Chronology Current Month Current Thread Current Date [Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

# Re: spherical geometry

Google reveals a history of heated contentions among the Islamic faithful as
to whether the rhumb line or the great circle is to be used to determine the
Qibla (local direction pointing to Mecca). In N. America this can mean a
question of pointing either S of E or N of E. The prayers of those using
the S of E direction were labelled as invalid by the enlightened N of E
faction in the late 1970's. For an interesting mixture of this religious
history and a calculation of the great circle direction, go to:

http://patriot.net/~abdali/ftp/qibla.pdf

Bob Sciamanda
Physics, Edinboro Univ of PA (Em)
http://www.velocity.net/~trebor/
trebor@velocity.net
----- Original Message -----
From: "Hugh Haskell" <hhaskell@MINDSPRING.COM>
To: <PHYS-L@LISTS.NAU.EDU>
Sent: Thursday, August 19, 2004 1:19 PM
Subject: Re: spherical geometry

| At 8:56 AM -0500 8/19/04, RAUBER, JOEL wrote:
| >
| >As a side note, the airlines and mariners have long been interested in
the
| >solution to this problem. And certain map projections have been designed
to
| >facilitate the solution.
| >
| If memory of my days doing navigation while in the Navy serves, There
| is not a single heading one can take to follow a great circle route
| from point A to point B, since the great circle route crosses each
| meridian at a different angle, and it is that angle that determines
| the compass heading one takes at that point. The straight line path
| on a Mercator projection map (called a "rhumb line") does have a
| constant heading, but it is not the great circle path.
| . . .|
| Hugh Haskell
| <mailto:haskell@ncssm.edu>
| <mailto:hhaskell@mindspring.com>