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Brad,
It never crossed y mind that a lunar distance can be reduced with a slide rule:-)
It seems that a much larger precision is required for a lunar distance...
And I missed this discussion.
Can you suggest how to find it?
(The dates, or titles of messages).

Alex.



________________________________________
From: NavList@fer3.com [NavList@fer3.com] on behalf of Brad Morris [NoReply_Morris@fer3.com]
Sent: Sunday, January 03, 2016 11:29 AM
To: eremenko@math.purdue.edu
Subject: [NavList] Re: Calculator v. Slide Rule for Ex-Meridian Correction

Hello Alex

Glad to see you!

There has been some discussion of performing the lunar distance computation 
with a slide rule.  What is your estimate of the number of significant digits 
for the lunar distance computation?

Brad

On Jan 2, 2016 4:42 PM, "Alexandre Eremenko" 
> wrote:

This kind of calculation requires few significant digits, and thus can be done 
with a slide rule. You can also time how much it takes by hand with pencil, 
as it was done in the old times, without a calculator and without a slide 
rule. However the main calculation which we do in CelNav, solving a spherical 
triangle, requires 5-6 digits, and this is not possible with a slide rule. 
Perhaps for this reason a slide rule is not in the list of standard equipment 
for a celestial navigator.

   

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