Welcome to the NavList Message Boards.

NavList:

A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Message:αβγ
Message:abc
Add Images & Files
    or...
       
    Reply
    Re: Mirror recoating
    From: Alexandre Eremenko
    Date: 2019 Mar 26, 21:09 +0000

    Tony,
    
    1. The advise to blaken the back surface is taken from an old sextant book.
    
    2. Your geometry is wrong: assuming that the front and back surface are parallel,
    t does not matter which one is reflecting. And it does not matter whether the axis
    passes through the plane of the surface or not.
    
    Theorem. The ray from the sun is rotated by exactly 2 times the angle between
    the index and horizon mirror. 
    
    So moving any mirror parallel to itself, does not change this.
    
    Alex.
    
    

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Join NavList

    Name:
    (please, no nicknames or handles)
    Email:
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.
    Email:

    Email Settings

    Posting Code:

    Custom Index

    Subject:
    Author:
    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site