This precise:

To tap the F1's full accuracy, scientists have to know their precise relative position to the clock, and account for weather, altitude and other externalities. An optical cable that links the F1 to a lab at the University of Colorado, for example, can vary in length as much as 10 mm on a hot day -- something that researchers need to continually track and take into account. At F1's level of precision, even general relativity introduces problems; when technicians recently moved F1 from the third floor to the second, they had to re-tune the system to compensate for the 11-and-a-half foot drop in altitude.

Wow, that F1 can do anything ... ;^)

At first it sounds like complete overkill but those are some mind-blowing applications.

Doesn't the performance of the F1 also depend on whether or not Michael Schumacher is driving?

/*rimshot

So is it accurate, or simply repeatable?

Furthermore, could some of the influences involved be something else besides general relativistic effects? For example, could those same temperature changes that are altering the length of the fiber-optic cable also be altering the geometry of a detector?

So is it accurate, or simply repeatable?

Furthermore, could some of the influences involved be something else besides general relativistic effects? For example, could those same temperature changes that are altering the length of the fiber-optic cable also be altering the geometry of a detector?

I wonder - if it really does detect the GR effects of 11 feet of altitude changes, then could an array of these be built as gravity wave sensors?

Could they use it to refine the earth-gravity model that those twin NASA sattelites mapped out?

Could they use it to cross-check the Europeans result last year of a surprisingly over-strong lenz-thirring effect off a spinning fly-wheel?

So is it accurate, or simply repeatable?

For a clock, what it means is that it ticks at a steady rate. You then determine by some other means just what that rate is, and can use it to tell time. These clocks tick at an extremely steady rate, so steady that slight shifts from GR or other effects can be detected (just compare the results of two or more clocks as some are moved or otherwise perturbed).

I wonder - if it really does detect the GR effects of 11 feet of altitude changes, then could an array of these be built as gravity wave sensors?

Sure, they'd easily be able to detect the bobbing of a boat as a gravity wave passed by. :)

Oh, you meant gravitational waves. No, I don't think so.