[net.astro] Tropics

msb@lsuc.UUCP (Mark Brader) (07/30/85)

This item entered net.space from the Arpa side.  On Usenet it obviously
belongs in net.astro.  I'm reposting it as a cross-posting so that followups
will go both to Usenet net.astro types and to the Arpans who originated it.

Reposted by Mark Brader

> From: Houser@MIT-MULTICS.ARPA
> 
> 
>           A book I was reading recently mentioned  that  over  time  the
> angle  of  the plane of the ecliptic changes.  The consequence is that
> the latitude of the tropics also move.  While this  makes  sense,  the
> book  also  stated that there is no formula which describes the motion
> over  time.  Is  this  really  true?  The  context  was  that  certain
> archeological  sites  are  solstice  oriented  and could be accurately
> dated if it was known in what year a Tropic was at  X  latitude.  Just
> curious.
> 
>                                         jim@tycho