Hi:

In the video about the Full Moon Curse (that's about measuring the distance to each of the 5 retro-reflectors on the moon to 1 mm) there's a plot showing the elevation change in the Apache Point Observatory of about 20 inches peak to peak. It's exactly the type of change the effects pendulum clocks.

I asked Tom Murphy if he used GPS to get the elevation plot and the answer is that it came from the gravitymeter with the use of Love numbers.
http://en.wikipedia.org/wiki/Love_number  <- has links to papers on Earth tides
Also see patent 3449956 and GWR instrument link at:
http://www.prc68.com/I/Pendulums.shtml

This means that the concrete piers where many Cesium clocks and GPS reference stations are located are bobbing up and down as if they were on a ocean, although only tens of inches. I think there was an earlier post saying this puts a limit (E-16?) on the ultimate quality of a clock because of it's movement. I wonder if NIST has one of the GWR gravitymeters on a pier and uses that to discipline their fountain clocks for the elevation change of the pier or if that's done for the GPS reference antennas?

--
Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html

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