Ok I now have a few minutes to comment on the few days's posts that I missed.
Family
My friend, Leigh, called me his "son." In a previous existence when we
started to talk about heat and energy, I thought that we concluded that I
am older than Leigh -- of course we never discussed who was the more
decrepit -- I think that maybe it is I. Back then Leigh agreed that there
was no such "thing" as heat but still wanted "energy" to flow. He may have
repented since then. He seems to have discovered a new prophet, Dick Feynman.
Blocks
Dick has his blocks (cf Ch 4 of his scripture). Larry Smith's Randall
Knight has his pennies (cf Ch 10). Yes Feynman does say that "energy" is
not "blocks." I think that the current expression would be "duh," but I am
not young enough to know how to spell it. But Dick goes on to say that
energy has "different forms" and he goes on to describe many of these
"forms" as if they were of several size blocks, Or maybe some are some of
Knight's pennies and some quarters. Feynman continues to talk as if energy
is a flowing substance. And, Leigh, he goes on to talk about "heat
energy," for Pete's sake! Leigh's prophet fails. And a parable of anything
moving is very unsound pedagogy.
I understand why he does this. He was brought up watching Bill Nye the
Science Guy. I have difficulty too. It is hard to get the reification of
some concepts out of my brain's synapses.
Aristotle
It all started with Aristotle. The poor man -- he watched TV and learned
about Earth, Fire, Air, and Water perhaps from Bill Nye or maybe Plato, who
had some very strange ideas. And he taught this to his students,
including Alexander the Great. (Maybe that is the problem.) And they
taught it to their students and they taught it to their students and they ....
Rumford
Until the traitor Benjamin Thompson, aka Count Rumford, had to deal with
this. But while he was boring his cannon, he realized that the caloric
idea was wrong. However, no one would pay attention -- (It is sometimes
very hard to get the attention of physicists.) -- until Carnot messed
things up further.
Carnot
Carnot was a French diplomat's son -- and we all know how strange the
French are -- and was worried about military transport -- mostly with
concern for the timid British, who had just trounced the French. So, as
were many scientific developments, thermo was born as a military
advancement as the investigation of steam engines. Because of this, thermo
has been warped out of all reasonable perspective. Just because of that
damn adiabatic cylinder.
Thomas Young
Meanwhile Thomas Young had entered the story. Young looked at a bouncing
ball -- if it isn't military, it is sports -- and _invented_ the idea of
"energy." It was just an innocent idea of how to look at physics, but
since then we have again warped physics to reify energy and have it
flow. Young on the other hand never seemed to picture energy as
flowing. To him it was a characteristic of moving things. He also talked
about work as a product of force and distance traveled.
Language
But we sometimes warp our ideas of physics. We do the same thing with our
language. Perhaps other languages are as warped as is English. But
English is weird: We now say the ghastly "You've got mail" and "20 items or
less." We even embrace "Walking up the street, I saw the sun." And then
I hear readers say "What's wrong with that?" Decay is all about us! In
language and in physics.
Inventions
Some of us bridle at the idea that these properties are inventions or
abstractions. Some worry that if these cherished ideas are abstractions,
then everything might be an abstraction. And maybe everything is --
everything is just a collection of vibrating strings. But in my meager
effort to understand the Universe, I still can tell the difference between
the oak tree outside my window and the idea of energy. And I can see the
value of the distinction.
Territory
Some say that we are well outside our proper intellectual territory. That
physics should only _describe_ the Universe. Well, Folks, chemists
describe the Universe and engineers tinker with it, but my physicist's soul
wants to understand it.
Properties
Many of our topics in physics have "properties" associated with them. Some
of which we have a tendency to reify. Consider an arbitrary system --
maybe one of Dick's blocks: It has a temperature, shape, color, density,
etc., etc. We would never say that temperature flows or that blue flows --
we might notice that blue ink smears, but it is the ink that moves not blue
per se. We have also invented other properties of a system: e.g., mass,
momentum, work, energy, entropy, etc., etc. (And while we are at it note
that we have also invented the idea of photons, which are not real. But
because my synapses are still warped, electrons may be.) Some properties
have special characteristics: e.g., energy seems to be conserved. But
NONE of these properties should be reified; None of them moves,
transports, converts, etc., etc.
Pedagogy
Some have said here that energy should be modeled as a flowing substance
because that concept is easier for young students to comprehend. Well,
perhaps it is easier because modelers and instructors don't understand the
truth and like Aristotle just teach what they heard from others. Could it
be that some modelers just demonstrate this in their inability to teach
physics correctly. I suppose sufficient PER is yet to be done. After
all, Piaget was not a physicist. I maintain that it is easier (at least
for me) to teach the truth than the myths. It is certainly more
honest. For example...
Work/Energy
The ONLY way to change the energy level of a system is to do work on the
system. What is so hard about that! Consider two abutting systems one is
at a higher temperature. Molecules of that system collide with their cooler
sisters and do net work on the second system. The first system
experiences a decrease in its energy level and the second system
experiences an increase in its energy level. Is that so hard to
understand? It may be hard for the weakly educated instructor to preach
the truth, but it is far easier for the students than trying to explain the
fiction of how energy flows from one system to the other. A good
instructor can say essentially the same thing for a myriad of situations.
Relativistic Mass
And now we come to relativistic mass. Look, Folks, the argument between
the pros and cons is silly. Each side wraps itself in so much verbiage
that they can't understand even themselves although they try
mightily. They seem to get lost in the words/equations/symbols. The
bottom line in my world is that the property of mass has the same effect in
the Universe as the property of energy -- that mass IS energy in any
frame. Neither flows or moves independently of its system. They are both
abstractions/inventions. They are both very handy in solving problems -- in
any frame.
And BTW, the melted ice cube weighs more than the ice!
And for heaven's sake please don't try to express yourself cyclically by
using the words of one view to explain that view. If it walks and quacks
like a duck, it is a duck. But how does a duck walk and quack? Like a duck.