[LEAPSECS] Time on time

[Rob Seaman]

On Nov 30, 2011, at 11:45 AM, Hal Murray wrote:


>> Speaking of time, what sort of time is the Long Now clock keeping,  anyway?

>> Solar, atomic, or something else entirely? 

> 

> Solar.  It's all mechanical.  No electronics.


Just to clarify, it is a digital mechanical device with a tenth-Hz "clock" in the computer science sense.  It relies on an external analog sync as the Sun crosses the local meridian.  The clock discipline can withstand a stretch of tens of thousands of overcast days by, among other things, carefully correcting for the equation of time.

Rob