Using a pendulum to measure gravity requires precision timekeeping. Wikipedia has a nice discussion of this at https://en.wikipedia.org/wiki/Pendulum#Gravity_measurement
There are number of very clever techniques developed long ago, such as Henry Kater's design for a reversible, dual pivot pendulum that made it possible to get quite precise measurements starting about the 1820s. Then, around 1835 Friedrich Bessel found ways to simplify calibration of Kater's design and even cancel out errors due to air drag. More interestingly, gravity measuring pendulums became not of the earliest ways used to standardize the measure of length, which shows how nearly all efforts at standardization ultimately rely on accurate timekeeping. Wayne _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
