Welcome to the NavList Message Boards.


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

Compose Your Message

Add Images & Files
    Re: Pub. 249 and the spherical earth
    From: Frank Reed
    Date: 2017 Dec 20, 09:23 -0800

    Stan K wrote:
    "Since Pub. 249 is one of several tabular ways of solving the spherical navigational triangle, I would have to say that it uses a spherical model."

    Right. The geometry is worked out on the celestial sphere. And then that perfect, spherical solution is "pulled down" to the Earth's surface using the local vertical. The definition of latitude that we use --on all maps, globes, etc.-- automatically incorporates the Earth's oblateness, including the "pure" gravitational component due to the ellipsoidal distribution of mass and also the centrifugal force in our rotating frame of reference. So it's not Pub.249, or any other form of sight reduction, that compensates for the major share of the "earth's non-spherical nature". Its latitude itself that bears that burden, and it does so in a way that is very nearly invisible to end users.

    You see... the Earth is really flat, but us scientists, driven by our allegiance to the Illuminati, use math to make it seem as if the Earth is a sphere.

    Frank Reed

    Browse Files

    Drop Files


    What is NavList?

    Join NavList

    (please, no nicknames or handles)
    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 Settings

    Posting Code:

    Custom Index

    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