NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Delta-T
From: George Huxtable
Date: 2004 Dec 4, 00:00 +0000
From: George Huxtable
Date: 2004 Dec 4, 00:00 +0000
In reply to my posting about the long-term unpredictability of planetary orbits, Alex replied >...I thought you were still talking about Tycho Brahe or anything else of >"practical importance". ================ Well, it depends on who it might be of practical importance to. Not to us, nor to many generations ahead. But the time-scales involved in significant changes to planetary orbits, such as that of the Earth, are not long in comparison with the time-scales for biological evolutionary changes here on Earth. Such orbital changes may well have a long-term effect on the future viability of our species, and may have made a significant impact on evolution in the past. But in terms of celestial navigation, not of "practical importance". Nor was Tycho Brahe's contribution. George. ================================================================ contact George Huxtable by email at george@huxtable.u-net.com, by phone at 01865 820222 (from outside UK, +44 1865 820222), or by mail at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. ================================================================
