Re: real-life physics

[Larry Woolf <larry.woolf@GAT.COM>]

> 1.  The quote is from me and not from John Denker who seems to be
an otherwise respectable fellow.

Agreed. My "reply" in my email program created this somehow - I did not
insert it.  Sorry for the confusion. The "Regards, Jack" at the end may have
made the responsible party clear.


> 2.  There are many examples from industry where one starts by
solving a solvable problem which is not the problem at issue.  One notable
example is in the design of aircraft where one gets guidance from
aerodynamic and stability calculations, further guidance from wind-tunnel
experiments but, in the end, must use cut and paste techniques to finally
achieve an acceptable product.

Agreed. But, your comment was "Problem is too ill-defined or too difficult
to solve, so solve exactly a well-defined and solvable problem that sheds
light on the problem at hand."  In basic research, it is common to solve a
model system as a substitute for a complex or real system.  This will shed
light on the real problem but the physicist still does not solve the real
problem - because, as you said, it "is too ill-defined or too difficult to
solve."  In industry it is common to solve many smaller solvable problems
and then combine the solutions to solve a more complex problem, as you
indicated. In addition, there are many times when you make your best guess
on how to solve a problem because it would take many lifetimes to obtain all
of the information you need to solve the problem in a systematic manner.
Sometimes this Edisonian approach works, sometime the systematic analytical
approach works.  My point was that these often bear little resemblance to
the physics problems at the end of the chapter.

Larry


-----Original Message-----
From: Forum for Physics Educators
Behalf Of Jack Uretsky
Sent: Wednesday, April 25, 2001 1:47 PM

Subject: Re: real-life physics


Hi all-
        Larry is mistaken on two counts.
        1.  The quote is from me and not from John Denker who seems to be
an otherwise respectable fellow.
        2.  There are many examples from industry where one starts by
solving a solvable problem which is not the problem at issue.  One notable
example is in the design of aircraft where one gets guidance from
aerodynamic and stability calculations, further guidance from wind-tunnel
experiments but, in the end, must use cut and paste techniques to finally
achieve an acceptable product.
                                Regards,
                                        Jack

On Wed, 25 Apr 2001, Larry Woolf wrote:

> In industry, you have to solve the practical research and development
> problem that is presented to you.  You either solve the problem, develop a
> material with the needed properties, meet the specification, etc. or you
> don't.  Your point holds true for the basic research physicist, but not
for
> the industrial physicist who has to make a real product or deliverable
that
> meets a previously agreed upon specification.
>
> Regards-
> Larry
>
>
> Subject: Re: real-life physics
>
>
> On Mon, 23 Apr 2001, John S. Denker wrote:
> Hi all-
>         While I'm in general agreement, I think that one important tool
> is omitted from "(3)": Problem is too ill-defined or too difficult to
> solve, so solve exactly a well-defined and solvable problem that sheds
> light on the problem at hand.
>         This is often what physics is all about.  To see the method in
> action in practical circumstances look at a copy of Morse and Kimball,
> "Methods of Operations Research", if any still exist.
>                                 Regards,
>                                         Jack