Hi, This is my first input to the list. >From what I've read, the jump in pendulum clocks is due to a spontaneous change in the rod length. This has actually been measured, and is accredited to crystal lattice slippage of the material. This has been found in metal and recently, crystal rod pendulum. It is significant in the latter because experimenters went to crystal rods for their temperance invariance, only to find the unpredictable spontaneous length change.
Carl Dreher ============== In : Accurate Clock Pendulums by Robert Matthys (2004) Oxford University Press ISBN 0198529716, Pp264 In Chapter 8 , "The Allen variance and the rms time error", on page 38 he writes: Figure 8.1 shows another characteristic of pendulum clocks - the clock will run relatively smoothly at one rate , and then after 3 - 6 months it will suddenly jump to a new rate as shown if Fig 8.1. He goes on to say that this is part of a random walk process. I hope that is of some help. Neville MIchie _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
