on the subject of pendulum vs. optical: please don't mix sensitivity to "g" directly with sensitivity to the gravitational potential "g delta-h / c**2" that the optical clocks can now measure.
changes in g seem to be at 1e-8 level according to [1]. the gravitational redshift is "g delta-h / c**2" or 1e-16 per meter of height. if optical clocks were really sensitive to "g" we would be in the same (horrible) boat as the kibble-balance experimenters who need a map of "g" in the lab before building the kibble balance and then need to re-measure that map every now and then... . Instead what optical clock labs need is a height measurement from the geoid to the experiment (where the cold atoms are). "accelerometer" (something that measures "g") is a poor word-choice IMO for the latest optical clock results... AW [1] http://www.leapsecond.com/hsn2006/pendulum-tides-ch3.pdf On 2018-12-01 06:17, Tom Van Baak wrote: > >> Surely, this is nothing new? > >> I thought standard pendulum clocks were quite good at detecting > >> gravity as well! > > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
