[time-nuts] Non electrical time-nuttery

[Lux, Jim (337C)]

On 1/9/10 4:36 PM, "Bob Camp" <lists at cq.nu> wrote:

> Hi
> 
> If you abandoned the non-elecronic side of the requirement, you could hit it
> with a pulsed LED and probably get phase data off of a couple of photo
> detectors.
> 
> Crazy stuff ...
> 
> Bob
> 

But that's the whole challenge... You can build an entirely mechanical clock
with a performance of what? 4E-6 ADEV with a tau of 24 hrs (Harrison clock)


A Shortt pendulum (whatever that is, I'll have to go look it up) is 1E-7.  A
friend of mine was trying to build a 1ppm pendulum clock 15 years ago, with
temperature compensated weights, etc.

So, can one build a 1E-8 performance clock, without electricity?