NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Oh No! Fundamental flaw in celestial navigation revealed!
From: Brad Morris
Date: 2019 Jan 17, 14:02 -0500
From: Brad Morris
Date: 2019 Jan 17, 14:02 -0500
Frank wrote
At most, celestial navigators use the predicted times of sunrise and sunset for sight planning --so that they know when to be out on deck to shoot the stars in evening or morning twilight.
Precisely! If anything, it provides a deadline as to when you know your precomputed altitudes and azimuths should be complete. That your sextant is acclimated to the environment and you are comfortably situated for your first observation, which would be the brightest star you can see against the most crisp horizon. Plus or minus a minute means very little in this context. Knowing the accurate time is critical for the moment of observation, but precise knowledge of sunrise / sunset times is not required.
On Jan 17, 2019 1:47 PM, "Tony Oz" <NoReply_TonyOz@fer3.com> wrote:
Thanks, Robin, for a nice bit of read.
:)
Still, I learned something new - the Novaya Zemlya (NZ) effect. Never ever heard of such a thing. The term caught my eye because these are two Russian words - the New Land if I may suggest a translation. Actually, I have another connotation to the Novaya Zemlya - the multi-megaton thermonuclear test conducted there. And the photo of the Sun just reminds (me) a shape of the blast.
Warm regards,
Tony
60°N 30°E
