The forbidden question

[Bob kb8tq]

Hi

….. ahhhh…. but what about modeling the atmosphere? I believe you will find that that is 
(at least to some degree) limited by the clocks involved.

Bob

> On Jun 6, 2019, at 5:17 PM, Michael Wouters <michaeljwouters at gmail.com> wrote:
> 
> My radio astronomer colleagues tell me that there is about a 20 minute
> limit to VLBI observing runs because of atmospheric instability so this
> limits improvements to be had from better clocks. My recollection is that a
> maser is still sufficient out to 100 GHz. There is a paper about this that
> I will dig out later.
> 
> Cheers
> Michael
> 
> On Thu, 6 Jun 2019 at 12:01 pm, Joseph B. Fitzgerald <
> jfitzgerald at alum.wpi.edu> wrote:
> 
>> 
>> Regarding Dana's remarks on VLBI, consider the recent black hole image
>> released by the Event Horizon Telescope.    Measurements were taken at 230
>> GHz, and they would like to begin measurements at 345 GHz.    Hydrogen
>> masers were used at each telescope.    I am no expert, but I strongly
>> suspect that a better clock would result in longer/better observations.
>> The H maser only runs at 1.42 GHz ... the astrophysicist wizards are
>> proposing to do their measurements at about 250 times higher in frequency!
>> 
>> 
>> -Joe
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