At 09:13 AM 6/21/02, Sean wrote: >At 03:22 AM 6/21/02 -0500, Ronn wrote: ><snip> >>Some (not all) recent books I've seen seem to go to great pains to never >>show the beginning student anything that looks like a "miniature solar >>system" diagram, but from the beginning show "fuzzy electron clouds" >>because "that's how it really is" even when the idea of electrons in >>discrete orbits makes the concept being discussed easier to grasp. So >>far, I haven't found that switching back and forth loses the students, >>particularly if one is careful to point out from the beginning that no >>model can possibly show what the interior of an atom "really looks >>like." After all, we have to switch back and forth all the time between >>the wave nature of light (most optics) and its particle nature (spectral >>line production and the photoelectric effect) . . . > >I've not looked at any textbooks for a long time... I guess some of them >are giving up on a partial historical background then?
I suppose it's one of the things that gets short shrift because there is just so much to cover in a semester. (One of the buttons I have reads "So many galaxies . . . so little time.") However, I do spend a bit of time in class to cover the history of the modern theory of the atom: Becquerel's discovery of natural radioactivity, the identification of the three types of radiation, Rutherford's gold foil experiment, the problem that according to Maxwell an orbiting electron should radiate away all its energy and fall into the nucleus very quickly and Bohr's ad hoc solution to the problem, etc. >I always thought it was a great way to get at the innards of atoms a >little at a time. Yes. You have to be careful when you open them up, or those suckers will go nuclear on you . . . >Of course I was also always a fan of presenting things in as many ways as >I could think of to catch the greatest number of students (office hours >tended to run long...). Have you seen those folding plastic carts that when open look kind of like a milk crate with two wheels and a handle? I use one of those to carry my overhead projector transparencies to class . . . (OK, to be fair: I teach alternate nights on two separate campuses, which means I pretty much have to haul everything back and forth rather than being able to leave most of it in one central location, so I have the transparencies in hopefully some sort of order in several fairly large 3-ring binders, and those, plus the textbooks and some other stuff, is what I haul in the cart. And I hope some semester real soon to finally start being able to transfer a fair amount of those visual aids onto CD-ROM and use a computer to project them. However, this is the first term I have been able to count on having a suitable computer with projector or large-screen monitor available for every class period, which is a long story, not to mention having another computer with enough hard drive space to hold a bunch of graphics files while I edit and sort them and also a CD burner . . . ) >Since that and the conviction that teaching causes ulcers are the extent >of my philosophy of teaching, I'm trying to stay clear of academia. ;-) I enjoy teaching. Apparently the feeling is mutual: if the powers that be would let us schedule it (another long story, and the kind of thing that probably comes closest to inducing ulcers, as when it comes to issues like this I am reminded of my position at the very bottom of the pecking order ;-) ), I could easily fill two sections for every one I teach. >>><snip> >>Most students, however, seem to see P-chem as something that must be >>endured and gotten over with as soon as possible, sort of like a root >>canal . . . ;-) > >Honk if you passed P-Chem! (actual bumper sticker) Yep, I've seen it. -- Ronn! :) Ronn Blankenship Instructor of Astronomy/Planetary Science University of Montevallo Montevallo, AL Disclaimer: Unless specifically stated otherwise, any opinions contained herein are the personal opinions of the author and do not represent the official position of the University of Montevallo.
