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: Prime Meridian on the move
    From: Bruce J. Pennino
    Date: 2016 Jan 15, 21:39 -0500
    Seems like everything is moving all the time. Continental drift,  internal molten mass, glaciers melting, mountains going up/down , giant rivers with moving banks, north magnetic pole moving , and all the other  stuff that would cause “brain ache”. Hard to believe “0” will ever be truly fixed (compared to what).
     
    When I made the obligatory trip  to Greenwich a few years ago I heard a great presentation..  Most interesting thing for me was the  following story....maybe true....maybe not...... To quote more or less from memory:  “ New observatory finished, telescope anchored in place, windows all done, chief astronomer does observations. He  found that a window was located improperly so that Zero longitude could not be sighted by a couple of inches, or something like that.  So 0 longitude was fudged by a small distance and the line was set”. Anyone else confirm this story for tourists?
     
    Happy  and Healthy New Year to all

    Bruce













     
    Sent: Friday, January 15, 2016 10:37 AM
    Subject: [NavList] Re: Prime Meridian on the move
     
    While I'm in tourist-exhibit-design mode:

    - show the ITRF velocity as well, so tourists can get a gut feel for tectonic motion
    - exaggerate the DoV by a factor of 100 in the optical plummet's field of view---problem solved

    Cheers,
    Peter

    View and reply to this message

       
    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