sci.physics.electromag

On Mar 18, 10:23 am, "Vince Morgan"
wrote:

> Unlurk,
> As Don has said below, "A field is a region of influence- no more no less."
> An aggregation perhaps.
> A field of wheat is certainly composed of individual units, each a "quanta"
> so to speak. Dealing with individual grains would not be timely and thus
> uneconomical.
> You can sell a field of grain. So in that specific context the field is
> certainly real. However, if you remove the grain you have,, errr,,, hmmm, a
> field of dirt I guess. Sill a field in some respects, but certainly not a
> field of wheat.

I see what you and Don are saying, but IIRC somewhere in these threads
I made the point that part of the problem here is that when we use
words which have a scientific meaning which is precise and ALSO have a
common usage which is much more loose there tends to be trouble. When
we say "magnetic field" there is a precise scientific definition.
First off, it means we are talking about VECTOR fields and all the
mathematics that goes with it. The point has been made here that
mathematics of vector fields is quite well defined and precise which
includes items such as continuity and extension through all space
(point pointed out early here by Maxwell (the poster not the one of
the equations fame).

On the other hand if we go with common usage, such as a "wheat field",
"Field of dirt" or "ouch field", it's clear that they are regions of
influence that do have a possibility of being modeled in some way
using a vector field to approximate the discrete forces so the common
term "field" sort of fits, but not really. But generally speaking,
nobody really is intending to be that precise about it. The point
being that science and talking on the phone are two different things.
Science demands precise exact definitions so that everybody knows
exactly what is being talked about. If one doesn't do that things like
this thread ensue.

> Clearly if quantum physics represents a reality, and I believe it does, then
> all electromagnetic fields are aggregates..

Precisely my point. Since Electromagnetic fields are Vector Fields,
by mathematical definition those vector fields cannot be "real" since
they are representing things that do not fit their own definition.
The point being made was that so often in physics there is the
unthinking tendency not only to use common language rather than more
precise definitions (because physics for example often doesn't make up
new words to carry the precise meaning as say does medicine) but also
there is the post-Einsteinian tendency to regard mathematics as the
only reality. The latter is a movement with which I am not in
agreement, and of course stirred the pot a bit to try to get people to
think about it.

> Which, if true would answer Szczepan's question from the previous thread,
> "Now we are able to emit artificial continuous radiation. Such are also in
> packets?"
> With all due respect I don't think Timo was speaking otherwise. Semantics I
> believe.
> Relurk,

Or take it even further. Ask the question: "Does SPACE itself have a
granularity?" If it does, then clearly NO vector field (taken in the
scientific sense) can EVER be real! A wheat field can be real but any
"field theory" approximation of it no matter how fine can never be
"real" if space has granularity!

And you are right. Semantics IS an important point here. All of which
so far tends to point out the importance of using precise definitions
that are mutually agreed upon if there is to be a meaningful argument
(debate :-) about anything.

PS. Hey, welcome to the discussion! If this got you to unlurk, at
least it accomplished something positive!