Post by Michael PressPost by Troels ForchhammerPhysical theory makes no claims about the reality of energy.
[...]
Post by Michael PressPost by Troels ForchhammerPhysical theory makes no claims about the reality of _anything_.
However, the claims about "energy" are no different from the
claims about the various ways that energy can be expressed --
such as, for instance, mass.
Did you read what I wrote about Penning traps?
Yes, but you appear not to have read what I wrote about physics . .
..
Post by Michael PressAn electron can be caged and exhibited for weeks.
You can prepare some system, and then use some complex measuring
equipment to make some measurements on that system. You then process
these measurements using some number-crusher, and you end with
results that are (more or less) equal to the results you get by
making some other calculations using a model that contains an
abstract entity called an electron. That is what physical theory is
limited to expressing itself about.
To say that physical theory holds that electrons are 'real' is
nonsense!
You appear to hold the mistaken belief that physical theory ascribes
some ontological status to the abstract entities in the model it
creates, but that is untrue. This realization has been an important
part of physics at least since Karl Popper's criticism of the use of
inductive reasoning in the natural sciences (excluding the purely
abstract mathematics).
In other words: modern physical theory does not claim that electrons
are real! Like most other physicists, I certainly believe that they
are, but this is _not_ something that is stated by physical theory --
this is a matter of belief and it may be that in 200 years the
physicists of that period will look back at our 'electrons' with the
same kind of overbearing smile with which we, today, look back at
e.g. the phlogiston theory.
It is a very important point to remmeber whenever we deal with the
natural sciences. The scientific method is a method of _doubt_, _not_
of certainty or 'truth' or 'reality' (I love Feynman's assertion that
'Science is the organized skepticism in the reliability of expert
opinion'). It may be that the model employed by modern physics is
closer to the objective reality than the model employed a century
ago, but we have no way of proving this: there is no way in which we
can infer from the specific to the universal (we should, of course,
also remember Russell's advice to remember that 'some things are much
more nearly certain than others.')
I can recommend the overview given at
<http://www.arachnoid.com/doubt/>. The view of science as a human
activity is, I'm afraid, somewhat idealistic (at least it deals more
with 'science as it should be' than 'science as it is') and not
necessarily in accordance with modern theories of science (which are,
of course, not themselves scientific <GG>), but this doesn't affect
the fundamentals. No scientific theory is held to be 'true', _even_
when there is solid evidence supporting it: instead it is considered
the best model we currently have, but likely to be eventually
superceded by a better one.
The discussion of the ontological status of the concepts we use in
physics becomes evidently ludicrous when it comes to such concepts as
energy, but also quarks, gluons and many other entitities employed in
modern physics. Physics can never make any statements about what is
'real' or 'true' -- such concepts simply have no place in physics
because physics has no way to say what is meant by them. There is
thus no way to distinguish the lack of ontological status ascribed to
electron from the lack of ontological status acribed to energy.
Another way to describe (going _beyond_ physical science, trying to
apply its descriptions to objective reality) what is going on in the
Penning trap is to say that you have trapped a certain amount of
energy in a form in which it has a certain electrical charge and
other characteristics. Energy with these particular characteristics
is then what we call an electron. This description is every bit as
much in accordance with modern physics as merely saying that an
electron is trapped.
Post by Michael PressE = m.c^2 does not mean what you think it means.
What it means certainly depends on whom you ask -- many physicists
will tell you that it means that matter and energy are just two words
for the same thing (I do, for instance, remember one professor of
high energy physics at the Niels Bohr Institute in Copenhagen who
told me precisely that). For my own part I am not an expert in
cosmology, general relativity or high energy physics (I did my M.Sc.
in electrophysics), so I will refrain from giving any opinion as to
what might be the _physical_ (i.e. 'real') meaning of the equation (I
know, of course, what it means in the abstract mathematical model
that is physical theory).
--
Troels Forchhammer <troelsfo(a)googlewave.com>
Valid e-mail is <troelsfo(a)gmail.com>
Please put [AFT], [RABT] or 'Tolkien' in subject.
And he that breaks a thing to find out what it is has left
the path of wisdom.
- Gandalf, /The Fellowship of the Ring/ (J.R.R. Tolkien)