Re: TC Secondary Currents - was ( Experimental Help - Terry?)

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Paul Nicholson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <paul-at-abelian.demon.co.uk>

Hi Terry,

> I think there is some concern that because there is an equation
> that explains something, that the equation is not "proof" of
> underlying principles.

Yes, I see what you mean.  It is sufficient for our purposes to take
it this way:  we use Curl H = J + dD/dt because it describes nature,
whereas Curl H = J doesn't.  There are deeper reasons as you'd expect,
and there are plenty of mature textbooks on the subject.

But of course, folk are free to believe that Curl H = J, just as they
may believe in a flat earth, it's just a pity they can't go somewhere
else.   They are kept out of other moderated lists, why does this one
have to deal with them?

> We all come from widely different backgrounds and perspectives and
> see things in many different ways.

Have you no wish to draw a distinction between well established facts
about nature and notions which are cranky because of their obvious
defects?  Don't we have some responsibility here to make a distiction
between fact and fancy. I mean, suppose someone posts an item which
is either nonsense or obviously wrong, we can either
a) let it go through without challenge, and thus by our silence lend
our tacit approval, thus confounding the audience which the list is
supposed to inform.  Surely learning about all the stuff needed to
understand TCs is difficult enough without throwing in all sorts of
imaginary and false concepts to muddle things up?
b) respond to crank posts with thorough refutations and explanations.
c) keep posts that assume incorrect or un-established physics off the
list.

Personally, I'm not keen on (a) at all. If folk come to this list
expecting to be informed about TCs, then that's what they should get.
Do you really want to see people forking out a lot of dosh for
expensive current sensors believing that they will break the
academic establishment's conspiracy over displacement currents? Are we
doing folk a favour by standing by and watching them spend days
winding a difficult coil in the hope of reproducing some non-existent
phenomena?  As for (b), it generates a huge volume of useless traffic,
and takes up a lot of time. The spectrum of crank topics is vast - must
we digress to revalidate every well established physical law,
responding respectfully to every ridiculous notion put forward?  In
the long run this doesn't work - the true believers will keep on
plugging away no matter how utterly they are refuted. 
I vote for (c) because it is simple, fair, and requires no effort
(from me at least!).  Budding geniuses with revolutionary new physics
can take their ideas to some other forum where folk are better
qualified to deal with them, so it's better for them, and it means
that your list members gain some assurance that the stuff coming their
way is reliable.

> radioactive metals ... p=mv/(1-v^2/c^2) ...

I'm astounded that you place the kind of cranky nonsense that we see
on here on the same footing as the ground breaking discoveries that 
occasionally overturn science such as radiation and relativity.
Becquerel was a dogged and meticulous experimenter - anybody else
finding those fogged plates would have dashed off an annoyed letter to
the supplier.  And that lowly patent clerk who submitted a paper that
completely overturned physics.  He wasn't ignored as a crank, and the
reason is because the paper he submitted was an absolute masterpiece.
Nobody reading it could fail to understand exactly what he meant,
because the exposition was so precise, unambiguous, and perfectly self
consistent. He had taken the trouble to become intimately acquainted
with the physics he was about to overturn, and to learn the necessary
mathematics with which to present his hypothesis.  Beats me why you
treat these nonsense posts as if they were in the same kind of league.

> I think we all learned something

The time would have been better spent sitting down with a textbook
for an hour or so.

> I have never seen proof that any are not correct.

There are lots of things that Maxwell's equations don't account for,
and we had to invent a whole new physics in order to get to the 
nature underneath.  And now we're having to come to terms with a level
even deeper than this in order to take proper account of the way
nature appears to behave.  Nothing in a TC comes close to stressing
the limits of Maxwell's equations.  We don't even need the full set
in order to describe the TC very accurately. For example, we can
drop the displacement current term dD/dt without introducing any
significant error.  The dD/dt term just produces a slight twist to the
magnetic field, something like 1 part in 1000.  It is that small
azimuthal component which goes on to develop the tiny amount of radio
wave radiation from the TC.

Lets drag the study of TCs out of the 19th century, through the 20th,
and plonk it down firmly in the 21st.  There are lots of genuine
frontiers to tackle and if we make a policy of starting from the known
laws of physics as an essential and firm foundation, we'll be in a 
good position to make progress.  I think that every other attempt to
gather a reliable body of knowledge about TCs has ultimately been
brought down by the infiltration of pseudoscience, and I'm kind of
hoping that the pupman list has reached a quorum where it can break
through that barrier and earn a reputation as a place that carries
good engineering based on sound science.

If you where a high school physics teacher, could you honestly
recommend pupman as a place for a student to find out about TCs?
--
Paul Nicholson
--