NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: The Star of Bethlehem and Navigation
From: Bill B
Date: 2009 Jan 04, 08:14 -0500
From: Bill B
Date: 2009 Jan 04, 08:14 -0500
FER wrote > While we worry about leap seconds once every year or two, if you want to work > the same problem 2,000 years backward in time, you need something like three > hours worth of leap seconds, give or take 500. In other words, we can specify > atomic time or ephemeris time without much ambiguity and calculate most > phenomena in the heavens, like occultations and eclipses, with great accuracy. > Their relative timings will be accurate. But we don't know the exact local > time when those events occurred as seen from the Earth since we don't know > exactly how much mean time differed from "true" time back then. Was it 4:30 or > 4:35 local apparent time? Right now, there's no way to know. Thank you for accurate observation, also IMHO relative to the (too) long-running thread on leap seconds and cel nav ("time" vs. body GP). Bill B. --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---