refutation of the nonreality of energy

[John Denker <jsd@MONMOUTH.COM>]

At 09:53 PM 8/2/99 -0700, Leigh Palmer wrote:
> in my rational realist philosophy,
[the system has]
> the property of reality, objective reality if you will. The system
> exists independently of whether or not it is being observed, and
> all observers can agree upon its extent and boundaries.

OK.

> The energy of this system has no objective reality whatever. It is
> an abstraction, a quantity which has meaning and utility only when
> one defines a frame of reference in which to reckon it. Different
> observers may ascribe to the system different energies. Observers
> in noninertial frames may even find that the system's energy
> varies with time!
>
> I will point out that the size and duration of the system are,
> likewise, abstractions.

It seems there's been a swtich from "rational realism" to some sort of
Platonism.  This passage attempts to make a very subtle distinction between
"extent and boundaries" which exist and "size and duration" which are only
abstractions.  To me, "extent" and "size" are synonymous for all practical
purposes.

I do recognize the distinction between vectors (which exist independent of
coordinate frames) and the *components* of vectors (which depend on the
choice of frame).  In the non-relativistic limit energy exists by itself
and is conserved by itself;  in general it is part of a vector which is
conserved and which exists independent of frame.

> Try to stop thinking of energy as being concrete. It is abstract
> and will always be so.

Energy is as real as distance.  Indeed, in a gravitational field, a
measurement of height is a measurement of energy.  Most people agree that
stones are real.  But the law of conservation of energy is stronger than
the law of conservation of stones.

And if you doubt the reality of stones, I refer you to Johnson via Boswell:

% After we came out of the church, we stood talking for some
% time together of Bishop Berkeley's ingenious sophistry to
% prove the nonexistence of matter, and that every thing in the
% universe is merely ideal. I observed, that though we are
% satisfied his doctrine is not true, it is impossible to refute it. I
% never shall forget the alacrity with which Johnson answered,
% striking his foot with mighty force against a large stone, till he
% rebounded from it -- "I refute it thus."

The typical person has more experience with stones than with pure energy,
but that doesn't make one more real than the other.  Have you ever tried to
land a plane, starting with too much energy?  A pilot's inventory of energy
is as real and as important as a mason's inventory of stones.

Furthermore, at 10:39 PM 8/2/99 -0700, Leigh Palmer wrote:
> [others] think of that energy as being distributed in space; and
> potentially in all of space!
>
> If we can't agree on where this stuff called energy is, how can we
> possibly ascribe reality to it?

Field energy is distributed in space, but not in "all" of space.  It must
be in very particular parts of space.  Energy is not just globally
conserved, it is *locally* conserved, which is a stronger statement.  That
is to say, it can't disappear from place A and reappear at place B without
crossing the boundary (any boundary we choose) between A and B.