[geeks] Watch prescision

[dave]

chris at chrisbyrne.com writes:

>The theoretical limit for crystal controlled timers in general is
>something like 1000th of a second per century (atomic clocks are about
>1000 times more precise than that, and the most precise clocks ever
>devised are 1000 times more precise than that as in a billionth of a
>second per century. These clocks are quantum based.). The natural
>entropy of the universe, cosmic rays, special particles, and local
>variations in gravity and space time which may effect the speed of light
>are more of a factor on these things than anything else. 

A friend of mine used to run the planetarium at a local museum and
is very interested in timekeeping issues. (He's hopefully going to
be working with a local 100 year old observatory on restoring their
clock.)

We were discussing all the subtleties of calibrating atomic clocks
for altitude and such, and I asked if they adjusted for latitude,
based on the fact the objects closer to the equator should be
experiencing subtle relatavistic effects due to the rotation of
the Earth.

This led to a two month argument about whether or not the periphery
of a rotating object "counts" as movement from the frame of reference
of the axis, in relativity.

(We eventually concluded that it does.)

But it's apparently too subtle an effect for the atomic-clock
crowd to care about. Since they account for *EVERYTHING* it
must be damned subtle! :-)

------ David Fischer ------- dave at cca.org ------- http://www.cca.org ------
------------------------ Qevax Lbhe Binygvar! -----------------------------