sci.physics.electromag

On Mar 8, 6:28 am, "Sue..." wrote:

> If the branch of physics says energy is observer dependent, no
> they are not the same. But 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? Isn't that called DoubleThink?

I WOULD enjoy personally observing the fruit box "disappearance"
experiment, however. (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. The real
question would be is it really possible for mass to "disappear"
leaving no energy residue behind? Of 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. Hence 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. You know physics used to be called
"natural philosophy" but the philosophical part seems to have vanished
and been replaced with mathematics. Let me rephrase the "do fields
exist" questions in a different "branch". Tell me. Do Imaginary
numbers exist? Is the square root of -1 a "real" thing? Can 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! The imaginary
axis is every bit as "real" as the flow of electrons in a wire or the
energy of waves in space!!! Do you guys (and Sue) agree with that?
Is the square root of minus one a "real" thing? Does it exist in
space, in reality? Or, (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? The 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.