Re: Keeping up with the theory (was is Corum and Corumforbidden topic?)

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

Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>



> 
> 1.  The advances in the construction of Tesla coils have been advancements in
> engineering
> and not fundamental science.  Engineering being defined as the application of
> established
> scientific fact to create a result, structure, or product.

Fully agree... what we are doing with TCs is engineering and/or
craftsmanship (depending on your particular orientation). Relatively few TC
experimenters are out trying to establish new theoretical underpinnings
with broad applicability.

> 
> 2.  The major source of Tesla's funds was probably  from
> companies/corporations.  He was a "Hired Gun" retained to produce a product.
> He did his job well.  He had investors who
> put up the money for some of his research.  They expected a return on their
> investment and
> frankly, didn't get it.  He probably plowed his own money back into his work
> which indicates
> he had faith in his idea.  The funding of research and development has always
> depended upon the profit that could be obtained from it.  There never has
been
> much money for "pure science".
> Witness the debacle of the Super Collider.

Depends on what you call "much money"...  part of my salary is paid by just
such funding for space research.. not much financial gain to be had from
going to Mars, and NASA certainly eschews such blatantly commercial
activities as "space tourism", although, much is made of "commercial
potential of space"... Probably, somewhere around half NASA's budget is for
pure science stuff... I'm sure it's on the web somewhere..  Granted, NASA
also funds things of direct commercial value, real time world wide
measurement of ocean winds, temperature, surface condition, for instance.
Or, real time worldwide measurement of atmospheric temperature and humidity
(at least, once Aqua gets off the ground, this weekend).

Even such "product and results" oriented organizations such as the
Department of Defense fund a fair amount (billions) of pure research into
all manner of physics, chemistry, etc., 


> 
> 3.  There is a lot of time and energy being spent in the development of the
> Tesla coil.  The
> problem is that most of the experimental methods are not documented in such a
> way that
> the results can be exactly duplicated.  Therefore, they remain unproved and
> suspect.
>  Example: What is the standard method of measuring the inductance of a
> solenoid?  What is an acceptable degree of precision and accuracy?  This
> recognizes that every setup varies to some degree or an other and produces
> errors in experimental results.  Good technique identifies all
> errors and accounts for them in the resultant measurement.


Even if you consider all the "engineering refinement" and "construction
time", the total value of the time is fairly small (in the context of other
large scientific endeavors, or even other hobby activities)... Say there
are 10,000 active tesla coilers in the world, and they spend, say, 5 hours
a week on their activities.  That's 50,000 workhours/week*52 weeks per
year, or around 2.6 million hours/year... At a $100/hr, that's about
$130M/yr being spent on tesla related work... (Wow.. that's impressive, now
that I've calculated it..)


If you were to only consider work on fundamental engineering development
(leaving out the immense time spent on fabrication of everyone's coil,
etc.) the total time is probably much less... I'd say, maybe 10,000 hours
per year? Or, around $1M.. (which, all things considered, is a respectable
research budget to work with)

So your point is well taken.... some rigor in the measurements, some
analysis, etc. and we can get a good return for that $1M... For what it's
worth, a research effort of that scale (a team of 5 workers for a year)
would probably produce maybe 1 or 2 decent papers/year (it is a LOT of work
getting a paper ready for publication...). As a comparison, a recent
development project I was involved with occupied 10 people (not all full
time), over about a year, and we produced 1 report and 2 conference papers
(the review standards are much lower for conference papers).

Off hand, I'd say that, considering the "theoretical" output of the list,
considered as a whole, over the past year, we've probably produced a couple
of publishable papers worth of stuff, (actually more, volume wise, but it
hasn't been beaten and edited into a paper.. and, as mentioned, that's a
pile o' work) so the scope and magnitude seem to be consistent.


> 
> Taking the example on inductance one step further:  There are several
equations
> which
> provide the inductance of a solenoid.   Most produce results in the form of
> 'current sheet inductance'  which is different from true inductance.  The
> correction from current sheet inductance to true inductance was authored by
> Rosa and published in 1908 by NBS.
> Who applies it today and why not?
> 
> How do you determine the distributed capacitance of a solenoid from its
> physical dimensions?
> That is a Holy Grail that has not been found.  True, Wheeler's work lets
you calculate
> it within practical limits for a limited number of coils.  But, I know of
no equation that is
> general in application and is provably accurate to the limits of physical
> measurement.  Now there is a problem worth working on!

There is an equation... (or more properly a set)... Maxwell's equations...
completely and totally will define the electromagnetic behavior of an
arbitrary "thing"...  

What you are really thinking of is a nice simple analytical expression..
and one probably doesn't exist, and can probably be proved so.. Things with
circular symmetry typically have analytical solutions that involve Bessel
functions, and those functions are infinite series.

A good approximation is another thing.. Medcalf for capacitors, Wheeler for
inductors..

This is a good example of a problem for which a sufficiently detailed
numerical model will produce a result that is as precise as you care to
calculate.  The real problem is not so much the capacitance, but the
circuit behavior of the secondary, which is not really a distributed
capacitor...

(although, with sufficient computer resources... you could numerically
model it.. Fire up those Beowulf's boys!)

> 
> The publication of information on Tesla coils is undoubtedly limited by the
> fact that
> there is little practical application.  Further, not much research is being
> done in laboratories
> because there is little that is not known about the science of tesla coils.
> There is probably a lot more to be learned about the engineering, but why
study
> it if there is no pay off?  If research is
> done, then it will be published.
> 
> Axiom:  "You don't really know unless you can write an equation about it."

But you CAN write an equation, at least for the discrete electrical
parts...It's just a very big equation (i.e. the matrices for a FEM) and the
underlying electromagnetic phenomena (i.e. Maxwell)

 The spark is more statistical, and much more troublesome, and that's where
the significant lack of understanding is..
> 
> Ray
>