Re: Impact of Spheroidicity

[Leigh Palmer <palmer@SFU.CA>]

> Leigh Palmer wrote:
>
> > meaning, I think, that the mouth of the river is farther from Earth's
> > center than is some point far upstream. One could also say that the
> > river's flow is impelled by centrifugal force. Such statements are ones
> > we physicists can all understand and enjoy, but until a student develops
> > the ability to see as we do, such a statement looms larger in importance
> > than it should. The student may even reject physics as being -
> > unphysical!
>
> But Leigh, it's an attention grabber, dontcha see. Tom has bushels of them. He
> would never throw it out and leave his students to grapple with it. But he
> uses
> it as a springboard to the subjects of this thread. Highly effective.

I believe you, and of course I do the same thing, too, all
the time in this group. The way I do it no damage is caused.
The way some others do it, the item ends up as an item on a
standardized multiple choice exam where the damage may be
great. For example, how many students know that "The entropy
is a measure of the degree of disorder of a system?" Many!
What fraction of those know that the entropy of an ordered
pack of cards is *exactly* the same as the entropy of the
same deck rearranged in any other specific manner, all other
factors being equal? Most students, armed with that little
bit of knowledge, will tell you that the entropy of the
ordered deck is lower, and a few physics students I've met
will even be able to calculate a finite difference! They
have been damaged by that little factoid that once appeared
on a multiple choice test; they may be unable to dislodge it
to understand the nature of entropy. That is a problem! If I
were king I would forbid the teaching of that particular
factoid until after the the student had been given a chance
to learn the classical and statistical meanings of entropy.

If a student leaves his last encounter with science knowing
that scientists think the Mississippi River flows uphill and
he does not firmly attach the rest of the knowledge needed
to make that counterintuitive statement meaningful, then I
fear he will be unfavorably disposed toward science for the
rest of his life. I would hate to be responsible for doing
something like that to a student.

Leigh

As a parting shot, does the gravitational force of the Sun
on the Earth point to the center of the Sun as we see it on
Earth?