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Re: [Phys-l] "Unlearning"

Very true. But there is no good term for "unlearning" things which are
contradictory to physics. So I would use the term unlearn in a more limited
sense that one can remove the inappropriate connections so that one uses
good physics concepts rather than the preconceptions. In other words
unlearning medieval physics concepts and instead embedding Newtonian
concepts. Technically one can "reconsolidate" memories which effectively
erases the old memory and replaces it with a new one. The term
reconsolidate is now used in psychology as a technical term.

As I have pointed out there is research that connections can be erased and
that facts can be changed in your mind, so in a sense unlearning can take
place. But of course for more complicated models, the number of connections
that must be changed may be quite large. That is where the student has to
consciously form a new model and understand that the older one is not
useful. With time the various old connections may be erased, but some may
still remain. I would call this unlearning.

Being able to pick the appropriate concepts for a physics situation is
another expert ability which does not require "unlearning".

John M. Clement
Houston, TX



I think that a good part of the discussion of this topic would be
unnecessary
if we realize that the word "unlearning" is a very unhappy choice of
terminology
when describing the progress of Physics. In most cases, the appearance of
a new
physical theory does not cancel the previous one. Learning QM or SR does
not
involve "unlearning" classical mechanics. No engineer will describe the
motion
of a street car using the Schrodinger equation or relativistic dynamics.
Classical mechanics is much more than merely a special case of QM - it is
a
necessary element of its foundations (see, e.g., Landau-Lifshits
textbook). The
same can be shown about the relationship between classical mechanics and
SR.
Even in the relativistic domain, F=ma and P = mv are not cancelled by SR,
- just
the concept of mass has been generalized. Learning about spacetime is not
unlearning the relativistic effects - length contraction and time dilation
are
not cancelled by spacetime - quite the contrary, they form its physical
underpinnings. Learning the GR is not unlearning the SR. Most good
textbooks on
GR start with SR. Even learning that the Earth is round is not unlearning
that
it is flat - for all practical purposes it is flat within a sufficiently
small
area, and no architect designs a building using the concept of round
Earth.
Similarly, learning that acceleration of free fall is mass-independent is
not
unlearning that the rate of fall increases with mass - the latter remains
true
in the presence of atmosphere.
Instead of term "unlearning" I would prefer to emphasize that a new
theory
does not cancel the old one but generalizes it and in doing so also
determines
the domain of its applicability. So there is no need to unlearn anything -
moreover, that would destroy our understanding of the modern picture of
the
world.
I think that we as physicists must be very careful when it comes to loose
use
of the language, especially when communicating with non-scientists. I am
afraid
that use of the term "unlearning" has to a large degree provoked a widely
spread
view of science as something permanently cancelling its own previous
pictures
and changing them with totally different ones, and therefore it cannot be
trusted.
I would suggest to discard the term "unlearning" as totally misleading
and
giving downright wrong picture of scientific progress.

Moses Fayngold,
NJIT



________________________________
From: "Espinosa, James" <JEspinosa@mail.twu.edu>
To: Forum for Physics Educators <phys-l@carnot.physics.buffalo.edu>
Sent: Thu, September 16, 2010 11:08:48 AM
Subject: [Phys-l] "Unlearning"

I always warn my students that it is more difficult to unlearn something
old
than to learn something new. This is a fact of psychology. My hope is
that
being aware of this fact will make them more careful in their thinking in
physics.

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




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