Re: Whence Degeneracy Pressure?

["John S. Denker" <jsd@MONMOUTH.COM>]

John Mallinckrodt wrote:
> ... my answer *might* now be *something* along
> these lines:
>
> Within the restrictions of the Newtonian model, the concept of
> "force" is associated exclusively with two phenomena--gravity and
> electromagnetism--in the sense that all Newtonian "forces" can be
> understood in terms of them.

Well, kinda sorta maybe.

In particular, this viewpoint would compel us to say that
"contact" forces are just a manifestation of the electromagnetic
interaction between the contacting objects.  That's not
terribly wrong, but it's not the whole story.  Purel 100%
electromagnetism doesn't suffice to explain the stable existence
of objects, let alone their interactions.  Quantum mechanics
has to come in there somewhere.

As I said before, we live in a universe governed by the laws
of quantum mechanics.  Get used to it.

> Quantum physics deals poorly with the concept of "force" and
> replaces it with the concept of "interaction."

I don't know about that.  Force is perfectly well defined
in QM.  Speaking of fundamental interactions sounds more
professional than speaking about fundamental forces (just
as speaking about "vehicles" sounds more professional than
speaking about "cars"), but if you want to talk about forces
there's nothing wrong with that.

> We now understand
> electromagnetism as the long range part of the electroweak
> interaction and we add the nuclear strong interaction for a total
> of three (not four) "fundamental interactions."  The Newtonian
> "forces"--and, therefore, Newtonian physics--are based on the
> properties of the long range interactions.

OK I guess.  But remember, there is no 100% self-consistent
Newtonian physics.

> Within quantum physics, we deal with mathematical entities known
> as "operators" which represent interactions and "wavefunctions"
> which represent entities.

That's not terribly wrong, but it's not the only way to view
things.  The "entities" themselves can be viewed as operators
(e.g. via creation operators) so there's nothing to be gained
by drawing a distinction between "entities" and "interactions".

> A "fundamental interaction" is
> identified by the fact that it shows up in the operators (and we
> *believe* that gravity will someday show up in those operators!)

The fundamental interactions, like everything else, can be
expressed in operator notation.  Non-fundamental operations
can be expressed this way, too.  So that's not a good criterion
for what's fundamental and what's not.

> Degeneracy pressure, however, arises from properties of the
> wavefunctions themselves.