Dot Physics

Re-thinking physical science

I am teaching physical science this semester. It appears that I will be teaching it again this summer. Ideally, I would like to switch to something like Physics and Everyday Thinking for large lecture courses. A course like this is being developed, but it isn’t quite finished. Also, the current version includes chemistry and physics. I really need something different (we offer physical science 101 is physics and 102 is chemistry).

The current course is pretty traditional. Your basic physical science stuff. It has the following content.

  • Forces and Motion
  • Newton’s Laws
  • Projectile motion and gravity (these first three are like 4 chapters)
  • Pressure, fluids, buoyancy
  • Thermodynamics and stuff
  • Circuits
  • Electric interactions
  • Waves and Sound
  • Light and electromagnetic waves

Maybe not exactly that order, but you get the idea. Pretty traditional stuff.

But here is what I am thinking. What is the purpose of this course? Why are students taking it? What do I want them to get out of it? Does it need to prepare them for any future courses? The answer to last question is “no”. The second physical science course (the chemistry one) does not have any pre-reqs. In fact, students can take these in any order. The other questions can maybe be answered by describing this as a course for non-science majors that satisfies their general education requirements.

Here is my new plan. Maybe structure the course something like this:

  • Fundamental forces (basically gravity and electromagnetic forces)
  • Force and motion (very simple – saying forces CHANGE motion)
  • Energy and conservation of energy
  • Atomic nature of matter
  • Basic quantum nature of matter – you know, Bohr model type stuff
  • Light and spectroscopy
  • Cool stuff that can be explained with the above for the rest of the semester

I would still use the same textbook, it basically has all these ideas in there, just not in the same order.

Comments

  1. #1 Joemac53
    March 26, 2010

    I have been a high school teacher of physics and math for over thirty years in a public school in a science-oriented town. I was sure that my physics course for seniors was probably the only physics they would be exposed to unless they majored in science in college. For many years I taught the same group math and physics. That job was the best job in the whole school system.
    I never considered my physics class to be a prep for another course. I wanted to get my students excited about analyzing how the observable world works. I counseled my students to take physics in college if they found any way to fit it in.
    Eventually they found out what a great time I was having and made me teach the AP curriculum squeezed into one year. Not as much fun. I applaud your approach, and I bet the students will benefit!

  2. #2 Chris
    March 26, 2010

    Ahhhh! Don’t do it! Stay classical! Quantum mechanics is the antithesis of “everyday thinking”.

  3. #3 Cameron
    March 26, 2010

    I found this book to be nice in applying the basic concepts to everyday life:

    http://www.amazon.com/How-Everything-Works-Physics-Ordinary/dp/047174817X/ref=tmm_hrd_title_0

  4. #4 Jim
    March 26, 2010

    I’ve taught physical science for about 20 years, but it is different from what you describe. The first semester is Astronomy,geology and meteorology. The second semester is physics and chemistry.

    As far as topics, I agree with Chris. Stay away from quantum mechanics. The target audience for physical science is non science majors. They really don’t care about the ‘cool stuff’ that gets physics majors like you and I excited, and the math concepts for quantum will just sail over their heads. I know what I just wrote sounds like heresy in a physics department, but its true. You are not trying to train physics majors in this class: these are accountants and Walmart managers and lawyers and kindergarten teachers. Ask yourself what affects their daily lives?

    How about Hurricanes and oil and natural gas? Everybody in southern Louisiana lives with those every day. You might call it a unit on global warming and how it effects southern Louisiana. Or if that title is too controversial, call it applications of energy. Try to straighten out some of their misconceptions on those topics.

  5. #5 josh g.
    March 26, 2010

    If you do end up covering electricity and circuits, I would love to hear your version of how to explain voltage. I have a computer engineering background, know (or knew once) how to work out and solve problems in circuit design, etc. But when I went to my wife’s science class to help teach the electricity unit, I realized that I really didn’t know how to explain what voltage actually *is* – where it comes from. I knew how it behaved but every time I thought I could see how it connected to, say, electric fields or static electric charge, it didn’t quite fit.

    High school texts (that I’ve seen) all do a horrible job of explaining voltage, which is why I was trying to do it justice. I’d love to hear a good explanation at a first-year / high school level if at all possible.

  6. #6 Alex
    March 26, 2010

    Is the course you’re describing a large lecture course or is the large lecture course what’s being developed for the future? When you say “forces CHANGE motion” does that mean you are going to avoid discussing acceleration? I find acceleration to be incredibly difficult for students to really understand.

    We’ve been talking a lot recently about what should be the purpose of our physical science course. One idea we’re kicking around is trying to use the course to teach students about levels of understanding. We might discuss Bloom’s Taxonomy with students and try to convince them that “understanding” isn’t binary it’s a continuum. Our hope is that this could help students become better learners in other subjects and really be something they take away from the class. This might also help students understand why we ask the kinds of questions we do (both on exams and in our own research) and why what they think of as a complete answer or explanation is often seen by us as an incomplete answer or explanation.

  7. #7 Rhett Allain
    March 27, 2010

    @Jim,

    Maybe you are right about what they think is “cool”. I guess there are two ways to approach this – what can they use or what is the very basics of science.

    Oh – and I think quantum could be covered with no math. I am not going to do the schrodinger equation or anything – but talk about the basic ideas that are important for other stuff.

  8. #8 Rhett Allain
    March 27, 2010

    @Josh,

    I will keep you updated. Actually, soon (hopefully) I will post on the basics of electric fields and change in electric potential. Maybe that will help.

  9. #9 Rhett Allain
    March 27, 2010

    @Alex,

    I agree that acceleration is perhaps too difficult for students. My feeling is that this problem with acceleration is basically due to student problems with the difference between a quantity and the rate of change of that quantity.

  10. #10 CCPhysicist
    April 5, 2010

    Are you using the Hewitt et al “conceptual” book? If not, look it over. Their treatment of voltage as a kind of “pressure” seems to work with students. They also do a great job of building up atomic physics before getting to the foundations of chemistry, so that could also be used if you wanted to examine that before going back to look at light. And my experience is that they ARE interested in quantum mechanics.

    I have also thought seriously about developing a “how things work” course, although my instinct is to base it on the original “popular” book rather than the textbook version that has been produced. However, I don’t teach the gen-ed class enough to make it worth my while to develop an entirely new course with all that entails.

    Starting with “outcomes” is a good idea for many reasons. The one thing I want my students to learn is why they should wear a seatbelt. (The odds of having a student who has rolled a car or knows someone who did is right up there with the odds of two students having the same birth date.) Newton’s first law can kill you!

    Velocity is bad enough. Acceleration, a change in a change, is really difficult. The concept that gravity can slow you down and then speed you up without the force changing direction … that is really REALLY tough.

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