@S1-A.ARPA,@MIT-MC.ARPA:jim@TYCHO.ARPA (08/19/85)
From: jim@tycho.arpa (James B. Houser) Hi Since I started all this let me try to clear up what I was trying to ask. The question was Q. Is there a way to mathematically describe the changes in the tilt of the earth's ecliptic over time. Note that this has no relation to PRECESSION, LEAP SECONDS, RENT RIOTS, or Julius Caesar. It does relate to the movement of the solstice lines or Tropics. One person did submit a formula but it appears to be bogus. >The tilt or obliquity of the ecliptic also changes. This is a >long period change of 41,000 years that takes the tilt from 24.5 >degrees to 22.1 degrees at about .47 seconds per year. This >change of tilt affects solar phenomena like sunrise, sunset, etc. >The formula for the tilt is: > > 23 degrees 26 minutes 21.448 seconds > - 46.8150*T seconds > - .00059*T*T seconds > + .001813*T*T*T seconds > > where T is the number of Julian centuries from 2000 > > This appears not to be a legitimate equation (my overworked floating point hardware agrees). Sorry if I was unclear in my original submission. Thanks for the attempts at help. jim@tycho -------