Re: Suggestions for new astronomy course

[John Denker <jsd@MONMOUTH.COM>]

At 04:15 PM 4/7/99 -0400, Michael Edmiston wrote:
> I fully support the use of binoculars as a starting point.  That's what
> we use first in our astronomy course.  In the very beginning of
> teaching astronomy, that's all I had,  but it was very successful.  We
> just eventually wanted to see more.  Ideally every student in the
> observing group should have their own.  Until we could purchase an
> adequate supply, we borrowed every pair we could get our hands on.  We
> borrowed from faculty, townspeople, and students.

Yes yes yes yes.

For anyone who is not already *really* into it, binoculars are much better
than any telescope.

I own 7x50 wide-angle binoculars, an Astroscan 2000, and an 11-inch
Schmidt-Cassegrain with clock drive, wide-angle Televue eyepieces, et
cetera.  I get vastly more use out of the binoculars than the Astroscan,
and vastly more out of the Astroscan than the big fella.

For viewing faint objects, you want all the aperture you can get.
The 7x50 has a 7mm exit pupil, which is a good match to the dark-adapted
human eye (especially for kids;  old folks may not be able to open up
enough to take full advantage of it).  This is in contrast to the
more-common 10x35, which has only a 3.5mm exit pupil, more appropriate for
daylight.

I paid 99 bucks couple of years ago for a 7x50 wide-angle with really sharp
optics.  I have no idea what the prices are these days.

There's a treeeeemendous physics lesson in here as to how to build a system
to deliver the brightest possible image (Liouville's theorem and all that)
which I won't go into right now.

Some students will feel disappointed if they never get to look through a
telescope, so maybe you ought to borrow one at some point -- or just crash
one of the star parties organized by the local astronomy club.  But
seriously, folks, most people feel *more* disappointed that looking through
the big telescope yields only marginally more "wow" value than looking
through the binoculars.  Again, there's a physics lesson here: if you were
standing in the thickest part of Barnard's Loop, it still wouldn't be very
bright -- and a telescope can't increase the brightness (at best, it can
only bring it closer).

Cheers --- jsd