In message , greywolf42
writes
Jonathan Silverlight wrote
in message ...

Then why are you attempting to claim results other than what the paper and
observations were about?

In my original question, I simply asked if the Bertotti paper shed any
light on the Pioneer anomaly, given that it reports much more accurate
figures and shows no unusual residual effect.


I don't know if the solar opposition experiment has been published, but
the point is that Bertotti et al.

Horsefeathers. The reference under discussion was Anderson and Lau -- not
Bertotti. And the difficulty of modelling the emission is not physically
different for Bertotti than four Anderson and Lau.


Both groups consider that most of the acceleration comes from thermal
emission, but Bertotti et al. say most of the RTG emission from Cassini
is isotropic. There is still a substantial net thrust. Has Anderson
answered Ned Wright's argument that the anomaly can be explained by
anisotropy of the emission? http://arxiv.org/abs/gr-qc/0107092

quote a figure for the acceleration
from the RTGs of 3 x 10^-9 m s^-2, with an error of 9 x 10^-11 m s^-2.
That error is about "an order of magnitude" less than the Pioneer
effect.

Not according to Anderson and Lau.

Could someone check my arithmetic? Anderson et al. use cm s^-2 rather
than meters - I don't know why - and their figure of -26.7 x 10^-8 cm
s^2 can be compared directly with the original Pioneer anomaly of 8 x
10^-8 cm s^2. They quote an error of 1.1 x 10^-8 cm s^2, which is about
the same as Bertotti et al. and is comfortably less than the "effect".
If that figure is actually wrong - inaccurate, as opposed to being
imprecise - wouldn't it show up in the residuals? That's what prompted
my original post, and I haven't seen a reply showing it wouldn't.


Anderson et al. quote a figure for a_r (the radial acceleration, mostly
due to the RTGs) of -26.7 x 10^-8 cm s^-2, which is essentially the same
when you convert.

Yes. And Anderson and Lau mention that "the uncertainty in the thermal
model overwhelms any plausible application of the Pioneer anomaly to
Cassini."

As Volker Hetzer says, there's a contradiction between the statements
that "the result is not anomalous" and "the uncertainty in the thermal
model overwhelms any plausible application of the Pioneer anomaly to
Cassini". The new measurements are much more accurate than the Pioneer
ones (compare the residuals) and the Pioneer effect doesn't appear.

How are they more accurate? According to Anderson, the measurements
of 'anomalous accelerations' would are 10 times less precise than the gross
effect measured to 2 sig figs on Pioneer. Due to "the uncertainty in the
thermal model" of Cassini.

I don't see how you get that figure. Anderson et al. say "Finally, the
error in ar from 27 days of Cassini Doppler data is about two times
better than the result from 11 years of Pioneer 10 Doppler data "
I think that's pessimistic; they are now getting Doppler residuals of
microns per second.
--
Rabbit arithmetic - 1 plus 1 equals 10
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