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: [Phys-l] Teaching elementary astronomy topics



I fail to see how teaching about Black Holes and Expansion of the Universe is an improvement (or even a change over) teaching "factoids". The topics may be more sophisticated and complex than factoids, but at the level they must be taught (and without a good course in physics beforehand) the "exiting topics" are just fancy factoids.

Pasachoff'stexts (which I have used) are very good, but they are very short on physics and long on scenario based narratives. I doubt very much that a student coming out of a one semester college level Astronomy course could read an old bit of pseudoscience like Velikovskys "Worlds in Collision" and even begin to explain at any level what is wrong with those ideas.

I have stopped teaching Astronomy in favor of Meteorology. I can directly incorporate more basic physics directly into the course and offer more meaningful hands-on experiments and work-book exercises using current weather than I felt able to do with astronomy. One thing I find fascinating is that the meteorology students have a much better grasp of the causes of season than my astronomy students did even though we spend less time covering it in the course.

I still hold observing sessions in astronomy throughout the year and they are surprisingly well attended by students who have not taken a science course. They relish the "factoids". They want to know the names of constellations, how to find the "North Star", and of course "How far away is that star?" Students who have never seen Saturn in a telescope just keep repeating "That's amazing - I had no idea you could see that - Thanks so much for showing this". They are truly excited by the factoids.

Bob at PC

________________________________________
From: phys-l-bounces@carnot.physics.buffalo.edu [phys-l-bounces@carnot.physics.buffalo.edu] On Behalf Of Leigh Palmer [palmer@sfu.ca]
Sent: Friday, November 12, 2010 8:28 PM
To: phys-l@carnot.physics.buffalo.edu
Subject: [Phys-l] Teaching elementary astronomy topics

Jay Pasachoff, whose astronomy textbooks must have made him a wealthy man (the books are pretty good, too), wrote a shocking letter* to The Physics Teacher. It appears in the October 2010 issue. In his letter he suggests that if students don't understand what I and many others consider to be important elementary astronomical topics, the mechanisms behind seasonal climate variation and lunar phases, then we should simply stop teaching them. He says we should teach "exciting topics", like black holes and expansion of the universe. I hope no one takes this suggestion seriously. Teaching factoids to high school students, which is all you can do regarding those interesting topics, surely gives the impression that astronomy is a descriptive discipline, like natural history. Astronomy is a rigorous discipline, like physics, and because it is the ancestor of all the rigorous sciences it is important to teach some of it to students of those disciplines. An argument similar to Pasachoff's could be made for skipping classical mechanics and proceeding directly to quantum physics because so many students perform poorly on the FCI. I don't see merit in that either, and for the same reason.

On 11 Nov 2010, at 05:50, John Clement wrote:

The period of the Earth's revolution around the sun is one where they have
been taught the facts, but not in a connected fashion. So students will
tell you summer is warmer because we are closer to the sun, but it is
actually the opposite. Since this is basically trivia to them, of course it
does not stick well. Sherlock Holmes didn't want to hear the astronomical
facts from Watson because he considered that it would clutter his limited
memory. This is highly dependent on how the ideas are taught. How many
students can tell you that flowers are for "plant sex"? How many students
will tell you that the phases of the moon are caused by the Earth's shadow?
See the "Private Universe" video!

I just looked at the Private Universe video for my first time. There are no surprises there. For example, the teacher seems to think that the student (Heather) has a problem with the concept of "direct" and "indirect" illumination. Both teacher and student have problems there. The teacher's problem is imprecise language and, I think, seasonal variation itself. To illustrate, let me point out that here in Vancouver we never get "direct" insolation, but we have seasons. A bright student might even challenge her teacher to explain why, given this mechanism, people living on the equator don't have two summers and two winters per year.

I suggest that teaching a student about "direct" and "indirect" insolation perhaps confuses the student unnecessarily. Talking about the seasonal variation in duration of insolation is probably easier to sell, and it is more important at most latitudes than angle of incidence of insolation.

Pasachoff's suggestion makes me think he believes the students are stupid, incapable of being taught. I believe that many of them are ignorant, but it has been a fundamental belief of mine that many ignorant students are not stupid, and that a worthwhile number of them are educable. I can teach any educable student the elementary topics discussed here one-on-one. It may turn out that individual tuition is the most economical way in which such student can be taught. In order to employ this method efficiently one should have a rigorous filter in place to weed out the stupid ones before trying to teach them. Cambridge University (which has very strict entrance criteria) employs grad students and postdocs, and even a few faculty, in "supervisions" that get the teaching down to the one-on-two level. It seems to work.

(I am convinced that these simple solar system topics should be taught in secondary schools or earlier. I think that teachers ought to understand these topics to teach them, and I think the teacher in the film does not understand the seasons. I am unsurprised that she was unable to teach the topic to a bright student.)

Leigh

There is another very similar video on the same site that bears watching. It is on a biological topic. See "Thin Air" at <http://www.learner.org/vod/vod_window.html?pid=77>

* For the benefit of those who do not read TPT or cannot obtain access to it I reproduce below an edited version of Jay Pasachoff's letter. Any errors in transcription are mine:

Regina Barrier's shocking result (1) that “only 4% … completely and accurately answered” how the phases of the Moon are produced, with 28% partially answered, is even worse than I expected. Further, even after explanations were given, only 16% gave completely correct answers and 44% partial answers. My conclusion, previously discussed in The Physics Teacher (2),(3) Astronomy Education Research (4),(5) and elsewhere, is that the three-dimensional spatial-relations nature of lunar phases is too complex to waste time on in high school or college courses.
Rather, I prefer to see students of high school and college ages taught about the exciting things in contemporary astronomy, such as black holes, the expansion of the Universe, the dynamic Sun, the evolution of stars, the exploration of the solar system, exoplanets, and so on. Dwelling on phases and seasons gives students a negative view of the nature of science and the activities of scientists, and is, well, a black hole.

References

1• Regina M. Barrier, “Astronomical misconceptions,” Phys. Teach. 48, 319–321 (May 2010).
2• Jay M. Pasachoff, “What should students learn?” Phys. Teach. 39, 381–382 (Sept. 2001).
3• Jay M. Pasachoff, “Pasachoff's points,” letter to the editor, Phys. Teach. 40, 196–198 (April 2002).
3• Jay M. Pasachoff, “What should college students learn?” Astron. Educ.Res. 1 (1), 124(2001).
5• Jay M. Pasachoff, “What should students learn? Stellar magnitudes?” Astron. Educ. Res. 2 (2), 162 (2003).

_______________________________________________
Forum for Physics Educators
Phys-l@carnot.physics.buffalo.edu
https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l