[time-nuts] 10811 crystal orientation

[Tom Van Baak]

> The Zhou paper should be taken with a grain of salt. It does report on a 
> number of deviations measured during eclipses. More investigations is 
> needed to characterize the cause of these deviations.

Agreed. It is not uncommon for well-done experiments to
spend more time on analysis of error sources than the
"signal" itself. One must be one's own worst critic.

By contrast, one reason I liked the paper by Udem, et al. is
that their experiment seemed objective and quite thorough.
They monitored ambient parameters including temperature,
mains voltage, 3-axis magnetic field and air pressure. They
used four different make/models of atomic clocks (from Rb
to maser). The graphs are an outstanding example to any
time-nut of correct and clear visual display of timing data.
And, they make all the raw data available anyone. Hard to
beat that.

Intro pages:
<http://www.mpq.mpg.de/~haensch/eclipse/eclipse.html>
<http://www.mpq.mpg.de/~haensch/eclipse/prosa.html>

Plots (see figure1.html through figure6.html)
<http://www.mpq.mpg.de/~haensch/eclipse/figure1.html>

Raw data:
<http://www.mpq.mpg.de/~haensch/eclipse/data.html>

One thing to remember about looking for obscure events or
subtle effects is that the best atomic clocks today are 100x
or 1000x more stable than those from a few decades ago.
So a small effect, if actually seen, in the 1990 's should be
huge with the level of precision available in today's timing
laboratories around the world.

/tvb