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On Jan 9, 2004, at 12:45 PM, George Huxtable wrote:

> Listmembers who are bored by details of the lunar distance method might
> just as well press the delete button now. This is for the others.
>
> It's (approximately) an
> amount to be added to the observed distance, not a multiplier, though
> the
> maths look more complicated than that. The result is a true (corrected)
> lunar motion that always ends up near 30 arc-minutes per hour, and an
> overall accuracy that relates to that motion, which isn't affected by
> what
> the apparent lunar motion happens to be.

For a while I thought George was becoming senile, but now I'm not so
sure, which pleases me :).  It would seem to me he might be right in
principle, but perhaps wrong in execution.

Let's say we have an observed distance of 75 degrees.  Let's say
clearing will change that distance to 74 degrees.  If we have measured
the distance of 75 degrees with an error of 0.5', the cleared distance
of 74 degrees would still have an error of 0.5' would it not, at least
to an accuracy of 74 parts in 75?  The important point is we're not
measuring a rate of change but rather the actual distance.  I also
agree with George that if the correction is additive not
multiplicative, it would not change the error.  But even if it were
multiplicative, it wouldn't change it much.

I know this is not analytical, but it might be a place to start.

Fred

   

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