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: Pi Problem for CN
    From: UNK
    Date: 2015 Mar 22, 18:57 -0700

    "As an ex-teacher, I would take points off for not showing your work."

    Es an ex-student, however, I would take points off the evaluation sheet of a teacher who presents his material in an overly complicated form.

    The largest circle on a sphere is a great circle.  All of them are the same size. The diameter as defined by David Fleming of any of them is just half of a great circle flipped 90 deg. So that ratio is clearly 1 : 2.

    And nobody who uses conformal projections of the sphere onto a flat sheet of paper for his daily coastal work doubts that the sphere can be locally approximated by a plane without ever dreaming of L'Hopital. So the rules and formulas of plane geometry hold on the sphere for reasonably small neighbourhoods. Which makes the sought ratio 1 : Pi.

    I would actually give David Fleming extra points for understanding the problem in the first place. I had problems understanding what was meant by "diameter", as well as with the term "prime rational number". In fact, I understood Karl's problem only after David Fleming had solved it.

    Herbert Prinz

    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