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-----Original Message-----
From: phys-l-bounces@mail.phys-l.org [mailto:phys-l-bounces@mail.phys-
l.org] On Behalf Of John Denker
Sent: Thursday, May 10, 2012 11:12 PM
To: Phys-L@Phys-L.org
Subject: Re: [Phys-L] Conceptual Physics Course
My first suggestion: Item 10 could be strengthened ... and then moved from
the bottom of the list to the top. That is, IMHO,
1') The most important goal is for students to love
learning and enjoy thinking.
Rationale: If they don't see the course as a whole (and almost every part of
it) as a positive experience, they will forget about it as quickly as possible ...
which means the whole exercise will have been a big waste of time and
money.
Also note the following, which is true but unfair and ironic:
a) Suppose the track coach says his goal is to teach people to run
better. That's OK. Everybody knows how to run, but a good coach
can teach them to run better.
b) Suppose the physics teacher says his goal is to teach people to
think better. That is not a tactful thing to say. People think
they know how to think and to learn, and they get resentful and
defensive if anybody suggests they should change their ways. The
ones who would benefit the most, the ones who have no clue what
hundreds (or thousands) of years of learning theory tell us ...
those are the ones who are most resistant.
There is a vicious circle here that can (in favorable cases) be turned into a
virtuous circle, if you can find a way to reverse the momentum: If they enjoy
learning, they will get better at it, and if they get better they will enjoy it
more.
Another semi-related suggestion: This is mostly implicit in several
of the original list items, but could perhaps be made more explicit:
2') Another important goal is for students to appreciate the unity
and power and grandeur of physics. This includes understanding
how each physics idea is connected to others, and connected to
important real-world applications.
Rationale: I really wanted to get the word "connection" in there.
I subscribe to a heavily connectionist theory of thinking and learning.
It has been know explicitly for over 100 years (William James, 1898)
-- and probably going back centuries earlier -- that an idea is
useless and might as well not exist if it cannot be called up when
needed. It is called up based on its /connections/ to other ideas.
There is no real distinction between memory and thought, because
recall is itself a thought process. The key to a good memory is
to take each new idea and mull it over, looking for connections to
what is already known ... and also (!) looking for inconsistencies.
Again we come to something that cannot tactfully be said in front
of students: It is just astonishing how many of them have gone
to school for 12 years yet do not exhibit any systematic understanding
how to learn or how to think. It's obvious that they *can* think,
because they show originality and creativity and abstract thinking
in the games they play outside of school ... yet it seems they have
been trained to never show any sign of critical thinking during school
hours.
All too often, students are led to believe that "learning" is synonymous
with writing down class notes verbatim. All too often, they are taught
never to disagree with the text, never to disagree with the teacher,
and never to ask questions.
We need to do better. This leads to:
3') Another important theme is the importance of asking questions
and the importance of being able to think for yourself. This
touches on creativity and originality, as well as scientific
independence and scientific integrity.
Einstein complained that his teachers expected Kadavergehorsamkeit :
the obedience of a corpse.
Let's be clear: I am not in favor of mindless disobedience any
more than I am in favor of mindless obedience. In fact I generally
recommend using the minimum amount of disobedience necessary to get
the job done.
A radical iconoclast smashes all the icons in sight, just for fun.
That's not me. I am a very conservative iconoclast. I like to
identify the one icon that needs smashing, and then smash it
precisely ... while leaving the other icons intact, or indeed
more secure than they were before.
Specifically, this is why I am offended by the school of thought
that claims special relativity is "exciting" because it allegedly
overthrows all of classical physics. IMHO that attitude is a step
in the wrong direction, very nearly 180 degrees from the right
direction.
Actually, the power and beauty of special relativity comes from the
fact that it is consistent with and /connected/ to everything you
knew about classical physics.
-- A rotation in the xt plane is profoundly similar to a rotation
in the xy plane. It is as similar as it possibly could be without
quite being identical.
-- This /connects/ geometry and trigonometry to kinematics, in
a new, simple, and beautiful way.
-- The relativistic kinetic energy is /connected/ to the classical
kinetic energy in the simplest possible way. Among other things,
this allows us to understand why KE = ½ p*v for slow-moving particles
while KE = p*v for fast-moving particles. We understand both of
those limiting cases _and everything in between_ in terms of the
geometry and trigonometry of spacetime.
-- More generally, we understand the /connection/ between mass,
momentum, and kinetic energy. They are in fact the 0th-order,
1st-order, and 2nd-order terms in a power series.
-- Special relativity /connects/ the electric field to the magnetic
field (and of course connects them both to the geometry and
trigonometry of spacetime).
I am reminded of expressions such as "connecting the dots" and
"seeing the big picture". Special relativity does not overthrow
the pre-existing dots. It connects the dots. If special relativity
seems weird and paradoxical, you're doing it wrong.
http://www.av8n.com/physics/spacetime-welcome.htm
I mention this as just one example of the unity and power and
grandeur of physics ... and also as an example of what the thinking
and learning process looks like, whereby one can be open to new
ideas /without/ overthrowing very many old ideas.
See also next message.
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