[time-nuts] Low power timekeeping

[Neville Michie]

Do not be so sure that a deep hole will give stable temperature.
I measured a nice sinusoid of about 0.3 *C over a year in a cave about 10 metres below the surface.
The attenuation function depends on the thermal diffusivity of the soil/rock, but that does not vary widely.
As you go deeper you get a delayed history of the surface temperature. 
A good oven runs rings around deep earth stability.
cheers, 
Neville Michie



On 26/09/2012, at 3:32 PM, Tom Van Baak wrote:

>> How good a clock could you get at much lower power?  I guess I'm looking for something (logarithmically) between a watch and a GPSDO.
> 
> This one keeps very good time long-term with no power: http://longnow.org/
> 
> /tvb
> 
> 
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