Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/5/84; site mordor.UUCP Path: utzoo!linus!philabs!cmcl2!seismo!ut-sally!mordor!@S1-A.ARPA,@MIT-MC.ARPA:Lynn.ES@Xerox.ARPA From: @S1-A.ARPA,@MIT-MC.ARPA:Lynn.ES@Xerox.ARPA Newsgroups: net.space Subject: Re: Precession of the equinoxes Message-ID: <2993@mordor.UUCP> Date: Thu, 8-Aug-85 12:36:18 EDT Article-I.D.: mordor.2993 Posted: Thu Aug 8 12:36:18 1985 Date-Received: Sun, 11-Aug-85 04:31:07 EDT Sender: daemon@mordor.UUCP Lines: 18 From: Lynn.ES@Xerox.ARPA Contrary to previous statements made here, the precession of the equinoxes IS related to the Gregorian Calendar. Without precession, the seasons would reoccur every 365.2564 days (a sidereal year), and thus occasional EXTRA leap years would be needed to cause the average year to be more than 365.25 days. With precession, the seasons reoccur every 365.2422 days, and thus occasional dropped leap years are needed (3 out of every 4 century years are dropped). In other words, the earth reaches the point where its pole points most nearly toward the sun (beginning of summer) slightly earlier due to precession (movement of the direction of that pole). Another way of viewing it is that our seasons cycle 25,799 times while we make 25,800 trips around the sun, the difference of one being that our axis rotated once in that time period due to precession. /Don Lynn