Re: [Phys-L] The Make-Believe World of Real-World Physics

[John Denker <jsd@av8n.com>]

On 07/11/2013 01:43 PM, Anthony Lapinski wrote:

> I disagree that physics concepts are simple. They are not! 

Not simple?  Compared to what?

Your students are old enough to get a job and raise a family.
Compared to living in the real world, classroom physics is trivial.

> Try to explain
> velocity and acceleration to students. Throw in some graphs, and it
> complicate matters. Roll a ball down a ramp and ask the kids when the
> instantaneous speed equals its average speed for the entire trip. Even my
> brightest students miss this one. This is difficult! Then do the three
> hill problem (from Hewitt), with a constant slope, concave, and convex
> hills. Which ball makes it to the bottom first? Few get this correct.
> Still, it's an interesting question to show that velocity an acceleration
> are different. And they are hard to understand!

Some of that is a question of style and a question of taste, so 
I am very hesitant to argue the point.  De gustibus non disputandum.

Still, though, perhaps I can get away with mentioning that another
style exists.  With rare exceptions, I would never tell students
that the subject is hard.  I say:
 -- We do *not* do hard problems in this class.
 ++ We do important problems.
 ++ We do interesting problems.
 ++ We do problems that /would be hard/ if you didn't know the 
  right technique for solving them.  So, let's get started learning 
  some useful techniques......

> Throw in some graphs, and it complicate matters.

Wow, that is just diametrically different from my style.  The whole 
point of the graph is to make the problem /easier/ to solve, easier
to understand.  If the graph doesn't make things easier, don't bother 
with the graph!


On 07/11/2013 04:12 PM, Marty Weiss wrote:

> The math may be the "fun" to those who "get" the math.  But to what
> seems like the majority of students who HATE math, the math is why
> they hate science in the first place.

It's not that simple.

/Some/ students have decided they're going to hate everything, and
there's nothing you can do about that ... but we should not tar all
the students with the same brush.

There are plennnnty of students out there who have been abused by
the system, and have every reason to hate the pseudo-math and pseudo-
science that has been inflicted upon them.  However, this is a fixable
problem.  I'm not saying it's easy to fix, but it's fixable.

Fixing it includes explaining why physics is important and useful in
the real world.  If somebody asks "What is physics good for" you should
be able to give ten good answers in thirty seconds.  If not, this is
something you need to work on.

Fixing it includes explaining that math is important and useful, partly 
for its own sake and partly because it is needed for doing physics.
The physics gives students a reason to care about math, perhaps their
first-ever reason.

Science minus math is not science.  Not even close.  Galileo is called
the father of modern science because he united methodical observation
with state-of-the-art mathematics.  If you try to undo this, you destroy
everything that science stands for.