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Re: Delta-T: was [NAV-L] Tycho Brahe Mars oppositions
From: Alexandre Eremenko
Date: 2004 Dec 2, 13:54 -0500
From: Alexandre Eremenko
Date: 2004 Dec 2, 13:54 -0500
Dear George, I think this statement needs some comments/corrections. On Thu, 2 Dec 2004, George Huxtable wrote: > Not everything in astronomy is deterministic. Even in a system, such as the > solar system, in which more than two bodies have a mutual gravitational > interaction, there's a limit to the long-term predictability of it all. > This is the famous "three-body problem". This is not a problem for modern astronomy. If we are talking of "predictions" (forward or backward) for the period of few thousand years, this will cause no problems (in principle). As I understand you were talking of Tycho Brahe observations. The algorithm of such calculations is contained in the book of Meeus "Astronomical Algorithms". I doubt that these calculations can be easily done by hand, but they can be done with a computer and I suppose that Frank Reed's program can do this. The "long term" prediction is indeed impossible, (because the many-body problem of celestial mechanics has no simple solution) but "long term" in this sentence refers to billions years. For all "practical purposes" such prediction can be done. Alex.