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Re: Real accuracy of the method of lunar distances
From: Jared Sherman
Date: 2004 Jan 15, 21:08 -0500
From: Jared Sherman
Date: 2004 Jan 15, 21:08 -0500
George- [js]".05 seconds of arc [or] 0.2 >seconds of time." [gh]I have no idea, none at all, what those numbers are supposed to represent In your reply to me, you said that an error or .05 seconds of arc, which is equivalent to a change of 0.2 seconds in the GMT figure resulting from clearing a lunar, could be ascribed to the effect of "parallatic retardation". I asked you what the gross error in local time ( or position relative to Greenwich, whatever one prefers to call it) calculation might be due to parallatic retardation. Your answer that this effect might cause a difference of 0.2 seconds, when a skilled observer can only ascertain their position within 60 seconds, is what your answer meant to me. Or did I completely misunderstand you? My question was and is, how great an effect this tempest in a teapot has on the final result produced by clearing a lunar. Does it or does it not cause a maximum change of 0.2 seconds in the final calculation of GMT, which a skilled observer can only hope to calculate within one minute (60 seconds) at the best of times?