[time-nuts] I've lucked it!
Palfreyman, Jim L
Jim.Palfreyman at team.telstra.com
Sun May 6 20:47:24 EDT 2007
As posted previously I recently bought a cheap Radio Controlled
multi-band travel clock off ebay and managed to receive the JJY signal
from Japan here in Tasmania, Australia. But only in a certain part of my
Based on that, I bought a Casio G-Shock Multi Band Solar Radio
Controlled all digital wrist watch.
Well the bad news was that it couldn't pick up the signal. I still need
to go up a mountain at 3am with it, but certainly I haven't picked up
anything with it yet - the travel alarm clock seems a lot more sensitive
for some reason.
The good news is that when I got this watch I set it accurately by hand
(of course!) and now two weeks later I still cannot detect any visible
difference as the seconds tick over. In my past experiments I've found
my eyes and ears together can detect at least a 100ms difference
(possibly much better, but this is what I've tested).
So I wear this watch during the day, take it off at night and it has
maintained an accuracy of under a 1/10 of a second in two weeks -
roughly 2.5 seconds per year if we extrapolate it out.
Now maybe this is a well designed watch and they are all like that, but
it got me thinking. Of all the millions of watch crystals out there must
be some that just out of pure chance are brilliant time keepers. For any
arbitrary level of precision (e.g. 1 sec per year) presumably there is a
probability (e.g. 1 in a million) that there is a crystal than can keep
that time based on my wrist temperature and various other watch wearing
Have I scored it lucky??
P.S. I have double checked and can guarantee you the watch hasn't picked
up a single LF time signal from anywhere!
More information about the time-nuts