re:Flow of energy

[David Bowman <dbowman@tiger.gtc.georgetown.ky.us>]

I do not wish to become embroiled in the controversy over whether energy can
flow or not.  I do agree with Leigh's repeated warnings against reification
of quantities such as energy.  I disagree with the fervor and perceived
importance of the crusade though.  For many things it is simply easier to
speak of abstract concepts using a loose reified and/or anthropomorhised
language than to use the overly pedantic conceptually correct language.  I
think we definitely *ought* to emphasize the fact that there is no such
thing as "pure energy", but I would not go so far as to mount a crusade
against against the language of energy flow.  In my intro to astronomy class
I speak of the life cycles of stars.  Now we all --even students-- know that
stars are not really alive (at least in the normal biological sense).  It is
simply easier to speak of a life cycle rather than a recognizable standard
sequence of developmental stages.  Likewise, I think there is no great harm
in speaking of energy flow as long as it is recognized that energy, as such,
is not a physical thing or a substance, but the value of a particular
function (i.e. the Hamiltonian) of the microscopic dynamical observable
variables characterizing the system itself.  It takes little further effort
to stretch an argument against energy flow into an argument against fluid
flow (once it is recognized that the motion of an elementary particle, as
conceived of in quantum field theory, involves a continuous sequence of the
destruction of a single particle exitation at some place concurrent with the
creation of another single particle exitation at an infinitesimally nearby
point).

> ...Richard Feynman means when he says there are no blocks. Until that simple
> concept is mastered it is difficult to approach other abstract concepts,
> notably entropy, which is on exactly the same conceptual footing. Entropy
> is easily conceived once energy has been conceived properly.

At the risk of opening a recently closed can of worms I would contend that
entropy is an *easier* concept to understand than energy, and both energy
and entropy are easier to understand than temperature (which depends for its
real meaning on the prior meanings of both entropy and energy).

David Bowman
dbowman@gtc.georgetown.ky.us