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
    Missed opportunities, was: Moon eclipse
    From: Alexandre Eremenko
    Date: 2004 Oct 30, 14:25 -0500

    According to our experiments with this moon eclipse,
    the records of similar observations in XIX century,
    and Frank Reed's assessment of precision
    of astrolabes,
    "Assuming roughly two minutes error in eclipse event
    timings and two minutes error in local time,
    the average expected error
    would be
    about three minutes --less than a degree error in longitude."
    "the world could have been
    mapped in longitude with good accuracy thousands of years ago."
    This is enormously more precise than
    you can hope to measure by "dead reckoning" in a land travel.
    (Speaking, for example of the longitude distances like
    Paris-Moscow or from Rome-Beijin).
    Given that the Lunar method was proposed by Hipparchus
    in III cent BC, it is surprising that it was so rarely used
    in the following 2000 years, as Herbert Prinz,
    apparently wery knowlegeable in the history of this question,
    But I agree that speculation on "why was this so" is out
    of the scope of this list. (On my opinion, this is related
    to the hudge decline in the general attitude to science
    in the almost 2000 period betweeh Hipparchus and XVIII century.)

    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