[time-nuts] Detecting gravity with optical atomic clocks

[Tom Van Baak]

> Surely, this is nothing new?

Once or twice a year some national lab, often NIST, makes an announcement of a new level of precision for their atomic clocks. It's pretty cool, actually. It's good PR. The rate of progress is amazing.

> I thought standard pendulum clocks were quite good at detecting gravity as well!

Yes and no. Modern uses for precision gravity measurement often require precise data while flying or in orbit. Pendulum clocks don't do well in those conditions.

> They make excellent earth-quake detectors - Randall Peters published many excellent papers on this subject many years ago, fascinating stuff.

Yes. For example, see the pendulum results of yesterday's earthquake:

http://leapsecond.com/pend/synchronome/quake.htm

> John Moran

/tvb