[Phys-L] Re: Energy is primary and fundamental? (was RE: First Day Activities or Demos)

[jbellina at SAINTMARYS.EDU (jbellina)]

Is it any more or less voodoo than whatever it is that maintains the
earth in its orbit about the sun?  I think it looks like voodoo because
it looks different.  What do you mean by concrete explanation?  Seems
to me the affects of energy transfer can be sensed as well as affects
of a force acting, so what is the difference.
Granted being unusual it is more abstract, and that is a pedagogical
challenge.

cheers,

joe

On Aug 10, 2005, at 5:12 PM, rlamont wrote:

> This approach seems too much like some form of "voodoo" to me.
> Ascribing some poorly defined entity called "energy" to anything
> that is thought of as change is too close to the pseudoscientific
> babble we hear from people who believe in ESP, faith healing,
> homeopathy, etc. If you have no concrete explanation for a
> phenomena you say some form of "energy" is transferred from one
> object to another. Of course, in most cases, that energy cannot
> be seen or sensed - or measured. If I was a student just
> encountering physics, I would be very turned off on the subject
> if introduced to it with this nonspecific mumbo jumbo.
>
> Bob at PC
>
> > Dan,
> > The Modeler's definition of energy is somewhat different from
> the
> > classic
> > "energy is the capacity to do work", which requires you to
> define work
> > and,
> > as a result, drag in the discussion of force.  Instead we have
> something
> > on
> > the order of "energy is the capacity for change", so the
> emphasis is on
> > the
> > location(s) of energy and the specific changes that occur as a
> result of
> > an
> > energy increase or decrease.  An energy change can result in
> changes
> > in
> > motion (kinetic energy change), positioning (potential energy
> change),
> > arrangement (potential energy change), etc.  Working,
> radiation, and
> > heating
> > only come in at the stage where one becomes concerned about HOW
> > energy
> > transfers from one thing to another.  All of this allows you to
> discuss
> > energy right away if you think it's appropriate.
> >
> > Note that this approach pretty much requires that fields be
> considered
> > as
> > "objects" rather than theoretical constructs, since for the
> Modeler,
> > energy
> > always has to reside "somewhere", and my personal approach to
> this
> > is to
> > liken fields to springs or rubber bands whose geometry changes
> as
> > energy
> > changes.  That's a lot farther down the road, of course, but it
> is a
> > bridge
> > one has to cross eventually if one is to be consistent.
Joseph J. Bellina, Jr. Ph.D.
Professor of Physics
Saint Mary's College
Notre Dame, IN 46556