Phys-L has been relatively quiet lately, so I'll try to spark some
controversy and discussion; perhaps revealing some of my own misconceptions.
First, I'll echo Poj with thanks to Bill for the Naive ideas file.
And now for the fun: Quibbles regarding some items on the list. I'll
assume here that all items are intended to be incorrect ideas; and ideas of
children. To save time I'll seperate each of the categories of the list;
this one just involves the "Forces and Motion"
So with some trepidation, here goes.
3. A rigid solid cannot be compressed or stretched.
My quibble here is similar to the state that the word "work" in physics has
a technical definition or meaning which is not isomorphic to its everyday
meaning. "rigid" has a technical meaning which is usually defined as an
object that cannot be compressed or stretched. Hence, the significance of a
corollary to the postulates of SR (special relativity) - "there is not such
thing as a rigid object". So I'd the statement is correct.
Of course, I assume the child's version is referring to ordinary solids that
exist in nature; in which case it is a misconception.
10. Frictional forces are due to irregularities in surfaces moving past each
other.
I believe this could be viewed as correct as long as we don't mean *all*
frictional forces and seek a statement that isn't at the deepest level of
understanding; which of course would have to talk about fricitional forces
in terms of electrostatic forces.
12. Time is defined in terms of its measurement.
Philosophers spend a lot of time discussing this. If one believes that the
true definition of all concepts must be reduced down to operation
definitions, then the statement is correct!
Joel Rauber
rauberj@mg.sdstate.edu
PS
Hi to everybody on Phys-l after being gone over the summer; while phys-l was
missed, I enjoy being away from technology on the AT for much of the summer!