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] kinematics objectives



On 05/09/2013 06:08 AM, Philip Keller wrote:
I am going to reword the section to remove the term "weight" and
replace it with "the earth pulling on the object".

Another good euphemism for "weight" (W)
is _"the force of gravity"_ (F sub g).

=======================

As for simulations: Galileo is called the father of modern science, in
part because he unified -- once and for all -- theory with experiment.
Nowadays, however, there are three components, not just two:

theory experiment

simulation
and
visualization

Computer simulation revolutionized physics about 60 years ago.
Incorporating it into the classroom is revolutionary ... and
several decades overdue. The simulations change how we think
about the theory. They also change how we think about the
experiments. Simulations can be used both as part of the
pre-experiment preparation, and as part of the post-experiment
analysis.

And I think they are good for targeting specific misconceptions.

Let's be careful about that.

As I have mentioned previously, in this forum and elsewhere, you
usually get better results from the positive approach (promoting
correct conceptions) than by the double-negative approach (trying
to suppress specific misconceptions one by one).
http://www.av8n.com/physics/pedagogy.htm#sec-miscon

In rare but important cases, a misconception may be so prevalent
and/or so pernicious that it must be confronted. Still, though,
this should be considered the exception, not the rule.

Part of the problem comes from the Anna Karenina principle:
"Every student who gets the right answer gets more-or-less
the same right answer; every student who is confused is
confused in his own way."

That means that even though you can sometimes get away with
confronting misconceptions in a one-on-one teaching situation,
it is much less practical in a classroom situation.

A solid understanding of /one/ correct concept (such as conservation
of momentum) will wipe out thousands of different misconceptions.

As a specific example of what I'm talking about:
I am absolutely appalled by the traditional method of teaching
special relativity. It involves /creating/ misconceptions (aka
paradoxes) that the students would never have thought of on their
own, and then trying to dispel the misconceptions.

In contrast, I recommend telling students that relativity is not
weird or even complicated. In fact, most of what relativity tells
us is stuff we already know. It provides a simplified and unified
explanation for things we would otherwise have to learn in a
helter-skelter non-unified way.
http://www.av8n.com/physics/spacetime-welcome.htm

There is a maxim that says "learning proceeds from the known to
the unknown" i.e. from the familiar to the not-yet-familiar.
So I would recommend starting with a simulation of the utterly
familiar case, where there is no chance of a misconception ...
and then gradually expanding the envelope to include less-familiar
cases ... at every stage emphasizing how the new situation makes
sense in terms of what is already known, emphasizing the
/connections/ between the various correct concepts.


With rare exceptions, the correct concepts crowd out misconceptions,
rather like the way a healthy lawn crowds out weeds.

There are (so far as I know) no paradoxes in the correctly-stated
laws of physics. To a first approximation, I would be happy to have
students understand the laws of physics so clearly that they cannot
even think of a paradox, and cannot even find the words to express a
paradox.

Bottom line:
-- simulations are good
-- the vast majority of simulations should be organized around
promoting and interconnecting the correct conceptions
(rather than "targeting specific misconceptions")

Reference: http://www.av8n.com/physics/pedagogy.htm#sec-miscon