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: Ecliptic, zodiac and history
    From: John Huth
    Date: 2010 Dec 11, 09:23 -0500
    The easiest way to do it is to chart the sunrise/sunset location against markers lying on the horizon.    Historically, you can find things like the Hopi sun calendar, or orientation of grave barrows in northern Europe.  The discussion of  astronomical alignments of places like Stonehenge seem to still be in flux, but there are pointers to the path of the ecliptic.    With decent markers on the horizon, you can see when the Sun appears to "stand still" against the markers at the solstices.  (Sostice = "sun stop")

    A more interesting issue is the knowledge of cycles of the Moon - the Saros cycle for example.    People would have to wait 18+ years to accumulate information from one eclipse to the next (18 years, 11.3 days between lunar eclipses).   Half a year is nothing compared to figuring out eclipses.

    On Sat, Dec 11, 2010 at 1:10 AM, Bill <billyrem42@earthlink.net> wrote:
    I am guessing when I get an answer to my question, I'll slap myself on the forehead and utter, "Of course." But here goes.

    I look at star charts and planispheres with the current ecliptic--the path of the sun through the stars--neatly added. I take it for granted that if I could see the stars and the Sun simultaneously that is the relationship I would see. Easy to confirm with an almanac and spherical trig.

    The zodiac signs--a form of right ascension or SHA--lie along the ecliptic as opposed to the celestial equator. The zodiac etc. have been around for about 3000 years, spanning the Sumerian's lunar calendar, the Babylonians, and the sexagesimal system. The shift of the First Point of Aries to its present location on the celestial equator also appears to indicate a long history of ecliptic knowledge.

    My question, how the heck did they figure out the ecliptic so long ago?  No pi, no trig.  A viewer would have to wait half a year to see the star pattern that would have that day's Sun superimposed on it. Yes?  A lunar calendar with 12 cycles a year and a leap month every three years would not be a big help.

    Bill B.

    Keeping up with the grind
    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