NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Bill Noyce
Date: 2012 Jul 27, 12:15 -0700
Alex wrote:
> Still I don't understand these numbers (bright, dim)=(3,5).
> We have 3 surfaces, say 1,2,3, counting from Sun to the eye.
> Then the three bright images must occur when two reflections
> happen, that is (2,1), (3,1) and (3,2). Now the dim ones must
> be due to 4 reflections for which we have these possibilities:
> (2,1,2,1), (2,1,3,1), (2,1,3,2), (3,1,2,1), (3,1,3,1), (3,1,3,2), (3,2,3,1),
> (3,2,3,2). So there should be 3 bright and 8 dim images
> Why then we have only 5 dim?
I think (2,1,3,1) produces the same image as (3,1,2,1).
Similarly for (3,1,3,2) and (3,2,3,2). And I think (2,1,3,2)
produces the same image as (3,1). Does that explain it?
-- Bill N.
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