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Old 12th Feb 2019, 03:42
  #37 (permalink)  
GordonR_Cape
 
Join Date: Dec 2015
Location: Cape Town, ZA
Age: 57
Posts: 239
Originally Posted by Bing View Post
From a practical point of view, as far as they could prove that's the position they were in, so they could claim they were simultaneously in those time zones. At the same time no one can prove they weren't there!
Of course if they were that convinced they should have kept the sighting so others could check their workings...
Good points, though its pretty clear the story is apocryphal. No sailor worth his salt tries to take position sights from the rolling deck of a ship at midnight, which is the crux of the tale.

A so-called noon sun sight takes several minutes of careful planning and relies on a visible horizon, while night time astronomical sights require the position of several stars for accuracy. The SR-71 had an expensive navigation system that could do this (even during daytime due to its high altitude).

Lots of useful background available online: https://en.wikipedia.org/wiki/Celestial_navigation
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