sci.physics.electromag

On Mar 8, 5:13=A0pm, Benj wrote:
> On Mar 8, 6:28 am, "Sue..." wrote:
>
> > If the branch of physics says energy is observer dependent, no
> > they are not the same. =A0But then that is why we need different
> > branches of physics.
>
> WHAT? You mean so that they can never talk to one another and compare
> notes? =A0Isn't that called DoubleThink?

No it is called intellectual-honesty.

>
> I WOULD enjoy personally observing the fruit box "disappearance"
> experiment, however. =A0(but no too closely!)
> Blowed up! Blowed up REAL GOOD!
>
> However allow me to point out that electron-positron annihilation is
> not precisely the "disappearance" of mass but rather the conversion of
> one real thing into another (energy). There was a day when Chemists
> and others would have vociferously argued that any "disappearance" of
> mass was impossible, but those views have changes slightly. =A0The real
> question would be is it really possible for mass to "disappear"
> leaving no energy residue behind? =A0Of course it is, but that is also a
> "trick" example, because if we shift mass from one dimensional
> manifold to another, while the mass seems to disappear in one, it also
> simultaneously spontaneously appears in the other. =A0Hence the mass is
> indeed conserved in the broad sense.
>
> > Physics isn't very good at answering philosophical questions.
> > It puts real things on one axis, imaginary things on another
> > axis and that assures total rejection by any philosopher worth
> > his salt.
>
> Yes, you've put your finger on it. =A0You know physics used to be called
> "natural philosophy" but the philosophical part seems to have vanished
> and been replaced with mathematics. =A0Let me rephrase the "do fields
> exist" questions in a different "branch". =A0Tell me. Do Imaginary
> numbers exist? =A0Is the square root of -1 a "real" thing? =A0Can I go
> look at a some sinusoidal signal or electromagnetic wave and start
> proclaiming (as Fred has) LOOK I can SEE the phase shifts! I can
> MEASURE the reactive components here in these signals! =A0The imaginary
> axis is every bit as "real" as the flow of electrons in a wire or the
> energy of waves in space!!! =A0

> Do you guys (and Sue) agree with that?

Your example is perfect. Of course, if we drop the imaginaries
from calculations, their predictions will become un-real in
every respect.


> Is the square root of minus one a "real" thing? =A0Does it exist in
> space, in reality? =A0Or, (think carefully now) have we taken a
> mathematical sytem which has NO basis in reality and APPLIED it to
> problems of sinusoids and reactive impedances as a MODEL? =A0The fact
> that this model or analogy if you will produces valid, physical
> answers that agree with experiment in NO way "proves" that the square
> root of minus one is a real physical thing. The accuracy of the
> calculations only proves that there is some kind of analogy between
> the mathematics of complex numbers and certain electromagnetic
> questions. There is NO basis to assume that the analogy some how
> establishes that these two systems are identical!
>
> I rest my case.

It it is convincing if are arguing that the reality of
any or all components in a maths expression can not be used
to resolve some dispute between Jeff and Max forms.

Scientific methodology requires some inquiry that
will classify strengths and weakness.

Which set of field equations makes
the correct predictions for:

on and off axis,
near and far field,
moving and stationary wrt free_space?

Sue...