[Phys-L] nuance versus Manichaeism

[John Denker <jsd@av8n.com>]

On 02/08/2014 08:40 PM, Richard Tarara wrote in part:

> ... there may be reasons we don't teach QED at these
> levels, but do Newton and thermal/kinetic/potential energies, or and
> other 'obsolete' science. :-)

There's a reasonable discussion to be had here, but that
isn't it.  That's not a reasonable way to frame the discussion.

For starters, nobody has been advocating for QED, so why
do you bring it up?

More generally, I assert that there is not a Manichaean
binary all-or-nothing choice between 
 a) QED on the one hand, and
 b) archaic wrong ideas on the other hand.

At the very least, one should consider some sort of gray scale, 
such as degrees of more modernity versus less modernity.  In 
other words:
  PLEASE DO NOT DRIVE THE DISCUSSION TO THE EXTREMES.

Black-versus-white is a gross oversimplification of the gray
scale.

====

Secondly, and at least as importantly, the gray scale itself
is a gross oversimplification of what is really going on.  In
reality, we have a multi-dimensional /color solid/ not just a
one-dimensional gray scale.

Here are just two of the many dimensions:


                       simple
                          |
                          |
                          |
                          |
                          |
                          |
                          |
   archaic ---------------|--------------- modern
                          |
                          |
                          |
                          |
                          |
                          |
                          |
                       complex

There are other important axes, including
   concrete <---> abstract
and
   good fit to the facts <---> lousy fit

It is simply wrong -- and a disservice to students -- to assume
that the modern ideas are always more complex, and the archaic
ideas are always simpler.

1) For example, consider the "heat energy" that set off the current
discussion.  In the vast majority of cases, you can just cross
out the word "heat" and discuss the energy instead.  This is 
more modern, more sophisticated, more correct ... and *not* more 
complicated.  It does not require QED.  It is what I recommended
when the question first came up:  "Energy is energy".

===

2) Here's an example that has been studied in detail:  The idea of
phlogiston was widely used in the scientific community, for quite
a long time.  Eventually it was replaced by /two/ ideas:

      phlogiston --> energy + oxygen

Now, at first glance that might look like an increase in complexity,
replacing one idea with two ideas.  However, we need to look closer.
What really happened was

        phlogiston
           plus            -->  energy + oxygen
    innumerable exceptions

That is to say, phlogiston by itself provided a lousy fit 
to the data.  The modern ideas of energy and oxygen were an 
enormous net simplification, because they provided a good 
fit to the data, not burdened by all those exceptions.

Looking at a different pair of axes, it would be equally wrong 
to assume that increasing modernity corresponds to increasing 
abstraction.  Energy is not more abstract than phlogiston ... 
and oxygen is actually very much more concrete, less abstract.

===

3) Here's a different example that leads to the same conclusion:
A tremendous amount of chemistry was done in the 19th century,
before atomic theory was widely accepted.  They used macroscopic
concepts such as "element" and "compound".  Indeed, to this day,
the mole is an SI base unit, /defined/ in macroscopic terms as
the "amount of substance" (not number of particles).

Note the contrast:
  A) Loosely speaking, "element" and "compound" and "amount of 
   substance" correspond to the modern concepts of atom and 
   molecule and number of particles.
  B) The correspondence is very imperfect.

It is a tribute to the intellect of the 19th century chemists
that they were able to accomplish so much in spite of being
handicapped by primitive ideas.

I find it astonishing and appalling that introductory chemistry
books still start with the 19th-century ideas.

My point is, the 19th century has been over for a while now.
Wake up and smell the atoms.  The modern atomic description is 
very much simpler.  Not only does it fit the facts better, it 
is just plain simpler.  

Considering another pair of axes:  The idea of "element" is 
exceedingly abstract.  The modern idea of atom is much less
abstract, more concrete.

===================

Let's be clear:  In this message:
 --  I am not arguing for or against QED.
 --  I am not arguing for or against modernity per se.
 --  I am not arguing for or against abstraction per se.
 ++ *I'm arguing for a more nuanced discussion.*

We should at least consider the possibility that modern ideas 
are sometimes /simpler/ than archaic ideas.

PLEASE DO NOT FRAME THE DISCUSSION AS A CHOICE BETWEEN EXTREMES.