NavList:

Joe Shields wrote:

"Everybody can relate to the Sun at high noon and the Sun at sunset."

 

Sure. But the flagpole analogy drives the point home and clarifies which aspects of celestial lines of position depend on the great distances of the stars and which do not. Of course, careless instructors can mess things up. If one is taught the flagpole business without that all-important word --analogy!-- it can create more confusion that it's worth.

 

And:

"Everything one needs to understand celestial navigation was learned in grade
school."

 

If you're counting grade school as running through 8th grade or so, then yes.

 

And added:

"(i.e. Declination = revolution of an earth tilted on it's axis)."

 

Hmmm. I can't think of any sense in which this 'equation' makes sense. Can you explain further?

 

And:
"Better to start with that then to start with an erroneous analogy.  Start with a flagpole if you must... just don't put a star on top of it."

 

First, the analogy is not necessarily erroneous (unless the word analogy is dropped). But the main thing here is that ANY student of celestial navigation can benefit from comparing a case of objects at fixed heights ("stars" on flagpoles) above a flat surface and a case of objects at infinite distance ("stars" idealized on the celestial sphere) above a spherical surface. The similarities AND the differences can help to illuminate the aspects of the celestial navigation problem which depend on the great distances of the stars.

 

And you concluded:

"In the student's mind it may be stuck there for too long a time and that (IMHO) is
not a star to steer her by."

 

Yes, this is the real risk in any educational situation. You need to make sure that analogies are not over-done. But you also can't throw them out and insist that all students must learn alike or not learn at all. Some students benefit from one sort of explanation. Others benefit from other sorts of explanation. And you need to be prepared as a teacher with a dozen different ways of saying the same thing. That's why teaching is an art and not a science.